CAR T cells attacking a cancer cell. (Source: National Cancer Institute)

On May 3, 2017 Cambridge Healthtech Institute’s (CHI’s) Insight Pharma Reports announced the publication of a new book-length report, Cancer Immunotherapy: Building on Initial Successes to Improve Clinical Outcomes, by Allan B. Haberman, Ph.D.

The new 2017 report includes an updated discussion of approved and clinical stage agents in immuno-oncology. It also addresses the means by which researchers and companies are attempting to build on prior achievements in immuno-oncology to achieve improved outcomes for more patients. This approach is often referred to as “immuno-oncology 2.0.” The American Society of Clinical Oncology (ASCO) named “immunotherapy 2.0” as its “Advance of the Year” for 2017.

As discussed in the report, researchers have found that checkpoint inhibitors such as pembrolizumab (Merck’s Keytruda) and nivolumab (Bristol-Myers Squibb’s Opdivo) produce tumor responses by reactivating TILs (tumor infiltrating lymphocytes). As a result, they have been developing biomarkers that distinguish inflamed (i.e. TIL-containing) tumors—which are susceptible to checkpoint inhibitor therapy—from “cold” tumors, which are not. They have also been working to develop means to render “cold” tumors inflamed, via treatment with various conventional therapies and/or development of novel agents. These studies constitute the major theme of immuno-oncology 2.0.

Meanwhile, cellular immunotherapy has also been advancing, with two chimeric antigen receptor (CAR) T-cell therapies (from Novartis and Kite Pharma) in preregistration with the FDA as of March 2017.

These and other areas of current cancer immunotherapy R&D are discussed in the new report.

The first wave of immuno-oncology 2.0 treatments has begun to achieve regulatory approval:

  • On May 12, 2017, Merck gained FDA approval to market a combination of pembrolizumab with chemotherapy (specifically, carboplatin plus pemetrexed) for first-line treatment of non-small cell lung cancer (NSCLC). This is based on a Phase 2 clinical study that showed that the chemo/pembrolizumab combination resulted in a much higher statistically-significant overall response than chemo alone — 55% vs. 29%. As we discuss in our report, certain types of chemotherapy can induce immune responses that convert “cold” tumors into inflamed tumors, thus making them susceptible to checkpoint inhibitor treatment.
  • On May 23, 2017, the FDA awarded accelerated approval to Merck’s pembrolizumab for the treatment of adult and pediatric patients with unresectable or metastatic solid tumors that exhibit high microsatellite instability (MSI-H) or are mismatch repair deficient (dMMR). This indication includes patients with solid tumors that have progressed following prior treatment, and who have no satisfactory alternative treatment options. It also includes patients with colorectal cancer that has progressed following treatment with chemotherapy. This is the first approval of an anticancer agent based on a tumor’s biomarker, regardless of where the tumor originated in the body. As we discuss in our report, mismatch-repair deficiency results in a large somatic mutation load. This supports a large and diverse population of TILs, which are specific for mutation-associated neoantigens. Treatment with checkpoint inhibitors may reactivate these TILs, resulting in effective antitumor immune responses.

Our report is designed to enable readers to understand current and future developments in immuno-oncology, especially including new developments in immunotherapy 2.0. It is also designed to inform the decisions of leaders in companies and in academic groups that are working in areas that relate to cancer R&D and treatment.

For more information on the report, or to order it, see the CHI Insight Pharma Reports website.

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

Steven Rosenberg

Steven Rosenberg

On September 6, 2014, we published an article on this blog announcing the publication of our book-length report, Cancer Immunotherapy: Immune Checkpoint Inhibitors, Cancer Vaccines, and Adoptive T-cell Therapies, by Cambridge Healthtech Institute (CHI).

In that article, we cited the example of the case of a woman with metastatic cholangiocarcinoma (bile-duct cancer), which typically kills the patient in a matter of months. The patient, Melinda Bachini, was treated via adoptive immunotherapy with autologous tumor-infiltrating T cells (TILs) resulting in survival over a period of several years, with a good quality of life.

Our report includes a full discussion of that case, as of the date of the May 2014 publication of a report in Science by Steven A. Rosenberg, M.D., Ph.D. and his colleagues at the National Cancer Institute (NCI). Ms. Bachini’s story was also covered in a May 2014 New York Times article.

Now comes the publication, in Science on December 2015, of an update from the Rosenberg group on their clinical studies of TIL-based immunotherapy of metastatic gastrointestinal cancers. This article discusses the results of TIL treatment of ten patients with a variety of gastrointestinal cancers, including cancers of the bile duct, the colon or rectum, the esophagus, and the pancreas. The case of Ms. Bachini (“patient number 3737”) was included.

Ms. Bachini, a paramedic and a married mother of six children, and a volunteer with the Cholangiocarcinoma Foundation, was 41 years old when first diagnosed with cancer. She remains alive today—a five-year survivor—at age 46.

The Foundation produced a video, dated March 13, 2015, in which Ms. Bachini gives her “patient perspective”. This video includes her story “from the beginning”—from diagnosis through surgery and chemotherapy, and continuing with adoptive immunotherapy at the NCI under Dr. Rosenberg. Although her tumors continue to shrink and she remains alive, she still is considered to have “Stage 4” (metastatic) cancer. Ms. Bachini is a remarkable woman.

The Cholangiocarcinoma Foundation has also produced an on-demand webinar (dated October 21, 2014) on the adoptive cellular therapy trial in patients with various types of metastatic gastrointestinal cancers, led by Drs. Eric Tran and Steven Rosenberg. Ms. Bachini is also a presenter on that webinar. The December 2015 Science article is an updated version of the results of this trial.

The trial, a Phase 2 clinical study (NCT01174121) remains ongoing, and is recruiting new patients.

The particular focus of Dr. Tran’s and Dr. Rosenberg’s study in TIL treatment of gastrointestinal cancers is whether TILs derived from these tumors include T-cell subpopulations that target specific somatic mutations expressed by the cancers, and whether these subpopulations might be harnessed to successfully treat patients with these cancers. Of the ten patients who were the focus of the December 2015 publication, only Ms. Bachini had a successful treatment. In the case of Ms. Bachini, she received a second infusion of TILs that were enriched for CD4+ T cells that targeted a unique mutation in a protein known as ERBB2IP. It was this second treatment that resulted in the successful knockdown of her tumors, which continues to this day.

Despite the lack of similar successes in the treatment of the other nine patients, the researchers found that TILs from eight of these patients contained CD4+ and/or CD8+ T cells that recognized one to three somatic mutations in the patient’s own tumors. Notably, CD8+ TILs isolated from a colon cancer tumor of one patient (patient number 3995) recognized a mutation in KRAS known as KRAS G12D. This mutation results in an amino acid substitution at position 12 in KRAS, from glycine (G) to aspartic acid (D). KRAS G12D is a driver mutation that is involved in causation of many human cancers.

Although two other patients (numbers 4032 and 4069, with colon and pancreatic cancer, respectively) had tumors that expressed KRAS G12D, the researchers did not detect TILs that recognized the KRAS mutation in these patients. The researchers concluded that KRAS G12D was not immunogenic in these patients. The TILs from patient 3995 were CD8+ T cells that recognized KRAS G12D in the context of the human leukocyte antigen (HLA) allele HLA-C*08:02. [As with all T cells, TILs express T-cell receptors (TCRs) that recognize a specific antigenic peptide bound to a particular major histocompatibility complex (MHC) molecule—this is referred to as “MHC restriction”.] The two patients for whom KRAS G12D was not immunogenic did not express the HLA-C*08:02 allele.

The results seen with KRAS G12D-expressing tumor suggest the possibility of constructing genetically-engineered CD8+ T cells that express a TCR that is reactive with the KRAS mutation in the context of the HLA-C*08:02 allele. The KRAS G12D driver mutation is expressed in about 45% of pancreatic adenocarcinomas, 13% of colorectal cancers, and at lower frequencies in other cancers, and the HLA-C*08:02 allele is expressed by approximately 8% and 11% of white and black people, respectively, in the U.S. Thus, in the U.S. alone, thousands of patients per year with metastatic gastrointestinal cancers would potentially be eligible for immunotherapy with this KRASG12D-reactive T cell.

Although only Ms. Bachini (“patient number 3737”) was a long-term survivor, the researchers were able to treat three other patients with enriched populations of TILs targeting predominantly one mutated tumor antigen. Patient 4069 experienced a transient regression of multiple lung metastases of his pancreatic adenocarcinoma, but patients 4007 and 4032 had no objective response. Whereas 23% of circulating T cells at one month after treatment were adoptively transferred mutation-specific TILs in the case of Ms. Bachini, the other three patients treated with enriched populations of mutation-specific TILs showed no or minimal persistence. The researchers concluded that they will need to develop strategies designed to enhance the potency and persistence of adoptively transferred mutation-specific TILs. Nevertheless, the researchers concluded that nearly all patients with advanced gastrointestinal cancers harbor tumor mutation-specific TILs. This finding may serve as the basis for developing personalized adoptive cellular therapies and/or vaccines that can effectively target common epithelial cancers.

Conclusions

Dr. Rosenberg pioneered the study and development of adoptive cellular immunotherapy, beginning in the 1980s. Most studies with TIL-based adoptive immunotherapy have been in advanced melanoma. Adoptive cellular immunotherapy is the most effective approach to inducing complete durable regressions in patients with metastatic melanoma.

As we discussed in our cancer immunotherapy report, melanoma tumors have many more somatic mutations (about 200 nonsynonymous mutations per tumor) than most types of cancer. This appears to be due to the role of a potent immunogen—ultraviolet light—in the pathogenesis of melanoma. The large number of somatic mutations in melanomas results in the infiltration of these tumors by TILs that target the mutations. As discussed in our report, Dr. Rosenberg and his colleagues cultured TIL cell lines that addressed specific immunodominant mutations in patients’ melanomas. Treatment with these cell lines in several cases resulted in durable complete remissions of the patients’ cancers.

Dr. Rosenberg and his colleagues used the same strategy employed in identification of TIL cell lines that targeted specific mutations in melanomas to carry out the study in gastrointestinal cancers, as discussed in our report. However, the small number of somatic mutations and of endogenous TILs in gastrointestinal cancers and in most other epithelial cancers has made studies in these cancers more difficult than studies in melanoma.

in addition, the susceptibility of melanoma to treatment with checkpoint inhibitors such as the PD-1 blockers pembrolizumab (Merck’s Keytruda) and nivolumab (Bristol-Myers Squibb’s Opdivo) correlates with the large number of somatic mutations in this type of cancer. As we discussed in our December 15, 2014 article on this blog, immune checkpoint inhibitors work by reactivating endogenous tumor-infiltrating T cells (TILs). In the case of melanoma, these endogenous TILs target the numerous somatic mutations found in these cancers, and—as suggested by Dr. Rosenberg’s studies with cultured TIL cell lines—those endogenous TILs that target immunodominant mutations can induce durable compete remissions. As discussed in our December 15, 2014 blog article, the three major types of immuno-oncology treatments—immune checkpoint inhibitors, cancer vaccines, and adoptive T-cell therapies, work via related mechanisms.

In 2015, researchers showed that other types of cancers that have numerous somatic mutations are especially susceptible to checkpoint inhibitor treatment. These include, for example, non-small cell lung cancers (NSCLCs) that have mutational signatures that indicate that the cancers were caused by smoking, and cancers that have mutations in genes involved in DNA repair. (Mutations in genes involved in DNA repair pathways result in the generation of numerous additional mutations.)

Moreover, as discussed in our December 15, 2014 blog article, cancer immunotherapy researchers have been expanding the types of tumors that can be treated with checkpoint inhibitors. Genentech/Roche’s PD-L1 inhibitor that was discussed in that article, MPDL3280A, is now called atezolizumab. The clinical trials of atezolizumab discussed in that article and in our report have continued to progress. In a pivotal Phase 2 study in locally advanced or metastatic urothelial bladder cancer (UBC), atezolizumab shrank tumors in 27 percent of people whose disease had medium and high levels of PD-L1 expression and had worsened after initial treatment with platinum chemotherapy. These responses were found to be durable. According to Genentech, these results may represent the first major treatment advance in advanced UBC in nearly 30 years. Atezolizumab also gave positive results in Phase 2 clinical trials in patients with NSCLC that expresses medium to high levels of PD-L1.

Meanwhile, NewLink Genetics (Ames, IA) has entered Phase 3 clinical trials in pancreatic cancer with its HyperAcute cellular immunotherapy vaccine therapy. A Phase 2 trial of the company’s HyperAcute cellular immunotherapy algenpantucel-L in combination with chemotherapy and chemoradiotherapy in resected pancreatic cancer (clinical trial number NCT00569387) appears to be promising.

Dr. Rosenberg’s studies of TIL therapies of gastrointestinal cancers represent another approach to moving immuno-oncology treatments beyond melanoma, based on mutation-specific targeting. The types of cancers that form the focus of these studies—gastrointestinal epithelial cancers—have proven difficult to treat. Moreover, several of them are among the most common of cancers. The researchers and patients involved in these and other immuno-oncology studies are heroes, and oncologists appear to be making measured progress against cancers that have been until recently considered untreatable.

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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.

Wayland MA Source: http://bit.ly/1N1TyRk

Wayland MA Source: http://bit.ly/1N1TyRk

Russell’s Garden Center, on Route 20, a family-owned business established in 1876, is a unique Wayland MA institution. When you shop at Russell’s and approach the check-out counter with your plants, flowers, or other purchases, you will see a donation box for a rare-disease charity called “Our Promise to Nicholas Foundation”.

This charity is named for Nicholas R. Dainiak, a Bedford MA boy who died on his 11th birthday in 2014, after “a courageous six year battle with Batten’s disease”. The primary mission of the foundation is to raise funds and create partnerships aimed at promoting awareness, providing education, and developing translational research in Batten disease.

One of the events that the Foundation sponsors in order to raise funds and awareness is the John Tanner Memorial 5-K Run and Walk, which this year took place on October 4, 2015 in Wayland. This event memorializes both Nicholas and John Tanner. John Tanner was a competitive runner who devoted all of his races over 5 years to raising awareness about Nicholas and Batten disease. He was also a long-time employee of Russell’s Garden Center—hence the Russell’s and Wayland connection to the Foundation. John Tanner died unexpectedly while running the NYC half marathon in the spring of 2013.

Batten disease

Batten disease is a very rare, fatal, autosomal recessive neurodegenerative disorder that usually begins in childhood. Juvenile Batten disease is one of a group of disorders known as neuronal ceroid lipofuscinoses (NCLs). NCLs may be caused by one of over 400 different mutations. They affect the nervous system with vision loss, seizures, movement disorders, slow learning, altered thought processes, and cognitive decline.

Although Batten disease was originally used to describe only the juvenile form of NCL the term “Batten disease” is now widely used to refer to all forms of NCL, including adult-onset disease. Juvenile NCL, the most prevalent form of Batten disease, has been linked to mutations in the CLN3 gene. Late infantile NCL has been linked to mutations in NCL2.

Batten disease is a type of lysosomal storage disease. The CLN3 gene codes for a protein called battenin, which is found principally in lysosomes and in endosomes. The protein’s function is currently unknown. The CLN2 gene codes for a lysosomal enzyme called tripeptidyl peptidase 1 (TPP1), which is an acid protease.

Mutations in CLN2, CLN3, and other Batten disease genes result in the accumulation of lipofuscins in the tissues of the body. Lipofuscins are lipoproteins that form autofluorescent ceroid (i.e., waxy) deposits throughout the body of Batten disease patients.  Lipopfuscin deposits can sometimes be detected visually in the back of the eye. As the disease progresses, the deposits in the retina appear more pronounced, and ophthalmologists see circular bands of different shades of pink and orange in the patient’s optic nerve and retina. Ceroid lipofuscins are a hallmark of Batten disease, and appear to cause disease symptoms.

Juvenile Batten disease has an estimated incidence between 0.5 – 8 per 100,000 live births, with an average of 1.2. Despite its rarity, juvenile Batten disease appears to be the most common form of pediatric neurodegenerative disease. In addition to Batten disease patients, there are approximately 440,000 asymptomatic people in the United States who are carriers of juvenile Batten disease who have one copy of a mutated version of the CLN3 gene.

As with other rare diseases, a typical Batten disease patient may visit 8 physicians and receives 2 to 3 misdiagnoses before being correctly diagnosed. This may take many years. In the case of Nicholas, he had several misdiagnoses and mis-treatments over the early course of his disease, from age 4 to age 5. It was a ophthalmologist who finally correctly diagnosed Nicholas with Batten disease.

Relationship between Batten disease and more common neurodegenerative diseases

The written material next to the donation box for “Our Promise to Nicholas” in Russell’s Garden Center claims that study of Batten disease may lead to a greater understanding of such neurodegenerative diseases of aging as Alzheimer’s and Parkinson’s disease. Some of the symptoms and consequences of Batten disease resemble those of Alzheimer’s and Parkinson’s. Nevertheless, Batten disease is classified as a lysosomal storage disease, while Alzheimer’s and Parkinson’s are thought to be caused via other mechanisms.

However, some researchers see common mechanisms in the pathobiology of neurodegenerative lysosomal storage diseases such as Batten and of other neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Specifically, these include impairment of autophagy and increase in cytoplasmic protein aggregation. For example, some researchers have found relationships between mutations in the Alzheimer’s disease-related protein presenilin 1 and lysosomal dysfunction.

Since clinical trials of drugs for Alzheimer’s disease have so far been unsuccessful, study of alternative mechanisms for the pathogenesis of Alzheimer’s may be useful in developing new ways of addressing drug discovery for this devastating and all-too-common disease.

Discovery and development of gene therapies for Batten disease

The “Our Promise to Nicholas” website has a page entitled “Where your donations go”. According to that Web page, Nicholas’ disease was caused by a splice mutation in CLN2, which blocked production of TPP1. This is the most common mutation in children with the late infantile subtype of Batten Disease.

The same Web page discusses a gene therapy program led by Beverly Davidson, Ph.D. (then at the University of Iowa, Iowa City, IA), which had been supported by Our Promise To Nicholas Foundation. As of April 2014, Dr. Davidson joined the Children’s Hospital of Philadelphia (CHOP). At that time, Dr. Davidson became the director of CHOP’s Center for Cellular and Molecular Therapeutics. She has also continued her research on gene therapy for neurodegenerative diseases, including Batten disease, other neurologic lysosomal storage disorders, Huntington’s and Alzheimer’s diseases, and others.

While at Iowa, and continuing at CHOP, Dr. Davidson and her colleagues were investigating the use of adeno-associated virus (AAV) vectors carrying a functional TPP1 gene in treatment of late infantile Batten disease in animal models.

On November 11, 2015, Spark Therapeutics (Philadelphia, PA) announced that its first gene therapy program targeting a central nervous system (CNS) disease will target late infantile Batten disease. In that press release, it also announced that a report published in the 11 November issue of Science Translational Medicine provides preclinical proof of principle for Spark’s gene therapy, known as SPK-TPP1. The preclinical study, in a naturally occurring dog model, was led by Dr. Davidson at CHOP.

The study demonstrated the potential of a one-time administration of SPK-TPP1 to delay onset and progression of Batten disease in the dog model. SPK-TPP1 consists of Spark’s AAV2 vector carrying a functional TPP1 gene. The preclinical study showed that one-time administration of SPK-TPP1 to the ependymal cells of the brain ventricular system produced steady expression of the enzyme in the cerebrospinal fluid, and throughout the CNS. It also resulted in delayed onset of clinical symptoms and disease progression, protection from cognitive decline and extension of lifespan, as compared to untreated controls.

Based on these results, Spark plans to initiate Investigational New Drug Application (IND)-enabling studies in 2015.

Our November 2015 book-length report, Gene Therapy: Moving Toward Commercialization (published by Cambridge Healthtech Institute), contains a discussion of gene therapy vectors, including AAV. It also highlights Spark Therapeutics as a leader in AAV-based gene therapy and in gene-therapy treatments for retinal diseases. Spark’s technology platform had been developed over a 20-year period at CHOP.

As also discussed in our November 16, 2015 article on this blog, Spark has recently completed a Phase 3 pivotal trial of SPK-RPE65, a gene therapy for treatment of inherited retinal diseases (IRDs) caused by mutations in the gene for RPE65. SPK-TPP1 uses the same AAV2 vector as SPK-RPE65, and will utilize the same manufacturing processes. AAV2 has a neural tropism. Since the retina is an extension of the brain, researchers can utilize AAV2 vectors to target both tissues.

Conclusions

On the Web page “Where your donations go”, Dr. Davidson says that funding from “family foundations such as Our Promise to Nicholas Foundation” has provided much needed support. Their donations have allowed cutting-edge research to be conducted in a timely manner, rather than months or years after researchers develop the ideas for these studies. Moreover, interacting with Batten disease families is especially motivating, and the advisory role of scientists who review grant proposals for family foundations is valuable as well.

Our Promise to Nicholas is far from the only Batten disease “family foundation”. Other families of patients with juvenile and adult-onset Batten disease have formed foundations to fund research and awareness. For example, there are Nathan’s Battle Foundation and the Batten Disease Support and Research Association (BDSRA). Our Promise to Nicholas participated in the 2015 BDSRA Annual Conference, and worked together with other Batten disease family foundations to provide nursing care and childcare for the event. Thus when Dr. Davidson refers to “family foundations”, she is referring to several such organizations.

Dr. Davidson also pointed out that grant funding from the National Institutes of Health (NIH) has dramatically decreased in recent years due to Federal budget constraints. This has especially affected research on rare diseases such as Batten disease. Dr. Davidson believes that “family foundation support is being increasingly relied upon to fill a growing void in NIH funding”.

Funding of Dr. Davidson’s research by Our Promise to Nicholas Foundation and other family foundations has resulted in a gene therapy R&D program that has been adopted by one of the world’s leading gene therapy companies, Spark Therapeutics. Spark (in collaboration with Dr. Davidson’s group at CHOP) is taking its Batten disease program into the clinic, and intends to commercialize SPK-TPP1. Spark is also using its Batten disease program as the basis for its larger neurodegenerative disease program. Thus Our Promise to Nicholas Foundation has much to be proud of.

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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.

Baby_Face Source: http://bit.ly/1OjMOyo

Baby_Face Source: http://bit.ly/1OjMOyo

In November 2015, the use of gene editing technology to treat an 11-month-old child with leukemia was reported in news articles in Nature and in Science. Because of the human-interest value of this story, it was also reported in Time magazine and in the New York Times.

Data from this first-in-humans clinical use of the therapy will be presented at the 57th American Society of Hematology (ASH) Annual Meeting in Orlando, FL in early December 2015.

The young patient was treated with a complex cellular immunotherapy regimen developed by Cellectis (Paris, France and New York, NY). Cellectis’ platform involves production of allogeneic (rather than autologous) chimeric antigen receptor (CAR) T-cells to create an “off-the-shelf solution” to cellular immunotherapy for cancer, potentially simplifying manufacturing and standardization of therapies.

We have discussed CAR T-cell therapies on this blog, and—in more detail—in two book-length reports published by Cambridge Healthtech Institute (CHI). These are our 2014 Cancer Immunotherapy report, and our new November 2015 report, Gene Therapy: Moving Toward Commercialization.

CAR T-cell therapies directed against the B-cell antigen CD19, being developed by Novartis/University of Pennsylvania, Juno Therapeutics, and Kite Pharma, have demonstrated impressive clinical results against B-cell leukemias and lymphomas. However, in order to avoid immune incompatibility, CAR T-cell must be constructed and manufactured using autologous T-cells derived from the patient to be treated. This is an expensive and laborious process. Hence the rationale for allogeneic CAR T-cell therapy.

Cellectis uses gene editing in construction of its allogeneic CAR T-cells. Specifically, the company first modifies T-cells from healthy donors with an anti-CD19 CAR gene construct, similar to the methods used by other companies that are developing anti-CD19 CAR cellular immunotherapies. Cellectis then uses gene editing based on transcription activator-like effector nucleases (TALENS) to disrupt expression of the T-cells’ TCR (T-cell receptor) genes. It is the TCRs of the transplanted T cells that recognize the patient’s own cells as foreign, and thus attack them. Cellectis also uses TALENS gene editing to disrupt expression of a gene for another cell-surface protein, CD52. CD52 is present on mature lymphocytes, and is the target of the monoclonal antibody drug alemtuzumab (Genzyme’s Lemtrada). Researchers can then use alemtuzumab to prevent host-mediated rejection of the HLA mismatched CAR19 T cells. Cellectis’ “Talen engineered universal CAR19 T cells” can thus in principle be used to treat any patient with B-ALL (B-cell acute lymphoblastic leukemia), instead of autologous anti-CD19 CAR T-cells.

The treatment of the young patient, Layla Richards of London, was on a compassionate use basis. She had refractory relapsed B-ALL, and was expected to die shortly. Meanwhile, Cellectis had a universal CAR19 (UCART19) cell bank in the same hospital in which Layla was being treated. The cell bank had been characterized in detail, in preparation for submission for regulatory approval and Phase 1 testing.

Prior to administration of the UCART19 cells, the patient received lymphodepleting chemotherapy (including administration of alemtuzumab). After getting the UCART19 cells in June 2015 (near her first birthday), Layla went into remission, and has no trace of leukemia. After about three months she had a bone marrow transplant to help her immune system recover, and is now at home. However the follow-up period since her treatment has only been 5 months. Therefore, Layla’s doctors do not yet know how durable the remission will be. The key question is how long the UCART19 cells can survive in the body and prevent recurrence of leukemia.

Gene editing companies and their technologies discussed in our November 2015 report

Our November 2015 gene therapy report includes a chapter (Chapter 8) that focuses on gene-editing technologies and on companies that are developing therapies based on these technologies. The gene-editing technology that has been getting the most attention from the scientific and financial communities is known as CRISPR/Cas9. The other two technologies discussed in Chapter 8 are TALENS and zinc-finger nucleases (ZFN). The basic principle of these gene-editing technologies is that a “molecular scissors” makes a specific double-strand break in a deleterious DNA sequence. This break is either repaired in such a way as to disrupt the gene by forming deletions or mutations, or—if a suitable donor DNA is provided—the deleterious gene is replaced with a desired, functional gene sequence.

Gene-editing specialty companies discussed in our report based on CRISPR/Cas9 technology include Editas Medicine (Cambridge, MA) (which also utilizes TALENS), Intellia Therapeutics (Cambridge MA), CRISPR Therapeutics (Basel, Switzerland; Stevenage, U.K.; and Cambridge MA), and Caribou Biosciences (Berkeley, CA). Sangamo BioSciences (Richmond, CA), which is also discussed in our report, is a pioneer in ZFN technology.

Despite the predominant focus on CRISPR/Cas9 technology and companies in the biotechnology and venture capital communities, the first clinical studies involving gene editing have used Sangamo’s ZFN technology. These studies are in the field of HIV/AIDS. They involve ex vivo treatment of HIV-infected patients’ T-cells with a specific ZFN-based vector, in order to render the patients resistant to further manifestations of the disease.

Meanwhile, Editas has developed a vector designed to enable the company to move its CRISPR/Cas9 technology into the clinic. Editas’ first clinical program will be a potential treatment for a form of the genetically-driven retinal disease, Leber congenital amaurosis (LCA). (This is a different form of LCA than the one being targeted by Spark Therapeutics, which we discussed in our November 16, 2015 article on this blog).

bluebird bio (Cambridge, MA) is also pursuing a gene-editing technology program based on homing endonucleases and MegaTAL enzymes. This research and preclinical-stage program came to bluebird via its 2014 acquisition of Precision Genome Engineering Inc. (Seattle WA).

Cellectis is not the only company that is combining CAR T-cell therapies with gene-editing technology. In May 2015, Editas formed a collaboration with Juno Therapeutics to pursue research programs that combine Editas’ genome editing technologies with Juno’s CAR and TCR T-cell technologies.

Conclusions

Despite the great deal of excitement about gene-editing technologies and companies (especially CRISPR/Cas9) these are early days for development of therapies based on these technologies. Despite the almost miraculous results in the treatment of Layla Richards, it is only one case, and the follow-up period has been short. Nevertheless, this one case may open the way for this therapy to be used in other “desperate situations” where there is no time, or it is not possible, to use a patient’s own T cells. And researchers are already speculating that a similar technique may be used to treat people with other blood cancers, and eventually people with solid tumors.

For more information on our November 2105 gene therapy report, or to order it, see the CHI Insight Pharma Reports website.

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

Adeno-associated virus, a common gene therapy vector. Source: http://bit.ly/1NR7tf4

Adeno-associated virus, a common gene therapy vector. Source: http://bit.ly/1NR7tf4

On November 6, 2015, Cambridge Healthtech Institute (CHI) announced the publication of a new book-length report, Gene Therapy: Moving Toward Commercialization, by Allan B. Haberman, Ph.D.

As demonstrated by several late-breaking news items that appeared as our report was in the process of publication, gene therapy is a “hot”, fast-moving field. For example:

On October 5, 2015, Spark Therapeutics (Philadelphia, PA) announced positive top-line results from the Phase 3 pivotal trial of SPK-RPE65, a gene therapy for treatment of inherited retinal diseases (IRDs) caused by mutations in the gene for RPE65. This trial met its primary endpoint, and there were no serious adverse events related to treatment with the therapy. In results presented at a scientific meeting later in October, SPK-RPE65 was found to give durable improvements in vision over a three-year period.

SPK-RPE65 is not only Spark’s most advanced gene therapy in development, but is the most advanced gene therapy for retinal disease of any company. It is covered in our report.

bluebird’s LentiGlobin BB305—including the company’s strategy for commercializing this product—is also discussed in our report. In bluebird’s November 5, 2015 presentation at the American Society of Hematology (ASH) Annual Meeting, it was revealed that in Phase 1/2 clinical trials, LentiGlobin BB305 rendered the few sickle-cell disease patients in the trials transfusion-free and hospitalization-free for at least six months. Among patients with severe beta-thalassemia, all except for those with the β0/β0 genotype were rendered transfusion-free for at least 90 days, with a median of 287 days transfusion-free. Two of the β0/β0 patients (who made no hemoglobin at baseline) received a single transfusion post-discharge, and the third β0/β0 patient remains transfusion-dependent.

The stock market had focused on the negative results with the β0/β0 patients, and thus bluebird stock lost over 20% of its value after the ASH abstracts were released. However, the β0/β0 patients represent only one-third of the beta-thalassemia market, and sickle-cell disease is a larger market than beta-thalassemia. Thus, provided further clinical trials are positive, LentiGlobin BB305 can still be a successful product. bluebird is increasing the number of patients who will be enrolled in the trial from eight to 20, so more data should be forthcoming in 2016.

In corporate gene therapy news, Spark Therapeutics recently opened a new satellite office in the Boston area, joining Boston-area gene therapy companies bluebird bio, Dimension Therapeutics, and Voyager Therapeutics. All are discussed in our report. Spark and bluebird are public companies, and Dimension and Voyager recently went public. In addition, uniQure, the company that developed the first approved gene therapy product, opened a Lexington MA office and manufacturing facility in 2013. Boston has thus become Gene Therapy Central. As discussed in our report, Boston is also the most important center for companies that focus on gene editing, based on CRISPR/Cas9 technology.

These and other recent news articles and scientific publications attest to the progress of gene therapy, which only a few years ago was considered to be a “premature technology”.

Our gene therapy report looks at how researchers have been working to overcome critical barriers to development of safe and efficacious gene therapy, from 1990 to 2015. It then focuses on clinical-stage gene therapy programs that are aimed at commercialization, and the companies that are carrying out these programs. A major theme of the report is whether gene therapy can attain near-term commercial success, and what hurdles still need to be overcome.

Topics covered in the report:

  • Development of improved vectors (integrating and non-integrating vectors)
  • Gene therapy for ophthalmological diseases
  • Gene therapy for hemophilias and other rare diseases
  • Gene therapy for more common diseases (e.g., Parkinson’s disease, osteoarthritis, and heart failure)
  • Companies whose central technology platform involves ex vivo gene therapy
  • Gene editing technology
  • Outlook for gene therapy
  • Outlook for eight gene therapy products expected to reach the market before 2020

The report also includes:

  • An exclusive interview with Sam Wadsworth, Ph.D., the Chief Scientific Officer of Dimension Therapeutics and former Head of Gene Therapy R&D at Genzyme
  • The results and an analysis of a survey of individuals working in gene therapy, conducted by Insight Pharma Reports in conjunction with this report.
  • Companies profiled: uniQure, Spark Therapeutics, GenSight, Dimension Therapeutics, Voyager Therapeutics, Oxford BioMedica, bluebird, Juno Therapeutics, Kite Pharma, Editas, and others.

Our report is designed to enable you to understand current and future developments in gene therapy. It is also designed to inform the decisions of leaders in companies and in academic groups that are working in gene therapy R&D and in development of gene therapy enabling technologies.

For more information on the report, or to order it, see the CHI Insight Pharma Reports website.

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