Biopharmconsortium Blog

Expert commentary from Haberman Associates biotechnology and pharmaceutical consulting.

Vertex cystic fibrosis therapeutics update


CFTR protein: A. normal B. gating mutant. Source: Lbudd14 http://bit.ly/1rGrzJ1

CFTR protein: A. normal B. gating mutant.
Source: Lbudd14 http://bit.ly/1rGrzJ1

As we said in our September 10, 2014 article, we intended to post updates on companies that we had been following on our blog, and that have achieved significant progress in recent months. So far, we have covered Agios and Zafgen. Both of these companies were featured in Boston-area meetings in October—Zafgen in Xconomy Xchange: Boston’s Life Science Disruptors on October 8, and Agios in the New Approaches to Cancer Drug Discovery symposium at Harvard Medical School on October 14.

Now we turn to the small-molecule cystic fibrosis (CF) therapeutics program at Vertex Pharmaceuticals (Boston, MA).

We covered Vertex’ CF program in our articles of January 24, 2013 and February 15, 2013. As a result of the publication of these articles, I was interviewed for and quoted in an article in the March 11, 2013 issue of Elsevier Business Intelligence’s The Pink Sheet entitled “Cystic Fibrosis Market Snapshot: Disease-Modifying Drugs Elusive 24 Years After Discovery Of Root Cause”. (A subscription is required to view the full text of this article.)

To summarize our discussions of CF in these earlier articles, CF causes a suite of symptoms that affect the skin, the lungs and sinuses, and the digestive, endocrine, and reproductive systems. The most important results of CF is that patients accumulate thick, sticky mucus in the lungs. This results in clogging of the airways with mucus. This leads to inflammation and bacterial infections. Lung transplantation is often necessary as the disease worsens. With proper management, patients can live into their late 30s or 40s.

The gene that is affected in cystic fibrosis encodes the cystic fibrosis transmembrane conductance regulator (CFTR).  CFTR is an ion channel that regulates the movement of chloride and sodium ions across epithelial membranes, including the epithelia of lung alveoli. CF is an autosomal recessive disease, which is most common in Caucasians. The most common mutation that causes CF, ΔF508, is a deletion of three nucleotides that causes the loss of the amino acid phenylalanine at position 508 of the CFTR protein. The ΔF508 mutation accounts for approximately two-thirds of CF cases worldwide and 90% of cases in the United States. However, there are over 1500 other mutations that can cause CF.

Ion channels constitute an important class of drug targets, which are targeted by numerous currently marketed drugs. These compounds were developed empirically by traditional pharmacology before knowing anything about the molecular nature of their targets. However, discovery of novel ion channel modulators via modern molecular methods has proven to be challenging.

The ΔF508 mutation results in defective cellular processing, and the mutant CTFR protein is retained in the endoplasmic reticulum. Some other mutations in CTFR (which affect a small percentage of CF patients) result in mutant proteins that reach the cell membrane, but are ineffective in chloride-channel function.

After a long discovery and development program (which we outlined in our February 15, 2013 article), Vertex identified two types of candidate small-molecule CF therapeutics:

  • CFTR potentiators, which potentiate the chloride channel activity of mutant CFTR molecules at the cell surface;
  • CFTR correctors, which partially correct the folding and/or trafficking defect of such mutant CFTRs as ΔF508, thus enabling a portion of these mutant proteins to exit from the endoplasmic reticulum and to deposit in the cell membrane.

Vertex’ CTFR potentiator ivacaftor (Kalydeco, formerly known as VX-770) was approved by the FDA in January 2012, and approved in Europe in July 2012. At that time, ivacaftor was only indicated for treatment of CF patients age 6 and over carrying the CFTR G551D mutation (Gly551Asp). Although the G551D mutation only affects approximately 4% of CF patients, it is the most common CFTR gating mutation (i.e., a mutation that affects transport of sodium and chloride ions across epithelial membranes).

New indications for ivacaftor (Kalydeco)

On July 31, 2014, Vertex announced that the European Commission had approved ivacaftor for treatment of CF patients age 6 and over who have one of eight non-G551D gating mutations in the CFTR gene. The eight additional gating mutations included in the new approval affect approximately 250 people ages 6 and older in the European Union.

The approval was based on data from a Phase 3 randomized, double-blind, placebo-controlled study of 39 people with CF ages 6 and older who have a non-G551D gating mutation.

The European approval followed the February 21, 2014 announcement that the FDA had approved ivacaftor for treatment of CF patients 6 and older who have one of the same additional eight mutations in the CFTR gene. In the U.S., approximately 150 people ages 6 and older have one of the additional eight mutations.

On October 21, 2014, the FDA’s Pulmonary Allergy Drugs Advisory Committee (PADAC) voted 13-2 to recommend approval of ivacaftor in CF patients age 6 and older who have the R117H mutation in the CTFR gene. This new indication is now under review by the FDA.

Thus Vertex has been pursuing a strategy of testing and seeking approval of ivacaftor for treatment of CF patients with gating mutations in the CTFR gene other than the G551D mutation, in a systematic, step-by-step fashion. As a result of this strategy, ivacaftor is currently approved to treat over 2,600 people ages 6 and older in North America, Europe and Australia.

Vertex’ development of the CFTR correctors lumacaftor (VX-809) and VX-661

Meanwhile, Vertex has also been pursuing approval for its CFTR correctors lumacaftor (VX-809) and VX-661. We have discussed these agents in our February 15, 2013 blog article.

As we discussed in that article, as of February 2013 Vertex had completed Phase 2 studies of a combination of ivacaftor and lumacaftor in CF patients who were homozygous for the CFTR ΔF508 mutation. They then planned pivotal phase 3 trials of the combination therapy in this patient population. The rationale for the combination treatment was that VX-809 potentates the deposition of CFTR ΔF508 in the cell membrane, and invacaftor potentiates the function of cell-surface CFTR ΔF508.

As of February 2013, Vertex was also conducting Phase 2 trials of another CTFR corrector, VX-661, alone and in combination with ivacaftor in CF patients homozygous for CFTR ΔF508.

On June 24, 2014, Vertex announced that results from two Phase 3 studies of lumacaftor in combination with ivacaftor showed statistically significant improvements in lung function in people ages 12 and older with cystic fibrosis (CF) who were homozygous for CFTR ΔF508. All four 24-week combination treatment arms in the studies, known as TRAFFIC and TRANSPORT, met their primary endpoint of mean absolute improvement in lung function from baseline compared to placebo at the end of treatment. The combination treatments were also generally well tolerated.

Data from a pre-specified pooled analysis also showed improvements in multiple key secondary endpoints, including lowering pulmonary exacerbations.

On October 9, 2014, Vertex announced updates of the results of the TRAFFIC and TRANSPORT studies, in conjunction with the company’ presentations at the 28th Annual North American Cystic Fibrosis Conference (NACFC). Patients who completed 24 weeks of treatment in TRAFFIC or TRANSPORT were eligible to enter a Phase 3 rollover study to receive a combination regimen of lumacaftor and ivacaftor. The first interim data from the rollover study (presented at NACFC) showed that the improvements in lung function observed in the 24-week TRAFFIC and TRANSPORT studies were sustained through 48 weeks of treatment with the combination treatment. At the time of the interim analysis, safety and tolerability results were also consistent with those observed in the initial Phase 3 TRAFFIC and TRANSPORT studies.

In the October 9, 2014 press release, Vertex also announced the submission of an NDA in the U.S. and an MAA in Europe for the approval of ivacaftor in children with CF ages 2 to 5 with one of the same 9 CTFR gene mutations for which the drug is approved in patients 6 or older. These line extension submissions are based on further Phase 3 studies, which were also presented at the NACFC.

On November 5, 2014, the company announced that it had submitted an NDA to the FDA and an MAA to the European Medicines Agency (EMA) for a fully co-formulated combination of lumacaftor and ivacaftor for CF patients age 12 and older who are homozygous for CFTR ΔF508. There are approximately 22,000 people with CF ages 12 and older who are homozygous for CFTR ΔF508 in North America, Europe and Australia. This includes approximately 8,500 people in the United States and 12,000 people in Europe. These new submissions are based on data from TRAFFIC and TRANSPORT, and on the first interim data from the subsequent rollover study.

Meanwhile, as also announced on October 9, 2014, clinical studies of VX-661 are continuing. Vertex presented data from Phase 2 studies of VX-661 in combination with ivacaftor at the 2014 NACFC. In the October 9 press release, Vertex announced that it plans to initiate a pivotal Phase 3 development program for VX-661 in combination with ivacaftor in CF patients who have one or two copies of the CFTR ΔF508 mutation, including patients with a second CFTR mutation that causes a defect in the gating of the CFTR protein. The initiation of this study is pending regulatory discussions and data from a fully enrolled 12-week Phase 2b study of VX-661 in combination with ivacaftor in patients who are homozygous for CFTR ΔF508.

The high cost of Kalydeco causes controversy

Kalydeco (ivacaftor) costs nearly $300,000 a year. These costs are usually borne by insurers and governments, and Vertex has pledged to provide the drug free to any U.S. patient who is uninsured or whose insurance won’t cover it.

However, the high cost of this drug—and the anticipated higher cost of combination therapies for treatment of CF—has generated controversy in some circles. This issue has been discussed, for example, in 2013 articles in the M.I.T. Technology Review and in MedPage Today. (MedPage Today is a peer-reviewed online medical news service for clinicians, which provides breaking medical news, professional medical analysis and continuing medical education (CME) credits to its physician readers.)

According to the Technology Review article, by Barry Werth, doctors and patients enthusiastically welcomed Kalydeco because it offers life-saving health benefits and there is no other treatment. Insurers and governments readily paid the cost. However, commentators quoted in the MedPage Today article said that the price of Kalydeco is exorbitant, and the increasing numbers of high-priced life-saving drugs to treat rare diseases (although nor usually borne directly by patients themselves) is unsustainable. Vertex—as quoted in the MedPage Today article—said that the price of Kalydeco reflects its high degree of efficacy, the time and cost [and risk] it took to develop the drug, and the company’s commitment to reinvest in continued development of newer drugs to help other CF patients.

The discussions of the high cost of Kalydeco echoes the discussions of the cost of novel drugs for life-threatening cancers, as mentioned in our October 2, 2014 article, “Late-breaking cancer immunotherapy news”, on this blog.

With respect to the development of Kalydeco and other small-molecule CF drugs, the publicly-funded—and successful—research to determine the molecular cause of CF was of little help in enabling researchers to develop disease-modifying drugs. (See our January 24, 2013 blog article, “Determining the molecular cause of a disease does not necessarily enable researchers to develop disease-modifying drugs”.) As outlined in our February 15, 2013 blog article, Vertex’ own drug discovery and development program (partially funded by the nonprofit Cystic Fibrosis Foundation, which now receives royalties on sales of Kalydeco) was long (beginning in 1998), expensive, risky, and involved considerable ingenuity.

Given the high barrier between the knowledge of the molecular biology of CF and its use in discovering and developing safe and efficacious small-molecule drugs, the development of such agents as ivacaftor, lumacaftor, and VX-661 is almost miraculous. Vertex’ arguments that justify the high cost of the drug thus have considerable merit. However, discussions in the medical community and beyond on how the costs of novel life-saving drugs for rare diseases and cancer may be sustained will and should continue.

Conclusions

The goal of Vertex’ CF program as a whole is the development, approval and marketing of multiple combinations of small-molecule therapeutics that will have disease-modifying efficacy in the great majority of CF patients. Especially with the recent progress with clinical studies of the ivacaftor/lumacaftor combination in patients with CFTR ΔF508 mutations, and with line extensions of ivacaftor, Vertex appears to be well on its way to accomplishing this, pending regulatory approvals.

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As the producers of this blog, and as consultants to the biotechnology and pharmaceutical industry, Haberman Associates would like to hear from you. If you are in a biotech or pharmaceutical company, and would like a 15-20-minute, no-obligation telephone discussion of issues raised by this or other blog articles, or an initial one-to-one consultation on an issue that is key to your company’s success, please contact us by phone or e-mail. We also welcome your comments on this or any other article on this blog.

Late-breaking cancer immunotherapy news

Source: Medical Progress Today 12/14/12 http://bit.ly/1sPO1WU

Source: Medical Progress Today 12/14/12
http://bit.ly/1sPO1WU

In our September 16, 2014 article on this blog, we announced the publication by Cambridge Healthtech Institute’s (CHI’s) Insight Pharma Reports of a new book-length report, Cancer Immunotherapy: Immune Checkpoint Inhibitors, Cancer Vaccines, and Adoptive T-cell Therapies, by Allan B. Haberman, Ph.D.

As we said in that blog article, “cancer immunotherapy is a ‘hot’, fast-moving field”. Thus—inevitably—in the short time since the publication of our report, a great deal of late-breaking news has come in.

This article is a discussion of several key late-breaking news items, which were not published in the report.

Pricing of checkpoint inhibitor agents

As discussed in the report, two PD-1 inhibitors have been recently approved. Bristol-Myers Squibb (BMS)/Ono’s nivolumab was approved in Japan (where it is know by the brand name Opdivo) in July 2014 for treatment of unresectable melanoma. Pembrolizumab (Merck’s Keytruda) was approved in the U.S. for treatment of advanced melanoma on September 5, 2014. The very first checkpoint inhibitor to reach the market, the CTLA-4 inhibitor ipilimumab (Medarex/BMS’s Yervoy), was approved in the U.S. in 2011.

At the same time as the news of the approval of the PD-1 inhibitors nivolumab and pembrolizumab came out, information on the pricing of these agents also became available. However, because of the need to complete the report for publication, there was no time to discuss the issue of pricing adequately.

As discussed in a September 4, 2014 article in FiercePharma, the cost of nivolumab in Japan (according to the Wall Street Journal) is $143,000. According to the FierceBiotech article, this was greater than the introductory price for any other cancer drug, especially in Japan, where prices tend to be somewhat lower than in the U.S.

Meanwhile, as reported in a September 4, 2014 article in FierceBiotech, the cost of pembrolizumab in the U.S. will be $12,500 a month, or $150,000 a year.

For comparison, the launch price of BMS’ ipilimumab was $120,000. As we discussed in the report, the PD-1 inhibitors nivolumab and pembrolizumab—as seen in early clinical trials—appear to be more efficacious and have fewer adverse effects in treatment of melanoma.

As discussed in our report, checkpoint inhibitors such as ipilimumab, nivolumab and pembrolizumab are eventually likely to be used in combination with other drugs, including other immuno-oncology drugs, targeted therapies, and others. The price per month or per year of these potentially life-saving and at least in some cases curative combination therapies may thus be expected to go still higher. However, if cancers are pushed into long-term remission or even cure, then it might be possible to discontinue treatment with these expensive drug combinations. In such cases, the cost of treatment may even be less than current therapeutic regimens.

There are no analyses of the costs of specific immunotherapy drugs or cellular therapies in our report. However, we do discuss the issue of drug costs in the survey and interviews that are part of the report.

The issue of the costs of expensive drugs for life-threatening cancers is under discussion in the cancer community. For example, the American Society of Clinical Oncology (ASCO) has initiated an effort to rate oncology drugs not only on their efficacy and adverse effects, but also on their prices. ASCO’s concern is that pricing be related to the therapeutic value of drugs. And commentators such as Peter Bach, MD, MAPP (the Director of the Memorial Sloan Kettering Cancer Center’s Center for Health Policy and Outcomes) have been weighing in with their analyses. As additional immunotherapy drugs and cellular therapies reach the market, these discussions will certainly continue.

The Bristol-Myers Squibb-Merck lawsuit over PD-1 inhibitors

Another late-breaking news item that came out at the time of the publication of our report is the lawsuit between BMS and Merck over PD-1 inhibitors. Specifically, as soon as Merck gained FDA approval for pembrolizumab, BMS and its Japanese partner Ono sued Merck for patent infringement.

The patent in question is U.S. patent number 8,728,474. It was filed on December 2, 2010, granted to Ono on May 20, 2014, and licensed to BMS. The patent covers the use of anti-PD-1 antibodies to treat cancer. According to BMS and Ono’s claims, Merck started developing pembrolizumab after BMS and Ono had already filed their patent and were putting it into practice by developing their own PD-1 inhibitor, nivolumab.

The lawsuit asks for damages, and for a ruling that Merck is infringing the BMS/Ono PD-1 patent. Such a ruling may mean that BMS and Ono are owed royalties on sales of all rival PD-1 drugs, not just Merck’s. BMS/Ono and Merck are involved in parallel litigation in Europe.

Merck acknowledges Ono’s method patent, but says that it is invalid. Merck also said the lawsuit will not interfere with the U.S. launch of pembrolizumab.

We shall have to watch the proceedings in the U.S. District Court for the District of Delaware to see the outcome of this case. Although this lawsuit was not discussed in our report, the report does include a discussion of the fierce race between PD-1 inhibitor developers Merck and BMS to be the first to market, and to gain the largest market share. The lawsuit is clearly one element in this race.

Merck Serono discontinues development of the cancer vaccine tecemotide

On September 18, 2014, Merck KGaA (Darmstadt, Germany; also known as Merck Serono and EMD Serono) announced that it has discontinued development of the cancer vaccine tecemotide. Tecemotide is a peptide vaccine that was formerly known as Stimuvax. It was originally developed by Oncothyreon (Seattle, WA) and licensed to Merck Serono in 2007.

We covered tecemotide in our report, both as an example of a cancer vaccine that had failed in Phase 3 clinical trials, and as an example of a vaccine that was nevertheless still under development. As discussed in our report, in a Phase 3 trial known as START in non-small cell lung cancer (NSCLC) patients, researchers found no significant difference in overall survival between administration of tecemotide or placebo. However, a subsequent analysis suggested that there was a statistically significant survival advantage for tecemotide compared with placebo in a pre-defined subset of patients. Based on these results, Merck Serono began a second Phase 3 trial in that subset.

However, as the result of a failure in a Phase 3 trial in Japan sponsored by Oncothyreon (reported on August 19, 2014), Merck Serono decided to discontinue development.

As stated by Merck Serono’s Executive Vice President and Global Head of R&D Luciano Rossetti, “While the data from the exploratory subgroup analysis in the START trial generated a reasonable hypothesis to warrant additional study, the results of the recent trial in Japanese patients decreased the probability of current studies to reach their goals.”

As we discussed in our report, the cancer vaccine field has been rife with clinical failures—from its beginnings in the 1990s to the present day. This has especially included late-stage failures, not only that of Merck Serono’s tecemotide, but also, for example, GlaxoSmithKline’s (GSKs) MAGE-A3 vaccine. Only one anticancer vaccine—sipuleucel-T (Dendreon’s Provenge) for treatment of metastatic castration-resistant prostate cancer—has ever reached the market, and its therapeutic effects appear to be minimal.

Despite these poor results, researchers and companies persist in their efforts to develop cancer vaccines. Our report discusses why cancer vaccine R&D continues despite the overwhelming history of failure, the hypothesized reasons for these failures, and what researchers and companies can do and are doing to attempt to obtain better results.

Conclusions

As a fast-moving, important field, cancer immunotherapy will continue to generate scientific, medical, and market news. There will continue to be periodic meetings, such as the 2014 European Society for Medical Oncology (EMSO) meeting (September 26-30, Madrid, Spain), in which positive results of small, early-stage trials of several checkpoint inhibitors were presented. Our report—an in-depth discussion of cancer immunotherapy—can enable you to understand such future developments, as well as current ones. It is also designed to inform the decisions of leaders in companies and in academia that are involved in cancer R&D and treatment.

For more information on Cancer Immunotherapy: Immune Checkpoint Inhibitors, Cancer Vaccines, and Adoptive T-cell Therapies, or to order it, see the Insight Pharma Reports website.

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As the producers of this blog, and as consultants to the biotechnology and pharmaceutical industry, Haberman Associates would like to hear from you. If you are in a biotech or pharmaceutical company, and would like a 15-20-minute, no-obligation telephone discussion of issues raised by this or other blog articles, or of other issues that are important to your company, please contact us by phone or e-mail. We also welcome your comments on this or any other article on this blog.

Obesity therapeutics update

Obesity, 12th century Japan.

Obesity, 12th century Japan.

The Biopharmconsortium Blog has over the years included numerous articles about obesity, and the attempts of researchers and companies to develop treatments for this disease.

Obesity, which has historically been considered the result of “lack of willpower” or other behavioral issues, was recognized as a disease by the American Medical Association in June 2013. This followed many years of genetic, molecular biology, and physiological studies that revealed the pathobiological basis of obesity. Nevertheless, many people—including many doctors, patients, and nutritionists—persist in the believing the older view of obesity. This continues to fuel an extremely lucrative diet industry, even thought most—if not all—attempts at dieting eventually fail.

However, researchers and companies have continued in their efforts to develop approved therapies for obesity. We have followed the results of companies that had come close to obtaining FDA approval for three central nervous system (CNS)-acting antiobesity agents in 2010—only to encounter opposition due to safety concerns. However, two of their agents were approved in 2012. Now the third one was approved in September 2014.

Orexigen/Takeda’s Contrave approved by the FDA

On September 11, 2014, Orexigen Therapeutics (La Jolla, CA) and its partner, Takeda, announced that the FDA had approved their antiobesity agent, Contrave (naltrexone HCI and bupropion HCI) extended-release tablets as an adjunct to diet and exercise for chronic weight management in obese adults [body mass index (BMI) of 30 kg/m2 or greater], and in overweight adults (BMI of 27 kg/m2 or greater) who have at least one weight-related comorbid condition (e.g, high cholesterol, Type 2 diabetes, or hypertension).

However, the FDA requires Contrave’s label to carry a boxed warning of increased risk of suicidal thoughts and other psychiatric issues. The label also warns that “The effect of Contrave on cardiovascular morbidity and mortality has not been established.” Orexigen is also required to conduct several post-marketing studies, including studies in pediatric patients, and assessment of the effects of long-term treatment with Contrave on the incidence of major adverse cardiovascular (CV) events in overweight and obese subjects with CV disease or multiple CV risk factors.

The September 2014 approval of Contrave followed the February 2011 issuance by the FDA of a Complete Response Letter requiring extensive clinical studies before Contrave could be approved. In 2010 the FDA had also rejected the applications of two other preregistration antiobesity drugs—Vivus’ Qnexa and Arena Therapeutics’ lorcaserin (Lorqess). Also in 2010, the then-marketed antiobesity drug sibutramine (Abbott’s Meridia) was withdrawn from the market at the FDA’s request.

Concern about long-term safety was the major consideration in all of these cases.

Nevertheless, lorcaserin (rebranded as Belviq) was approved in June 2012, and Qsymia (formerly known as Qnexa) was approved in July 2012.

Thus there are now three CNS-targeting weight-loss drugs on the U.S. market—all of which are “adjuncts to diet and exercise”, all of which work by suppressing appetite, and all of which have safety concerns that require post-marketing studies. Moreover, at least two of these drugs have levels of efficacy less than might be desired. For example, in one trial of Contrave, significant weight loss — defined as the loss of at least 5% of body weight — was achieved by 42% of Contrave-treated subjects, and 17% of subjects in the placebo group. The FDA says that patients taking Contrave should be evaluated after 12 weeks of treatment. Those who have failed to lose at least 5% of their body weight should discontinue Contrave.

Lorcaserin is the least efficacious of these drugs. Qsymia is the most efficacious, with 66.7% of patients on high-dose Qsymia losing at least 5% of body weight, as compared to 17.3% for placebo. The average weight loss in that trial was 10.9% of body weight with high-dose Qsymia and 1.2% with placebo.

A drop in weight of as little as 5% can have positive effects on risk of obesity’s comorbidities (e.g., insulin resistance, diabetes, high blood pressure, dyslipidemia, cardiovascular disease). Nevertheless, all three of these drugs are aids in management of obesity, rather than effective treatments. Moreover, their potential adverse effects are significant. It must be remembered that it was adverse effects that resulted in the withdrawal from the market of several antiobesity drugs (including sibutramine), and prevented the approval of any obesity drugs at all in 2010.

The FDA’s approval of these three drugs indicates that the agency is more willing to make antiobesity drugs available to patients than it has been previously, even in the face of continuing concerns about long-term safety. Rather than rejecting these drugs, the FDA is handling its concerns about safety via post-marketing studies, and restricted distribution of the drugs.

Liraglutide for treatment of obesity?

Meanwhile, Novo Nordisk is awaiting the FDA’s decision on the approval of its high-dose formulation of liraglutide (Saxenda) for treatment of obesity. An FDA advisory board recommended approval of the agent on September 11, 2014. The drug has an October 20 PDUFA date. The advisory board vote was based on Phase 3 results, which indicated that liraglutide produced an average 8% weight loss in obese subjects, when combined with diet and exercise. 69% of prediabetic obese individuals who were treated with liraglutide also showed no signs of prediabetes after 56 weeks, as compared to 33% for the placebo group.

We have discussed the potential use of liraglutide in treatment of obesity on this blog. A lower-dose formulation of this agent, under the trade name of Victoza, is already approved for treatment of type 2 diabetes. Liraglutide is a recombinant protein drug. It is a member of a class of drugs called incretin mimetics. An incretin is a gastrointestinal hormone that triggers an increase in insulin secretion by the pancreas, and also reduces gastric emptying. The latter effect slows nutrient release into the bloodstream and appears to increase satiety and thus reduce food intake. The major physiological incretin is glucagon-like peptide 1 (GLP-1), and incretin-mimetic drugs are peptides with homology to GLP-1 that have a longer half-life in the bloodstream than does GLP-1.

Although liraglutide does not act in the CNS, its major mechanisms of action in treatment of obesity appears to be—like CNS drugs—appetite control. Moreover, clinical trial results indicate that liraglutide is more of an aid in management of obesity than an effective treatment. Nevertheless, liraglutide’s antidiabetic effects and lack of CNS adverse effects constitute potential advantages over CNS-acting antiobesity drugs.

Sales of approved antiobesity drugs have been struggling

Despite the excitement over the approval of antiobesity drugs after so many roadblocks, sales of these drugs have fallen short of estimates. Estimates for Qsymia sales have fallen to $141 million in 2016 from the $1.2 billion projection for 2016 when the drug was approved in 2012. Eisai estimates that Belviq will generate $118 million in sales. Producers and marketers of these two drugs hope that the approval of Contrave will drive patient acceptance of all three CNS-targeting antiobesity drugs. At least one analyst projects that Contrave may achieve $740 million in sales in 2018.

If it is approved, Saxenda may have a sales advantage over the CNS-targeting drugs, since the low-dose formulation, Victoza for type 2 diabetes, is an established drug, with relationships with doctors and insurers already in place. Analysts project that liraglutide (branded as Saxenda) will generate $556 million in weight-loss sales in 2018, in addition to $3.2 billion for the antidiabetic low-dose formulation, Victoza.

A big factor in the level of sales of antiobesity drugs has been insurance reimbursement. It is estimated that some 50 percent of people with private insurance receive at least some coverage for diet drugs. However, insurers tend to classify Qsymia and Belviq as third-tier medications, requiring large patient co-payments. Moreover, Medicare and Medicaid do not pay for the drugs. Analysts hope that the approval of Contrave will result in expanded insurer coverage.

Obesity specialist company Zafgen continues to make progress

The vast majority of efforts to develop antiobesity drugs—over several decades—have been aimed at targeting the CNS. However, obesity is a complex metabolic disease that involves communication between numerous organs and tissues, notably adipose tissue (white, brown, and beige fat), skeletal muscle, the liver, the pancreas, the brain (especially the hypothalamus), the digestive system, and the endocrine system. The pathophysiology of obesity is also related to that of other major metabolic diseases, especially type 2 diabetes.

The mechanistic basis of obesity is not well understood, even though breakthroughs in understanding aspects of this disease have occurred in recent years. Thus there is great need for continuing basic research, and for novel programs aimed at development of breakthrough treatments for obesity based on non-CNS pathways.

One company that has been active in this area is Zafgen (Cambridge, MA), which we have been following on this blog. On June 24, 2014, Zafgen announced the closing of its Initial Public Offering. Zafgen is thus a young company pursuing an alternative approach to antiobesity drug discovery and development that has been able to go public.

In our May 23, 2012 article on this blog, we discussed Zafgen’s lead drug candidate, beloranib (ZGN-433). Beloranib is a methionine aminopeptidase 2 (MetAP2) inhibitor, which exerts an antiobesity effect by downregulating signal transduction pathways in the liver that are involved in the biosynthesis of fat. Animals or humans treated with beloranib oxidize fat to form ketone bodies, which can be used as energy or are excreted from the body. The result is breakdown of fat cells and weight loss. Obese individuals do not usually have the ability to form ketone bodies.

On June 22, 2013, Zafgen announced the interim results of an ongoing double blind placebo-controlled Phase 2 study of beloranib in a group of obese men and women. These results were presented in a poster session at the American Diabetes Association’s 73rd Scientific Sessions in Chicago on June 23, 2013.

Subjects had a mean age of 40.3 years, a mean weight of 101.2 kg (223.1 lbs.), and a mean BMI of 37.9 kg/m2 at the beginning of the study. 38 subjects receiving 12 weeks of treatment in the full trial were randomized to one of three doses of subcutaneous beloranib vs. placebo. The subjects were counseled not to change their usual diet and exercise patterns—this protocol thus differed from trials of the agents discussed earlier in this article. The interim analysis was of results from the first 19 subjects who completed 12 weeks of treatment.

Beloranib appeared safe and showed dose responsive weight loss. After 12 weeks, subjects on 0.6 mg, 1.2 mg, or 2.4 mg of beloranib lost an average of 3.8, 6.1 and 9.9 kg, respectively (8.4, 13.4, and 21.8 lbs.), versus 1.8 kg (4.0 lbs.) for placebo; these results were statistically significant. In addition, beloranib treated subjects showed improvements versus placebo in CV risk factors including levels of triglycerides, LDL cholesterol and C-reactive protein. Sensation of hunger also was reduced significantly.

Subcutaneous beloranib treatment over 12 weeks was generally well-tolerated. There were no major adverse events or deaths.

If later clinical trials confirm these interim Phase 2 clinical results, beloranib may have significant advantages over the three approved CNS-targeting drugs and over Saxenda, because of beloranib’s apparent benign adverse-effect profile, and major effects on weight and fat loss, even in the absence of diet and exercise advice. However, beloranib is years away from reaching the market for treatment of severe obesity with no known genetic causation.

Zafgen is attempting to develop beloranib not only as a superior alternative to “diet drugs”, but also as an alternative to bariatric surgery. In order to obtain approval for that indication, beloranib must (in late-stage, long-term clinical trials) demonstrate both the degree of weight loss and the positive metabolic effects seen in severely obese patients treated via bariatric surgery.

In addition to developing beloranib for severe obesity, Zafgen is developing this drug for treatment of the rare genetic disease Prader-Willi syndrome (PWS). Patients with PWS exhibit such symptoms as low muscle mass, short stature, incomplete sexual development, cognitive disabilities, and a chronic feeling of hunger that can result in life-threatening obesity. PWS is the most common genetic cause of life-threatening obesity. Many children with PWS become morbidly obese before age 5.

In January 2013, the FDA granted Zafgen orphan designation to treat PWS with beloranib. On July 10, 2014, the European Commission also granted orphan drug designation for beloranib for this indication. These regulatory actions were based on the initial results of Zafgen’s Phase 2a clinical trial of beloranib in PWS. This trial showed improvements in hunger-related behaviors and body composition, including reductions in body fat and preservation of lean body mass.

On October 1, 2014, Zafgen announced that it had begun a randomized, double-blind, placebo-controlled Phase 3 clinical trial of beloranib in obese adolescents and adults with PWS (clinical trial number NCT02179151). The company is also testing beloranib in Phase 2 trials in obesity due to hypothalamic injury, and is in preclinical studies with a second-generation MetAP2 inhibitor for treatment of general obesity.

Energesis Pharmaceuticals

The Biopharmconsortium Blog has also been following an earlier-stage company, Energesis Pharmaceuticals (Cambridge, MA), whose approach to developing antiobesity therapeutics is based on targeting brown fat. On June 19, 2014, FierceBiotech and Energesis announced that Janssen Pharmaceuticals and Johnson & Johnson Innovation had entered into a collaboration with Energesis, aimed at identifying agents that stimulate the formation of new brown fat in order to treat metabolic diseases.

Conclusions

The antiobesity drug field, which in 2010 was the domain of a “pall of gloom”, is now populated by three approved CNS-targeting drugs, perhaps to be soon joined by Saxenda. These drugs promise to give patients and physicians a new set of tools to aid in the management of obesity. However, the history of the CNS-targeting obesity drug field is littered with tales of the withdrawal of drug after drug due to unacceptable adverse effects. Moreover, the market—and especially payers—have not yet fully accepted the new antiobesity agents.

As readers of this blog well know, we favor approaches to treatment of obesity and its comorbidities based on targeting somatic physiological pathways that appear to be at the heart of the causation of obesity, not just the CNS. The progress of Zafgen in addressing a set of these pathways is very encouraging. However, these results must be confirmed by Phase 3 clinical trials.

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As the producers of this blog, and as consultants to the biotechnology and pharmaceutical industry, Haberman Associates would like to hear from you. If you are in a biotech or pharmaceutical company, and would like a 15-20-minute, no-obligation telephone discussion of issues raised by this or other blog articles, or of other issues that are important to your company, please contact us by phone or e-mail. We also welcome your comments on this or any other article on this blog.

Cancer Immunotherapy Report Published By CHI Insight Pharma Reports

T cells attached to tumor cell. Source: MSKCC. http://bit.ly/1uPr5nl

T cells attached to tumor cell. Source: MSKCC. http://bit.ly/1uPr5nl

 

On September 9, 2014, Cambridge Healthtech Institute’s (CHI’s) Insight Pharma Reports announced the publication of a new book-length report, Cancer Immunotherapy: Immune Checkpoint Inhibitors, Cancer Vaccines, and Adoptive T-cell Therapies, by Allan B. Haberman, Ph.D.

As attested by the torrent of recent news, cancer immunotherapy is a “hot”, fast-moving field. For example:

  • On September 5, 2014, the FDA granted accelerated approval to the PD-1 inhibitor pembrolizumab (Merck’s Keytruda, also known as MK-3475) for treatment of advanced melanoma. This approval was granted nearly two months ahead of the agency’s own deadline. Pembrolizumab is the first PD-1 inhibitor to reach the U.S. market.
  • On May 8, 2014, the New York Times published an article about a woman in her 40’s who was treated with adoptive immunotherapy with autologous T cells to treat her cancer, metastatic cholangiocarcinoma (bile-duct cancer). This deadly cancer typically kills the patient in a matter of months. However, as a result of this treatment, the patient lived for over 2 years, with good quality of life, and is still alive today.

These and other recent news articles and scientific publications attest to the rapid progress of cancer immunotherapy, a field that only a few years ago was considered to be impracticable.

Our report focuses on the three principal types of therapeutics that have become the major focuses of research and development in immuno-oncology in recent years:

  • Checkpoint inhibitors
  • Therapeutic anticancer vaccines
  • Adoptive cellular immunotherapy

The discussions of these three types of therapeutics are coupled with an in-depth introduction and history as well as data for market outlook.

Also featured in this report are exclusive interviews with the following leaders in cancer immunotherapy:

  • Adil Daud, MD, Clinical Professor, Department of Medicine (Hematology/Oncology), University of California at San Francisco (UCSF); Director, Melanoma Clinical Research, UCSF Helen Diller Family Comprehensive Cancer Center.
  • Matthew Lehman, Chief Executive Officer, Prima BioMed (a therapeutic cancer vaccine company with headquarters in Sydney, Australia).
  • Marcela Maus, MD, PhD, Director of Translational Medicine and Early Clinical Development, Translational Research Program, Abramson Cancer Center, University of Pennsylvania in Philadelphia.

The report also includes the results and an analysis of a survey of individuals working in immuno-oncology R&D, conducted by Insight Pharma Reports in conjunction with this report. The survey focuses on market outlook, and portrays industry opinions and perspectives.

Our report is an in-depth discussion of cancer immunotherapy, an important new modality of cancer treatment that may be used to treat as many as 60% of cases of advanced cancer by the late 2010s/early 2020s. It includes updated information from the 2014 ASCO (American Society of Clinical Oncology) and AACR (American Association for Cancer Research) meetings. The report is designed to enable you to understand current and future developments in immuno-oncology. It is also designed to inform the decisions of leaders in companies and in academic groups that are working in areas that relate to cancer R&D and treatment.

For more information on Cancer Immunotherapy: Immune Checkpoint Inhibitors, Cancer Vaccines, and Adoptive T-cell Therapies, or to order it, see the Insight Pharma Reports website.

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As the producers of this blog, and as consultants to the biotechnology and pharmaceutical industry, Haberman Associates would like to hear from you. If you are in a biotech or pharmaceutical company, and would like a 15-20-minute, no-obligation telephone discussion of issues raised by this or other blog articles, or of other issues that are important to your company, please contact us by phone or e-mail. We also welcome your comments on this or any other article on this blog.

Agios Pharmaceuticals continues to progress

Agios Kirykos, Ikaria, Greece. Source: http://commons.wikimedia.org/wiki/File:Agios_Kirikos,_Ikaria.jpg

Agios Kirykos, Ikaria, Greece. Source: http://commons.wikimedia.org/wiki/File:Agios_Kirikos,_Ikaria.jpg

Because of being very busy with other projects, we have not posted an article on this blog since April 10, 2014. However, the Biopharmconsortium Blog is still here. More importantly, Haberman Associates biotech/pharma consulting is still here, and we’re still accepting new clients.

Thanks to the many readers who have continued to follow our website and blog during our blogging hiatus, and who have linked to our blog on Twitter and on other social media.

During the hiatus, several of the companies that we have been following on our blog have been progressing. Over the next several months, we shall be blogging about some of these companies, as well as about other notable industry events that have occurred in recent weeks and that will occur during the remainder of 2014.

The first company that we are writing about is cancer metabolism specialist Agios Pharmaceuticals (Cambridge, MA). Our most recent three articles about Agios on this blog are:

In our September 23, 2013 article, we noted that Agios had initiated its first clinical study—a Phase 1 clinical trial of AG-221 in patients with advanced hematologic malignancies bearing an isocitrate dehydrogenase 2 (IDH2) mutation. AG-221 is a first-in-class, orally available, selective, potent inhibitor of the mutated IDH2 protein. It is thus a targeted (and personalized) therapy for patients with cancers with an IDH2 mutation.

On June 14, 2014, Agios reported on new clinical data in its ongoing Phase 1 trial of AG-221, which was presented at the 19th Congress of the European Hematology Association (EHA) in Milan, Italy by Stéphane de Botton, M.D. (Institut de Cancérologie Gustave Roussy, Villejuif, France).

The presentation reported on the results of AG-221 treatment of 35 patients with IDH2 mutation positive hematologic malignancies. The researchers observed objective responses in 14 out of 25 evaluable patients, and stable disease in an additional 5 patients. Six patients experienced complete remissions which lasted from one to four months, and are still ongoing. AG-221 has shown favorable pharmacokinetics at all doses tested, with large reductions in serum levels of the oncometabolite 2-hydroxyglutarate (2HG). AG-221 was also well tolerated.

The new data confirms and builds upon previously results. The favorable safety and efficacy data supports Agios’ plan to initiate four expansion cohorts in the second half of 2014. Agios also expects to submit additional data from the ongoing Phase 1 trial for presentation at a later scientific meeting in 2014.

Meanwhile, as announced on June 13, 2014, Agios’ partner Celgene exercised its option to an exclusive worldwide license for AG-221. It exercised this option early, based on the Phase 1 data generated so far.

On June 16, 2014, Agios announced that the FDA granted orphan drug designation for AG-221 for treatment of patients with acute myelogenous leukemia (AML). On August 13, 2014, the FDA also granted Fast Track designation to AG-221 for the treatment of patients with AML that carry an IDH2 mutation.

Thus development of Agios’ lead compound, AG-221, continues to progress. Several other Agios R&D programs are also progressing, as detailed in the company’s report for the second quarter of 2014.

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As the producers of this blog, and as consultants to the biotechnology and pharmaceutical industry, Haberman Associates would like to hear from you. If you are in a biotech or pharmaceutical company, and would like a 15-20-minute, no-obligation telephone discussion of issues raised by this or other blog articles, or of other issues that are important to your company, please contact us by phone or e-mail. We also welcome your comments on this or any other article on this blog.

Forma Therapeutics’ expanded R&D collaboration with Celgene

 

Ubiquitin pathway. Source: Rogerdodd, English language Wikipedia

Ubiquitin pathway. Source: Rogerdodd, English language Wikipedia

On April 1, 2014, Forma Therapeutics (Watertown MA) announced that it had entered into an expanded strategic collaboration with Celgene (Summit, NJ).

Under the new agreement, Forma has received an upfront cash payment of $225 million. The initial collaboration between the two companies under the new agreement will be for 3 1⁄2 years. Celgene will also have the option to enter into up to two additional collaborations with terms of two years each for additional payments totaling approximately $375 million. Depending on the success of the collaborations and if Celgene elects to enter all three collaborations, the combined duration of the three collaborations may be at least 7 1⁄2 years.

Under the terms of the new agreement, Forma will control projects from the research stage through Phase 1 clinical trials. For programs selected for licensing, Celgene will take over clinical development from Phase 2 to commercialization. Forma will retain U.S. rights to these products, and Celgene will have the rights to the products outside of the U.S. For products not licensed to Celgene, FORMA will maintain worldwide rights.

During the term of the third collaboration, Celgene will have the exclusive option to acquire Forma, including the U.S. rights to all licensed programs, and worldwide rights to other wholly owned programs within Forma at that time.

The April 2013 agreement between Forma and Celgene

The new collaboration between Forma and Celgene builds on an earlier agreement between the two companies. On April 29, 2013, the two companies entered into a collaboration aimed at discovery, development, and commercialization of drug candidates to modulate targets involved in protein homeostasis.

Protein homeostasis, also known as proteostasis, involves a tightly regulated network of pathways controlling the biogenesis, folding, transport and degradation of proteins. The ubiquitin pathway (illustrated in the figure above) is one of these pathways. We recently discussed how the ubiquitin pathway is involved in the mechanism of action of thalidomide and lenalidomide (Celgene’s Thalomid and Revlimid).

Targeting protein homeostasis has application to discovery and development of drugs for oncology, neurodegenerative disease, and other disorders. However, the April 2013 Forma/Celgene agreement focused on cancer. Under that agreement, Forma received an undisclosed upfront payment. Upon licensing of preclinical drug candidates by Celgene, Forma was to be eligible to receive up to $200 million in research and early development payments. FORMA was also to be eligible to receive $315 million in potential payments based upon development, regulatory and sales objectives for the first ex-U.S. license, as well as  up to a maximum of $430 million per program for further licensed products, in addition to post-sales royalties.

On October 8, 2013, Forma announced that it had successfully met the undisclosed first objective under its April 2013 strategic collaboration agreement with Celgene. This triggered an undisclosed payment to Forma. Progress in the April 2013 collaboration was an important basis for Celgene’s decision to enter into a new, broader collaboration with Forma a year later.

The scope of the new April 2014 Forma/Celgene collaboration

Unlike the April 2013 agreement, the April 2014 agreement between Forma and Celgene is not limited to protein homeostasis, or to oncology. The goal of the new collaboration is to “comprehensively evaluate emerging target families for which Forma’s platform has exceptional strength” over “broad areas of chemistry and biology”.  The expanded collaboration will thus involve discovery and development of compounds to address a broad range of target families and of therapeutic areas.

According to Celgene’s Thomas Daniel, M.D. (President, Global Research and Early Development), Celgene’s motivation for signing the new agreement is based not only on the early success of the existing Forma/Celgene collaboration, but also on “emerging evidence of the power of Forma’s platform to generate unique chemical matter across important emerging target families”.

According to Forma’s President and CEO, Steven Tregay, Ph.D., the new collaboration with Cegene enables Forma to maintain its autonomy in defining its research strategy and conducting discovery through early clinical development. It also aligns Forma with Celgene’s key strengths in hematology and in inflammatory diseases.

Forma Therapeutics in Haberman Associates publications

We have been following Forma on the the Biopharmconsortium Blog since July 2011. At that time, I was a speaker at Hanson Wade’s World Drug Targets Summit (Cambridge, MA). At that meeting, Mark Tebbe, Ph.D. (then Vice President, Medicinal and Computational Chemistry at Forma) was also a speaker. At the conference, Dr. Tebbe discussed FORMA’s technology platforms, which are designed to be enabling technologies for discovery of small-molecule drugs to address challenging targets such as protein-protein interactions (PPIs).

In particular, Dr. Tebbe discussed Forma’s Computational Solvent Mapping (CS-Mapping) platform, which enables company researchers to interrogate PPIs in intracellular environments, to define hot spots on the protein surfaces that might constitute targets for small-molecule drugs. FORMA has been combining CS-Mapping technology with its chemistry technologies (e.g., structure guided drug discovery, diversity orientated synthesis) for use in drug discovery.

We also discussed Forma’s earlier fundraising successes as of January 2012, and cited Forma as a “built to last” research-stage platform company in an interview for Chemical & Engineering News (C&EN).

Finally, we discussed Forma and its technology platform in our book-length report, Advances in the Discovery of Protein-Protein Interaction Modulators, published by Informa’s Scrip Insights in 2012. (See also our April 25, 2012 blog article.)

In our report, we discussed Forma as a company that employs “second-generation technologies” for the discovery of small-molecule PPI modulators. This refers to a suite of technologies designed to overcome the hurdles that stand in the way of the accelerated and systematic discovery and development of PPI modulators. Such technologies are necessary to make targeting of PPIs a viable field.

Forma’s website now has a brief explanation of its drug discovery engine, as it is applied to targeting PPIs. This includes links to web pages describing:

Our 2012 book-length report discusses technologies of these types, as applied to discovery of PPI modulators, in greater detail than the Forma website.

According to Dr. Daniel: “Progress in our existing [protein homeostasis] collaboration, coupled with emerging evidence of the power of FORMA’s platform to generate unique chemical matter across important emerging target families” led Celgene to enter into its new, expanded collaboration with Forma in April 2014. This suggests that Celgene is especially impressed by Forma’s chemistry and chemical biology platforms. it also suggests that chemistry technology platforms developed to address PPIs may be applicable to areas of drug discovery beyond PPIs as well.

Concluding remarks

Despite the enthusiasm for Forma and its drug discovery engine shown by Celgene, Forma’s other partners, and various industry experts, it must be remembered that Forma is still a research-stage company. The company has not one lone drug candidate in the clinic, let alone achieving proof-of-concept in humans. It is clinical proof-of-concept, followed by Phase 3 success and approval and marketing of the resulting drugs, that is the “proof of the pudding” of a company’s drug discovery and development efforts.

We await the achievement of such clinical milestones by Forma Therapeutics.

From a business strategy point of view, we have discussed Forma’s efforts to build a stand-alone, independent company for the long term in this blog and elsewhere. Now Forma has entered into an agreement with Celgene that might—in around 7-10 years—result in Forma’s acquisition. This would seem to contradict Forma’s “built to last” strategy.

However, in the business environment that has prevailed over the past several years, several established independent biotech companies, notably Genentech and Genzyme, have been acquired by larger companies. Even several Big Pharmas (e.g., Schering-Plough and Wyeth) have been acquired.

Nevertheless, we do not know what the business environment in the biotech/pharma industry will be like in 7-10 years, despite the efforts of strategists to predict it. And Celgene might forgo its option to acquire Forma, for any number of reasons. So the outlook for Forma’s status as an independent or an acquired company (which also depends on its success in developing drugs) is uncertain.

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As the producers of this blog, and as consultants to the biotechnology and pharmaceutical industry, Haberman Associates would like to hear from you. If you are in a biotech or pharmaceutical company, and would like a 15-20-minute, no-obligation telephone discussion of issues raised by this or other blog articles, or of other issues that are important to  your company, please contact us by phone or e-mail. We also welcome your comments on this or any other article on this blog.

Neandertals, diabetes, and drug discovery

Neanderthal Family

Neanderthal Family

In our 2010 end-of-year blog article entitled “2010: Breakthroughs, Newsmakers, And Deals Of The Year”, we proposed an alternative nominee for the life science breakthrough of the year: the determination of the sequence of approximately two-thirds of the Neandertal genome by Svante Pääbo (Max-Planck Institute for Evolutionary Anthropology, Leipzig, Germany.) and his colleagues. We stated that this momentous achievement was “of great cultural significance, since it indicates that Neandertals contributed some 1-4 percent of the genome sequences of non-African present-day humans.” (This figure is now thought to be 1.5 to 2.1 percent.)

However, we also said that we had not blogged on this work “simply because it [had] nothing to do with drug discovery and development.” We then further stated that “perhaps someday, for example, some of the products of genes that are found in present-day humans but not in Neandertals could emerge as potential drug targets…researchers [had] begun studying some of these gene products in cell culture systems.”

Now, as of early 2014, one of the genes identified via sequencing Neandertal genomes has been implicated in a novel pathway involved in type 2 diabetes in present-day humans. However, rather than being a modern human gene not present in Neandertals, it is a haplotype that introgressed into modern humans via admixture with Neandertals.

The study that identified this gene initially had no connection with Neandertal genome studies at all. I was published by the SIGMA (Slim Initiative in Genomic Medicine for the Americas) Type 2 Diabetes Consortium in the 6 February 2014 issue of Nature. SIGMA is a joint U.S.-Mexico project funded by the Carlos Slim Foundation. It focuses on several important diseases that have particular relevance to public health in Mexico and Latin America, including type 2 diabetes and cancer. Type 2 diabetes has approximately twice the prevalence in Mexican and other Latin American populations, as compared to U.S. non-Hispanic whites.

The researchers performed a genome-wide association study (GWAS), in which they analyzed 9.2 million single nucleotide polymorphisms (SNPs) in each of 8,214 Mexicans and other Latin Americans, including 3,848 with type 2 diabetes and 4,366 non-diabetic controls. As a result of that analysis, the researchers replicated the identification of haplotypes previously associated with type 2 diabetes. They also identified a novel locus associated with type 2 diabetes at genome-wide significance.  This locus spans the genes that encode the solute carrier proteins SLC16A11 and SLC16A13. The risk haplotype carries four amino acid substitutions, all in SLC16A11.  It is present at approximately 50% frequency in Native American individuals and around 10% in East Asians, but is rare in Europeans and Africans.

Each copy of the risk newly-identified haplotype is associated with an approximately 20% increased risk of type 2 diabetes. The haplotype would thus be expected to contribute to the higher burden of type 2 diabetes in Mexican and Latin American populations. Mutations in SLC16A11 had never before been associated with type 2 diabetes. SLC16A11 thus represents a novel type 2 diabetes pathway.

The Neandertal connection

The researchers noted that the sequence of the risk haplotype is highly divergent, with an estimated time to the most recent common ancestor of both the novel haplotype and a European haplotype of 799,000 years. This is long before modern humans migrated from Africa into Eurasia. Moreover, the novel haplotype is not found in Africans and is rare in European populations. The researchers therefore hypothesized that the novel haplotype entered modern human populations via admixture with Neandertals.

At the time that this research was being conducted, the variant was not seen in published Neandertal (or Denisovan) genome sequences. However, with the help of Svante Pääbo, the researchers obtained access to a then-unpublished full-length Neandertal genome sequence from a Central Asian specimen. The Central Asian Neandertal genome sequence was homozygous across 5 killobases for the risk haplotype including all four missense SNPs in SLC16A11 . Over a span of 73 kb, the Neandertal sequence is nearly identical to that of individuals from the 1000 Genomes Project who are homozygous for the risk haplotype. The full-length Central Asian Neandertal genome has recently been published.

Moreover, the genetic length of the 73-kb risk haplotype is longer than would be expected if it had undergone recombination for the approximately 9,000 generations since the split with Neandertals. This is consistent with the hypothesis that the risk haplotype is not only similar to the Neandertal sequence, but was probably introduced into modern humans relatively recently through archaic admixture. Although this particular Neandertal-derived haplotype is common in the Americas, Native Americans and Latin Americans have the same proportion of Neandertal ancestry genome-wide as other Eurasian-derived populations. In general, although non-African populations have about the same percentage of Neandertal genes, different populations have different complements of genes derived from Neandertals.

Functional studies of SLC16A11

Although the risk haploype encodes four missense mutations in a single gene, the gene for SLC16A11, there is no formal genetic proof that SLC16A11 is responsible for increased risk of type 2 diabetes. Therefore, the researchers performed preliminary functional studies of SLC16A11.

Via immunofluorescence studies, the researchers found that SLC16A11 was expressed in the liver, the salivary glands and the thyroid. When the gene for SLC16A11 was introduced into HeLa cells, SLC16A1 was found to localize in the endoplasmic reticulum, but not in the plasma membrane, Golgi apparatus, or mitochondria. Other SLC16 family members show distinct intracellular localization pattern within the membranous structures of the cell.

SLC16A11, and other SLC16 family members, are solute carrier transporters (SLCs). We discussed SLCs and their role in transporting small-molecule nutrients and drugs across the blood-brain barrier in our 2009 book-length report, Blood-Brain Barrier: Bridging Options for Drug Discovery and Development, published by Cambridge Healthtech Institute. We also discussed SLCs in a 2009 article entitled “Strategies to Overcome Blood-Brain Barrier” in Genetic Engineering and Biotechnology News.

SLC16 family proteins are monocaboxylate transporters, which transport such compounds as lactate, pyruvate and ketone bodies, as well as thyroid hormone and aromatic amino acids, across biological membranes. As of 2008, of the 14 known members of this family, eight (including SLC16A11) had unknown functions.

The SIGMA researchers expressed SLC16A11 (or control proteins) in HeLa cells, and looked for changes in intracellular concentrations of approximately 300 polar and lipid metabolites. Expression of SLC16A11 resulted in substantial increases in intracellular triacylglycerol (triglyceride) levels, with smaller increases in intracellular diacylglycerols, and decreases in lysophosphatidylcholine, cholesteryl esters, and sphingomyelin. Since triglyceride synthesis occurs in the endoplasmic reticulum of hepatocytes, the researchers hypothesized that SLC16A11 may have a role in hepatic lipid metabolism.

Moreover, serum levels of triglycerides and accumulation of intracellular lipids are associated with insulin resistance, the metabolic syndrome, and the risk of developing type 2 diabetes. Thus, although further functional studies of SLC16A11 are needed, the researchers hypothesize that the novel risk allele for type 2 diabetes that they identified may exert its pro-diabetic effect by altering lipid metabolism in the liver.

Conclusions

This study, a GWAS in Mexican and other Latin American samples, is an illustration of how genetic mapping studies in understudied populations may identify previously undiscovered aspects of disease pathogenesis.

The risk gene identified in this study, SLC16A11, has not previously been associated with type 2 diabetes. It thus potentially represents a novel diabetes pathway, which might yield new targets for drug discovery. This new pathway might be important in type 2 diabetes not only in Native Americans and Latin Americans, but in other populations as well, even in those that lack mutations in SLC16A11.

The study initially had nothing to do with Neandertal genetics. However, the researchers noted unusual population genetics features of the risk haplotype that they identified, which led them to identify this haplotype as having entered modern human populations via introgression from Neandertals. Via the initial introgression, natural selection and/or genetic drift, the haplotype became fixed in Native Americans and some East Asians, but not in other Eurasian-derived populations such as Europeans and Euro-Americans.

It is extremely unlikely that either Neandertals, or Native Americans and Latin Americans in pre-modern times, had type 2 diabetes. However, modern diets, perhaps in concert with other risk genes, produced type 2 diabetes in carriers of the mutant SLC16A11 gene. The well-know case of the Pima Indians indicates that change from native diets and high levels of physical activity to processed foods and a more “Western” lifestyle is the major cause of the high levels of type 2 diabetes and obesity in this genetically-predisposed population. (It is not known, however, whether SLC16A11 is a factor in Pima Indians.)

As for studies of the Neandertal genome, John Hawks, Ph.D. (University of Wisconsin), an anthropologist who has been active in studies of the genetics of Neandertals and of Upper Paleolithic modern humans, believes that studies of the genomes of these ancient peoples may have relevance for the biology of present-day humans. [I took a Massive Open Online Course (MOOC) led by Dr. Hawks, entitled “Human Evolution: Past and Future” between late January and early March, 2014.]

Other researchers who study ancient genomes generally agree. As indicated by the SIGMA diabetes study, both genes for modern humans that were not present in Neandertals, and genes introgressed from Neandertals into modern humans may be relevant to modern human biology—and perhaps eventually to drug discovery.

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As the producers of this blog, and as consultants to the biotechnology and pharmaceutical industry, Haberman Associates would like to hear from you. If you are in a biotech or pharmaceutical company, and would like a 15-20-minute, no-obligation telephone discussion of issues raised by this or other blog articles, or of other issues that are important to your company, please contact us by phone or e-mail. We also welcome your comments on this or any other article on this blog.

Thalidomide, multiple myeloma, Protein-Protein interactions, and drug discovery

Ikaros. Source © Marie-Lan Nguyen / Wikimedia Commons

Ikaros. Source © Marie-Lan Nguyen / Wikimedia Commons

Thalidomide is a notorious drug that was approved in Europe in the late 1950s for use as a sedative, but was withdrawn in the early 1960s after the drug caused thousands of devastating birth defects. The FDA did not approve thalidomide at that time. However, beginning in the late 1990s, thalidomide has been repurposed and rehabilitated, provided that proper precautions are maintained to prevent its use in pregnant women and women who may become pregnant.

Currently, thalidomide (under the brand name Thalomide) is marketed by Celgene (Summit, NJ) mainly as a treatment for multiple myeloma (MM) and of a certain form of leprosy. Celgene has also been developing derivatives of thalidomide, the most important of which are lenalidomide (Celgene’s Revlimid) and pomalidomide (Celgene’s Pomalyst). All three agents are now approved in the U.S. and in Europe. Although lenalidomide and pomalidomide are more potent in treating MM and have fewer adverse effects than thalidomide, they are still teratogenic (as determined by animal studies), and are available only in a restricted distribution setting to avoid their use during pregnancy.

Celgene calls thalidomide and its derivatives “immunomodulatory drugs” (IMiDs). Until recently, their mechanism of action was poorly understood. IMiDs were found to have a wide range of activities, including antiangiogenic activity, induction of oxidative stress, upregulation of interleukin-2 (IL-2) production by activated T cells, inhibition of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α), and stimulation of natural killer (NK) cells. It is thalidomide’s antiangiogenic activity that appears to be responsible for its teratogenic effects.

However, it was the antiangiogenic activity of thalidomide that gave rise to the hypothesis that this agent might be used to treat MM. MM is a B-cell malignancy that involves the proliferation of abnormal plasma cells, which accumulate in the bone marrow.  In MM, the intimate interaction between the plasma cells and bone marrow stromal cells results in induction of the angiogenic factor vascular endothelial growth factor (VEGF) as well as the MM survival factor IL-6. Disruption of this interaction would reduce the induction of new blood vessels and of IL-6, thus decreasing tumor growth and survival. When tested against MM, thalidomide—and later lenalidomide and other IMiDs—were found to be effective in controlling MM, as predicted by the hypothesis.

However, as of 2010, researchers found that although IMiDs are indeed antiangiogenic, that is not the mechanism that explains their therapeutic effect. Now—in 2014—two papers were published in Science that expand upon that earlier effort and identify that pathway by which IMiDs work against MM. These studies were by Krönke et al. and Lu et al. The studies were led, respectively, by Benjamin L. Ebert, M.D., Ph.D. and William G. Kaelin Jr., M.D., both at the Dana-Farber Cancer Institute (Boston, MA). These two papers were accompanied by a brief Perspective by A. Keith Stewart, M.B., CH.B., of the Mayo Clinic (Scottsdale, AZ), in the same issue of Science (17 January, 2014).

The key to understanding the pathway by which lenalidomide (the drug that was used in both of the 2014 research studies) and other IMiDs work against MM is the finding that that they bind to an intracellular protein known as cereblon (CRBN). In a 2010 study, Astellas researchers and their academic collaborators demonstrated that thalidomide binds to zebrafish CRBN. Treatment of zebrafish with CRBN morpholinos or thalidomide caused fin defects, reminiscent of the limb defects seen with thalidomide in the 1960s.

As also demonstrated in the 2010 study, CRBN forms an E3 ubiquitin ligase complex with three other proteins—damaged DNA binding protein 1 (DDB1), Cullin-4A (CUL4A), and regulator of cullins 1 (Roc1). The complex is known as the CRBN-CRL4 ubiquitin ligase.

E3 ubiquitin ligases carry out the terminal step of the ubiquitin pathway—specific attachment of ubiquitin (and via repeated steps, ubiquitin chains) to substrate proteins. Attachment of ubiquitin (and especially of ubiquitin chains) to substrate proteins can tag them for destruction  by the proteasome.

Lu et al. and Krönke et al. showed that lenalidomide binding to CRBN results in the selective ubiquitination and proteasomal degradation of two lymphoid transcription factors, IKZF1 and IKZF3, by the CRBN-CRL4 ubiquitin ligase.  IKZF1 and IKZF3 are Ikaros family zinc finger proteins 1 and 3 (IKZF1 and IKZF3); they are also known, respectively as Ikaros and Aiolos.

Although IKZF1 is highly expressed in early lymphoid progenitors, studies in mice have shown that IKZF3 is required for the generation of plasma cells, which are the physiologic counterparts of MM cells. Both Krönke et al. and Lu et al. studied the roles of IKZF1 and IKZF3 via RNAi knockdown and other methods. Inhibition of IKZF1 or IKZF3 expression inhibited growth of lenalidomide-sensitive MM cell lines, but lenalidomide-insensitive cell lines were not affected. Downregulation of either IKZF protein in these cell lines led to loss of the other. Downregulation of IKZF1 and IKZF3 resulted in a decrease in interferon regulatory factor 4 (IRF4) and IRF4 mRNA, consistent with IRF4 acting downstream of IKZF1 and/or IKZF3 in lenalidomide-sepsitive MM cells. Previous studies have shown that IRF4 inhibition is toxic for MM cells.

In addition to its effects on MM cells, lenalidomide treatment also upregulates IL-2 expression in T cells. Since IKZF3 binds the IL-2 gene promoter and represses IL-2 transcription in T cells, Lu et al. and Krönke et al. investigated whether lenalidomide’s effects on IL-2 expression in T cells might work via the CRBN-CRL4 ubiquitin ligase-IKZF1/3 pathway. They found that RNAi knockdown of CRBN abrogated the effect of lenalidomide on IL-2 expression. They further found that lenalidomide treatment caused marked decreases in IKZF1 and IKZF3 protein levels In primary human T cells. Finally, they showed that RNAi knockdown of IKZF3 or IKZF1 induced IL-2 expression and repressed further response to lenalidomide. These studies thus show that lenalidomide indeed works via the CRBN-CRL4 ubiquitin ligase-IKZF1/3 pathway to upregulate IL-2 in T cells.

Thus IMiDs, working via the CRBN-CRL4 ubiquitin ligase-IKZF1/3 pathway, downregulate IRF4 in MM cells, resulting in cell death. They also upregulate IL-2 in T cells. A diagram of the pathway is given in Dr. Stewart’s Perspective.

The studies of Krönke et al. and Lu et al. have greatly advanced our understanding of the mechanism of action of IMiDs in MM. As pointed out by Krönke et al., other B cell malignancies against which lenalidomide has activity, such as mantle cell lymphoma and chronic lymphocytic leukemia, also exhibit high IKZF3 expression. Celgene is testing lenalidomide against chronic lymphocytic leukemia and other cancers in the clinic, and the drug is approved for treatment of myelodysplastic syndromes in Europe, in addition to MM. So the recent studies of the CRBN-CRL4 ubiquitin ligase-IKZF1/3 pathway may also apply to other cancers for which lenalidomide is being developed.

Nevertheless, there are still gaps in our understanding of the mechanism of action of IMiDs. For example, the proteasomal inhibitor bortezomib (Millennium’s Velcade) is used to treat MM. Combination therapies of bortezomib and lenalidomide have shown efficacy in early clinical trials, and further trials are continuing. This creates an apparent paradox, because proteasomal blockade prevents the destruction of IKZF1 and IKZF3 by lenalidomide via the CRBN-CRL4 ubiquitin ligase-IKZF1/3 pathway. Lu et al. hypothesize that since proteasomal inhibition by bortezomib is incomplete with therapeutic dosing, this might allow sufficient destruction of IKZF1 and IKZF3 while retaining bortezomib’s other therapeutic effects. Alernatively, they hypothesize that IKZF1 and IKZF2, once polyubiquitylated, may be inactive or act as dominant-negatives.

Implications for drug discovery

The most immediate implications of these findings is that they might be used to discover novel, more effective and safer modulators of the CRBN-CRL4 ubiquitin ligase-IKZF1/3 pathway as therapies for MM and other B cell malignancies. Such efforts might include finding a non-teratogenic modulator of this pathway, since thalidomide-CRBN-mediated teratogenicity may be mediated by substrates other than Ikaros family proteins in different cellular lineages.

Moreover, the 2010 zebrafish study suggested that thalidomide’s teratogenic effects are due to a loss of function of cereblon. In contrast, the 2014 studies in MM indicate that the therapeutic effects of the IMiDs reflect a cereblon gain of function. This supports the possibility of finding non-teratogenic modulators of the CRBN-CRL4 ubiquitin ligase-IKZF1/3 pathway.

The studies of Krönke et al. and Lu et al. may have wider implications for the targeting of E3 ubiquitin ligases in drug discovery for other diseases. We have discussed the possibility of targeting E3 ubiquitin ligases in our 2012 book-length report, Advances in the Discovery of Protein-Protein Interaction Modulators, published by Informa’s Scrip Insights.

The ubiquitin system is a fundamental regulatory system in all eukaryotic cells, comparable in importance to protein phosphorylation. In recent years, researchers have discovered and developed numerous important agents that modulate protein phosphorylation pathways, namely the protein kinase inhibitors. However, there as yet are very few approved and experimental drugs that modulate the ubiquitin system. Most are proteasome inhibitors, which indirectly target this system. The approved agent, bortezomib, has achieved blockbuster status despite its nonspecificity and limited field of application.

Despite the central importance of the ubiquitin system, there are only a handful of compounds that directly target it in clinical trials.

The reason that drug discovery of ubiquitin system-targeting drugs has lagged behind, for example, the discovery and development of protein kinase inhibitors is that modulating the ubiquitin system involves targeting protein-protein interactions (PPIs). Nevertheless, our 2012 report discusses novel technologies and strategies that might be applied to the discovery of PPI modulators.

As discussed in our April 25, 2012 article on this blog, there has been new interest in the discovery of PPIs by leading biotech/pharma companies in recent years, motivated by the development of these technologies and of the increasing strategic importance of PPI modulator development.

As we discussed in our 2012 report, the greatest drug discovery opportunity in the ubiquitin cascade is in targeting E3 ubiquitin ligases. That is because as one moves down the ubiquitinylation cascade, the degree of specificity of the process increases. There are over 600 E3 ubiquitin ligases encoded in the human genome, each of which targets its own specific class of proteins. Moreover, the total number of ubiquitin cascade enzymes encoded by the human genome is greater than the number of protein kinases.

As discussed by Krönke et al., their study (and that of Lu et al.) reveals that the small-molecule drug lenalidomide modulates the activity of the CRBN-CRL4 ubiquitin ligase complex to increase ubiquitination of two transcription factors, IKZF1 and IKZF3. It does so by specific binding to one component of the system, cereblon. This was found serendipitously—not by either classical or advanced technologies for discovering PPI modulators. Moreover, the targets of the CRBN-CRL4 ubiquitin ligase, IKZF1 and IKZF3, are transcription factors that act by forming PPIs. They are also involved in the complex process of chromatin remodeling, and the nature of their interactions are poorly understood. They are therefore considered “undruggable.”

Nevertheless, researchers can screen for compounds that bind cereblon, and which thus modulate the CRBN-CRL4 ubiquitin ligase. Might it also be possible to screen for compounds that modulate one component of other E3 ubiquitin ligases, and thus increase the interactions between these ligases and their specific substrates? If so, this might provide a novel means to discover drugs that modulate the ubiquitin system.

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As the producers of this blog, and as consultants to the biotechnology and pharmaceutical industry, Haberman Associates would like to hear from you. If you are in a biotech or pharmaceutical company, and would like a 15-20-minute, no-obligation telephone discussion of issues raised by this or other blog articles, or of other issues that are important to  your company, please contact us by phone or e-mail. We also welcome your comments on this or any other article on this blog.

RNAi therapeutics stage a comeback

Transthyretin protein structure

Transthyretin protein structure

Not so long ago, the once-promising field of RNA interference (RNAi)-based drugs was on the downswing. This was documented in our August 22, 2011 article on this blog, entitled “The Big Pharma Retreat From RNAi Therapeutics Continues”. That article discussed the retreat from RNAi drugs by such Big Pharma companies as Merck, Roche, and Pfizer. In our March 30, 2012 blog article, we also mentioned leading RNAi company Alnylam’s (Cambridge, MA) January 20, 2012 downsizing. This restructuring was made necessary by Alnylam’s inability to continue capturing major Big Phama licensing and R&D deals, as it had once done.

As we discussed in our August 22, 2011 article, the therapeutic RNAi (and microRNA) field represented an early-stage area of science and technology, which may well be technologically premature. This level of scientific prematurity was comparable to that of the monoclonal antibody (MAb) drug field in the 1980s. Big Pharmas did not have the patience to continue with the RNAi drug programs that they started.

In that article, we cited an editorial by oligonucleotide therapeutics leader Arthur Krieg, M.D. This editorial discussed the issues of therapeutic RNAi’s scientific prematurity, but predicted a rapid upswing of the field once the main bottleneck–oligonucleotide drug delivery–had been validated.

The January 2014 Alnylam-Genzyme/Sanofi deal

Now–as of January 2014–there is much evidence that the therapeutic RNAi field is indeed coming back. This is especially true for Alnylam. On January 13, 2014, it was announced that Genzyme (since 2011 the rare disease unit of Sanofi) invested $700 million in Alnylam’s stock. Alnylam called this deal “transformational” for both Alnylam and the RNAi therapeutics field.

Genzyme had previously been a partner in developing Alnylam’s lead product patisiran (ALN-TTR02) for the treatment of transthyretin-mediated amyloidosis (ATTR). [ATTR is a rare inherited, debilitating, and often fatal disease caused by mutations in the transthyretin (TTR) gene.] Under the new agreement, Genzyme will gain marketing rights to patisiran everywhere except North America and Western Europe upon its successful completion of clinical trials and approval by regulatory agencies. Genzyme will also codevelop ALN-TTRsc, a subcutaneously-delivered formulation of patisiran. Intravenously-delivered patisiran is now in Phase 3 trials for a form of ATTR known as familial amyloidotic polyneuropathy (FAP), and ALN-TTRsc is in Phase 2 trials for a form of ATTR known as familial amyloidotic cardiomyopathy (FAC).

The Alnylam/Genzyme deal will also cover any drugs in Alnylam’s pipeline that achieve proof-of-concept before the end of 2019. Genzyme will have the option to development and commercialize these drugs outside of North America and Western Europe.

On the same day as the announcement of the new Alnylam/Genzyme deal, Alnylam acquired Merck’s RNAi program, which consists of what is left of the former  Sirna Therapeutics, for an upfront payment of $175 million in cash and stock. (This compares to the $1.1 billion that Merck paid for Sirna in 2006.) Alnylam will receive Merck’s RNAi intellectual property, certain preclinical drug candidates, and rights to Sirna/Merck’s RNAi delivery platform. Depending on the progress of any of Sirna/Merck’s products in development, Alnylam may also pay Merck up to $105 million in milestone payments per product.

Alnylam’s Phase 1 clinical studies with its ALN-TTR RNAi drugs

In August 2013, Alnylam and its collaborators published the results of their Phase 1 clinical trials of ALN-TTR01 and ALN-TTR02 (patisiran) in the New England Journal of Medicine. At the same time, Alnylam published a press release on this paper.

ALN-TTR01 and ALN-TTR02 contain exactly the same oligonucleotide molecule, which is designed to inhibit expression of the gene for TTR via RNA interference. They differ in that ALN-TTR01 is encapsulated in the first-generation version of liponanoparticle (LNP) carriers, and ALN-TTR02 is encapsulated in second-generation LNP carriers. Both types of LNP carriers are based on technology that is owned by Tekmira Pharmaceuticals (Vancouver, British Columbia, Canada) and licensed to Alnylam.

Tekmira’s LNP technology was formerly known as stable nucleic acid-lipid particle (SNALP) technology. Alnylam and Tekmira have had a longstanding history of collaboration involving SNALP/LNP technology, as described in our 2010 book-length report, RNAi Therapeutics: Second-Generation Candidates Build Momentum, published by Cambridge Healthtech Institute. Although the ownership of the intellectual property relating to SNALP/LNP technology had been the subject of litigation between the two companies, these disputes were settled in an agreement dated November 12, 2012. On December 16, 2013, Alnylam made a milestone payment of $5 million to Tekmira upon initiation of Phase 3 clinical trials of patisiran.

LNP-encapsulated oligonucleotides accumulate in the liver, which is the site of expression, synthesis, and secretion of TTR. As we discussed both in our book-length RNAi report, and in an article on this blog, delivery of oligonucleotide drugs (including “naked” oligonucleotides and LNP-encapsulated ones) to the liver is easier than targeting most other internal organs and tissues. The is a major reason for the emphasis on liver-targeting drugs by Alnylam and other therapeutic oligonucleotide companies.

To summarize the published report, each of the two formulations was studied in a single-dose, placebo-controlled Phase 1 trial. Both formulations showed rapid, dose-dependent, and durable RNAi-mediated reduction in blood TTR levels. (Both mutant and wild-type TTR production was suppressed by these drugs.)

ALN-TTR02 was much more potent than ALN-TTR01. Specifically, ALN-TTR01 at a dose of 1.0 milligram per kilogram, gave a mean reduction in TTR at day 7 of 38%, as compared with placebo. ALN-TTR02 gave mean reductions at doses from 0.15 to 0.3 milligrams per kilogram ranging from 82.3% to 86.8% at 7 days, with reductions of 56.6 to 67.1% at 28 days. The main adverse effects seen in the study were mild-to-moderate acute infusion reactions. These were observed in 20.8% of subjects receiving ALN-TTR01 and in 7.7% (one patient) of subjects receiving ALN-TTR02. These adverse effects could be managed by slowing the infusion rate. There were no significant increases in liver function test parameters in these studies.

The results of these studies have established proof-of-concept in humans that Alnylam’s TTR RNAi therapies can successfully target messenger RNA (mRNA) transcribed from the disease-causing gene for TTR. Alnylam also said in its press release that these results constitute “the most robust proof of concept for RNAi therapy in man to date”, and that they demonstrate proof-of-concept not only for RNAi therapeutics that target TTR, but also for therapeutic RNAi targeting of liver-expressed genes in general. They also note that this represents the first time that clinical results with an RNAi therapeutic have been published in the New England Journal of Medicine.

Other recent RNAi therapeutics deals, and the resurgence of the therapeutic RNAi field

The January 2014 Alnylam/Genzyme/Sanofi agreement is not the only therapeutic RNAi deal that has been making the news in 2013 and 2014. On July 31, 2013, Dicerna Pharmaceuticals (Watertown, MA) secured $60 million in an oversubscribed Series C venture financing. These monies will be used to conduct Phase 1 clinical trials of Dicerna’s experimental RNAi therapies for hepatocellular carcinoma and for unspecified genetically-defined targets in the liver. So far, Dicerna has raised a total of $110 million in venture capital.

Dicerna’s RNAi therapeutics are based on its proprietary Dicer substrate siRNA technology, and its EnCore lipid nanoparticle delivery vehicles.

On January 9, 2014, Santaris Pharma A/S (Hørsholm, Denmark) announced that it had signed a worldwide strategic alliance with Roche to discover and develop novel RNA-targeted medicines in several disease areas, using Santaris’ proprietary Locked Nucleic Acid (LNA) technology platform. Santaris will receive an upfront cash payment of $10 million, and a potential $138M in milestone payments. On January 10, 2014, Santaris announced another agreement to develop RNA-targeted medicines, this time with GlaxoSmithKline. Financial details of the agreement were not disclosed.

As in the case of Alnylam, we discussed Dicerna’s and Santaris’ technology platforms in our 2010 book-length report, RNAi Therapeutics: Second-Generation Candidates Build Momentum.

A January 15, 2014 FierceBiotech article reported that RNAi therapeutic deals were a hot topic at the 2014 J.P. Morgan Healthcare Conference in San Francisco, CA. This is a sign of the comeback of the therapeutic RNAi field, and of the return of interest by Big Pharma and by venture capitalists in RNAi drug development.

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As the producers of this blog, and as consultants to the biotechnology and pharmaceutical industry, Haberman Associates would like to hear from you. If you are in a biotech or pharmaceutical company, and would like a 15-20-minute, no-obligation telephone discussion of issues raised by this or other blog articles, or of other issues that are important to  your company, please contact us by phone or e-mail. We also welcome your comments on this or any other article on this blog.

Can Merck’s R&D restructuring enable it to improve its productivity?

Simvastatin (Merck's Zocor)

Simvastatin (Merck’s Zocor)

On December 27th, 2013 the Wall Street Journal published an article by staff reporters Peter Loftus and Jonathan Rockoff about Merck’s new R&D restructuring. Fierce Biotech’s John Carroll also discussed the WSJ article in his own analysis dated December 28th, 2013.

According to these articles, Merck is in the process of cutting its internal R&D operations. This will include selling off dozens of pipeline compounds that have been under development in its labs. Merck also plans to cut its workforce by 20% over the next two years, as it had announced in October 2013. This will include reductions in its internal R&D staff.

At the same time, Merck will create new innovation hubs in Boston, the San Francisco Bay area, London and Shanghai.  The company has identified these geographic areas as having a critical mass of academic and commercial life science R&D. Merck intends to use its hubs as bases to scout for promising research that the company might license or acquire.

The overall plan is to reduce reliance on Merck’s internal R&D operations and to increase reliance on external R&D in academia and in biotech companies.

This is a similar strategy to that being followed by other Big Pharma companies, especially Johnson & Johnson and GlaxoSmithKline. All three of these companies are targeting some of the same geographic areas, especially Boston, California, London, and China.

Why are pharmaceutical companies struggling to develop new drugs?

The unveiling of Merck’s restructuring plans has triggered a wave of articles commenting on the wider implications of the move. David Shaywitz, M.D., Ph.D. (Director, Strategic and Commercial Planning at Theravance in South San Francisco, CA) writes in Forbes (12/29/2013) that pharma companies’ restructuring plans may save neither the companies carrying them out nor the pharmaceutical industry.

The reason that Merck and other pharma companies are carrying out these restructurings is that the companies are struggling to develop new drugs, and their internal labs are not producing them. The hope is that shifting from–as Dr. Shaywitz puts it–research and development to [external] search and development will produce more and better developable drugs. However, it may not do so. Outside partners may not necessarily know more about drug discovery than Merck Research Laboratories does.

The basic question then becomes why pharma companies are struggling to produce new products in the first place. One highly cited possibility is that Big Pharma companies are too bureaucratic, and thus inhibit their own ability to innovate. However, the underlying problem may well be that our understanding of biology–in health and disease–is limited.

The new President of Merck Research Laboratories, Roger M. Perlmutter, M.D., Ph.D. said, as quoted in another Forbes article:

“…if we’re discovering drugs, the problem is that we just don’t know enough. We really understand very little about human physiology. We don’t know how the machine works, so it’s not a surprise that when it’s broken, we don’t know how to fix it. The fact that we ever make a drug that gives favorable effects is a bloody miracle because it’s very difficult to understand what went wrong.”

Dr. Perlmutter then goes on to cite the example of statin drugs such as Merck’s Zocor (simvastatin) and Pfizer’s LIpitor (atorvastatin). Beginning in Merck’s own laboratories, under the company’s legendary R&D leader and CEO Roy Vagelos, statins were designed to lower blood cholesterol levels by inhibiting the enzyme HMG-CoA reductase. However, statins also appear to prevent atherosclerosis by a variety of other mechanisms (e.g., modulating inflammation). Thus their true mechanisms of action are not well understood.

How can companies carry out biology-driven R&D?

Despite the fact that our knowledge of biology is limited, we and others have noted that the most successful drug discovery and development strategy in the last two decades or so has been biology-driven R&D. For example, this is the basis of the entire R&D program of such companies as Novartis and Genentech. How is it possible to conduct reasonably successful biology-driven R&D if our knowledge of human biology is so limited?

We have discussed reasons for the success of biology-driven R&D in our book-length report Approaches to Reducing Phase II Attrition, and in our published article in Genetic Engineering and Biotechnology News “Overcoming Phase II Attrition Problem”.

Briefly, biology-driven drug discovery has often utilized academic research into pathways, disease models, and other biological systems, which have been conducted over a period of years or of decades. Targets and pathways derived from this research are usually relatively well understood and validated, with respect to their physiological functions and their roles in disease.  Examples of drugs derived from such research include most approved biologics (e.g., Genentech’s Herceptin and Biogen Idec/Genentech’s Rituxan), as well as the numerous protein kinase inhibitors for treatment of cancers. It was the successful development of the kinase inhibitor imatinib (Gleevec/Glivec) that led Novartis to adopt its pathway-based strategy in the first place.

A more recent example is the work on discovery and development of monoclonal antibody (MAb)-based immunotherapies for cancer, which we highlighted in our January 3, 2014 blog article on Science’s Breakthrough of the Year. These drugs include the approved CTLA4-targeting agent ipilimumab (Bristol-Myers Squibb’s Yervoy), and several other agents that target the PD-1/PD-L1 checkpoint pathway, including Merck’s own anti-PD-1 agent lambrolizumab.

The development of these agents was made possible by a line of academic research on T cells that was begun in the 1980s by James P Allison, Ph.D. Even after Dr. Allison’s research demonstrated in 1996 that an antibody that targeted CTLA-4 had anti-tumor activity in mice, no pharmaceutical company would agree to work on this system. However, the MAb specialist company Medarex licensed the antibody in 1999. Bristol-Myers Squibb acquired Medarex in 2009, and Yervoy was approved in 2011.

The above examples show that although we do not understand human physiology in health and decease in general, we do understand pieces of biology that are actionable for drug discovery and development. This understanding often comes after decades of effort. One strategy for a scout in a Big Pharma innovation hub might be to look for such actionable pieces of biology, and to contract with the academic lab or biotech company that developed them for licenses or partnerships. However, the case of Yervoy shows that pharmaceutical companies may not recognize these actionable areas, or may be slow to do so.

Moreover, for many diseases of great interest to physicians and patients, academic researchers, and/or companies, we may not have an actionable piece of biology that is backed by decades of research. We may only have interesting (and perhaps breakthrough) research that has been carried out over only a few years. In these cases (and even in cases based on deeper understand based on decades of research), companies will need to develop a set of “fail fast and fail cheaply” strategies. Such strategies usually reside in small biotechs rather than in Big Pharmas. Moreover, these strategies remain a work in progress.

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As the producers of this blog, and as consultants to the biotechnology and pharmaceutical industry, Haberman Associates would like to hear from you. If you are in a biotech or pharmaceutical company, and would like a 15-20-minute, no-obligation telephone discussion of issues raised by this or other blog articles, or of other issues that are important to  your company, please contact us by phone or e-mail. We also welcome your comments on this or any other article on this blog.