Archive for the ‘Drug development’ Category.

FDA proposes accelerated approval of early-stage Alzheimer’s drugs based on cognitive improvement alone

 

Pittsburgh compound B staining in AD. Source: National Institute on Aging/NIH.

Pittsburgh compound B staining in AD. Source: National Institute on Aging/NIH.

In our February 28, 2013 article on the Biopharmconsortium Blog, we discussed the FDA’s February 7, 2013 Draft Guidance for Industry entitled “Alzheimer’s Disease: Developing Drugs for the Treatment of Early Stage Disease”.

This document had been distributed for comment purposes only, and the FDA has been seeking public comment on the draft guidance for 60 days following publication.

As we discussed, by issuing this Draft Guidance, the FDA added its voice to that of an ever-increasing segment of the scientific community that calls for a new focus on conducting clinical trials in early-stage Alzheimer’s disease (AD). This is in order to  focus industry R&D on developing treatments for patients whose disease is in a stage prior to the development of extensive irreversible brain damage. It is in this early stage of disease in which researchers believe that new drugs have the best chance of providing benefits to patients, by preventing further damage to the brain.

In our February 28, 2013 article, we also discussed several clinical trials being carried out by industry and academic researchers in early-stage AD. These trials should allow the scientific and medical community to answer the question as to whether treating patients with pre-AD or very early-stage AD with anti-amyloid MAb drugs can have a positive effect on the course of the disease, and slow or prevent cognitive decline.

Readers of our article may have noticed that the February 7, 2013 Draft Guidance was somewhat vague or confused. That is because there is currently no evidence-based consensus as to which biomarkers might be appropriate to support clinical findings in trials in early AD. Moreover, in “pre-AD” or very early-stage AD (i.e., before the onset of overt dementia) disease-related impairments are extremely challenging to assess accurately. Thus both measuring clinical outcomes and assessment via biomarkers in very early-stage AD are fraught with difficulty, making determination of drug efficacy very difficult.

In issuing the Draft Guidance, The FDA appeared to be seeking guidance from industry and from the academic community on how these issues might be resolved. As we said in our article, the early-stage AD trials now in progress might help the scientific and medical community, and the FDA, with issues of evaluation of biomarkers and clinical outcome measures in determining disease prognosis and the efficacy of drug treatments.

More recently–on March 13, 2013–the FDA proposed a further modification of its proposed guidelines for regulation of early-stage AD therapeutics. This was published online in an article in the New England Journal of Medicine (NEJM), entitled “Regulatory Innovation and Drug Development for Early-Stage Alzheimer’s Disease”, by Nicholas Kozauer, M.D. and Russell Katz, M.D. (As we stated in our earlier article, Dr.Katz is the director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research. Dr. Kozauer is a Clinical Team Lead in the same division of the FDA.)

The new proposal attempts to deal with some of the apparent confusion in the February 7, 2013 Draft Guidance, and to facilitate the development and approval of new drugs for early-stage AD. The NEJM article notes that traditional measures of AD drug efficacy at the FDA had included assessment both of improved cognition and improvements in function. Specifically, as stated by a New York Times article discussing the new FDA proposal, “cognition” refers to such mental processes as memory and reasoning (as assessed by various tests), and “function” refers to performing such day-to-day activities as cooking, dressing or bathing.

In the FDA’s March 13, 2013 NEJM article, the authors note that researchers and regulatory agencies “simply do not yet have drug-development tools that are validated to provide measures of function in patients with Alzheimer’s disease before the onset of overt dementia”. Thus, although one can test early-stage AD patients for improvements in cognition with the appropriate tests, testing for deficits and improvements in function is extremely difficult.

The authors of the NEJM article therefore suggest that it might be feasible that a drug for treating early-stage AD be approved via the FDA’s accelerated approval pathway, on the basis of assessment of cognitive outcome alone. The agency’s accelerated-approval pathway allows drugs that address an unmet medical need to be approved on the basis of a surrogate or an intermediate clinical endpoint–in this case, a sensitive measure of improvement in cognition. Drugs approved via “accelerated approval” must be subjected to postmarketing studies to verify the clinical benefit. This regulatory pathway might facilitate the approval of treatments that appear to be effective in early AD, when patients might be expected to derive a greatest benefit than after the development of overt dementia.

With respect to selection of patients for trials in early-stage AD, the authors of the NEJM article suggest that (based on “the consensus emerging within the AD research community”) clinical diagnosis of early cognitive impairment be combined with appropriate biomarkers. These biomarkers might include brain amyloid load [as measured by positron-emission tomography (PET)] and cerebrospinal fluid levels of β-amyloid and tau proteins. The FDA places a high priority on efforts by the researchers to qualify such biomarkers in clinical trial design in early-stage AD.

The author of the New York Times article, veteran science and medicine reporter Gina Kolata, says that the FDA’s new proposal could “help millions of people at risk of developing [AD] by speeding the development and approval of drugs that might slow or prevent it.”

She also says that the proposal could be a boon for the pharmaceutical industry and AD researchers. They have often been hampered by regulations that left them uncertain of how to get drugs tested and approved for early-stage AD. Not only might anti-AD therapies provide greater benefit to patients with early-stage AD than with later stage disease, but clinical trials in early-stage AD would have a greater potential for success–provided that researchers had appropriate means of determining efficacy in early-stage AD. The new FDA proposal may increase the likelihood of identifying such appropriate means.

As pointed out in the Times article, several leading AD researchers agree, with some important caveats. For example, AD researcher P. Murali Doraiswamy, M.D. (Duke University School of Medicine) said that the new proposed regulations would lead to more clinical trials, and more motivation now to invest in the AD field. However, many companies never manage to do postmarking studies required for drugs given accelerated approval, and such studies might not be randomized clinical trials as required in gaining approval of the drugs in the first place.

Sean Bohen, M.D., Ph.D. (Senior Vice President for Early Development at Genentech) was very positive about the proposed new FDA policy, but wondered how researchers could develop appropriate tests to identify subtle cognitive changes in early AD or pre-AD. Nevertheless, he said, “We have to start somewhere.”

Thus clinical trials in early-stage AD, and development of regulatory frameworks for approval and postmarketing studies of agents that emerge from these trials, 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 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.

Japanese group to take induced pluripotent stem (iPS) cell-derived retinal cells into the clinic

 

Stem cells. Source: http://bit.ly/ZnYuFS

Stem cells. Source: http://bit.ly/ZnYuFS

As reported in Nature News on 27 February 2013 ophthalmologist Masayo Takahashi M.D., Ph.D. and her colleagues at the RIKEN Center for Developmental Biology (Kobe, Japan), plan to submit an application to the Japanese health ministry for a clinical study of induced pluripotent stem cell (iPS)-derived cells. The researchers planned to submit their application in March 2013; if approved, they could begin recruiting patients as early as September.

The author of the Nature News article is Nature‘s Asian-Pacific Correspondent, David Cyranoski, who is based in Tokyo.

The researchers plan to treat approximately six people with severe age-related macular degeneration (AMD). Specifically, the researchers are targeting “wet” AMD, in which angiogenic blood vessels invade the retina, destroying the retinal pigment epithelium (RPE) that supports the light-sensitive photoreceptors.

AMD is a common cause of blindness that affects at least 1% of adults over 50. Wet AMD can be treated with anti-vascular endothelial growth factor (anti-VEGF) agents such as ranibizumab (Genentech/Novartis’ Lucentis), pegaptanib (Gilead/OSI/Pfizer’s Macugen), aflibercept (Sanofi/Regeneron’s Eylea), and–off-label–small doses of the anticancer agent bevacizumab (Genentech/Roche’s Avastin). However, the use of these agents requires that they be injected repeatedly into the eye.

According to the Nature News article, Dr. Takahashi and her colleagues will take an upper arm skin sample the size of a peppercorn, and transform the cells from this sample into iPS cells by using specific proteins. They will then add other factors that will induce differentiation of the iPS cells into retinal cells. Then a small sheet of these retinal cells will be placed under the damaged area of the retina, where they are expected to grow and repair the damaged RPE.

Although the researchers would like to demonstrate efficacy of this treatment in ameliorating the disease, the main focus of these studies will be on safety. Safety concerns include immunogenicity of the transplanted cells, and formation of tumors if the transplanted cells multiply uncontrollably. Another concern is that the transplanted cells might fail to engraft, and to integrate with the host tissue. It is also possible that the RPE identity of the transplanted and differentiated cells might not be stable over time.

With respect to these concerns, studies published by Japanese researchers in 2013 (Araki et al.) and reviewed in a recent Nature News article contradicted the original mouse studies that suggested that syngeneic or autologous iPS cells might be immunogenic.

With respect to tumor formation, Dr. Takahashi’s proposed studies will involve using only a few iPS cells, thus reducing the probability of forming tumors. Moreover, since the eye is relatively accessible, any tumors would be relatively easy to remove.

In addition, Dr, Takahashi has presented preclinical studies at conferences, which indicate that her iPS cells do not form tumors in mice and are safe in non-human primates. (Dr. Takahashi’s preclinical studies have also been submitted for publication.) The studies have provided reassurance of the cells’ safety to at least some leading researchers, such as Martin Pera (University of Melbourne, Australia) and George Daley (Harvard Medical School, Boston MA).

However, other researchers believe that to take iPS cell-derived tissue into the clinic at this time is premature. Robert Lanza, M.D., the chief scientific officer at Advanced Cell Technology (ACT) (Santa Monica CA) says that he cannot imagine regulatory agencies permitting studies such as Dr. Takahashi’s without years of preclinical testing.

As mentioned in the Nature News article, ACT has a program involving human embryonic stem cell (hES cell) and iPS-derived platelets for transfusion. This program is in the preclinical stage. Since platelets lack a nucleus and cannot form tumors, it is inherently less risky that clinical programs of stem-cell (and especially iPS cell) derived differentiated cells that have nuclei.

Dr. Takahashi’s proposed study of her therapy in humans is considered a “clinical study”, not a clinical trial. In Japan’s regulatory system, clinical studies are less tightly regulated than clinical trials. However, a clinical study cannot by itself lead to approval of a potential therapeutic for clinical use as a treatment. If Dr. Takahashi’s clinical study data is positive, that might attract investors or help her to get approval for a formal clinical trial. As in the U.S. or Europe, successful clinical trials will be required if Dr. Takahashi’s cellular therapy is ever to be used to treat patients.

Dr. Takahashi’s clinical study was approved by institutional review boards at both the natural sciences institute RIKEN in Wako and the Institute of Biomedical Research and Innovation in Kobe, where the surgical procedures will be carried out. Final approval will depend on the action of a committee of the Japanese Ministry of Health, Labour and Welfare. If Dr. Takahashi wins approval by September 2013 as expected, it will take another eight months to produce the tissue implants needed for her clinical study.

Other retinal repair programs involving human embryonic stem cell-derived RPE cells

Dr. Takahashi’s research does not represent the only RPE cell-based retinal repair program now being developed. There are at least two others, both of which are based on hES cells, not iPS cells.

As was not mentioned in the Nature News article, ACT has Phase 1 trials underway in its own RPE retinal repair program. ACT’s RPE cells are derived from human embryonic stem cells (hES cells). The company’s Phase 1 safety studies are in Stargardt’s Macular Dystrophy (SMD) and in dry AMD (which results from atrophy of the RPE layer, and causes vision loss through loss of photoreceptors in the central part of the eye. Dry AMD does not involve angiogenesis.). SMG is a rare inherited juvenile macular degeneration.

In February 2012, Dr. Lanza and his academic collaborators at the University of California at Los Angeles published a preliminary report of their clinical studies in dry AMD and SMG. In this study, one patient with each of the two conditions was treated with hES cell-derived RPE cells. The hES cell-derived RPE cells showed no signs of hyperproliferation, tumorigenicity, ectopic tissue formation, or apparent rejection after 4 months. Neither patient showed loss of vision, and there were signs of improvement of vision. As a result of this very preliminary study, the researchers decided in the design of future clinical studies to treat patients earlier in the disease processes, potentially increasing the likelihood of improvement of vision.

The other RPE-based retinal repair program is a collaborative effort between Neusentis (A Cambridge U.K. and Durham NC-based Pfizer research unit) and “The London Project” which was formed by Professor Pete Coffey [Institute of Ophthalmology, University College London (UCL)] and his collaborator Lyndon da Cruz (Moorfields Eye Hospital) to develop cellular therapies for all types of AMD. The London Project began collaborating with Pfizer in 2008; this collaboration was brought under the aegis of Neusentis when it was formed in 2011. Research is based on RPE cells derived from hES cells.

The Neusentis/London Project group claims to have developed a deep understanding of the biology of hEC cell-derived RPE cells, and to have worked out methods of producing enough RPE cells under GMP conditions to support clinical studies. They also claim to have developed a clear approach to establishing the safety of the therapy via preclinical studies. The collaborative group is now moving towards clinical studies of their therapies, which they “hope to achieve in the not too distant future”.

As we discussed in our February 15, 2011 article on this blog, Pfizer–as of February 1, 2011–closed its Memorial Drive laboratory in Cambridge, MA. This laboratory housed most of Pfizer’s regenerative medicine research, as well as the company’s RNAi therapeutics research group. However, as we said in this article, Pfizer was folding its Cambridge, UK regenerative medicine group–”which had been focusing on development of preclinical embryonic stem (ES) cell-based ophthalmology therapies, in collaboration with the University of London”–into a “new pain and sensory disorder research unit”. According to its website, Neusentis, which was formed in 2011, has “a particular focus on pain and sensory disorders”.

Japanese government backing for iPS cell research and commercialization

Japan has been a hotbed of iPS cell research, since these cells were first produced by Shinya Yamanaka, M.D. Ph.D. (Kyoto University) in 2006. He received The Nobel Prize in Physiology or Medicine in 2012 for his work on iPS cells. The co-recipient of the Prize, Sir John B. Gurdon, successfully cloned a frog using intact nuclei from the somatic cells of a Xenopus tadpole back in 1958. The two scientists received the 2012 Prize “for the discovery that mature cells can be reprogrammed to become pluripotent”. Since their discovery, iPS cells have been employed in such areas as basic research, disease modeling, and drug screening. (Follow this link for a recently-published example of the potential use of iPS cells in designing personalized treatments for Alzheimer’s disease.)

In 2013, as part of its stimulus package, the Japanese government has been providing generous funding for iPS research. This funding includes ¥700 million for a cell-processing centre at the Foundation for Biomedical Research and Innovation in Kobe, mainly to support Dr. Takahashi’s regenerative medicine research. In general, the iPS funding under the stimulus is aimed at moving university research on iPS cells into commercial and medical applications.

Moreover, according to Mr. Cyranoski’s 27 February 2013 Nature News article, the Japanese parliament is expected to rule by late June 2013 on a provision of a revised drug law, which would fast-track iPS-based therapies that appear to be effective in phase 2 or phase 3 trials. However, the success of the Japanese government’s efforts to accelerate commercialization of iPS-based therapies may depend in part on the success of Dr. Takahashi’s clinical research.

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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.

Haberman Associates in “Pink Sheet” article on the cystic fibrosis drug market

 

Lumacaftor (Vertex' VX-809)

Lumacaftor (Vertex’ VX-809)

I was quoted in an article in the March 11, 2013 issue of Elsevier Business Intelligence’s The Pink Sheet by senior writer Joseph Haas. The article is 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.

The article focused on the newly-approved disease modifying drug ivacaftor (Vertex’ Kalydeco), as well as programs in drug discovery and development of disease-modifying drugs for cystic fibrosis (CF) at Vertex, PTC Therapeutics, Proteostasis Therapeutics, Pfizer, and Genzyme. It also discussed pipeline products aimed at treating or preventing life-threatening infections in CF patients at such companies as KaloBios, Insmed, and Savara.

Mr. Haas interviewed me for this article. Most of the content of our interview is available in our February 15, 2013 article on the Biopharmconsortium Blog. One company whose R&D program we did not cover in that article is Proteostasis. Proteostasis’ CF program, which is being carried out in collaboration with the Scripps Research Institute, is aimed at discovery and development of compounds that promote CFTR ΔF508 folding and trafficking. This program is in the research and lead optimization stage. We discussed R&D programs at other companies (Vertex, Pfizer) that are also aimed at correction of improper CFTR ΔF508 folding and trafficking in our February 15, 2013 article.

KaloBios’ KB001-A, a bacterial virulence factor-targeting agent

Among the agents aimed at ameliorating life-threatening infections in CF patients that were discussed in the Pink Sheet article is KB001-A, a monoclonal antibody (MAb) agent being developed by KaloBios (South San Francisco, CA). KB001-A is now in Phase 2 development for prevention of Pseudomonas aerguinosa infections in the lungs of CF patients. KB001-A targets an extracellular component of the bacterium’s type III secretion system. This system enables the bacteria to kill immune cells by injection of protein toxins into these cells.

The type III secretion system is an example of a virulence factor. Virulence factors are not expressed by a strain of pathogenic bacteria in vitro, but are expressed only when the bacteria infect a host. Once expressed, they enable the bacteria to colonize the host and cause disease.

In our June 11, 2012 article on this blog, we discussed an antibacterial drug discovery strategy aimed at targeting two related physiological systems that are important in the ability of pathogenic bacteria to cause disease, but are not essential for bacterial proliferation or survival. These systems are virulence factors and quorum sensing. At least by hypothesis, agents that disrupt these systems will prevent pathogenic bacteria from causing disease without selecting for resistant strains of the bacteria. This will give such agents an advantage over conventional antibiotics, which notoriously generate resistant strains when used to treat infections. According to the Pink Sheet article, KaloBios believes that P. aerguinosa bacteria will not develop resistance to KB001-A, which is in accord with this hypothesis.

Another issue with anti-infectives used to treat CF that is discussed in the Pink Sheet article is the definition of a “disease-modifying” agent for CF. We define disease-modifying agents as drugs that ameliorate or cure a disease by targeting the root cause of that disease. However, KaloBios considers KB001-A to be a disease-modifying agent. That is because the company believes that most CF patients die of the effects of P. aerguinosa infection, which causes deterioration of the patients’s lungs. Thus an effective anti-P. aerguinosa agent may produce dramatic increases in patients’ lifespans.

Perhaps the real issue is that one should not classify CF drugs as “disease-modifying” agent and agents that merely treat “symptoms” (as is done in the Pink Sheet article) but should define infections of CF patients as “complications” of the disease. Thus anti-infectives such as KB001-A may effectively treat a major life-threatening complication of CF, without modifying the underlying disease. Such an agent would result in increased lifespans (and improved quality of life) for CF patients, without affecting their underlying disease. As KaloBios asserts, anti-infective agents like KB001-A would be complementary to such disease-modifying agents as ivacaftor.

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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.

FDA publishes Draft Guidance on developing drugs for early stages of Alzheimer’s disease

 

Normal and Alzheimer's brains compared.

Normal and Alzheimer’s brains compared.

Once again, approaches to improving clinical trials for candidate disease-modifying drugs for Alzheimer’s disease (AD) are in the news. On February 7, 2013, the FDA issued a Draft Guidance for Industry entitled “Alzheimer’s Disease: Developing Drugs for the Treatment of Early Stage Disease”.

This document has been distributed for comment purposes only, and the FDA is seeking public comment on the draft guidance for 60 days.

The wording of the Draft Guidance illustrates the extreme difficulty of defining populations with pre-AD or very early-stage AD, and of demonstrating the efficacy of a drug in ameliorating early-stage disease, and/or in preventing its progression to later-stage disease. The document states that the FDA is “open to considering the argument that a positive biomarker result (generally included as a secondary outcome measure in a trial) in combination with a positive finding on a primary clinical outcome measure may support a claim of disease modification in AD.”

However,  there is currently no evidence-based consensus as to which biomarkers might be appropriate to support clinical findings in trials in early AD. Moreover, in “pre-AD” or very early-stage AD (i.e., before the onset of overt dementia) mild disease-related impairments are extremely challenging to assess accurately. Thus both measuring clinical outcomes and assessment via biomarkers in very early-stage AD are fraught with difficulty, making determination of drug efficacy extremely difficult. The FDA thus appears to be seeking guidance from industry and from the academic community on how these knotty problems might be solved.

The move toward conducting clinical trials in early-stage AD patients

By issuing the Draft Guidance, the FDA adds its voice to that of an ever-increasing segment of the scientific community that calls for a new focus on conducting clinical trials in early-stage AD. We discussed this trend in our August 19, 2012 and August 28, 2012 articles on the Biopharmconsortium Blog.

As we discussed, this trend is driven in part by the Phase 3 failures of Pfizer/Janssen’s bapineuzumab and Lilly’s solanezumab in 2012. Now–in February 2013–Russell Katz, M.D. (director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research) says, “The scientific community and the FDA believe that it is critical to identify and study patients with very early Alzheimer’s disease before there is too much irreversible injury to the brain. It is in this population that most researchers believe that new drugs have the best chance of providing meaningful benefit to patients.”  In line with this statement, the FDA refused to entertain Lilly’s  secondary analysis of early stage patients in the solanezumab study that we discussed in our August 28, 2012 blog article. Instead, the FDA mandated that Lilly conduct a new Phase 3 trial that will exclude the moderate-stage patients who hadn’t responded, and focus only on early-stage patients.

Recent news on clinical trials in early-stage AD

Despite the difficulties highlighted in the Draft Guidance in conducting clinical trials in early-stage AD patients, three research groups are actually conducting such trials. We outlined these studies in our August 28, 2012 blog article, and discussed one of these studies, the one begin carried out by Genentech, in greater detail in our August 19 2012 article.

The three studies are:

  • Roche/Genentech’s Phase 2a trial of its its anti-amyloid MAb crenezumab, in presymptomatic members of a large Colombian kindred who harbor a mutation in presenilin 1 (PS1) that causes dominant early−onset familial AD.
  • Studies conducted in conjunction with the Dominantly Inherited Alzheimer Network (DIAN), a consortium led by researchers at Washington University School of Medicine (St. Louis, MO). This study will include people with mutations in any of the three genes linked to early-stage, dominantly-inherited AD–PS1, PS2, and amyloid precursor protein (APP). Initial studies focused on changes in biomarkers and in cognitive ability as a function of expected age of AD onset in people with these mutations. These included changes in concentrations of amyloid-β1–42 (Aβ42) in cerebrospinal fluid (CSF), and amyloid accumulation in the brain. In the first stage of the actual trial, three drugs (which have not yet been selected) will be tested in this population, and changes in biomarkers and cognitive performance will be followed.
  • The Anti-Amyloid Treatment of Asymptomatic Alzheimer’s (A4) trial, will involve treating adults without mutations in any of the above three genes, whose brain scans show signs of amyloid accumulation. A4 is thus designed to study prevention of sporadic AD (by far the most common form of the disease). It will enroll 500 people age 70 or older who test positive on a scan of amyloid accumulation in the brain. (This is in contrast to the two trials in subjects with gene mutations, who are typically in their 30s or 40s.) A4 will also have a control arm of 500 amyloid-negative subjects. Amyloid-positive and control subjects will be entered into a three-year double-blind clinical trial that will look at changes in cognition with drug treatment. The A4 researchers [led by Reisa Sperling, Brigham and Women’s Hospital/Harvard University (Boston, MA), and Paul Aisen, University of California, San Diego] planned to select a drug for testing by December 2012.

Now there is more recent news on two of these trials.

1. On December 13, 2012, the Los Angeles Times reported that Genentech and its collaborators [affiliated with the University of Antioquia medical school (Medellin, Colombia), the University of California at Los Angeles (UCLA), and the Banner Alzheimer's Institute (Phoenix, AZ)] will begin their $100 million clinical trial of crenezumab with 100 Colombians who carry the PS1 mutation in the spring of 2013. Genentech is contributing $65 million of the study’s $100-million cost. The NIH and the Banner Alzheimer’s Institute (Phoenix, AZ) are financing the remainder.

This story was also reported on December 14, 2012 by Fierce Biotech.

The design of the trial calls for 100 additional patients in Colombia with the same Alzheimer’s-related gene to receive a placebo, and an equal number of other at-risk patients without the gene to take crenezumab.  A branch of the trial will include U.S. patients as well. A “branch study” will also be conducted at UCLA, where researchers have discovered a similar genetic disposition among members of an extended family from Jalisco, Mexico. Some 30 individuals from this family who have immigrated to Southern California could participate. Around 150 other U.S. patients with similar mutations will also participate in the trial.

The trial is designed to provide evidence that targeting amyloid with crenezumab at an early stage or even before patients show signs of dementia can have a positive effect on the course of disease.

2. On January 18, 2013, Fierce Biotech reported that the researchers conducting the A4 study have chosen Lilly’s solanezumab as as the first therapeutic drug candidate to be evaluated in the trial. The A4 trial’s principal investigator, Reisa Sperling said that the researchers chose solanezumab (after considering a number of anti-amyloid drugs) because the compound has a good safety profile, and appeared to show a modest clinical benefit in the mild AD patients in Lilly’s Phase 3 trial. The A4 researchers’ confidence in solanezumab grew when this was confirmed via an independent academic analysis by the Alzheimer’s Disease Cooperative Study (ADCS), a consortium of academic Alzheimer’s disease clinical trial centers. The ADCS, which was established by NIH, will help facilitate the A4 trial.

The A4 researchers hope that starting treatment with solanezumab before symptoms are present, as well as treating for a longer period of time, will slow cognitive decline and ultimately prevent AD dementia.

After the failure of solanezumab in Lilly’s own Phase 3 studies, and the FDA’s rebuff of the company’s secondary analysis of early stage patients, the A4 study’s choice of solanezumab gives the drug a new lease on life. Meanwhile, Lilly will be continuing its own clinical trial program for solanezumab.

Conclusions

The three clinical trials discussed in this article should allow the scientific and medical community to answer the question as to whether treating patients with pre-AD or very early-stage AD with anti-amyloid MAb drugs can have a positive effect on the course of the disease, and slow or prevent cognitive decline. The studies may also help the scientific and medical community, and the FDA, with issues of evaluation of biomarkers and clinical outcome measures in determining disease prognosis and the efficacy of drug treatments. Given the large size and rapid growth of the at-risk population, finding safe and efficacious disease-modifying preventives and treatments for AD is of increasing urgency.

________________________________

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.

A new wave of small-molecule disease-modifying drugs for cystic fibrosis

 

Ivacaftor

Ivacaftor

In our January 24, 2013 article on this blog, we discussed the cases of two genetic diseases, sickle cell disease (SCD) and cystic fibrosis (CF). In both cases, the genetic cause of the disease was identified decades ago. However, no disease-modifying drugs for SCD have yet been developed.

In the case of CF, small-molecule disease-modifying drugs have only recently entered the pipeline. In one case, such a drug–ivacaftor (Vertex’ Kalydeco), was approved both in the U.S. and in Europe in 2012.

In this article, we discuss the development of small-molecule drugs for CF.

Cystic fibrosis

As we discussed in our earlier article, CF causes a number of symptoms, which affect the skin, the lungs and sinuses, and the digestive, endocrine, and reproductive systems. Notably, people with CF accumulate thick, sticky mucus in the lungs, resulting in clogging of the airways due to mucus build-up. This leads to inflammation and bacterial infections. Ultimately, lung transplantation is often necessary as the disease worsens. With proper management, patients can live into their late 30s or 40s.

The affected gene in CF and the most common mutation that causes the disease (called ΔF508 or F508del) were identified by Francis S Collins, M.D., Ph.D. (then at the Howard Hughes Medical Institute and Departments of Internal Medicine and Human Genetics, University of Michigan, Ann Arbor, MI) and his colleagues in 1989. (Dr. Collins was subsequently the leader of the publicly-funded Human Genome Project and is now the Director of the National Institutes of Health, Bethesda, MD.)

The gene that is affected in cystic fibrosis encodes a protein known as the cystic fibrosis transmembrane conductance regulator (CFTR).  CFTR 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; one in 2000–3000 newborns in the European Union is found to be affected by 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.

CFTR is an ion channel–specifically a chloride channel.  Ion channels constitute an important class of drug targets, which are targeted by numerous currently marketed drugs, e.g., calcium channel blockers such as amlodipine (Pfizer’s Norvasc; generics) and diltiazem (Valeant’s Cardizem; generics). These compounds were mainly 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, mainly because of the difficulty in developing assays suitable for drug screening. In addition, development of suitable assays for assaying chloride channel function has lagged behind the development of assays for the function of cation channels (e.g., sodium and calcium channels).

Moreover the most common CFTR mutation that causes CF, ΔF508, results in defective cellular processing, and the mutant CTFR protein is retained in the endoplasmic reticulum. In the case of some other mutant forms of CTFR (accounting for a small percentage of CF patients), the mutant proteins reach the cell membrane, but are ineffective in chloride-channel function.

Vertex’ program for the development of small molecule CF drugs

Efforts aimed at the discovery of small-molecule drugs for CF began in 1998, when the nonprofit Cystic Fibrosis Foundation (CFF) established its Therapeutics Development Program. This included a drug discovery unit, through which CFF would support both academic and industrial research. An early recipient of CFF funding via this program was a small biotech company, Aurora Biosciences (San Diego, CA).  Aurora had developed technology for ultra-high-throughput screening in cellular assays, which they were applying to the discovery of small-molecule drugs for CF. In 2001, Vertex Pharmaceuticals (Cambridge, MA) acquired Aurora. Vertex then incorporated Aurora’s technology into its drug discovery programs, including its CF program. Vertex’ CF program received continuing support from CFF.

Vertex researchers screened thousands of drug-like and lead-like synthetic compounds in recombinant mouse cells expressing mutant human CFTR. Positive hits that met criteria for developability were further tested in a rat epithelial cell line that expressed the mutant CFTR. Compounds selected for further study were also tested for rescue of CFTR activity in cultured primary human lung airway epithelial cells from CF patients, which expressed the same mutant CFTRs studied in the recombinant cell assays. Performing the latter studies required isolating the epithelial cells from lung tissue of CF patients. The thick mucus found in CF lungs made this isolation very challenging. According to Vertex researcher and project head Fred Van Goor, researchers had to use tweezers to extract the mucus, in order to isolate the cells. It reportedly took all of 2003 to develop cellular assays (both in primary and recombinant cells) to conduct the drug discovery studies.

Vertex’ high-throughput screening studies resulted in the identifications of two types of lead compounds:

  • 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 facilitating exit from the endoplasmic reticulum and deposition of a portion of the mutant CFTR in the cell membrane.

Vertex’ ivacaftor, a CFTR potentiator

The Vertex screening studies discussed in the previous section, published in 2006, resulted in clinical candidates in both the potentiator and corrector classes. The company pursued development of one potentiator compound, ivacaftor (formerly known as VX-770) (Vertex’ Kalydeco). Ivacaftor is indicated only in patients with the G551D (Gly551Asp) mutation in CFTR, which only accounts for around 4% of CF patients.

Ivacaftor was discovered via high-throughput screening as described in the previous section, followed by lead optimization. The compound increased chloride channel function both in recombinant cells carrying mutant CFTR, and in cultured primary human lung airway epithelial cells from CF patients. Ivacaftor was found to be efficacious in opening both CFTR G551D and CFTR ΔF508 present in the cell membranes of recombinant cells. However, because of the retention of  CFTR ΔF508 in the endoplasmic reticulum in human lung airway epithelial cells, this compound is not efficacious in treating CF patients carrying this mutation. The lack of efficacy in patients homozygous for CFTR ΔF508 was confirmed in a subsequent clinical trial.

On February 23, 2011, the CFF and Vertex announced that a Phase 3 trial of ivacaftor (then called VX-770) showed marked improvement in lung function in CF patients carrying the CFTR G551D mutation. Treated patients also had significant weight gain, showed reduced sweat chloride (a CF biomarker), and were less likely to have a pulmonary exacerbation. The results of this Phase 3 trial were published in the New England Journal of Medicine. Also in 2011, Vertex submitted a New Drug Application (NDA) for ivacaftor.  In January 2012, the FDA approved ivacaftor for treatment of CF patients carrying the CFTR G551D mutation. In July 2012, Vertex received European approval for this drug.

Vertex’ lumacaftor (VX-809) and VX-661, CFTR correctors

Vertex is currently developing the CFTR corrector lumacaftor (VX-809). The company has completed Phase 2 studies of a combination of ivacaftor and lumacaftor/VX-809 in CF patients who are homozygous for the CFTR ΔF508 mutation. It is now planning pivotal phase 3 trials of the combination therapy in this patient population. The rationale for the combination treatment is that VX-809 potentates the deposition of CFTR ΔF508 in the cell membrane, and invacaftor potentiates the function of cell-surface CFTR ΔF508.

Vertex is also conducting Phase 2 trials of another CTFR corrector, VX-661, alone and in combination with ivacaftor/VX-770 in CF patients homozygous for CFTR ΔF508.

The Cystic Fibrosis Foundation’s collaboration with Pfizer

The CFF has also been collaborating with Pfizer to discover drugs to treat patients carrying the the CFTR ΔF508 mutation. This collaboration began after the 2010 acquisition by Pfizer of FoldRX (Cambridge, MA). In November 2012, the CFF and Pfizer expanded their collaboration.

The Pfizer/CFF collaboration builds on FoldRx’s cystic fibrosis research program in collaboration with the CFF, which started in 2007. FoldRX (now a wholly-owned subsidiary of Pfizer) specializes in discovering and developing drugs to treat diseases of protein misfolding. The correction of protein misfolding clearly applies to CFTR ΔF508 protein.

Under the expanded six-year CFF/Pfizer collaboration, the CFF will invest up to $58 million to support and accelerate the discovery and development of disease-modifying therapies for CFTR ΔF508 CF. The goal of the collaboration is to advance one or more drug candidates into the clinic by the end of the six-year period. The CFF will provide scientific as well as financial support to help advance this discovery program.

Ataluren, for treatment of patients with CFTR nonsense mutations

Ataluren (formerly known as PTC124), is being developed by PTC Therapeutics for various genetic diseases caused by nonsense mutations in critical genes. The drug is currently being investigated for use in patients with nonsense mutation Duchenne/Becker muscular dystrophy (DBMD) and cystic fibrosis (CF). PTC Therapeutics’ efforts in CF are supported by a grant from the CFF.

Ribosomes normally translate messenger RNAs (mRNAs) into protein until arriving at a normal stop codon in the mRNA, at which point the ribosome stops translation, resulting in a functional protein. Nonsense mutations, however, create a premature stop signal in the mRNA coding sequence. This causes the ribosome to stop translation before a functioning protein is generated, creating a truncated, nonfunctional protein. This can result in disease.

Ataluren is designed to allow the ribosome to ignore the premature stop signal and continue translation of the mRNA, resulting in formation of a functioning protein. Ataluren does not cause the ribosome to read through the normal stop signal.

The results of clinical trials of ataluren in pediatric (Phase 2a) and adult (Phase 2) patients with nonsense-mutation CF showed that the drug resulted in production of functional CFTR protein and statistically significant improvements in CFTR chloride channel function. Ataluren treatment was also associated with significant reductions in cough frequency and trends toward improvement in pulmonary function tests.

Conclusions

As we discussed in our January 24, 2013 article on this blog, the 1989 identification of the genetic cause of CF did not immediately lead to the development of disease-modifying drugs. Bottlenecks in the pathway from genetic research to small-molecule drugs included understanding the different ways (e.g., deficiencies in chloride channel function, deficiencies in protein processing, blockages in protein translation due to nonsense mutations) in which the many mutations that can cause CF act, and the need to develop effective assays for use in drug discovery.

The 2012 approval of the CFTR potentiator ivacaftor (Vertex’ Kalydeco) in the U.S. and Europe represents a real milestone in CF drug development. Vertex and the CFF should be congratulated on their breakthrough CF R&D program, which required the willingness to pursue a long pathway to development.

Other compounds that target CFTR are in Phase 2 development. All indications suggest that treatment for CF will represent a case of “personalized medicine”, as befits a disease that is caused by multiple mutations that act at different levels of protein synthesis, processing, and function.

As is typical for personalized medicines that target rare diseases, Kalydeco is expensive. The drug reportedly costs upwards of $294,000 for a year’s supply. Vertex says that it will supply Kalydeco free to U.S. patients with no insurance and a household income of under $150,000.

With the interest of pharmaceutical and biotechnology companies in developing targeted therapies and therapies for rare diseases, the story of the development of small-molecule drugs for CF represents an important case study in drug discovery and development in the 2010s. According to the FDA, the emphasis on targeted drugs and rare diseases has also resulted in the the recent increase in FDA drug approvals; the agency approved 39 new drugs in 2012, which represents a 16-year high.
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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.

FDA approves mipomersen (Isis/Genzyme’s Kynamro)–the first systemically-delivered oligonucleotide drug to reach the market

 

Atherosclerosis. Source: Nephron http://bit.ly/jL6Zos

Atherosclerosis. Source: Nephron http://bit.ly/jL6Zos

In our November 20, 2012 Biopharmconsortium Blog article, entitled “Novel hypercholesterolemia drugs move toward FDA decisions”, we discussed two drugs–Aegerion Pharmaceuticals’ lomitapide, and Isis/Sanofi/Genzyme’s mipomersen. These drugs were nearing approval decisions by the FDA, following the recommendations of the FDA’s Endocrinologic and Metabolic Drugs Advisory Committee that both drugs be approved for treatment of homozygous familial hypercholesterolemia (HoFH).

In our December 31, 2012 blog article, we reported that the FDA had approved Aegerion’s small-molecule drug lomitapide (Juxtapid). That left us waiting for “the other shoe to drop”–the decision on the approval of mipomersen.

On January 29, 2013, Genzyme (a Sanofi company) and Isis Pharmaceuticals (Carlsbad, CA) reported that the FDA had approved mipomersen (Kynamro) for the treatment of HoFH. Mipomersen, given as a 200 mg weekly subcutaneous injection, has been approved as an adjunct to lipid-lowering medications and diet for the treatment of dyslipidemia in patients with HoFH. In contrast to mipomersen, Aegerion’s lomitapide is an oral drug.

The approval of mipomersen triggered a $25 million milestone payment to Isis from Genzyme.

MIpomersen is an antisense oligonucleotide that targets the messenger RNA for apolipoprotein B. This agent represents the first oligonucleotide drug capable of systemic delivery to be approved in a regulated market. (The two previously marketed oligonucleotide drugs both treat ophthalmologic diseases and are delivered locally.) Mipomersen targets the liver, without the need for a delivery vehicle. Thus mipomersen represents the “great hope” for proof-of-concept for oligonucleotide drugs, including antisense and  RNAi-based drugs.

In the January 29, 2013 press release, Stanley T. Crooke, M.D., Ph.D., Chairman of the Board and CEO of Isis, said:

“Kynamro is the first systemic antisense drug to reach the market and is the culmination of two decades of work to create a new, more efficient drug technology platform. As evidenced by our robust pipeline, our antisense drug discovery technology is applicable to many different diseases.” This indicates that Isis considers the approval of mipomersen as a proof-of-concept for its approach to antisense oligonucleotide drug discovery and development, and in particular for its pipeline.

Clinical trials of mipomersen

The FDA approval of mipomersen is based on the results of a randomized, double-blind, placebo-controlled, multi-center trial that enrolled 51 HoFH patients age 12 to 53 years, including 7 patients age 12 to 16 years, who were on lipid lowering medications. The trial found that mipomersen treatment further reduced LDL-cholesterol levels by an average of 113 mg/dL, or 25%, from a treated baseline of 439 mg/dL, and further reduced all measured endpoints for atherogenic particles. In March 2010, these data were published in The Lancet.

Safely data for mipomersen are based on pooled results from four Phase 3 trials. Eighteen percent of patients on the drug and 2% of patients on placebo discontinued treatment due to adverse effects. The most common adverse effects of mipomersen treatment were injection site reactions, increases in the liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) , flu-like symptoms, and an abnormal liver function test.

As a result of these safety findings, the label for Kynamro contains a Boxed Warning citing the risk of hepatic toxicity. The label for Aegerion’s Juxtapid (lomitapide) also contains such a Boxed Warning. A Boxed Warning is the strongest warning that the FDA requires.

The FDA is also requiring four postmarketing studies of mipomersen, and wants the developers to carefully track the long-term safety of the drug.

As an antisense drug, mipomersen is metabolized without affecting the CYP450 pathways used in commonly prescribed drugs. It thus is potentially free of drug-drug interactions. No clinically relevant pharmacokinetic interactions were reported between mipomersen and warfarin, or between mipomersen and simvastatin or ezetimibe.

The safety and effectiveness of mipomersen have not been established in patients with hypercholesterolemia who do not have HoFH. Nor has the effect of mipomersen on cardiovascular morbidity and mortality been determined.

Because of the risk of hepatotoxicity, mipomersen is available only through a Risk Evaluation and Mitigation Strategy (REMS) called the Kynamro REMS. The goals of the REMS are:

  • To educate prescribers about the risk of hepatotoxicity associated with the use of mipomersen, and the need to monitor patients during treatment with mipomersen as per product labeling.
  • To restrict access to therapy with mipomersen to patients with a clinical or laboratory diagnosis consistent with homozygous familial hypercholesterolemia (HoFH).

Genzyme has also developed an HoFH and Kynamro support program for healthcare providers, patients, and their families.

Wider implications of the FDA approval of mipomersen

Mipomersen achieved FDA approval despite an unenthusiastic 9-6 recommendation for approval by the FDA’s Endocrinologic and Metabolic Drugs Advisory Committee. This compares to a 13-2 vote to recommend approval of lomitapide. Meanwhile, mipomersen received a negative opinion from a European Medicines Agency panel. And it faces strong competition in the market from lomitapide. Therefore, mipomersen is unlikely to become a large-selling drug.

Nevertheless, Sanofi has been positioning itself around Genzyme (and its rare disease platform) in its drug discovery and development strategy. Therefore, any and all Genzyme/Sanofi drug approvals represent important victories.

Although the FDA Advisory Committee and industry commentators favor lomitapide over mipomersen, they also believe that not all patients with HoFH would be likely to benefit from only one drug. Thus having two alternative drugs may well be better in treating this disease.

Does the approval of mipomersen herald a new age of oligonucleotide drugs? The first antisense agent to reach the market, fomivirsen (Isis/ Novartis Ophthalmics’ Vitravene), which is indicated for treatment of cytomegalovirus retinitis in AIDS patients was approved in 1998. However, it is delivered locally to the eye, and has not been profitable.

Even though mipomersen is unlikely to become a large-selling drug, it could become the first commercially successful antisense agent. As stated by Arthur Krieg, M.D., chief executive of RaNA Therapeutics, “What many people have been waiting for is validation where someone actually makes a profit and where patients actually benefit.”

As we have discussed in earlier blog posts, oligonucleotide drugs (especially antisense and RNAi) represent a premature technology. It is therefore not unusual that it would take over 20 years for the first profitable drug in this class to reach the market. This was also recently stated by Dr. Crooke.

Finally, as we stated in our November 20, 2012 blog article:

For oligonucleotide drug developers and enthusiasts, the case of mipomersen–considered the “great hope” for proof-of-concept for oligonucleotide drugs by many in the field–provides several lessons. 1. At the end of the day, oligonucleotide drugs must meet the same standards of safety and efficacy as other drugs. 2. Oligonucleotide drugs may encounter competition from drugs in other classes, such as small molecules or monoclonal antibodies.

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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.

HDL drug update

 

Niacin

Niacin

We have published two articles on high-density lipoprotein (HDL, or “good cholesterol”) raising drugs on this blog:

The more recent of these article has received quite a few hits lately. This is probably because of recent news of a clinical trial failure in the HDL drug field. It therefore seems appropriate to publish an update on HDL-raising drug clinical trials, in order to bring our blog up to date.

Update on the trials and tribulations of niacin-based HDL-raising drugs

As of the time of our June 1, 2011 article, high-dose niacin was the only drug that was approved by the FDA for raising HDL. However, generic high-dose niacin can cause adverse effects such as skin flushing and itching. Therefore, two companies, Abbott and Merck, were developing high-dose niacin-based products designed to reduce these adverse effects.

In May 2011, as discussed in our June 1, 2011 article, the National Heart Lung and Blood Institute (NHLBI) of the National Institutes of Health (NIH) stopped a large clinical trial (known as AIM-HIGH) of Abbott’s Niaspan, an extended-release formulation of high-dose niacin, because the drug failed to prevent heart attacks and strokes. There was also a small increased rate of strokes in patients taking Niaspan, which researchers cautioned may have been due to chance. Niaspan remains an FDA-approved drug, and it is now owned by Abbot spin-off AbbVie. However, Niaspan is scheduled to go off-patent later in 2013.

Merck’s high-dose non-flushing niacin product is known as Tredaptive or Cordaptive in different markets. It is a combination product consisting of extended-release high dose niacin plus laropiprant. Laropiprant is designed to block the ability of prostaglandin D2 to cause skin flushing; niacin-induced skin flushing works via the action of prostaglandin D2 in the skin.

In 2008, the FDA rejected Merck’s New Drug Application for Tredaptive/Cordaptive, so the drug remained investigational in the US. However, in 2009 Merck launched Tredaptive in international markets including Mexico, the UK and Germany. The drug has been approved in over 45 countries. Merck had also been conducting a 25,000-person trial of Tredaptive for reducing the rate of cardiovascular events in patients who are at risk for cardiovascular disease (CVD). Merck intended to file for approval of the drug in the US in 2012, based on the results of this trial if it had been positive.

However, on December 20, 2012, Merck announced that its clinic trial of Tredaptive, known as the HPS2-THRIVE Study (Heart Protection Study 2-Treatment of HDL to Reduce the Incidence of Vascular Events), did not achieve its primary endpoint.

As a result of this finding, Merck does not plan to seek regulatory approval for this medicine in the United States. It also–as of January 11, 2013–began a recall of Tredaptive in the 40 countries in which it had been approved. The  HPS2-THRIVE Study not only showed that Tredaptive was of no benefit in reducing cardiovascular events in high-risk patients on statins, but it also significantly raised the incidence of such adverse effects as blood, lymph and gastrointestinal problems, as well as respiratory and skin issues.

The results of a new study published online on February 26 2013 showed that around a quarter of all patients taking the niacin/laropiprant combination Tredaptive had dropped out of the trial–compared to fewer than 17% in the placebo arm.  This was mostly due to itching, rashes, indigestion and muscle problems. There were also dozens of serious reactions, including 29 cases of myopathy.

Skin-related adverse effects seen in some patients with Tredaptive resemble those seen with high-dose niacin. The addition of laropiprant was supposed to ameliorate these adverse effects, but may not have done so in all patients. As for the serious adverse effects such as myopathy, several medical researchers assert that it is not known whether niacin, laropiprant or drug-drug interactions between these two agents and/or the statin (simvastatin) used in the study was responsible. Simvastatin is known to have adverse interactions with certain other drugs. Moreover, one-third of subjects enrolled in HPS2-THRIVE were Chinese, a patient population that is known to be more sensitive to the effects of statins, especially the 40-milligram dose of simvastatin used in the trial. It was the Chinese patients enrolled in the trial who showed the highest risk of myopathy.

In addition, some of the researchers question whether laropiprant is a “clean drug” that has no effects on atherosclerosis and thrombosis. A recent study has shown aneurysm formation and accelerated atherogenesis in mice with deleted prostaglandin D2 receptors; these receptors are the target of laropiprant. Thus the use of laropiprant may have been a factor in the failure of the trial, as well as in the adverse effects seen in patients treated with the niacin/laropiprant combination.

Full results of the HPS2-THRIVE study will be presented by lead investigator Dr Jane Armitage (Oxford University, UK) on March 9, 2013 at the American College of Cardiology 2013 Scientific Sessions (San Francisco, CA.)

Thus–although generic niacin and Niaspan remain FDA-approved HDL-raising drugs–the results of the AIM-HIGH and the HPS2-THRIVE studies have put niacin-based HDL-raising drugs–and the whole HDL-raising drug field–under a cloud.

Update on development of CETP inhibitors

As discussed in our earlier articles, the development of cholesteryl ester transfer protein (CETP) inhibitors has been a particular focus of several pharmaceutical companies.  CETP catalyzes the transfer of cholesteryl esters and triglycerides between LDL/VLDL and HDL, and vice versa. In vivo (in animals and in humans), CETP inhibitor drugs raise HDL and lower LDL.

The clinical failure of Pfizer’s CETP inhibitor torcetrapib in 2006 put a severe damper on development of drugs in this class. However, the toxicity of torcetrapib was found to be due to an off-target effect, and other CETP inhibitors do not display this toxicity. Thus companies have been developing three CETP inhibitors: Roche’s dalcetrapib, Merck’s anacetrapib, and Lilly’s evacetrapib.

However, on May 7, 2012 Roche announced that it had–following the recommendation of an independent group of experts (the Data and Safety Monitoring Board)–halted its Phase 3 trial of dalcetrapib “due to a lack of clinically meaningful efficacy.”

Dalcetrapib’s lack of efficacy might possibly be due to its relatively low potency in raising HDL. Dalcetrapib boosted HDL by 30%, as compared to 138% for anacetrapib and 130% for evacetrapib, depending on the dose. Moreover, anacetrapib and evacetrapib, unlike dalcetrapib, also lower LDL (“bad cholesterol”).

Currently, anacetrapib and evacetrapib are being evaluated in large Phase 3 clinical trials–REVEAL (Randomized EValuation of the Effects of Anacetrapib Through Lipid-modification) and ACCELERATE (A Study of Evacetrapib in High-Risk Vascular Disease), respectively.

Is HDL-raising drug development high-stakes gambling or rational clinical research?

Given the lack of success–so far–in developing a safe HDL-raising drug that lowers the frequency of cardiovascular events in high-risk patients, some commentators speculate that attempting to develop HDL-raising drugs such as CETP inhibitors might be a form of high-stakes gambling. Chemist and leading pharmaceutical industry blogger Derek Lowe in particular takes this point of view. As we discussed in our June 1, 2011 article, the biology of HDL is complex. For example, HDL particles in blood serum are heterogeneous, with some HDL particles having a greater degree of positive effects on atherosclerotic plaque biology than others. As a result, treatments (e.g., drugs, diet) that raise HDL, as determined by standard clinical assays for serum HDL, may not necessarily result in clinical benefit, because of qualitative changes in populations of HDL particles.

The unknowns of HDL biology, combined with the need to conduct huge expensive clinical trials and the big payoffs for success in the large dyslipidemia market, convinced Derek Lowe that CETP inhibitor development more resembles gambling (in which only Big Pharmas can play) than rational clinical research. The same, according to Lowe, applies to Alzheimer’s disease drug development. According to Lowe, Big Pharmas may be undertaking these “go-for-the-biggest-markets-and-hope-for-the-best” research undertakings because they think that success in large markets are the only things that can rescue them.

Nevertheless, Steven Nissen, M.D. (chief of cardiovascular medicine at Cleveland Clinic), a veteran HDL researcher who has often been critical of the pharmaceutical industry, persists in running clinical studies of novel HDL-raising drugs. Although he considered dalcetrapib a “long-shot”, he continues to believe that anacetrapib and evacetrapib have a reasonable chance of success. And he has expressed particular enthusiasm for anacetrapib.

Dr. Nissen is involved in clinical trials of Resverlogix’s epigenetic agent RVX-208, a first-in-class small-molecule drug related to resveratrol that induces endogenous production of the protein component of HDL, apolipoprotein A1. On August 28, 2012, Resverlogix reported that RXV-208 significantly increased HDL-C, the primary endpoint of a Phase 2b clinical trial known as SUSTAIN. SUSTAIN also successfully met secondary endpoints–showed increases in levels of Apo-AI and large HDL particles. Both of these are believed to be important factors in enhancing reverse cholesterol transport activity. Safety data from SUSTAIN indicate that increases in the liver enzyme alanine aminotransferase (ALT) reported in previous trials were infrequent and transient, with no new increases observed beyond week 12 of the 24-week trial. Thus the drug appears to be suitable for chronic use.

Thus, despite the features of CETP-inhibitor clinical trials that resemble high-stakes gambling, we must wait for the results of the clinical trials to draw any meaningful conclusions about the prospects for development of these agents. Moreover, other approaches to developing HDL-raising drugs, such as Resverlogix’ epigenetic strategy, may turn out to be superior to older approaches. And as with Alzheimer’s disease, continuing studies on the basic biology of HDL may eventually yield breakthrough strategies to discovery and development of novel antiatherosclerotic drugs.

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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.

Determining the molecular cause of a disease does not necessarily enable researchers to develop disease-modifying drugs

 

NBD1 of human CFTR. Source: PDBbot http://bit.ly/11UmpkS

NBD1 of human CFTR. Source: PDBbot http://bit.ly/11UmpkS

A major objective of research in genomics is to identify mutations that cause genetic diseases. However, doing so does not necessarily directly enable researchers to discover and develop drugs to treat these diseases.

Two examples of genetic diseases whose causes were identified decades ago, without directly enabling the development of any disease-modifying drug, are sickle cell disease (SCD) (also known as sickle cell anemia) and cystic fibrosis (CF).

Sickle cell disease

The causative mutation of SCD was identified by protein researchers, decades before the era of genomics. Vernon M. Ingram, Ph.D. showed in 1957 that a glutamic acid to valine mutation at position 6 of the β-chain of hemoglobin was the sole abnormality in SCD. For this discovery, Dr. Ingram has been called The Father of Molecular Medicine. Dr. Ingram’s work was made possible by a 1949 study by Linus Pauling and his colleagues, which showed that SCD hemoglobin had a different electrophoretic mobility than normal hemoglobin. Thus the sickle cell trait was likely to be due to a mutation in the β-hemoglobin gene that changed its amino acid composition, as confirmed by Dr. Ingram.

Yet to this day, although SCD (which occurs in individuals who are homozygous for the sickle-cell mutation) can be managed by various treatments (such as hydroxyurea and blood transfusions and bone marrow transplants) that can result in survival into one’s fifties, there is no mechanism-based therapy for this disease. Thus the identification of the causative mutation of SCD has not led to any treatments.

The reason why discovery and development of drugs for SCD has been so very difficult is that the mutation that causes this disease affects an intracellular protein, hemoglobin, which is neither a receptor nor an enzyme. Unlike secreted proteins such as insulin, it is not possible to develop protein drugs to replace missing or defective hemoglobin. It is also not possible to replace the missing function of normal hemoglobin by treatment with a small molecule drug.

Diseases such as SCD–in which the function of an essential intracellular protein is defective or missing–have often been cited as candidates for gene therapy.

However, as we discussed in our October 11, 2012 and our November 8, 2012 Biopharmconsortium Blog articles, it is only this past fall that the first gene therapy was approved for marketing in a regulated market. As we discussed in the first of these articles, gene therapy has a history going back to at least the early 1970s. However, gene therapy has displayed the characteristics of a premature technology. Several notable failures, including some that caused the deaths of patients, put a severe damper on the gene therapy field. Only recently–between around 2003 and 2012–have researchers been developing more advanced gene therapy technologies and conducting clinical studies, with some success. Entrepreneurs have also been building gene therapy specialty companies to commercialize this research.

As also we discussed in our October 11, 2012 article, among the many companies that are developing gene therapies, bluebird bio (Cambridge, MA) has been singled our for special attention lately. Among the diseases being targeted by bluebird bio are SCD, and beta-thalassemias, which are also genetic diseases that affect hemoglobin. bluebird bio is in Phase 1/2 trials for its beta-thalassemia therapy, and in Phase 1 for its SCD program.

Cystic fibrosis

CF causes a number of symptoms, which affect the skin, the lungs and sinuses, and the digestive, endocrine, and reproductive systems. Notably, people with CF accumulate thick, sticky mucus in the lungs, resulting in clogging of the airways due to mucus build-up. This leads to inflammation and bacterial infections. Ultimately, lung transplantation is often necessary as the disease worsens. With proper management, patients can live into their late 30s or 40s.

The affected gene in CF and the most common mutation that causes the disease (called ΔF508 or F508del) were identified by Francis S Collins, M.D., Ph.D. (then at the Howard Hughes Medical Institute and Departments of Internal Medicine and Human Genetics, University of Michigan, Ann Arbor, MI) and his colleagues in 1989. Dr. Collins was subsequently the leader of the publicly-funded Human Genome Project and is now the Director of the U.S. National Institutes of Health, Bethesda, MD.

The gene that is affected in cystic fibrosis encodes a protein known as the cystic fibrosis transmembrane conductance regulator (CFTR).  CFTR 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; one in 2000–3000 newborns in the European Union is found to be affected by 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.

In the case of CF, the affected protein, CFTR, is an ion channel–specifically a chloride channel.

Ion channels constitute an important class of drug targets, which are targeted by numerous currently marketed drugs, e.g., calcium channel blockers such as amlodipine (Pfizer’s Norvasc; generics) and diltiazem (Valeant’s Cardizem; generics). These compounds were mainly 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, mainly because of the difficulty in developing assays suitable for drug screening. In addition, development of suitable assays for assaying chloride channel function has lagged behind the development of assays for the function of cation channels (e.g., sodium and calcium channels).

Moreover the most common CFTR mutation that causes CF, ΔF508, results in defective cellular processing, and the mutant CTFR protein is retained in the endoplasmic reticulum. In the case of some other mutant forms of CTFR (accounting for perhaps 5% of CF patients), the mutant proteins reach the cell membrane, but are ineffective in chloride-channel function.

Given these difficulties, researchers first attempted to develop gene therapies for CF. Genzyme (a Sanofi company since 2011) has been a leader in developing gene therapy for CF, and has been conducting research in this area since the 1990s. However, as with most gene therapies, development of treatments capable of reaching the market has been elusive.

Genzyme is still researching gene therapies for CF, as are others. An academic group in the U.K., known as the U.K. Cystic Fibrosis Gene Therapy Consortium is working to develop CF gene therapies, using Genzyme’s nonviral cationic lipid vector GL67 (Genzyme lipid 67) as the delivery vehicle. GL67 is the current “gold-standard” for in vivo lung gene transfer. Recently, the Consortium received funding from the U.K. Medical Research Council and National Institute of Health Research to continue its Phase 2B trial of its CF gene therapy product,GL67A/pGM169. This is a combination of GL67 and plasmid DNA expressing CFTR (pGM169).

Very recently, R&D on disease-modifying small-molecule drugs for CF has begun to bear fruit. In January 2012, the FDA approved the first such drug, ivacaftor (Vertex’ Kalydeco.) In July 2012, Vertex received European approval for this drug. Ivacaftor only works in patients with the G551D  (Gly551Asp) mutation in CFTR, which only accounts for around 4% of CF patients. Vertex and other companies–including Genzyme–are working on development of other small-molecule disease-modifying drugs with the potential to treat greater numbers of CF patients.

We shall discuss the new wave of disease-modifying CF drugs, including ivacaftor, in a later post on this blog.

Conclusions

SCD and CF are two examples of cases in which the identification of the genetic or molecular cause of a disease did not directly lead to new treatments. In the case of SCD, even though over 55 years have elapsed since the identification of the genetic cause of the disease, no therapy had yet emerged from this discovery. In the case of CF, it took over two decades from the identification of the molecular cause of the disease to the approval of the first disease-modifying drug.

Many other cases in which molecular targets involved in disease have been identified also lack disease-modifying treatments because the targets are “undruggable”. This especially applies to protein-protein interactions (PPIs). However, PPIs have assumed increasing strategic importance in drug discovery and development in recent years, and researchers and companies have been developing new technologies and strategies to discover  developable drugs that address PPIs.

Back in the early 2000s, researchers and commentators hailed the sequencing of the human genome as heralding a new era in drug discovery and development. However, the “industrialized biology” approach that grew out of the genomics of that era gave very few successes in terms of drug development. Now–a decade later–we have next-generation sequencing and  are approaching the “$1000 genome.” Once again, at least some commentators are expecting immediate breakthroughs in therapeutic development to come out of these breakthroughs in sequencing technology. Others, such as CFTR gene discoverer Francis Collins, believe that we can “speed the development of genetic advances into treatments” by more rapidly weeding out “what turn out to be..nonviable compounds.”

However, in the case of CF there were barriers to drug discovery, such as limited understanding of disease biology and difficulties in assay development, that were the true causes of lack of progress in developing disease-modifying genes. Moreover, once they had good assays, researchers needed to come up with effective strategies to develop small-molecule drugs for CF. In the case of SCD, because of the nature of the target, only gene therapy–with its manifold difficulties–had any hope of addressing the disease. In the case of PPIs, there was the need to discover new breakthrough strategies to address these “undruggable” targets.

Thus, despite breakthroughs in sequencing technologies, determining of disease-related sequences is likely to only be the first step in effective discovery of disease-modifying drugs. And there may continue to be a considerable time lag between sequence determination and 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 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.

FDA Approves Aegerion’s lomitapide (Juxtapid) for Homozygous Familial Hypercholesterolemia

 

Happy New Year from Haberman Associates!

Happy New Year from Haberman Associates!

In our November 20, 2012 article on this blog, entitled “Novel hypercholesterolemia drugs move toward FDA decisions”, we discussed two drugs–Aegerion Pharmaceuticals’ lomitapide, and Isis/Sanofi/Genzyme’s mipomersen. In October 2012, the FDA’s Endocrinologic and Metabolic Drugs Advisory Committee recommended that both drugs be approved for treatment of homozygous familial hypercholesterolemia (HoFH).

In that article, we discussed issues involved in the development and commercialization of lomitapide–a small-molecule drug, and mipomersen–an antisense oligonucleotide, for treatment of HoFH, a rare genetic disease which is mechanistically related to more common types of hypercholesterolemia. We also stated that were were awaiting FDA action–expected in the next several weeks after publication of our article–on the approval of the two drugs.

On Christmas Eve–December 24, 2012–a day on which few people in the United States and in many other countries were thinking about work–Aegerion (Cambridge, MA) announced that the FDA had approved lomitapide for treatment of HoFH. Lomitapide has been given the brand name Juxtapid.

The FDA based its approval of lomitapide on the results of a pivotal Phase 3 study, which evaluated the safety and effectiveness of the drug in 29 adult patients with HoFH. As we discussed in our November 20, 2012 article, the results of this study were published in the online version of The Lancet on November 2, 2012.

As we also discussed in our earlier article, lomitapide has serious adverse effects, including hepatic fat accumulation and elevated liver aminotransferase levels. According to the December 24, 2012 Aegerion press release, the most common adverse reactions seen in the Phase 3 study were gastrointestinal, including diarrhea, nausea, vomiting, dyspepsia and abdominal pain. Ten of the 29 patients in the study had at least one elevation in liver enzymes greater than or equal to three times the upper limit of normal. Liver enzyme elevations were managed through dose reduction or temporary discontinuation of dose. Hepatic fat accumulation was also observed in the Phase 3 trial.

As we also discussed in our earlier article, a finding of elevated liver aminotransferase levels is enough to stop development of most drugs. As of October 2012, the FDA and its Advisory Panel believed that a risk evaluation and mitigation strategy (REMS) would support appropriate use of these drugs in patients with homozygous FH, because of their life threatening disease, and because they have limited therapeutic options.

According to the December 24, 2012 Aegerion press release, the label for lomitapide contains a Boxed Warning citing the risk of hepatic toxicity. A Boxed Warning is the strongest warning that the FDA requires.

Lomitapide is avaiable only through the Juxtapid Risk Evaluation and Mitigation Strategy (REMS) Program. Aegerion will certify all health care providers who prescribe Juxtapid and the pharmacies that will dispense the medicine.

The goals of the REMS are:

  • To educate prescribers about the risk of hepatotoxicity associated with the use of lomitapide, and the need to monitor patients during treatment with the drug.
  • To restrict access to therapy with lomitapide to patients with a clinical or laboratory diagnosis consistent with HoFH.

The safety and efficacy of lomitapide have not been established in patients with hypercholesterolemia who do not have HoFH. The effects of the drug on cardiovascular morbidity and mortality has not been determined. The safety and effectiveness of lomitapide have not been established in pediatric patients.

In addition to establishing the REMS, Aegerion has made a commitment to the FDA to conduct a post-approval, observational cohort study.  The company has also developed a comprehensive support services program for patients and their healthcare providers.

As we discussed in our November 20, 2012 article, Aegerion will be marketing lomitapide on its own, without a larger partner, and has been ramping up its marketing and sales organization in anticipation of approval. The company has set up a website for the product, www.juxtapid.com.

We await the FDA’s decision on the approval of mipomersen, to see how this chapter in the hypercholesterolemia drug development story will unfold.

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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.

Haberman Associates in Chemical & Engineering News (C&EN) article on Agios Pharmaceuticals

 

Agios Germanos, Greece. Source: http://bit.ly/YRDIBJ

Agios Germanos, Greece. Source: http://bit.ly/YRDIBJ

I was quoted in an article in the November 19, 2012 issue of Chemical & Engineering News (C&EN) by senior editor Lisa M Jarvis. The article is entitled “Agios Takes A Long View In Cell Metabolism.”

The article focuses on Agios Pharmaceuticals’ (Cambridge, MA) strategy for building a company that can endure as an independent firm over a long period of time, and that can also demonstrate sustained performance.

This contrasts with the recent trend toward “virtual biotech companies”–lean companies with only a very few employees that outsource most of their functions, and that are designed for early acquisition by a Big Pharma or large biotech company. The virtual company strategy is designed to deal with the inability of most young biotech companies to go public in the current financial environment. Without the ability to go public, young companies cannot provide early-stage venture capital investors with a profitable exit within a few years after launching the company. Virtual companies typically have a few assets, such as molecules that are ready for preclinical studies or early clinical trials. The goal is to obtain enough evidence that their compounds can become drugs to interest a Big Pharma.

In contrast, there are a few young  “platform companies” that are built on a broad technology platform, which aim to address important areas of biology and potentially to develop numerous products with the potential to address important areas of unmet medical need. One of these is Agios.

“Built to Last” in the current biotech ecosystem

In the C&EN article, I was quoted as saying that only a few platform companies have been launched in recent years. In the Boston area, in addition to Agios, such companies include Forma Therapeutics and Aileron Therapeutics. I was further quoted as saying “These companies are built to last.”

That brings up the old business paradigm from the 1990s and early 2000s–“Built to Last” versus “Built to Flip”. Those involved in building virtual biotech companies–especially venture capitalists and angel investors–do not like the use of “Built to Flip” to characterize their companies. And there are some fine virtual biotechs–some, such as Energesis and Zafgen–which we have covered in our blog.

(Plexxikon, the developer of targeted melanoma drug vemurafenib, also operated as a virtual company. However, it had a technology platform, and had the potential to become an independent biotech with marketed products. Thus Plexxikon did not fit the usual “virtual biotech model”. Nevertheless, it was acquired by Daiichi Sankyo in 2011.)

However, some industry commentators believe that “Built to Flip” is an appropriate designation for virtual biotech companies, and that the virtual model is likely to be detrimental to drug discovery and to the biotech/pharma industry as a whole.

Meanwhile, the 2012 BIO International Convention in Boston had a session entitled “Moving the Goal Posts: How to Build a Free-Standing Biotech from Scratch in Today’s Environment.” This session focused on how to build the “next Vertex or even the next Genentech” (i.e., a “Built to Last” biotech company) in today’s environment. John Evans, the Vice President of Business Development & Operations of Agios was a speaker at that session. The session was moderated by Bruce Booth of Atlas Ventures. Thus, despite the preference for lean virtual biotech companies in the current funding environment, there is an interest in the entrepreneurial and venture capital communities for how free-standing biotechs might emerge under current conditions.

How to build a young platform biotech company

The Biopharmconsortium Blog has included three articles about Agios:

These articles, as well as the November 19 2012 C&EN article, outline how Agios has been building a free-standing biotech in today’s unfavorable environment. Agios’ strategy is based on three elements:

  • A stellar group of scientific founders–Drs. Craig B. Thompson, Tak W. Mak, and Lewis C. Cantley.
  • A strong proprietary technology platform based on cancer metabolism
  • A financing strategy that includes both venture capital and partnerships with established companies. In the case of Agios, their partner is Celgene. The Agios/Celgene partnership provides Agios with $150 million, and allows Agios to maintain control over the direction of its early stage research.

As stated in the C&EN article, the financial security gained via Agios’ funding by its venture investors and by Celgene enables Agios to work on multiple potential targets, with the goal of dominating the field of cancer metabolism. Agios focuses on two types of targets: metabolic enzyme species that are found only in cancer cells, and enzyme species on which a cancer cell has become dependent. Agios researchers intend to develop drugs against targets for which their are predictive biomarkers that identify the right patients for clinical studies.

New developments outlined in the November 19, 2012 C&EN article

Both the November 19, 2012 C&EN article and our Bipharmconsortium Blog articles outline Agios’ program to target a mutated form of isocitrate dehydrogenase 1 (IDH1), which together with mutated IDH2 has been implicated in 70% of human brain cancers. As stated in the C&EN article, Agios researchers have recently reported a series of compounds that selectively inhibit the mutant form of IDH1. This research had been carried out in collaboration with researchers from Ember Therapeutics (Watertown, MA). As we stated in another Biopharmconsortium Blog article, Ember specializes in targeting beige adipocytes for treatment of metabolic diseases.

As we noted in our November 30, 2011 Biopharmconsortium Blog article, Agios had slated a portion of the $78 million that it raised in its Series C financing to expand its R&D efforts into inborn errors of metabolism (IEMs). IEMs comprise a large class of inherited disorders of metabolism, most of which are defects in single genes that code for metabolic enzymes. These rare metabolic diseases have a high level of unmet medical need.

As outlined in the C&EN article, Agios’ work with mutant IDH1 and IDH2 is serving as a bridge to the company’s programs in IEMs. IDH2 mutations have been found in a class of children with 2-hydroxyglutaric aciduria, a rare inherited neurometabolic disorder that can cause developmental delay, epilepsy, and a set of other pathologies.

According to the C&EN article, IEMs are of special strategic interest to Agios. Agios CEO David Schenkein stated that expanding the company’s R&D efforts into IEMs helps the company to manage the risk profile of its portfolio. In the case of cancer, Agios researchers must identify and validate targets involved in the pathobiology of these diseases, and then to find drugs that modulate these targets. In the case of IEMs, disease biology is already validated by genetics.

Moreover, IEMs have small patient populations. Thus only small clinical trials are needed to bring a drug to market. Agios therefore believes that it can bring drugs for these diseases to market on its own, without the need for a larger partner such as Celgene or a Big Pharma.

As we discussed in a Biopharmconsortium Blog article on improving the clinical trial system, although rare diseases only require small clinical trials, finding and recruiting patients for the trials is made more difficult because of the very small number of patients with a particular disease. One solution is to work with patient advocates and “disease organizations”, some of which have patient registries. In the case of 2-hydroxyglutaric aciduria and other organic acidemias, a “disease organization” exists–the Organic Acidemia Association (OAA). Perhaps Agios will find it fruitful to work with the OAA in its patient recruitment efforts.

Currently, Agios is focused on getting compounds into the clinic–both for IEMs and for cancer. Looking down the road, the company’s $180 million war chest should enable Agios to put several compounds through proof-of-concept studies, according to Dr. Schenkein. (This is besides any cancer drug candidates that are licensed by Celgene.) Despite Agios’ strategy of conducting small trials for IEM drug candidates, Dr. Schenkein said that the company will eventually need to go public to achieve its strategic goal of dominating the cancer metabolism field.

________________________________

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