FDA Revokes Approval of Avastin Use For Metastatic Breast Cancer; Major U.S. Ovarian Cancer Advocacy Organization Concerned

Today, the U.S. Food and Drug Administration (FDA) Commissioner Hamburg revoked approval of Avastin for treatment of metastatic breast cancer in the U.S. The decision does not impact Avastin’s availability for its approved uses for other cancer types in the U.S. A major U.S. ovarian cancer advocacy organization is concerned that the FDA decision will make it more difficult for ovarian cancer patients to gain access to Avastin.

FDA Revocation of Avastin Approval For Metastatic Breast Cancer

FDA Commissioner Margaret A. Hamburg, M.D., said today she is revoking the agency’s approval of the breast cancer indication for Avastin® (bevacizumab) after concluding that the drug has not been shown to be safe and effective for that use.

Avastin will still remain on the market as an approved treatment for certain types of colon, lung, kidney and brain cancer (glioblastoma multiforme).

“This was a difficult decision. FDA recognizes how hard it is for patients and their families to cope with metastatic breast cancer and how great a need there is for more effective treatments. But patients must have confidence that the drugs they take are both safe and effective for their intended use,” Dr. Hamburg said. “After reviewing the available studies it is clear that women who take Avastin for metastatic breast cancer risk potentially life-threatening side effects without proof that the use of Avastin will provide a benefit, in terms of delay in tumor growth, that would justify those risks. Nor is there evidence that use of Avastin will either help them live longer or improve their quality of life.”

Avastin’s risks include severe high blood pressure; bleeding and hemorrhaging; heart attack or heart failure; and the development of perforations in different parts of the body such as the nose, stomach, and intestines.

Today’s decision, outlined in Dr. Hamburg’s 69-page opinion, involves Avastin used in combination with the cancer drug paclitaxel (Taxol) for those patients who have not been treated with chemotherapy for their form of metastatic breast cancer known as “HER-2 negative.” This indication must now be removed from Avastin’s product labeling.

Dr. Hamburg’s decision is based on an extensive record, which includes thousands of pages submitted to a public docket, data from several clinical trials, and the record from a two-day hearing held in June, 2011.

Avastin was approved for metastatic breast cancer in February 2008 under the FDA’s accelerated approval program, which allows a drug to be approved based on data that are not sufficiently complete to permit full approval. The accelerated approval program provides earlier patient access to promising new drugs to treat serious or life-threatening conditions while confirmatory clinical trials are conducted. If the clinical trials do not justify the continued approval of the drug or a specific drug indication, the agency may revoke its approval. In this case, the accelerated approval was based on promising results from one study that suggested that the drug could provide a meaningful increase in the amount of time from when treatment is started until the tumor grows or the death of the patient.

After the accelerated approval of Avastin for breast cancer, the drug’s sponsor, Genentech (a member of the Roche Group) completed two additional clinical trials and submitted the data from those studies to the FDA. These data showed only a small effect on tumor growth without evidence that patients lived any longer or had a better quality of life compared to taking standard chemotherapy alone – not enough to outweigh the risk of taking the drug.

The FDA’s Center for Drug Evaluation and Research (CDER), which is responsible for the approval of this drug, ultimately concluded that the results of these additional studies did not justify continued approval and notified Genentech that it was proposing to withdraw approval of the indication.

Genentech did not agree with CDER’s evaluation of the data and, following the procedures set out in FDA regulations, requested a hearing on CDER’s withdrawal proposal, with a decision to be made by the FDA Commissioner. That two-day hearing, which took place June 28-29, 2011, included recommendations from the FDA’s Oncologic Drugs Advisory Committee (ODAC), voting 6-0 in favor of withdrawing approval of Avastin’s breast cancer indication. After the hearing, the public docket remained open until August 4, 2011. In an earlier meeting of the ODAC, that committee had voted 12-1 in favor of the removal of the breast cancer indication from the Avastin label.

“FDA is committed to working with sponsors to bring promising cancer drugs to market as quickly as possible using tools like accelerated approval,” Dr. Hamburg said. “I encourage Genentech to consider additional studies to identify if there are select subgroups of women suffering from breast cancer who might benefit from this drug.”

Genentech Response

In a press release issued earlier today, Genentech’s Hal Barron, M.D., chief medical officer and head, Global Product Development, stated:

“We are disappointed with the outcome. We remain committed to the many women with this incurable disease and will continue to provide help through our patient support programs to those who may be facing obstacles to receiving their treatment in the United States. Despite today’s action, we will start a new Phase III study of Avastin in combination with paclitaxel in previously untreated metastatic breast cancer and will evaluate a potential biomarker that may help identify which people might derive a more substantial benefit from Avastin.”

Genentech emphasizes the following points in its press release:

  • The FDA Commissioner revoked approval of Avastin for treatment of metastatic breast cancer in the U.S.
  • The FDA’s action concludes its review of Avastin’s use for metastatic breast cancer.
  • The FDA decision does not impact Avastin’s approved uses for other cancer types in the U.S. or other countries.
  • The FDA decision does not impact the approval of Avastin for metastatic breast cancer in more than 80 foreign countries.
  • Roche will initiate a new clinical trial of Avastin plus paclitaxel in metastatic breast cancer.
  • Genentech will issue a letter to healthcare providers and will also provide them with a letter to distribute to their patients. Both letters will be made available on Genentech’s website.
  • Patients with questions or concerns about insurance coverage, or doctors with questions about reimbursement, can call Genentech’s Access Solutions Group at (866)-4- ACCESS.
  • Doctors with questions about Avastin can call Genentech’s Medical Communications group at (800) 821-8590.
  • The FDA’s action does not impact ongoing clinical trials with Avastin in breast cancer. For more information, please call Genentech’s Trial Information Support Line at (888) 662-6728 or visit clinicaltrials.gov.

Major U.S. Ovarian Cancer Advocacy Organization Concerned About Future Impact of FDA Decision

Karen Orloff Kaplan, MSW, MPH, ScD, Chief Executive Officer, Ovarian Cancer National Alliance

Karen Orloff Kaplan, MSW, MPH, ScD, the Chief Executive Officer for the Ovarian Cancer National Alliance (OCNA), expressed concern that the removal of metastatic breast cancer from the Avastin label could negatively affect women with ovarian cancer, for whom the drug is used “off-label.”  OCNA is one of the most influential advocates for women with ovarian cancer in the United States.

Dr. Kaplan stated:

“Results from three Phase III clinical studies show that Avastin is beneficial for some women with ovarian cancer. We are deeply concerned that the Food and Drug Administration’s decision regarding metastatic breast cancer will make it difficult for women with ovarian cancer to access Avastin, and that patients could be denied insurance coverage for this treatment. The Ovarian Cancer National Alliance will continue our work to ensure that drugs that are useful and medically appropriate are available to women with this disease.”

In the FDA report accompanying her decision, Commissioner Hamburg cited a lack of evidence that Avastin improved overall survival for women with metastatic breast cancer in its decision. “Given how difficult it is to measure overall survival in ovarian cancer clinical trials, we are concerned that today’s ruling may set an unfortunate precedent,” said Dr. Kaplan.

Currently, various national cancer treatment guidelines, such as the National Comprehensive Cancer Network (NCCN) Compendium™, include Avastin as a treatment for ovarian cancer. Despite that fact, the FDA’s decision could prompt a reexamination of industry treatment guidelines by various groups, including the NCCN. The NCCN  is a nonprofit alliance which consists of 21 leading U.S. cancer centers.

Specifically, OCNA is concerned that the FDA Avastin label change, mandated by today’s FDA decision, will lead to restrictions by third party payers, including the U.S. Medicare federal insurance program, who generally reimburse for Avastin when a woman’s cancer has returned. OCNA’s concern may be warranted because Reuters reported earlier today that some healthcare insurers have already started pulling back on Avastin reimbursement coverage for breast cancer.

As of now, according to Reuters, Medicare will continue to pay for Avastin used in the treatment of breast cancer, despite  the FDA’s revocation decision. “Medicare will continue to cover Avastin,” said Don McLeod, a spokesman for the Centers for Medicare and Medicaid Services (CMS). “CMS will monitor the issue and evaluate coverage options as a result of action by the FDA but has no immediate plans to change coverage policies.” The CMS statement may mitigate concerns that patients using the drug would lose critical drug reimbursement insurance coverage in the future.

Sources:

Addtional Information:

ASCO 2011: Genetic Biomarker Predicts Taxane Drug-Induced Neuropathy

A new study has identified the first genetic biomarkers for taxane-induced peripheral neuropathy, a potentially severe complication of taxane chemotherapy that affects nerves in about one-third of patients with cancer receiving such treatment.

ASCO Releases Studies From Upcoming Annual Meeting – Important Advances in Targeted Therapies, Screening, and Personalized Medicine

The American Society of Clinical Oncology (ASCO) today highlighted several studies in a press briefing from among more than 4,000 abstracts publicly posted online at http://www.asco.org in advance of ASCO’s 47th Annual Meeting. An additional 17 plenary, late-breaking and other major studies will be released in on-site press conferences at the Annual Meeting.

The meeting, which is expected to draw approximately 30,000 cancer specialists, will be held June 3-7, 2011, at McCormick Place in Chicago, Illinois. The theme of this year’s meeting is “Patients. Pathways. Progress.”

“This year marks the 40th anniversary of the signing of the National Cancer Act, a law that led to major new investments in cancer research. Every day in our offices, and every year at the ASCO meeting, we see the results of those investments. People with cancer are living longer, with a better quality of life, than ever before,” said George W. Sledge Jr., M.D., President of ASCO, Ballve-Lantero Professor of Oncology and professor of pathology and laboratory medicine at the Indiana University School of Medicine.

“With our growing understanding of the nature of cancer development and behavior, cancer is becoming a chronic disease that a growing number of patients can live with for many years,” said Dr. Sledge. “The studies released today are the latest examples of progress against the disease, from new personalized treatments, to new approaches to screening and prevention.”

New study results involving a genetic marker which can predict taxane drug-induced neuropathy were highlighted today in the ASCO press briefing, as summarized below.

Genetic Biomarker Predicts Taxane-Induced Neuropathy

A new study has identified the first genetic biomarkers for taxane drug-induced peripheral neuropathy, a potentially severe complication of taxane chemotherapy that affects nerves in about one-third of patients with cancer receiving such treatment. The finding may eventually lead to a simple blood test to determine whether a patient is at high risk for neuropathy.

Bryan P. Schneider, M.D., Physician & Researcher, Indiana University Melvin & Bren Simon Cancer Center; Associate Director, Indiana Institute for Personalized Medicine

“If these findings can be replicated, this may allow physicians to know prior to recommending therapy whether the patient is at an inordinate risk for developing taxane-induced neuropathy,” said Bryan P. Schneider, M.D., lead author and a physician/researcher at the Indiana University Melvin and Bren Simon Cancer Center and Associate Director for the Indiana Institute for Personalized Medicine. “This may allow for better counseling, use of alternative drugs or schedules, or omission of taxanes in the appropriate settings. These genetic findings might also provide insight into the mechanism of this side effect and help develop drugs to prevent this toxicity altogether.”

Such damage to the nerves can cause pain and numbness and limit the dose of chemotherapy a patient can receive. While only a few factors seem to predict which patients are likely to get peripheral neuropathy, including a history of diabetes and advanced age, genetic variations may explain why some patients are more sensitive to taxane drugs.

The authors conducted a genome wide association study on 2,204 patients enrolled in an Eastern Cooperative Oncology Group breast cancer clinical trial (E5103) in which all patients received taxane-based chemotherapy, namely paclitaxel (Taxol). The study looked for variations in DNA (deoxyribonucleic acid) called single nucleotide polymorphisms, or SNPs (pronounced “snips”), by evaluating more than 1.2 million SNPs in each patient.  A SNP is a DNA sequence variation which occurs when a single nucleotide — A (adenine), T (thymine), C (cytosine), or G (guanine) — in the genome (or other shared sequence) differs between two individuals, or between paired chromosomes located within the nucleus of an individual’s cells.

With a median follow-up of 15 months, the study identified genetic subgroups that were markedly more likely to develop peripheral neuropathy.

Those who carried two normal nucleotides in the RWDD3 gene had a 27 percent chance of experiencing neuropathy; those who carried one normal nucleotide and one SNP had a 40 percent risk; and those who carried two SNPs had a 60 percent risk.

In contrast, those who carried two normal nucleotides in the TECTA gene had a 29 percent chance of experiencing neuropathy; those who carried one normal nucleotide and one SNP had a 32 percent risk; and those who carried two SNPs had a 57 percent risk.

The study also found that older patients and African Americans were much more likely to have peripheral neuropathy, and further analysis of SNPs in these groups is underway.

The authors plan to continue their work in additional trials to validate these findings and to determine whether a different type or schedule of taxane therapy would result in less neuropathy in the more susceptible genetic groups. The authors also are collaborating with neurobiologists to understand why these genetic variations might make the nerves more sensitive to these drugs.

____________________

Sources:

Resources:

Blunting the Activity of Protein Abcc10 May Help Counter Taxane Drug Resistance In Ovarian Cancer

New findings by Fox Chase Cancer Center researchers identify one protein, Abcc10, as being intimately involved in resistance to certain drugs used to treat breast, ovarian, lung, and other cancers. The results suggest that blunting the activity of Abcc10 might help counter resistance and extend the effectiveness of these anticancer drugs.

Today’s anticancer drugs often work wonders against malignancies, but sometimes tumors become resistant to the effects of such drugs, and treatment fails. Medical researchers would like to find ways of counteracting such resistance, but first they must understand why and how it happens. New findings by Fox Chase Cancer Center researchers identify one protein, Abcc10 (ATP-binding cassette transporter 10) (also known as multidrug resistance protein 7 (Mrp7)), as being intimately involved in resistance to certain drugs used to treat breast, ovarian, lung, and other cancers. The results suggest that blunting the activity of Abcc10 might help counter resistance and extend the effectiveness of these anticancer drugs.

The findings appear in the May 15, 2011 issue of the journal Cancer Research.

Elizabeth A. Hopper-Borge, Ph.D., Assistant Professor, Fox Chase Cancer Center, Philadelphia, Pennsylvania

In earlier work, Elizabeth A. Hopper-Borge, Ph.D., an assistant professor at Fox Chase, showed that Abcc10 confers resistance to a number of anticancer agents, particularly taxanes, which include paclitaxel (Taxol) and docetaxel (Taxotere). These drugs––originally derived from the Pacific yew tree––work by disrupting cell division, thus arresting the growth and spread of tumors. The initial finding that Abcc10, a member of a ubiquitous family of proteins called ATP-binding cassette transporters, thwarts taxanes’ anti-tumor activity was something of a surprise, says Hopper-Borge, because none of the other family members seem to have that ability.

In the new research, Hopper-Borge and colleagues wanted to further explore, in both cultured cells and mice, the role of Abcc10. They developed a “knockout” mouse, in which the gene that codes for Abcc10 was missing, or knocked out. These mice appeared normal and healthy in every other respect, suggesting that Abcc10 is not essential for overall health and survival.

The researchers isolated cells from the knockout mice and tested the cells’ reactions to taxanes and two other anticancer drugs, vincristine and Ara-C. Compared to cells from normal mice that still possessed the gene for Abcc10, the knockout mouse cells were much more sensitive to the drugs.

Abcc10 and its ilk work by pumping drugs out of cells, so one might expect to see the drugs accumulating in cells that lack Abcc10, and that’s exactly what Hopper-Borge’s group saw. It had been suggested that other proteins might take over for Abcc10 if that protein were knocked out, but the researchers found no evidence suggesting that had happened.

Next, the research team studied the effects of one particular taxane, paclitaxel, on mice and found that the knockout mice were more sensitive to the drug, as reflected in body weight, white blood cell count, and ability to survive escalating doses of the drug.

“After seeing the effects on white blood cells, we decided to look at the tissue types that produce white blood cells to see if we could actually see differences there,” says Hopper-Borge. As expected, knockout mice treated with paclitaxel had smaller spleens and thymus glands and underdeveloped bone marrow, compared to normal mice treated with the same drug.

The results provide the first evidence from living organisms that Abcc10 is a cell’s built-in protection against the effects of powerful drugs, and raises the possibility of using Abcc10 inhibitors to break down that resistance and sensitize tumor cells to anticancer agents. The fact that mice lacking the protein have no obvious health problems is encouraging, suggesting that Abcc10 inhibitors could be used in human patients without causing side effects that might be expected to result from interfering with the pump’s normal functions.

Several Abcc10 inhibitors already have been identified, but they also inhibit other cellular transporters, which could have deleterious effects. For that reason, Hopper-Borge thinks the best approach may be developing inhibitors that work only in tumor cells or coming up with compounds that modulate, rather than completely inhibit the protein’s activity.

But using such treatments in patients is still far in the future, she emphasizes.

“I’d like to stress that we did this work in a mouse model,” Hopper-Borge says. “Our results so far suggest that this protein may be a clinically relevant target, but we need to do more studies to find out for sure.”

Co-authors on the study include Timothy Churchill, Chelsy Paulose, Emmanuelle Nicolas, Joely D. Jacobs, Olivia Ngo, Andres J. Klein-Szanto and Martin G. Belinsky of Fox Chase; Yehong Kuang of Central South University, Changsha, China; Alex Grinberg and Heiner Westphal of the National Institute of Child Health and Human Development; and Gary D. Kruh of the University of Illinois at Chicago.

The research was supported by the National Institutes of Health.

Sources:

Genentech Announces Positive Results of Avastin Phase III Study in Women with Advanced Ovarian Cancer

Genentech announces positive results of Avastin Phase III study (GOG 218) in women with advanced ovarian cancer. The study showed that women who continued maintenance use of Avastin alone, after receiving Avastin in combination with chemotherapy, lived longer without the disease worsening compared to those who received chemotherapy alone. This is the first Phase III study of an anti-angiogenic therapy in advanced ovarian cancer to meet its primary endpoint.

Tumor angiogenesis is the proliferation of a network of blood vessels that penetrates into cancerous growths, supplying nutrients and oxygen and removing waste products. Tumor angiogenesis actually starts with cancerous tumor cells releasing molecules that send signals to surrounding normal host tissue. This signaling activates certain genes in the host tissue that, in turn, make proteins to encourage growth of new blood vessels. Photo credit: NCI

Genentech, Inc., a wholly owned member of the Roche Group , today announced that a Phase III study showed the combination of Avastin® (bevacizumab) and chemotherapy followed by maintenance use of Avastin alone increased the time women with previously untreated advanced ovarian cancer lived without the disease worsening (progression-free survival or PFS), compared to chemotherapy alone. A preliminary assessment of safety noted adverse events previously observed in pivotal trials of Avastin. Data from the study will be submitted for presentation at the American Society of Clinical Oncology (ASCO) annual meeting, June 4 – 8, 2010.

In the three-arm study, known as Gynecologic Oncology Group (GOG) 0218, women with newly diagnosed advanced ovarian cancer who already had surgery to remove as much of the tumor as possible were randomized to receive one of the following:

  • Arm 1: Placebo in combination with carboplatin and paclitaxel chemotherapy followed by placebo alone, for a total of up to 15 months of therapy
  • Arm 2: Avastin in combination with carboplatin and paclitaxel chemotherapy followed by placebo alone, for a total of up to 15 months of therapy
  • Arm 3: Avastin in combination with carboplatin and paclitaxel chemotherapy followed by the maintenance use of Avastin alone, for a total of up to 15 months of therapy.

The study showed that women who continued maintenance use of Avastin alone, after receiving Avastin in combination with chemotherapy (Arm 3), lived longer without the disease worsening compared to those who received chemotherapy alone. Women who received Avastin in combination with chemotherapy, but did not continue maintenance use of Avastin alone (Arm 2), did not live longer without the disease worsening compared to chemotherapy alone.

“Additional medicines are urgently needed for women with newly diagnosed advanced ovarian cancer, as most women’s cancer will worsen after their initial treatment,” said Hal Barron, M.D., F.A.C.C., Executive Vice President, Global Development and Chief Medical Officer. “We are encouraged by the positive findings of this study, which highlight the importance of continuing maintenance Avastin after combining Avastin with chemotherapy in this setting. We will discuss these results with the U.S. Food and Drug Administration.”

Robert Allen Burger, MD, FACOG, FACS, Fox Chase Cancer Center, Philadelphia, Pennsylvania

“This is good news for women with ovarian, primary peritoneal or fallopian tube cancers,” said GOG 0218 study chair Robert Burger, M.D., Fox-Chase Cancer Center in Philadelphia. “This study showed that after initial surgery, the combination of Avastin and chemotherapy followed by extended treatment with Avastin improves progression-free survival in women with newly diagnosed advanced tumors.”

The trial is sponsored by the National Cancer Institute (NCI) under a Cooperative Research and Development Agreement between the NCI and Genentech, and is being conducted by a network of researchers led by the GOG.

Avastin is being studied worldwide in more than 450 clinical trials for multiple types of cancer, including approximately 25 ongoing clinical trials in the United States for women with various stages of ovarian cancer.

About Ovarian Cancer

According to the American Cancer Society, ovarian cancer is the fifth leading cause of cancer death among American women. In 2009 an estimated 21,500 women were diagnosed with ovarian cancer and approximately 14,500 died from the disease in the U.S. The disease causes more deaths than any other gynecologic cancer, and the American Cancer Society estimates that nearly 70 percent of women with advanced disease will die from it within five years.

Ovarian cancer is associated with high levels of vascular endothelial growth factor (VEGF), a protein associated with tumor growth and spread. Studies have shown a correlation between a high level of VEGF and a poorer prognosis in women with ovarian cancer. Currently, treatment options for women with this disease are limited to surgery and chemotherapy.

About the GOG 0218 Study

GOG 0218 is an international, multicenter, randomized, double-blind, placebo-controlled Phase III study in 1,873 women with previously untreated advanced epithelial ovarian, primary peritoneal or fallopian tube carcinoma. The study evaluates Avastin (5 cycles) in combination with carboplatin and paclitaxel chemotherapy (6 cycles) compared to carboplatin and paclitaxel chemotherapy alone (6 cycles). The trial is also designed to assess the maintenance use of Avastin alone following the initial combined regimen of Avastin and chemotherapy (for a total of up to 15 months of therapy), compared to carboplatin and paclitaxel chemotherapy alone (6 cycles).

The primary endpoint of the study is PFS as assessed by trial investigators. Secondary and exploratory endpoints of the study include overall survival, PFS by independent review, objective response rate, safety, quality of life measures and analysis of patient tumor and blood samples.

Detailed safety assessments are ongoing. A preliminary assessment of safety performed by the GOG identified Avastin-related serious adverse events noted in previous pivotal studies, including fatal neutropenic infection and gastrointestinal perforation. The full study results, including safety information, will be presented at a future medical meeting.

About Avastin

Avastin is a solution for intravenous infusion and is a biologic antibody designed to specifically bind to a protein called VEGF. VEGF plays an important role throughout the lifecycle of the tumor to develop and maintain blood vessels, a process known as angiogenesis. Avastin interferes with the tumor blood supply by directly binding to the VEGF protein to prevent interactions with receptors on blood vessel cells. Avastin does not bind to receptors on normal or cancer cells. The tumor blood supply is thought to be critical to a tumor’s ability to grow and spread in the body (metastasize). For more information about angiogenesis, visit http://www.gene.com.

Boxed WARNINGS and Additional Important Safety Information

People treated with Avastin may experience side effects. In clinical trials, some people treated with Avastin experienced serious and sometimes fatal side effects, including:

Gastrointestinal (GI) perforation: Treatment with Avastin can result in the development of a potentially serious side effect called GI perforation, which is the development of a hole in the stomach, small intestine or large intestine. In clinical trials, this side effect occurred in more people who received Avastin than in the comparison group (0.3 percent to 2.4 percent). In some cases, GI perforation resulted in fatality.

Surgery and wound healing problems: Treatment with Avastin can lead to slow or incomplete wound healing (for example, when a surgical incision has trouble healing or staying closed). In some cases, this event resulted in fatality. Surgery and wound healing problems occurred more often in people who received Avastin than in the comparison group. Avastin therapy should not be started for at least 28 days after surgery and until the surgical wound is fully healed. The length of time between stopping Avastin and having voluntary surgery without the risk of having surgery and wound healing problems following surgery has not been determined.

Severe bleeding: Treatment with Avastin can result in serious bleeding, including coughing up blood, bleeding in the stomach, vomiting of blood, bleeding in the brain, nosebleeds and vaginal bleeding. These events occurred up to five times more often in people who received Avastin. Across cancer types, 1.2 percent to 4.6 percent of people who received Avastin experienced severe to fatal bleeding. People who have recently coughed up blood (greater than or equal to a half teaspoon of red blood) or have serious bleeding should not receive Avastin.

In clinical trials for different cancer types, there were additional serious and sometimes fatal side effects that occurred in more people who received Avastin than in those in the comparison group. The formation of an abnormal passage from parts of the body to another part (non-GI fistula formation) was seen in 0.3 percent or less of people. Severe to life-threatening stroke or heart problems were seen in 2.4 percent of people. Too much protein in the urine, which led to kidney problems, was seen in less than 1 percent of people. Additional serious side effects that occurred in more people who received Avastin than those in the comparison group included severe to life-threatening high blood pressure, which was seen in 5 percent to 18 percent of people, and nervous system and vision disturbances (reversible posterior leukoencephalopathy syndrome), which was seen in less than 0.1 percent of people. Infusion reactions with the first dose of Avastin were uncommon and occurred in less than 3 percent of people and severe reactions occurred in 0.2 percent of people.

Common side effects that occurred in more than 10 percent of people who received Avastin for different cancer types, and at least twice the rate of the comparison group, were nosebleeds, headache, high blood pressure, inflammation of the nose, too much protein in the urine, taste change, dry skin, rectal bleeding, tear production disorder, back pain and inflammation of the skin (exfoliative dermatitis). Across all trials, treatment with Avastin was permanently stopped in 8.4 percent to 21 percent of people because of side effects.

Avastin may impair fertility. Patients who are pregnant or thinking of becoming pregnant should talk with their doctor about the potential risk of loss of the pregnancy or the potential risk of Avastin to the fetus during and following Avastin therapy, and the need to continue an effective birth control method for at least six months following the last dose of Avastin.

For full Prescribing Information and Boxed WARNINGS on Avastin please visit http://www.avastin.com.

About Genentech

Founded more than 30 years ago, Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes medicines to treat patients with serious or life-threatening medical conditions. The company, a wholly owned member of the Roche Group, has headquarters in South San Francisco, California. For additional information about the company, please visit http://www.gene.com.

About The Gynecologic Oncology Group (GOG)

The Gynecologic Oncology Group is a non-profit organization of more than 300 member institutions with the purpose of promoting excellence in the quality and integrity of clinical and basic scientific research in the field of Gynecologic malignancies. The Group is committed to maintaining the highest standards in the clinical trial development, execution, analysis and distribution of results. Continuous evaluation of our processes is utilized in order to constantly improve the quality of patient care.

GOG receives support from the National Cancer Institute (NCI) of the National Institutes for Health (NIH).

Sources:

Identifying & Overcoming Taxane Drug Resistance

Proteomics study reveals a protein that, when suppressed, makes cancers more susceptible to chemotherapy involving taxane drugs.

Taxanes, a group of cancer drugs that includes paclitaxel (Taxol®) and docetaxel (Taxotere®), have become front-line therapy for a variety of metastatic cancers. But as with many chemotherapy agents, resistance can develop, a frequent problem in breast, ovarian, prostate and other cancers. Now, cancer researchers at Children’s Hospital Boston report a protein previously unknown to be involved in taxane resistance and could potentially be targeted with drugs, making a cancer more susceptible to chemotherapy.

The researchers believe that this protein, prohibitin1, could also serve as a biomarker, allowing doctors to predict a patient’s response to chemotherapy with a simple blood test. The study was published online by the Proceedings of the National Academy of Sciences in its online early edition during the week of January 25.

Bruce Zetter, Ph.D., Charles Nowiszewski Professor of Cancer Biology, Vascular Biology Program, Department of General Surgery, Children's Hospital Boston

The study, led by Bruce Zetter, PhD, of Children’s Vascular Biology Program, used proteomics techniques to compare the proteins present in Taxol-susceptible versus Taxol-resistant human tumor cell lines. The researchers found that the resistant cell lines, but not the susceptible cell lines, had prohibitin1 on their surface. When they suppressed prohibitin1 with RNA interference techniques, the tumor cells became more susceptible to Taxol, both in cell culture and in live mice with implanted Taxol-resistant tumors.

Zetter’s lab is still investigating why having prohibitin1 on the cell surface makes a tumor cell resistant to taxanes. But in the meantime, he believes that not only could prohibitin1 be suppressed to overcome taxane resistance, but that it could also be exploited as a means of targeting chemotherapy selectively to resistant cancer cells.

“We are working to target various cancer drugs to taxane-resistant cells by attaching them to compounds that bind to prohibitin,” Zetter explains. One such compound is already known, and works well in animals to target other prohibitin-rich cells, but has yet to be tested in humans.

Suppressing prohibitin1 alone probably isn’t enough to make a cancer fully Taxol-susceptible, but could be combined with other strategies aimed at increasing taxane susceptibility, such as targeting another protein called GST Pi, the researchers say. Other mechanisms of resistance are known, but they so far haven’t been shown to present effective targets for therapy.

Zetter’s lab is also trying to develop prohibitin1 as a biomarker for taxane resistance that physicians could use in the clinic. Since it’s on the surface of the cell, Zetter believes prohibitin1 may circulate in the blood where it could easily be detected. His lab is in talks with several cancer centers to obtain serum samples from patients who did and didn’t respond to Taxol, so that prohibitin1 levels could be measured and compared.

Zetter notes that prohibitin1 could easily have been overlooked, and was found only because the team happened to look specifically at proteins in the cell membrane, rather than simply doing a whole-cell proteomic analysis.

“The interesting finding was that prohibitin was not just another over-expressed protein,” Zetter says. “It was up-regulated primarily on the cell surface. When we looked at the whole cell, the absolute amount of prohibitin wasn’t changed. Instead, prohibitin was moving from the inside of the cell to the cell surface. It had shifted from one location to another, and when it did, the tumor cells became resistant to taxanes. The fact that it moves to the cell surface also makes it easier to direct drugs to it.”

Children’s Hospital Boston has pending and issued international patents on this technology.  Nish Patel, PhD, was the study’s first author. The study was funded by a grant from the National Institutes of Health.

About Children’s Hospital Boston

Founded in 1869 as a 20-bed hospital for children, Children’s Hospital Boston today is one of the nation’s leading pediatric medical centers, the primary pediatric teaching hospital of Harvard Medical School, and the largest provider of health care to Massachusetts children. In addition to 396 pediatric and adolescent inpatient beds and more than 100 outpatient programs, Children’s houses the world’s largest research enterprise based at a pediatric medical center, where its discoveries benefit both children and adults. More than 500 scientists, including eight members of the National Academy of Sciences, 11 members of the Institute of Medicine and 13 members of the Howard Hughes Medical Institute comprise Children’s research community. For more information about the hospital visit: www.childrenshospital.org/newsroom.

Sources:

UCLA Researchers Significantly Inhibit Growth of Ovarian Cancer Cell Lines With FDA-Approved Leukemia Drug Dasatinib (Sprycel®)

The drug dasatinib (Sprycel®), approved for use by the U.S. Food and Drug Administration in patients with specific types of leukemia, significantly inhibited the growth and invasiveness of ovarian cancer cells and also promoted their death, say UCLA researchers in the November 10th issue of the British Journal of Cancer. The drug, when paired with a chemotherapy regimen, was even more effective in fighting ovarian cancer cell lines in which signaling of the Src family kinases — associated with approximately one-third of ovarian cancers– is activated. Clinical trials that involve the testing of dasatinib against ovarian cancer and solid tumors are currently ongoing.

Researchers affiliated with the University of California, Los Angeles (UCLA), Mayo Clinic and Harvard Medical School announced that they have established a biological rationale to support the clinical study of the U.S. Food & Drug Administration (FDA)-approved leukemia drug dasatinib (U.S. brand name: Sprycel®), either alone or in combination with chemotherapy, in patients with ovarian cancer. The study appears in the November 10th edition of the British Journal of Cancer.

Background

Dasatinib is an FDA-approved drug for the treatment of chronic myeloid leukemia (CML) and Philadelphia chromosome positive acute lymphoblastic leukemia (ALL). Dasatinib is a small-molecule inhibitor that targets several tyrosine kinases, including the Src kinase family, Ephrin type-A receptor 2 ( EphA2) , and the focal adhesion kinase (FAK).

Src is the prototypic member of a family of nine non-receptor tyrosine kinases (Src, Lyn, Fyn, Lck, Hck, Fgr, Blk, Yrk, and Yes). The Src family kinase (SFK) proteins regulate four main cellular fuctions that ultimately control the behavior of transformed cancer cells:  cell proliferation, adhesion, invasion, and motility.

Eph receptors and ephrins are integral players in cancer formation and progression, and are associated with advanced ovarian cancer and poor clinical outcome.

FAK is a non-receptor tyrosine kinase involved in the regulation of cell adhesion, survival, and migration.  Preclinical studies indicate that FAK plays a signficant role in ovarian cancer cell migration and invasion.

Dasatinib Study Methodology & Findings

slamon1

One of the dasatinib study authors is Dennis J. Slamon, M.D. Ph.D. Dr. Slamon is the Director of Clinical/Translational Research & Director of the Revlon/UCLA Women's Cancer Research Program, at the UCLA Jonsson Comprehensive Cancer Center. He is also the co-discoverer of Herceptin®, a targeted therapy that revolutionized the treatment of HER-2 positive breast cancer.

The researchers carried out the study by testing the effects of dasatinib on human ovarian cancer cells in vitro, using a panel of 34 established human ovarian cancer cell lines.  The 34 cell lines selected were representative of the major epithelial ovarian cancer subtypes:

On this basis, the researchers examined the effects of dasatinib on ovarian tumor cell proliferation, invasion, apoptosis, and cell-cycle arrest.  To more fully understand the activity of dasatinib, the researchers also studied the efficacy of chemotherapeutic drugs (i.e., carboplatin and paclitaxel) in combination with dasatinib against ovarian cancer cells that were previously determined to be dasatinib-sensitive.

The overarching goals of the study were (i) to provide a rationale to test dasatinib as a single agent or in combination with chemotherapy in patients with ovarian cancer, and (ii) to identify molecular markers that may help define subsets of ovarian cancer patients most likely to benefit from treatment with dasatinib.

Significant findings reported in the dasatinib study are summarized below.

  • Concentration-dependent, anti-proliferative effects of dasatinib were seen in all ovarian cancer cell lines tested.
  • Dasatinib significantly inhibited tumor cell invasion, and induced tumor cell death, but was less effective in causing tumor cell-cycle arrest.
  • At a wide range of clinically achievable drug concentrations, additive and synergistic interactions were observed for dasatinib plus carboplatin or paclitaxel.
  • 24 out of 34 (71%) representative ovarian cancer cell lines were highly sensitive (i.e.,  ≥ 60% growth inhibition) to dasatinib.
  • 6 cells lines were moderately sensitive (i.e., 40% – 59% growth inhibition) to dasatinib.
  • 4 cell lines were resistant (i.e., < 40% growth inhibition) to dasatinib.
  • When comparing dasatinib sensitivity between cell lines based solely upon histological subtype (i.e., serous papillary, clear cell, endometrioid, mucinous, and undifferentiated ovarian cancer cell lines), no single histological subtype was more sensitive than another.
  • Ovarian cancer cell lines with high expression of Yes, Lyn, Eph2A, caveolin-1 and 2, moesin, annexin-1 and 2 and uPA (urokinase-type Plasminogen Activator), as well as those with low expression of IGFBP2 (insulin-like growth factor binding protein 2), were particularly sensitive to dasatinib.
  • Ovarian cancer cell lines with high expression of HER-2 (Human Epidermal growth factor Receptor 2), VEGF (Vascular endothelial growth factor) and STAT3 (Signal Transducer and Activator of Transcription 3) were correlated with in vitro resistance to dasatinib.

Based upon the findings above, the researchers concluded that there is a clear biological rationale to support the clinical study of dasatinib, as a single agent or in combination with chemotherapy, in patients with ovarian cancer.

Konecny

Gottfried E. Konecny, M.D., UCLA Assistant Professor of Hematology/Oncology, UCLA Jonsson Comprehensive Cancer Center Researcher & First Author of the Dasatinib Study

Ovarian cancer, which will strike 21,600 women this year and kill 15,500, causes more deaths than any other cancer of the female reproductive system. Few effective therapies for ovarian cancer exist, so it would be advantageous for patients if a new drug could be found that fights the cancer, said Gottfried E. Konecny, M.D., a UCLA assistant professor of hematology/oncology, a Jonsson Comprehensive Cancer Center researcher, and first author of the study.

“I think Sprycel® could be a potential additional drug for treating patients with Src dependent ovarian cancer,” Konecny said. “It is important to remember that this work is only on cancer cell lines, but it is significant enough that it should be used to justify clinical trials to confirm that women with this type of ovarian cancer could benefit.”

Recent gene expression studies have shown that approximately one-third of women have ovarian cancers with activated Src pathways, so the drug could potentially help 7,000 ovarian cancer patients every year. Notably, a gene expression study published in 2007 reported Src activation in approximately 50% of the ovarian cancer tumors examined.

In the dasatinib study, the UCLA team tested the drug against 34 ovarian cancer cell lines and conducted genetic analysis of those lines. Through these actions, the researchers were able to identify genes that predict response to dasatinib. If the work is confirmed in human studies, it may be possible to test patients for Src activation and select those who would respond prior to treatment, thereby personalizing their care.

“We were able to identify markers in the pre-clinical setting that would allow us to predict response to Sprycel®,” Konecny said. “These may help us in future clinical trials in selecting patients for studies of the drug.”

Dasatinib is referred to as a “dirty” kinase inhibitor, meaning it inhibits more than one cellular pathway. Konecny said it also inhibits the focal adhesion kinase (FAK) and ephrin receptor, also associated with ovarian cancer, in addition to the Src cellular pathway.

The next step, Konecny said, would be to test the drug on women with ovarian cancer in a clinical trial. The tissue of responders would then be analyzed to determine if the Src and other pathways were activated. If that is confirmed, it would further prove that dasatinib could be used to fight ovarian cancer. In studies, women would be screened before entering a trial and only those with Src dependent cancers could be enrolled to provide further evidence, Konecny said, much like the studies of the molecularly targeted breast cancer drug Herceptin® enrolled only women who had HER-2 positive disease.

“Herceptin® is different because we knew in advance that it only worked in women with HER-2 [gene] amplification,” he said. “In this case, we don’t clearly know that yet. The data reassures us that the drug works where the targets are over-expressed but we need more testing to confirm this.”

The tests combining the drug with chemotherapy are significant because chemotherapy, namely carboplatin and paclitaxel, is considered the standard first line treatment for ovarian cancer patients following surgery. Because dasatinib proved to have a synergistic effect when combined with chemotherapy, it may be possible to add this targeted therapy as a first line treatment if its efficacy is confirmed in future studies.

Dasatinib Study Significance

The dasatinib study is potentially significant to the area of ovarian cancer treatment for several reasons.

First, although this study only tested dasatinib in vitro against ovarian cancer cell lines, the drug is already FDA-approved.  Accordingly, the general safety of the drug has already been established by the FDA.

Second, 71% of the ovarian cancer lines were highly sensitive to dasatinib.

Third, dasatinib was additive to, or synergistic with, the standard of care chemotherapy drugs used in first line ovarian cancer treatment, i.e., carboplatin and paclitaxel.

Fourth, the study established molecular markers that may be predictive of dasatinib effectiveness in particular patients.  In theory, a patient’s tumor biopsy could be tested for the presence of those molecular markers to determine whether a patient will benefit from dasatinib.

Fifth, one of the dasatinib study authors is Dennis J. Slamon, M.D. Ph.D. Dr. Slamon is the director of Clinical/Translational Research, and director of the Revlon/UCLA Women’s Cancer Research Program, at the UCLA Jonsson Comprehensive Cancer Center. Dr. Slamon is also the co-discoverer of Herceptin®, a targeted therapy that revolutionized the treatment of HER-2 positive breast cancer.  Herceptin® is a targeted therapy that kills HER-2 positive breast cancer cells while leaving normal cells unaffected.  The potential use of dasatinib to treat select ovarian cancer patients who test “positive” for specific molecular markers (e.g., Src cellular pathway activation) is similar to the extremely successful drug development approach used for Herceptin®.

Open Clinical Trials Testing Dasatinib (Sprycel®) Against Ovarian Cancer & Solid Tumors

As of this writing, there are several open (i.e., recruiting) clinical trials that involve testing dasatinib against ovarian cancer and solid tumors.

For a list of open clinical trials that involve testing dasatinib against ovarian cancer, CLICK HERE.

For a list of open clinical trials that involve testing dasatinib against solid tumors, CLICK HERE.

All potential volunteers must satisfy the clinical trial entrance criteria prior to enrollment.  Depending on the drug combination being tested, one or more of the solid tumor clinical trials may not be appropriate for an ovarian cancer patient.

About the UCLA Jonsson Comprehensive Cancer Center

UCLA’s Jonsson Comprehensive Cancer Center (JCCC) has more than 240 researchers and clinicians engaged in disease research, prevention, detection, control, treatment and education. One of the nation’s largest comprehensive cancer centers, JCCC is dedicated to promoting research and translating basic science into leading-edge clinical studies. In July 2009, JCCC was named among the top 12 cancer centers nationwide by U.S. News & World Report, a ranking it has held for 10 consecutive years. For more information on JCCC, visit the website at http://www.cancer.ucla.edu.

Sources:

Modified Chemo Regime Increases Survival In Advanced Ovarian Cancer Patients But Adds Toxicity

Women with advanced ovarian cancer lived longer and without their tumors growing after receiving a modified regimen of a standard chemotherapy drug combination, Japanese researchers reported last week. In a large phase III clinical trial, women who received carboplatin every 3 weeks and a reduced dose of paclitaxel (Taxol®) once a week for 3 weeks instead of carboplatin and a higher single dose of paclitaxel every 3 weeks had a 29 percent improvement in progression-free survival and a 25 percent improvement in overall survival after 3 years of follow-up.

Women with advanced ovarian cancer lived longer and without their tumors growing after receiving a modified regimen of a standard chemotherapy drug combination, Japanese researchers reported last week. In a large phase III clinical trial, women who received carboplatin every 3 weeks and a reduced dose of paclitaxel (Taxol®) once a week for 3 weeks instead of carboplatin and a higher single dose of paclitaxel every 3 weeks had a 29 percent improvement in progression-free survival and a 25 percent improvement in overall survival after 3 years of follow-up. The results were published online September 18 in The Lancet.

Although the toxicities of this dose-dense regimen were greater than they were in women who received the standard combination, survival benefits of this magnitude “have been rare in women with advanced ovarian cancer,” wrote Dr. Noriyuki Katsumata and colleagues from the Japanese Gynecologic Oncology Group (JGOG).

trimble

Edward L. Trimble, MD, MPH; Head - Gynecologic Cancer Therapeutics and Quality of Cancer Care Therapeutics, Clinical Investigation Branch, Cancer Therapy Evaluation Program, Division of Cancer Treatment and Diagnosis.

The results, explained Dr. Ted Trimble, from NCI’s Division of Cancer Treatment and Diagnosis, are consistent with what has been seen in breast cancer using a dose-dense chemotherapy regimen. The idea, he continued, is “to balance efficacy and toxicity by using a weekly schedule rather than every 3 weeks.”

Although the findings are important, “they won’t change practice overnight,” Dr. Trimble said. There are still several significant unknowns, including whether a lower dose of paclitaxel might be as effective but less toxic; the optimal timing of surgery; and where intraperitoneal chemotherapy fits into the treatment mix. The JGOG trial results, however, will influence the design of a number of phase III clinical trials, all of which include dose-dense chemotherapy, he added.

More than 630 women at 85 hospitals across Japan enrolled in the trial. Patients were randomly assigned to either of the two treatment groups. After 3 years of follow-up, women who received the dose-dense treatment had a median progression-free survival of 28 months, compared with 17 months for those who received the standard treatment.

bookman

Michael A. Bookman, M.D., Chief, Hematology/Oncology Section, Arizona Cancer Center

Not enough time has passed to determine with statistical confidence whether the overall survival advantage will be maintained. However, in ovarian cancer, improvements in progression-free survival tend to predict overall survival, said Dr. Michael A. Bookman, chief of the Hematology/Oncology Section at the Arizona Cancer Center, in an accompanying editorial in The Lancet.

The dose-dense chemotherapy regimen used in the trial was also dose-intense, meaning the total dose of paclitaxel patients received was actually higher than in those who received standard treatment. This was associated with some toxic side effects that caused treatment delays and modifications and also led to patients receiving less caboplatin than intended. In fact, more than half of the women in the dose-dense group discontinued treatment early, and most of them did so because of the toxicity.

Although it’s possible that the dose intensity was responsible for the survival improvements, Dr. Bookman wrote, the more frequent, lower-dose treatment schedule is the most “plausible explanation.” As a result, “similar results might be achieved” with a lower dose, he concluded, “with improved tolerability.”

As for why the dose-dense approach is more effective than the standard approach, the Japanese researchers suggested that it hampers the formation of blood vessels that feed tumors. In animal model studies, dose-dense chemotherapy, like a similar treatment also under active investigation called metronomic chemotherapy, has been shown to have such an antiangiogenic effect. And in the JGOG trial, the researchers noted, tumor shrinkage following treatment did not differ between those receiving dose-dense chemotherapy and standard chemotherapy. This suggests that the dose-dense treatment “might promote tumor dormancy by maintaining tumor size and preventing outgrowth,” they wrote.

alvarez

Ronald Alvarez, M.D., Director, Division of Gynecologic Oncology, University of Alabama at Birmingham

The U.S.-based Gynecologic Oncology Group is planning to launch a phase III clinical trial in advanced ovarian cancer combining the dose-dense approach with the targeted antiangiogenic drug bevacizumab (Avastin), said Dr. Ronald Alvarez, director of the Division of Gynecologic Oncology at the University of Alabama at Birmingham. This should help to confirm the Japanese trial’s results.

In the meantime, “Given the potential toxicity, clinicians should discuss with their patients the risks versus the benefits of this approach in comparison with other treatment strategies,” Dr. Alvarez said, particularly with those patients who have advanced disease and whose tumors could not be mostly eradicated by surgery.

Source: Modified Chemo Regimen Effective in Advanced Ovarian Cancer, by Carmen Phillips, NCI Cancer Bulletin Volume 6 / Number 18, National Cancer Institute, September 22, 2009.

References: