Eating a low-carbohydrate, high-protein diet may reduce the risk of cancer and slow the growth of tumors already present, according to a study published in Cancer Research, a journal of the American Association for Cancer Research.
Gerald Krystal, Ph.D., Professor, Pathology & Laboratory Medicine, University of British Columbia; Distinguished Scientist, Terry Fox Laboratory, British Columbia Cancer Agency
Eating a low-carbohydrate, high-protein diet may reduce the risk of cancer and slow the growth of tumors already present, according to a study published in Cancer Research, a journal of the American Association for Cancer Research.
The study was conducted in mice, but the scientists involved agree that the strong biological findings are definitive enough that an effect in humans can be considered.
Cancer Research editor-in-chief George Prendergast, Ph.D., CEO of the Lankenau Institute for Medical Research, agreed. “Many cancer patients are interested in making changes in areas that they can control, and this study definitely lends credence to the idea that a change in diet can be beneficial,” said Prendergast, who was not involved with the study.
Krystal and his colleagues implanted various strains of mice with human tumor cells or with mouse tumor cells and assigned them to one of two diets. The first diet, a typical Western diet, contained about 55 percent carbohydrate, 23 percent protein and 22 percent fat. The second, which is somewhat like a South Beach diet but higher in protein, contained 15 percent carbohydrate, 58 percent protein and 26 percent fat. They found that the tumor cells grew consistently slower on the second diet.
As well, mice genetically predisposed to breast cancer were put on these two diets and almost half of them on the Western diet developed breast cancer within their first year of life while none on the low-carbohydrate, high-protein diet did. Interestingly, only one on the Western diet reached a normal life span (approximately 2 years), with 70 percent of them dying from cancer while only 30 percent of those on the low-carbohydrate diet developed cancer and more than half these mice reached or exceeded their normal life span.
Krystal and colleagues also tested the effect of mTOR inhibitor CCI-779 (temsirolimus/Torisel®), which inhibits cell growth, and COX-2 inhibitor celecoxib (Celebrex®), which reduces inflammation, on tumor development, and found these agents had an additive effect in the mice fed the low-carbohydrate, high-protein diet.
When asked to speculate on the biological mechanism, Krystal said that tumor cells, unlike normal cells, need significantly more glucose to grow and thrive. Restricting carbohydrate intake can significantly limit blood glucose and insulin, a hormone that has been shown in many independent studies to promote tumor growth in both humans and mice.
Furthermore, a low-carbohydrate, high-protein diet has the potential to both boost the ability of the immune system to kill cancer cells and prevent obesity, which leads to chronic inflammation and cancer.
About the American Association For Cancer Research (AACR)
The mission of the AACR is to prevent and cure cancer. Founded in 1907, the AACR is the world’s oldest and largest professional organization dedicated to advancing cancer research. The membership includes 33,000 basic, translational and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and more than 90 other countries. The AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants, research fellowships and career development awards. The AACR Annual Meeting attracts more than 18,000 participants who share the latest discoveries and developments in the field. Special conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment and patient care. Including Cancer Discovery, the AACR publishes seven major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; Cancer Epidemiology, Biomarkers & Prevention; and Cancer Prevention Research. AACR journals represented 20 percent of the market share of total citations in 2009. The AACR also publishes CR, a magazine for cancer survivors and their families, patient advocates, physicians and scientists.
Hemispherx Biopharma’s Ampligen® is being tested in combination with an experimental ovarian cancer vaccine developed by the Penn Ovarian Cancer Research Center.
Hemispherx Biopharma, Inc. (“Hemispherx”) announced yesterday that it entered into a Material Transfer and Research Agreement with the University of Pennsylvania School of Medicine to provide Ampligen® [rintatolimod; poly(I)•poly(C12,U)], an experimental therapeutic, for testing as a vaccine adjuvant in a human ovarian cancer clinical study.
George Coukos, M.D., Ph.D., Celso Ramon Garcia Associate Professor of Reproductive Biology; Associate Chief, Division of Gynecologic Oncology & Director, Ovarian Cancer Research Center; Abramson Cancer Center, University of Pennsylvania
The principal investigator is Dr. George Coukos, who is the Celso Ramon Garcia Associate Professor of Reproductive Biology, Associate Chief of the Division of Gynecologic Oncology, and Director, Ovarian Cancer Research Center, at the University of Pennsylvania School of Medicine Abramson Cancer Center. He is a recognized global leader in ovarian cancer treatment and research. His research focus over the last several years has been on understanding the immune system’s response to ovarian cancer, and on developing therapies which enhance that response.
This study is a Phase 1/2randomized clinical trial for subjects with recurring ovarian, fallopian tube or primary peritoneal cancer to determine the feasibility, safety, and immunogenicity of a vaccine comprised of autologous oxidized tumor cell lysate (OC-L) administered by intradermal /subcutaneous injection in combination with intravenous Ampligen®. The OC-L vaccine is an experimental cancer immunotherapy under development by the University of Pennsylvania. This study represents the first use of Ampligen® as a cancer vaccine adjuvant in a well-controlled clinical study.
Dr. William A. Carter, CEO and Chief Scientific Officer at Hemispherx stated “…we are excited to have the opportunity to work with Dr. Coukos and his colleagues to combine Ampligen®, our selective Toll-like receptor 3agonist which has potent immune modulating activity, with their creative OC-L autologous cancer vaccine. We are particularly pleased that the first patient has already been enrolled in the study and has received their initial dose of study drug.”
Hemispherx views the potential use of Ampligen® as a component of cancer immunotherapy as an important development opportunity. The company’s near term focus in cancer is to initiate a series of collaborations with renowned cancer research experts at premier institutions to help define the best mode of integrating Ampligen® into immunotherapy strategies to potentially advance the treatment of cancer.
Nucleic acid compounds represent a potential new class of pharmaceutical products that are designed to act at the molecular level for treatment of human diseases. The Hemispherx Biopharma drug technology utilizes specifically-configured RNA (Ribonucleic acid). The Hemispherx double-stranded RNA drug product, trademarked Ampligen®, an experimental, unapproved drug, which is administered intravenously, is in human clinical development for various therapeutically oriented studies, including treatment for chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME), HIV, renal cell carcinoma and malignant melanoma.
Based on the results of pre-clinical studies and clinical trials, Hemispherx believes that Ampligen®, an experimental agent, may have broad-spectrum anti-viral and anti-cancer properties. Approximately 500 patients have received Ampligen® in clinical trials authorized by the Food and Drug Administration (“FDA”) at over twenty clinical trial sites across the U.S., representing the administration of more than 40,000 doses of this drug, and Ampligen® is available only through clinical trials for limited indications.
Clinical trials already conducted by Hemispherx U.S. include treatments of CFS/ME, other infectious diseases such as Hepatitis B, HIV, and clinical trials for cancer including patients with renal cell carcinoma and malignant melanoma. Certain of these studies to date have not been well-controlled and accordingly additional tests will be necessary for support of regulatory approvals.
Hemispherx believes that Ampligen® has been generally well tolerated with a low incidence of clinical toxicity, particularly given the severely debilitating or life threatening diseases that have been treated. A mild flushing reaction has been observed in approximately 15% of patients treated in our various studies. This reaction is occasionally accompanied by erythema, a tightness of the chest, tachycardia, anxiety, shortness of breath, subjective reports of “feeling hot,” sweating and nausea. The reaction is usually infusion-rate related and can generally be controlled by slowing the infusion rate. Other adverse side effects include liver enzyme level elevations, diarrhea, itching, urticaria (swelling of the skin), bronchospasm, hypotension, photophobia, rash, bradycardia, transient visual disturbances, arrhythmias, decreased platelets and white blood cell counts, anemia, dizziness, confusion, elevation of kidney function tests, occasional temporary hair loss and various flu-like symptoms, including fever, chills fatigue, muscular aches, joint pains, headaches, nausea and vomiting. These flu-like side effects typically subside within several months.
About Hemispherx Biopharma
Hemispherx Biopharma, Inc. is an advanced specialty pharmaceutical company engaged in the manufacture and clinical development of new drug entities for treatment of seriously debilitating disorders. Hemispherx’s flagship products include Alferon N Injection® (FDA approved for a category of sexually transmitted diseases) and the experimental therapeutics Ampligen® and Alferon® LDO. Ampligen® is an experimental RNA nucleic acid being developed for globally important debilitating diseases and disorders of the immune system. Hemispherx’s platform technology includes components for potential treatment of various severely debilitating and life threatening diseases. Hemispherx has patents comprising its core intellectual property estate and a fully commercialized product (Alferon N Injection®). Hemispherx wholly owns and exclusively operates a GMP-certified manufacturing facility in the United States for commercial products. For more information please visit www.hemispherx.net.
According to a study reported in the Cancer Discovery journal, scientists at Harvard University imaged the beginning stages of ovarian cancer metastasis, and identified a mechanism used by cancer cells to bully their way through normal tissue.
Scientists at Harvard University have created a laboratory model using time-lapse video microscopic technology that allows observation of early stages of ovarian cancer metastasis.
Joan Brugge, Ph.D., Professor & Chair, Cell Biology Department, Harvard University.
“We were able to observe key molecular mechanisms that are necessary for the force-dependent processes associated with metastasis,” said Joan Brugge, Ph.D., professor and chair of the Cell Biology department at Harvard University.
These findings are published in Cancer Discovery, the newest journal of the American Association for Cancer Research (AACR). According to Brugge, who served as program chairperson for the AACR 102nd Annual Meeting 2011, ovarian cancer cells spread throughout the peritoneum by attaching to the outer cell layer of organs in this area and then clearing away this layer of cells and embedding themselves on the organ, where they then proliferate and expand.
“The reason these tumors are so morbid is that the metastatic tumors grow large enough to interfere with the function of the organs in the peritoneum,” she said.
By using the time-lapse video microscopic technique, Brugge and colleagues were able to visualize the detailed sequence of events associated with insertion of tumor cells into peritoneal monolayers in cell culture, and then determine that the mechanism involves tumor cells’ use of force via αlpha-5 beta-1 integrin, talin I and muscle myosin II. These results suggest that ovarian tumor cell clusters gain access to the submesothelial environment by exerting force on the mesothelial cells lining target organs, driving migration and clearance of the mesothelial cells.
Researchers also determined that blockade of force-conducting molecules, including alpha-5 beta-1 integrin, talin I, and nonmuscle myosin II, in the ovarian cancer cells abrogated mesothelial displacement from underneath attached cancer cells.
“Theoretically, by targeting these molecules, it may be possible to prevent the formation of new metastatic tumors,” said Brugge.
About the American Association for Cancer Research (AACR)
The mission of the AACR is to prevent and cure cancer. Founded in 1907, the AACR is the world’s oldest and largest professional organization dedicated to advancing cancer research. The membership includes 33,000 basic, translational and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and more than 90 other countries. The AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants, research fellowships and career development awards. The AACR Annual Meeting attracts more than 18,000 participants who share the latest discoveries and developments in the field. Special conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment and patient care. Including Cancer Discovery, the AACR publishes seven major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; Cancer Epidemiology, Biomarkers & Prevention; and Cancer Prevention Research. AACR journals represented 20 percent of the market share of total citations in 2009. The AACR also publishes CR, a magazine for cancer survivors and their families, patient advocates, physicians and scientists.
Exelixis, Inc. reported expanded Phase 2 study data with respect to cabozantinib (XL184) use in advanced ovarian cancer patients at the recent 2011 American Society of Clinical Oncology Annual Meeting. The overall solid tumor Phase 2 safety and tolerability data reference six deaths, including two ovarian cancer patients.
Ronald J. Buckanovich, M.D., Ph.D., Assistant Professor, Departments of Internal Medicine & Obstetrics and Gynecology, University of Michigan
On May 19, 2011, we reported promising cabozantinib phase 2 solid tumor (including ovarian) data, which was presented at an ASCO press briefing held in advance of the 2011 ASCO Annual Meeting. As noted in our May 19 article, cabozantinib demonstrated excellent activity against several solid tumors, including ovarian cancer. In addition, we reported that cabozantinib showed promising activity in ovarian cancer patients independent of prior response to platinum drug-based therapies.
Ronald J. Buckanovich, M.D., Ph.D., Assistant Professor, Departments of Internal Medicine & Obstetrics and Gynecology, University of Michigan, presented the expanded cabozantinib Phase 2 data relating to use of the drug in advanced ovarian cancer patients, on June 4 at the 2011 ASCO Annual Meeting.
Ovarian Cancer Patient Population & Overall Response Rate
(Image Source: Exelixis, Inc.)
The cabozantinib trial is an ongoing phase 2 adaptive randomized discontinuation trial. As of the February 11, 2011 cut-off date, accrual in the cabozantinib study cohort was complete at 70 patients.
The 70 patients enrolled in the ovarian cancer cohort received oral cabozantinib (100 mg) daily over a 12 week “Lead-in Stage.” These patients had a minimum follow-up of at least 12 weeks and were thus evaluable for safety and the primary efficacyendpoint of response per RECIST (Response Evaluation Criteria in Solid Tumors).
Patient tumor response was assessed every 6 weeks. Receipt of cabozantinib treatment beyond the 12 week open label Lead-in Stage was based upon patient response: (1) patients with a partial response (PR) or complete response (CR) continued taking cabozantinib, (2) patients with stable disease (SD) were randomized to the cabozantinib treatment arm or the placebo treatment arm (collectively referred to as the “Blinded Randomized Stage”), and (iii) patients with progressive disease (PD) discontinued study treatment. The study primary endpoint was overall response rate (ORR) per RECIST in the Lead-in Stage, and progression free survival (PFS) in the Blinded Randomized Stage. Accrual in any cohort could be halted for high ORR or PD.
Approximately half of the 70 patients enrolled in the cohort were considered platinum drug-refractory/-resistant (49%), defined as a platinum drug-free interval of 6 months or less, and the remainder of patients (51%) had platinum-sensitive disease based on a platinum-free interval greater than 6 months.
The baseline patient tumor histologiccharacteristics are as follows: serous ovarian cancer (79%), clear cell ovarian cancer (4%), endometrioid ovarian cancer (6%), and other forms of ovarian cancer (11%)
More than half the patients (57%) received 2 or more prior lines of platinum therapy prior to trial enrollment. Some patients also had additional prior lines of therapy with agents such as pegylated liposomal doxorubicin (brand name: Doxil®) or topotecan (brand name: Hycamtin®) (32%), gemcitabine (brand name: Gemzar®) (29%), and VEGF (vascular endothelial growth factor) pathway inhibitors (10%).
Evidence of objective tumor regression was observed in 73% of patients with at least 1 post-baseline medical imaging scan. The best overall response rate per RECIST criteria was 24% (16 PRs and 1 CR). The overall Week-12 disease control rate (DRC = CR + PR + SD) was 53%. The Week-12 DCRs in the platinum drug-refractory, -resistant, and -sensitive groups were 36%, 39%, and 67%, respectively.
Based on an observed high rate of clinical activity, randomization was halted, and randomized patients were unblinded. At this point, the unblinded randomized patients that were treated with placebo were allowed to “cross-over” to treatment with cabozantinib. Disease stabilization was experienced by some ovarian cancer patients who had progressive disease prior to treatment cross-over.
“These latest results in metastatic ovarian cancer demonstrate the potential broad utility of cabozantinib beyond bone-predominant types of cancers such as castration-resistant prostate cancer. The high rates of durable response with our dual inhibitor of MET and VEGFR2 compare favorably to those of other single-agent targeted therapies and cytotoxic agents in development,” said Michael M. Morrissey, Ph.D., president and chief executive officer of Exelixis. “These results underscore the potential of cabozantinib in metastatic ovarian cancer, and we are in discussions with leading cooperative groups to plan further evaluation of cabozantinib in randomized trials for this indication.”
Activity in Platinum Drug-Sensitive, -Refractory, and -Resistant Disease
Ignace Vergote, M.D., Ph.D., senior author of the cabozantinib (XL184) ASCO presentation & Chairman, Leuven Cancer Institute, University of Leuven, European Union
(Image Source: Exelixis, Inc.)
Two of 11 patients (18%) with platinum refractory disease, defined as a platinum-free interval of <1 month, achieved a confirmed response (1 CR and 1 PR).
In the subset of patients with platinum-resistant disease, defined as a platinum-free interval of 1-6 months, 5 of 23 (22%) achieved a PR.
Ten of 36 patients (28%) with platinum sensitive disease achieved a PR.
A total of 37 patients experienced reductions in the ovarian cancer tumor marker CA-125 (cancer antigen-125), including 8 with decreases greater than 50%. There is no consistent concordance between CA-125 changes and tumor regression. The median duration of response has not yet been reached with 36 weeks of median follow-up.
“The continued activity of cabozantinib in a larger population of ovarian cancer patients is very encouraging, especially with respect to the clinical benefit observed in both platinum-sensitive and platinum-resistant/refractory disease. This activity profile has not been observed with other single-agent TKIs [tyrosine kinase inhibitors], and cabozantinib has the potential to be an important new treatment for ovarian cancer,” said Ignace Vergote, M.D., Ph.D., senior author of the presentation and Chairman of the Leuven Cancer Institute at the University of Leuven, European Union. “The high rate of disease control in platinum-resistant and platinum-refractory disease suggests that cabozantinib may help to address the substantial unmet medical need faced by patients who have sub-optimal responses to platinum-based therapies. I believe that further evaluation will help to define the potential role of cabozantinib in the treatment of ovarian cancer.”
General Safety & Tolerability Data
Safety data are available for the 70 patients in the Lead-In phase of the cabozantinib study. The most common CTCAE (Common Terminology Criteria for Adverse Events) grade 3 or 4adverse events (AEs), regardless of causality, were diarrhea (10%), fatigue (9%), palmar-plantar erythrodysesthesia syndrome (also referred as “hand-foot syndrome”)(7%), vomiting (4%), abdominal pain (3%), hypomagnesemia (3%), and nausea, constipation, rash, increased transaminase, and hypertension (each 1%). At least one dose reduction was reported in 37% of patients. Less frequent important medical events, regardless of causality, were hemorrhage (11% all CTCAE grades, 0% CTCAE grade 3 or 4), venous thrombosis (6% all CTCAE grades, 4% CTCAE grade 3 or 4), and gastrointestinal perforation (6% all CTCAE grades, 0% CTCAE grade 3 or 4).
Six Deaths Reported (Including Two Ovarian Cancer Patients)
If you examine the Exelixis press release dated June 4 (entitled, Exelixis’ Cabozantinib Demonstrates Encouraging Clinical Activity in Patients with Metastatic Ovarian Cancer — Disease control rate of 53% at week 12, response rate of 24%), which addresses data for cabozantinib use in advanced ovarian cancer patients, pay particular attention to the wording under the heading entitled, “Safety and Tolerability.” Within the wording set forth under that heading, you will find the following statement: “Two cabozantinib-related grade 5 AEs [adverse events], one enterocutaneous fistula and one intestinal perforation, were reported after the Lead-In phase.” Pursuant to the CTCAE guidelines, a “grade 5 adverse event” is defined as “death related to AE [adverse event].”
We should also note that the two ovarian cancer deaths were summarized briefly in the ASCO presentation regarding cabozantinib use in advanced ovarian cancer.
The reporting of all six deaths is set forth in the Exelixis press release, dated June 5, 2011 (entitled, Exelixis’ Cabozantinib Demonstrates Broad Clinical Activity in Multiple Tumor Types), in similar fashion. Within this release, the sentence provided under the heading “Safety and Tolerability” states: “There were 6 (1%) cabozantinib-related grade 5 [adverse] events, all of which were reported after the Lead-In phase of the trial: respiratory compromise (breast cancer), hemorrhage (NSCLC [non-small cell lung cancer]), enterocutaneous perforation (ovarian cancer), intestinal perforation (ovarian cancer), gastrointestinal hemorrhage (pancreatic cancer), and death (CRPC [castrate resistant prostate cancer]).”
Exelixis Chief Executive Michael Morrissey said the safety statistics are consistent with targeted cancer therapies like cabozantinib that block a pathway used by tumor cells to secure blood vessels.
Cowen & Co analyst Eric Schmidt said the rate of cabozantinib treatment-related deaths — 1 percent — was “no different from what we have seen for every other Phase 1 and 2 trials here at ASCO.”
“While drug safety is of less concern in cancer indications than in others, the apparent morbidities associated with cabo[zantinib] use will confound interpretation of clinical benefit in a trial designed to show anything less than overall survival,” Canaccord analyst George Farmer said in a research note.
In a note to investors, Piper Jaffray analyst Edward Tenthoff said: “The company is exploring lower doses, but the concern is that cabo[zantinib] will not retain the impressive efficacy seen to date.”
Mr. Morrissey said Exelixis plans to move forward with the current daily 100 mg dose of the drug.
Dr. Nicholas J. Vogelzang (Director, Comprehensive Cancer Centers of Nevada) Discusses Mortalities in the Cabozantinib (XL184) Trial
Take Away Message
Cabozantinib demonstrates promising activity in both platinum drug-sensitive and platinum drug-resistant/-refractory ovarian cancer.
Week 12 overall disease control rate of 53%.
Response rates of 18% in platinum-refractory, 22% in platinum-resistant and 28% in platinum-sensitive patients.
Cabozantinib shows encouraging duration of response.
After 36 weeks of follow-up, median duration of response not reached.
Tolerability profile is consistent with that of other tyrosine kinase inhibitors (6 solid tumor patient deaths (1% of all solid tumor pts), including 2 ovarian cancer patients (3% of ovarian cancer pts)).
Discordant effects observed between CA-125 changes and clinical activity.
Simultaneous targeting of MET and VEGFR2 with cabozantinib results in robust effects in patients with advanced ovarian cancer.
Non-randomized expansion cohort is currently accruing in platinum-resistant/-refractory ovarian cancer.
About the MET & VEGFR2 Pathways
To learn more about (i) the role of MET in cancer, (ii) the relationship between the MET and VEGFR pathways, and (iii) the dual inhibition of MET and VEGFR2, visit http://www.metinhibition.com/.
About Cabozantinib (XL184)
Cabozantinib (XL184) is a potent, dual inhibitor of MET and VEGFR2. Cabozantinib is an investigational agent that provides coordinated inhibition of metastasis and angiogenesis to kill tumor cells while blocking their escape pathways. The therapeutic role of cabozantinib is currently being investigated across several tumor types. MET is upregulated in many tumor types, thus facilitating tumor cell escape by promoting the formation of more aggressive phenotypes, resulting in metastasis. MET-driven metastasis may be further stimulated by hypoxic conditions (i.e., deprivation of adequate oxygen supply) in the tumor environment, which are often exacerbated by selective VEGF-pathway inhibitors. In preclinical studies, cabozantinib has shown powerful tumoricidal, anti-metastatic and anti-angiogenic effects, including: (i) extensive apoptosis of malignant cells; (ii) decreased tumor invasiveness and metastasis; (iii) decreased tumor and endothelial cell proliferation; (iv) blockade of metastatic bone lesion progression; and (v) disruption of tumor vasculature.
About Exelixis
Exelixis, Inc. is a biotechnology company committed to developing small molecule therapeutics for the treatment of cancer. Exelixis is focusing its resources and development efforts exclusively on cabozantinib, its most advanced solely-owned product candidate, in order to maximize the therapeutic and commercial potential of this compound. Exelixis believes cabozantinib has the potential to be a high-quality, differentiated pharmaceutical product that can make a meaningful difference in the lives of patients. Exelixis has also established a portfolio of other novel compounds that it believes have the potential to address serious unmet medical needs. For more information, please visit the company’s web site at www.exelixis.com
Positive results from two bevacizumab (Avastin®) phase III clinical studies were presented at the 2011 American Society of Clinical Oncology Annual Meeting on June 4. The data reported add to the growing body of evidence in support of bevacizumab use to treat recurrent and newly-diagnosed ovarian cancer.
A diagram illustrating the role of the VEGF protein in the formation of new blood vessels that support tumor growth. Click on the picture above to view a video regarding the mechanism of action with respect to bevacizumab (Avastin®). (Photo: Genentech)
“Angiogenesis” refers to the process of new blood vessel formation. When tissues need more oxygen, they release molecules that encourage blood vessel growth. Angiogenesis is a normal and vital process in human growth and development, as well as in wound healing. Unfortunately, cancer tumors also utilize this same process to enhance their own blood supply in order to nourish their aberrant growth.
Ovarian cancer is associated with high concentrations of vascular endothelial growth factor (VEGF), a protein associated with tumor growth and spread. Studies have shown a correlation between a high concentration of VEGF and ascites (excess fluid in the body cavity) development, disease worsening, and a poorer prognosis in women with ovarian cancer.[1-2]
Bevacizumab is a humanized monoclonal antibody designed to specifically bind to the VEGF protein, which plays an important role throughout the lifecycle of the tumor to develop and maintain blood vessels through angiogenesis. The drug interferes with the tumor blood supply by directly binding to the VEGF protein to prevent interactions with receptors on blood vessel cells. The tumor blood supply is thought to be critical to a tumor’s ability to grow and spread in the body (metastasize).
Bevacizumab is the first U.S. Food and Drug Administration (FDA) approved therapy designed to inhibit angiogenesis. Although FDA-approved for several forms of cancer, bevacizumab is not yet approved for the treatment of ovarian cancer. Patients treated with bevacizumab may experience side effects. In past clinical trials, some people treated with bevacizumab experienced serious and sometimes fatal side effects, related to gastrointestinal (GI) perforation, surgery and wound healing, and severe bleeding. For more information, review the Avastin BOXED WARNINGS and Additional Important Safety Information.
OCEANS Phase III Clinical Study: Women with Recurrent Platinum Sensitive Ovarian Cancer Experience 78% Response Rate & 52% Reduction In Disease Progression Risk
About the OCEANS Study
“OCEANS” is a multicenter, randomized, double-blind, placebo-controlled Phase III study in 484 women with platinum drug-sensitive recurrent ovarian, primary peritoneal or fallopian tube cancer.[3] Women in the OCEANS study received no more than one treatment regimen prior to study enrollment. The OCEANS study randomized enrolled women to one of two clinical study arms:
Arm A: Intravenous carboplatin (area under the curve (AUC) 4; Day 1) + gemcitabine (1,000 mg/m2; Day 1 & 8; brand name: Gemzar®) + placebo (Day 1) every 21 days x 6 cycles, followed by placebo maintenance every 21 days, until disease progression or unacceptable toxicity occurred.
Arm B: Carboplatin + gemcitabine + bevacizumab (15 mg/kg; Day 1) every 21 days x 6 cycles, followed by single agent bevacizumab maintenance every 21 days, until disease progression or unacceptable toxicity occurred.
Carol Aghajanian, M.D. speaks during the Oral Abstract Session: Gynecologic Cancer at the American Society of Clinical Oncology Annual Meeting on Saturday June 4, 2011. (Photo: ASCO/GMG/Silas Crews 2011)
Carol Aghajanian, M.D., chief of the gynecologic medical oncology service at Memorial Sloan-Kettering Cancer Center, presented the data from the OCEANS study comparing efficacy and safety of chemotherapy and antiangiogenic therapy in platinum drug-sensitive recurrent ovarian cancer.
Two hundred forty-two women were allocated to each study arm and the median follow-up period was 24 months. Patient characteristics were well-matched in the two treatment groups with regard to age (median age ~60), race (~91% white), performance status (~75%, PS = 0), histologic subtype (~80% serous), cytoreductive surgery (~11%), and platinum-free interval (defined as the time between finishing front-line platinum-based therapy and starting second-line chemotherapy) of more than 12 months (~60%). The study stratification variables were platinum-free interval (6 to 12 months vs. more than 12) and cytoreductive surgery for recurrent disease (yes vs. no).
The median number of chemotherapy cycles was six for each group, and a median of 11 cycles of bevacizumab or placebo was given. At least one-third of the patients received more than six cycles of carboplatin and gemcitabine, although slightly more of the placebo-treated group continued chemotherapy beyond six cycles.
Progression-free survival was significantly longer for women given bevacizumab (12.4 months vs. 8.4 months in the placebo-treated group (hazard ratio [HR]: 0.484; 95% confidence interval (CI) [0.388, 0.605]; p < 0.0001). These results were corroborated by the analyses of an independent review committee. Analyses according to platinum-free interval, cytoreductive surgery, age, and baseline performance status indicate a consistent benefit in all subgroups.
Objective response rate increased by 21.1% (p < 0.0001), from 57.4% in the placebo group to 78.5% in the bevacizumab treated group; duration of response increased from a median of 7.4 months to 10.4 months, respectively (HR: 0.534; 95% CI [0.408, 0.698]; p < 0.0001). Overall survival data are still premature, with median survival of 29.9 months in the placebo group and 35.5 months in the bevacizumab treatment group.
Sixty-five percent of the patients in the placebo group were withdrawn from the protocol due to disease progression, compared with only 41% of the treatment group, but 23% of the discontinuations in the bevacizumab group were due to adverse events, compared with only 5% in the placebo group. Much of this increase was due to grade 3 (or worse) adverse events; specifically hypertension and proteinuria associated with bevacizumab therapy. Overall, the safety profile of bevacizumab was consistent with past trials.
OCEANS Study Commentary
Dr. Aghajanian concluded that the OCEANS study results demonstrate a statistically significant and clinically relevant benefit when bevacizumab is added to carboplatin and gemcitabine. Aghajanian stated that this regimen should be considered a new option for the treatment of recurrent, platinum drug-sensitive ovarian cancer. As expected, the rate of adverse events was higher among patients who received bevacizumab, explained Dr. Aghajanian. “Hypertension and proteinuria were increased, but febrile neutropenia was the same in both arms.” “The safety data are reassuring and consistent with the known bevacizumab side-effect profile, and there were no new safety signals,” said Dr. Aghajanian.
“In advanced ovarian cancer, just as in advanced breast cancer, there is often an opportunity to intervene with different lines of chemotherapy,” said Andrew Seidman, M.D., attending physician for the breast cancer medicine service at Memorial Sloan-Kettering Cancer Center and professor of medicine at Weill Medical College of Cornell University. “There are many chapters in the story, so to speak,” said Dr. Seidman, who moderated a press briefing held in advance of the presentation. “We want to prolong each and every chapter in the disease, and make the story longer and ultimately improve survival. These trials results are certainly an important step in that direction.”
“Women with recurrent ovarian cancer need new treatment options, and it is therefore an important advance to halve the risk of disease progression in this incurable cancer,” said Hal Barron, M.D., chief medical officer and head of Roche Holdings Global Product Development. “These data add to the growing body of evidence supporting Avastin’s potential role in this disease, which includes two previously presented Phase III clinical trials [Gynecologic Oncology Group (GOG)-218[4] & ICON7] in women with newly diagnosed ovarian cancer.”
In his discussion of the study, Anil K. Sood, M.D., professor and director of the Blanton-Davis Ovarian Cancer Research Program in the Departments of Gynecologic Oncology and Cancer Biology at the University of Texas M.D. Anderson Cancer Center, suggested that further understanding of the timing and dosing of bevacizumab should be pursued in light of (i) its great financial cost, and (ii) reports that inhibition of angiogenesis in animal models reduces primary cancer tumor growth, but accelerates invasion and metastasis — unintended consequences that might be linked to the failure of bevacizumab to extend overall survival in most clinical trials.
ICON7 Phase III Clinical Study: Newly-Diagnosed Women with High-Risk Ovarian Cancer Experience 36% Reduction in Risk of Death
Gunnar Kristensen M.D., Ph.D. speaks during the Women's Cancers Press Briefing at the American Society of Clinical Oncology Annual Meeting on June 4, 2011. (Photo: ASCO/GMG/Scott Morgan 2011)
ICON7 was designed to investigate safety and efficacy of adding bevacizumab to standard chemotherapy in women with newly diagnosed ovarian cancer. [5] Gunnar Kristensen, M.D, Ph.D., senior consultant in the Department for Gynecologic Oncology of the Norwegian Radium Hospital located in Oslo, reported the Phase III clinical study results.
About the ICON7 Study
From December 2006 to February 2009, 1,528 women were randomized from 263 centers in 7 Gynecologic Cancer InterGroups. Eligible women with high-risk early FIGO (Federation of International Gynecology and Obstetrics) stage I or IIa (grade 3 or clear cell histology), capped ≤10%) or advanced (stage IIb-IV) epithelial ovarian, primary peritoneal or fallopian tube cancer were randomizsed (1:1) to one of two study arms:
Arm A: 6 cycles of 3 weekly chemotherapy (carboplatin AUC 5 or 6 and paclitaxel 175mg/m2) alone; or
Arm B: Same chemotherapy as in Arm A, given concurrently with bevacizumab (7.5mg/kg) for 5 or 6 cycles, followed by continued 3-weekly single-agent bevacizumab maintenance therapy for 12 additional cycles (up to 12 months) or until disease progression (whichever event occurs first).
The baseline patient characteristics were balanced between both study arms: median age (57 years); ECOG Performance Status 0-1 (47%); high-risk early-stage disease (9%); poor prognosis patients (30%); histology (69% serous, 8% endometrioid, 8% clear cell).
Updated ICON7 Progression Free Survival Data
Data from the ICON7 study were presented for the first time at the 2010 European Society of Medical Oncology (ESMO) Congress. As reported at ESMO, chemotherapy-naïve ovarian cancer patients who received bevacizumab in combination with standard chemotherapy, and then continued with single agent bevacizumab maintenance therapy, experienced approximately 27% improvement (18.3 months versus 16 months) in the likelihood of living longer without the disease worsening (i.e., progression-free survival) compared to those women who received only chemotherapy (hazard ratio = 0.79, p=<0.0010), which corresponds to a 21% reduction in risk of cancer progression or death. The ICON7 data presented at ESMO was based upon mature progression-free survival results.
The updated ICON7 progression-free survival data presented at the ASCO annual meeting were consistent with the data reported last year at ESMO. In the updated analysis, women assigned to the bevacizumab arm experienced longer progression-free survival than those in the control group (19.8 months vs 17.4 months; HR, 0.87; p =.039). “There is a substantial prolongation of time to progression,” said Dr. Kristensen, adding that the gain was 2.4 months.
ICON7 Overall Survival Data Immature; But Clear Benefit To Women With “Poor Prognosis.”
At a median follow-up of 28 months, there were fewer deaths among women who received bevacizumab than among those who received standard chemotherapy (178 vs 200). Although this represents a 15% overall reduction in mortality risk, the difference did not reach statistical significance (hazard ratio [HR], 0.85; P = .11). The final analyses for overall survival will be performed when 715 patient deaths have occurred. The current analysis was conducted because an interim analysis with at least 365 deaths was requested by the FDA and the European Medicines Agency for licensing consideration.
Although the overall survival data is not mature, a subgroup analysis of women with a “poor prognosis” (defined as FIGO stage III patients debulked to >1.0cm of visible diease or FIGO stage IV with debulking) was performed. Within this subgroup, there were 79 deaths within the bevacizumab arm and 109 deaths in the control arm. Based on this data, there was a 36% reduction in the risk of death (HR=0.64, 95% CI=0.48 to 0.85, p=0.0022 with p=0.015 for test for interaction (treatment/risk group)) among the poor prognosis subgroup. This result was statistically significant. “We have previously shown that [the high-risk] group has a greater benefit from bevacizumab than the other patients,” said Dr. Kristensen. “For this group, there is a very clear gain for overall survival.”
ICON7 Study Commentary
“We conclude that the addition of concurrent and continued bevacizumab for 12 months does improve progression-free survival,” said Dr. Kristensen. Kristensen also noted that, on the basis of an interim analysis involving approximately 53% of the number of deaths needed for the final analysis, there is an overall trend for improvement in overall survival.
“In this study, we see the ability of antiangiogenic therapy to delay the progression of ovarian cancer, this time in the first-line setting,” said Andrew Seidman, M.D. He added that previous studies have demonstrated the efficacy of bevacizumab in ovarian cancer. “These lend support to a potential role for bevacizumab as the first biologic agent to be used in this disease,” said Seidman, who moderated a press briefing during which study highlights were presented.
There are many strengths in a study like this, in that it addresses questions about the role of anti-VEGF therapies in this setting, said Anil Sood, M.D., who served as a discussant for this paper. “The randomized design is obviously a major strength.”
However, there are potential issues to examine, explained Dr. Sood. “One is the role of bevacizumab in the combination setting, compared with the maintenance setting.”
“How useful is bevacizumab in the combination setting up front? Is the real role for bevacizumab in the maintenance setting following initial chemotherapy,” he asked.
The issue of bevacizumab dosing was also raised by Dr. Sood. “One of the questions is whether higher doses are needed,” he said. “There are data emerging from other studies showing that lower doses are as efficacious, if not more so.”
EC145, in combination with pegylated liposomal doxorubicin (Doxil®/Caelyx®) in patients with platinum-resistant ovarian cancer, met its primary endpoint by showing an 85 percent (2.3 month) improvement in median progression-free survival in the intent-to-treat population, and a 260 percent (4.0 month) improvement in a subset of folate receptor positive patients. The final EC145 phase 2 clinical study data were presented today at the 2011 American Society of Clinical Oncology Annual Meeting.
EC145 delivers a very potent vinca chemotherapy directly to cancer cells by targeting the folate receptor expressed on cancer cells, but not on most normal cells. Approximately 80-90 percent of ovarian and lung cancers express the receptor, as do many other types of cancer. Click on the picture above to view a video regarding EC145's mechanism of action. (Photo: Endocyte, Inc.)
Endocyte, Inc., a biopharmaceutical company developing targeted small molecule drug conjugates (SMDCs) and companion imaging diagnostics for personalized therapy, today announced that the phase 2 PRECEDENT trial, which is investigating the company’s lead drug candidate, EC145, in combination with pegylated liposomal doxorubicin (PLD)(brand name: Doxil®/Caelyx®) in patients with platinum-resistant ovarian cancer, met its primary endpoint by showing: (i) an 85 percent (2.3 month) improvement in medianprogression-free survival (PFS) in the intent-to-treat population, and (ii) a 260 percent (4.0 month) improvement in a subset of folatereceptor positive patients. EC145 in combination with PLD showed limited additional toxicity compared to standard therapy with PLD alone. The most commonly occurring adverse events were neutropenia, small intestine obstruction, and palmar-plantar erythrodysesthesia (or hand-foot syndrome). EC145 is a therapeutic that targets the folate receptor and EC20 is a companion imaging diagnostic used to assess folate receptor presence.
These final PFS data from the PRECEDENT trial were presented today at the 2011 Annual Meeting of the American Society of Clinical Oncology (ASCO), in Chicago, Illinois and are available at http://investor.endocyte.com/events.cfm.
“I am encouraged by these data as EC145 is the first drug candidate to demonstrate a significant improvement in PFS in a randomized trial of patients with platinum-resistant ovarian cancer, a very challenging disease with a high unmet need. Historical data show that for these patients on standard therapy, PFS is approximately three months and overall survival is approximately twelve months. No new drug has been approved in the U.S. for this indication in over a decade,” said Wendel Naumann, M.D., Associate Director of Gynecologic Oncology at Blumenthal Cancer Center, Carolinas Medical Center. “In addition the companion imaging diagnostic, EC20, is designed to identify patients who over-express the targeted receptor and are most likely to respond to EC145. This represents a personalized therapeutic approach that I believe will help oncologists direct patients to the most promising treatment.”
EC145 Phase 2 PRECEDENT Clinical Study Data
The Phase 2 PRECEDENT trial was an international, multi-center, randomized study of 149 women with platinum-resistant ovarian cancer. Patients were randomized to receive EC145 plus PLD or PLD alone at a standard dose until disease progression or death. The primary endpoint of the study was progression-free survival. Secondary endpoints included response rate and overall survival.
The EC145 phase 2 PRECEDENT trial results are summarized below.
85 Percent (2.3 Month) Improvement in Median Progression-Free Survival for All Patients
Patients receiving EC145 in combination with PLD, regardless of folate receptor expression, had a median progression free survival of 5.0 months compared to 2.7 months for patients receiving single agent PLD. The hazard ratio for PFS was 0.626 (p=0.031). The overall response rate was 28 percent in the EC145 combination group versus 16 percent in the PLD-alone group. CA-125 (cancer antigen-125) responses were also more common in patients receiving EC145 in combination with PLD compared to those receiving PLD alone, with response rates (based on CA-125 blood serum measurement) of 38 percent and 19 percent, respectively.
260 Percent (4.0 Month) Improvement in Median Progression-Free Survival for Patients Most Positive for Folate Receptor
The study also utilized EC20, an investigational companion imaging diagnostic that is designed to identify patients with folate receptor positive tumors. As expected, in the folate receptor positive patients the improvement in PFS was even greater. In the subpopulation most positive for the folate receptor, PFS increased 4.0 months from 1.5 months to 5.5 months. The hazard ratio for PFS was 0.381 (p=0.018). This represents more than a 60 percent reduction in the risk of progression and provides evidence supporting the mechanism of action through targeting of the folate receptor. The overall response rate was 22 percent in the EC145 combination group versus 7 percent in the PLD alone group. CA-125 responses were also more common in patients receiving EC145 in combination with PLD compared to those receiving PLD alone, 43 percent and 13 percent, respectively.
“We see tremendous potential for continued development of EC145 based on these data that demonstrate, for the first time, a significant improvement in PFS in patients with platinum resistant ovarian cancer,” said Ron Ellis, President and Chief Executive Officer of Endocyte. “We have already advanced EC145 into Phase 3 evaluation with the PROCEED trial, which has a similar design to the PRECEDENT trial, and plan to file for regulatory approval in the European Union based on the PFS data from the PRECEDENT study.”
Plan to File PRECEDENT Data for Conditional Approval in Europe
As a result of Endocyte’s interaction with the European Medicines Agency (EMA), including a meeting with the Scientific Advice Working Party and written advice from the Committee for Medicinal Products for Human Use (CHMP), the Company will prepare marketing applications for both EC145 and EC20. Based on feedback from the CHMP, Endocyte plans to seek conditional marketing authorization for patients with platinum-resistant ovarian cancer who test positive for the folate receptor using the EC20 companion imaging diagnostic.
Phase 3 PROCEED Trial Initiated
Endocyte recently announced the initiation of patient enrollment in the Phase 3 PROCEED trial of EC145, which is structured to replicate the PRECEDENT trial design. The Phase 3 trial is a randomized, double-blinded trial of EC145 in combination with PLD compared to PLD plus placebo. The patient population — those with platinum-resistant ovarian cancer — will be the same as in the PRECEDENT trial, and the primary endpoint will be progression-free survival in patients selected by EC20 as folate-receptor positive. The trial will also be statistically powered for overall survival as a secondary endpoint with projected enrollment in excess of 500 patients. The trial will be conducted in approximately 150 sites in the U.S., Canada, and Europe. More information regarding the trial is available at www.clinicaltrials.gov.
About EC145
EC145 is a conjugate of the vitamin folate and a super-potent vinca alkaloid. Folate is required for cell division and rapidly dividing cancer cells often over-express folate receptors in order to capture enough folate to support cell division. By attaching a chemotherapy drug to folate through proprietary chemistry, EC145 targets cancer cells while avoiding most normal cells. This targeted approach is designed to provide treatment with super-potent drugs while lowering toxicity compared to standard chemotherapy.
About EC20
EC20 is a folate-targeted molecular imaging agent that is being developed as a non-invasive method to identify tumors that over-express folate receptors. These tumors are the molecular target of Endocyte’s folate-targeted therapeutic compounds such as EC145. To date, EC20 has been administered to over 500 patients and has been found to be well tolerated.
About Endocyte
Endocyte is a biopharmaceutical company developing targeted therapies for the treatment of cancer and inflammatory diseases. Endocyte uses its proprietary technology to create novel small molecule drug conjugates (SMDCs) and companion imaging diagnostics for personalized targeted therapies. The company’s SMDCs actively target receptors that are over-expressed on diseased cells, relative to healthy cells. This targeted approach is designed to enable the treatment of patients with highly active drugs at greater doses, delivered more frequently, and over longer periods of time than would be possible with the untargeted drug alone. The companion imaging diagnostics are designed to identify patients whose disease over-expresses the target of the therapy and who are therefore more likely to benefit from treatment.
EC145 PRECEDENT Trial Results — 2011 American Society of Clinical Oncology Annual Meeting Poster Presentation, June 5, 2011. [Adobe Reader PDF document]
Women with the BRCA1 or BRCA2 gene mutations, which are linked to a very high risk of breast and ovarian cancer, can safely take hormone-replacement therapy (HRT) to mitigate menopausal symptoms after surgical removal of their ovaries, according to new research from the Perelman School of Medicine at the University of Pennsylvania
Research has shown that in women who carry the BRCA gene mutations, the single most powerful risk-reduction strategy is to have their ovaries surgically removed by their mid-30s or early 40s. The decrease in cancer risk from ovary removal comes at the cost of early menopause and menopausal symptoms including hot flashes, mood swings, sleep disturbances and vaginal dryness — quality-of-life issues that may cause some women to delay or avoid the procedure.
Lead study author Susan M. Domchek, M.D., Associate Professor, Divison of Hematology-Oncology & Director, Cancer Risk Evaluation Program, Abramson Cancer Center, University of Pennsylvania
“Women with BRCA1/2 mutations should have their ovaries removed following child-bearing because this is the single best intervention to improve survival,” says lead author Susan M. Domchek, M.D., an associate professor in the division of Hematology-Oncology and director of the Cancer Risk Evaluation Program at Penn’s Abramson Cancer Center. “It is unfortunate to have women choose not to have this surgery because they are worried about menopausal symptoms and are told they can’t take HRT. Our data say that is not the case — these drugs do not increase their risk of breast cancer.”
Senior author Timothy R. Rebbeck, Ph.D., associate director of population science at the Abramson Cancer Center, notes that BRCA carriers may worry — based on other studies conducted in the general population showing a link between HRT and elevated cancer risk — that taking HRT may negate the effects of the surgery on their breast cancer risk. The message he hopes doctors will now give to women is clear: “If you need it, you can take short-term HRT. It doesn’t erase the effects of the oophorectomy.”
In the current study, Domchek, Rebbeck, and colleagues followed 795 women with BRCA1 mutations and 504 women with BRCA2 mutations who have not had cancer enrolled in the PROSE consortium database who underwent prophylactic oophorectomy, divided into groups of those who took HRT and those who did not. Women who underwent prophylactic oophorectomy had a lower risk of breast cancer than those who did not, with 14 percent of the women who took HRT after surgery developing breast cancer compared to 12 percent of the women who did not take HRT after surgery. The difference was not statistically significant.
Domchek says some of the confusion about the role of HRT in cancer risk elevation comes from the fact that the risks and benefits associated with HRT depend on the population of women studied. In this group of women — who have BRCA1/2 mutations and who have had their ovaries removed while they are quite young — HRT should be discussed and considered an option for treating menopausal symptoms. “People want to make hormone replacement therapy evil, so they can say ‘Don’t do it,'” she says. “But there isn’t one simple answer. The devil is in the details of the studies.”
By contrast, Penn researchers and their collaborators in the PROSE consortium have shown definitively that oophorectomy reduces ovarian and breast cancer incidence in these women, and reduces their mortality due to those cancers. But paying attention to the role that hormone depletion following preventive oophorectomy plays in women’s future health is also important.
“We know for sure that using HRT will mitigate menopausal symptoms, and we have pretty good evidence that it will help bone health,” she says. “Women need to be aware that going into very early menopause does increase their risk of bone problems and cardiovascular problems. And even if they aren’t going to take HRT, they need to be very attentive to monitoring for those issues. But they also need to know that HRT is an option for them and to discuss it with their doctors and other caregivers.”
About Penn Medicine
Penn Medicine is one of the world’s leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation’s first medical school) and the University of Pennsylvania Health System, which together form a $4 billion enterprise. Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2010, Penn Medicine provided $788 million to benefit our community.
About the University of Pennsylvania Perelman School of Medicine
Penn’s Perelman School of Medicine is currently ranked #2 in U.S. News & World Report’s survey of research-oriented medical schools and among the top 10 schools for primary care. The School is consistently among the nation’s top recipients of funding from the National Institutes of Health, with $507.6 million awarded in the 2010 fiscal year.
About the University of Pennsylvania Health System
The University of Pennsylvania Health System’s patient care facilities include: The Hospital of the University of Pennsylvania — recognized as one of the nation’s top 10 hospitals by U.S. News & World Report; Penn Presbyterian Medical Center; and Pennsylvania Hospital – the nation’s first hospital, founded in 1751. Penn Medicine also includes additional patient care facilities and services throughout the Philadelphia region.
EntreMed, Inc. announced that ENMD-2076 demonstrated clinical activity — a six-month progression free survival rate of 19% — when administered as a single agent to platinum drug-resistant recurrent ovarian cancer patients. The announcement is based upon interim phase 2 data presented today at the 2011 American Society of Clinical Oncology Annual Meeting.
Ursula A. Matulonis, M.D., Medical Director, Gynecologic Oncology, Dana-Farber Cancer Institute; Associate Professor of Medicine, Harvard Medical School
ENMD-2076 demonstrated clinical activity when administered daily orally as a single agent. Interim data from 57 evaluable patients showed a six-month progression free survival rate of 19 percent. Of the evaluable patients, four patients achieved a partial response and 30 patients achieved stable disease as measured by RECISTv1.1. Median overall survival has not yet been reached. The side effect profile was consistent with activity against ENMD-2076’s molecular targets, in particular, VEGFR2 (vascular endothelial growth factor receptor-2) and Aurora A. Studies to evaluate potential markers of ENMD-2076 in this patient group are ongoing.
Dr. Matulonis commented on the results of the study, “ENMD-2076 has demonstrated impressive anti-cancer activity in platinum-resistant ovarian cancer which is notoriously difficult to treat, and these patients have few options.”
EntreMed’s chief medical officer, Carolyn F. Sidor, M.D., M.B.A., added, “These results are very encouraging as they support further development of ENMD-2076 and also help us clarify its developmental path in ovarian cancer. We are currently designing the next clinical trial in this indication and look forward to opportunities to make ENMD-2076 available to ovarian cancer patients in the future.”
About ENMD-2076
ENMD-2076 is an orally-active, Aurora A/angiogenickinase inhibitor with a unique kinase selectivity profile and multiple mechanisms of action. ENMD-2076 has been shown to inhibit a distinct profile of angiogenic tyrosine kinase targets in addition to the Aurora A kinase. Aurora kinases are key regulators of mitosis (cell division), and are often over-expressed in human cancers. ENMD-2076 also targets the VEGFR, Flt-3 and FGFR3 kinases which have been shown to play important roles in the pathology of several cancers. ENMD-2076 has shown promising activity in phase I clinical trials in solid tumor cancers, leukemia, and multiple myeloma. While ENMD-2076 is currently in a phase 2 trial in ovarian cancer, preclinical and clinical activities are ongoing in assessing the compound’s applicability in other forms of cancer.
EntreMed, Inc. is a clinical-stage pharmaceutical company committed to developing ENMD-2076, a selective angiogenic kinase inhibitor, for the treatment of cancer. ENMD-2076 is currently in a multi-center phase 2 study in ovarian cancer and in several phase 1 studies in solid tumors, multiple myeloma, and leukemia.
Customizing targeted therapies to each tumor’s molecular characteristics, instead of a “one-size-fits-all” approach by tumor type, may be more effective for some types of cancer, according to research presented today at the American Society of Clinical Oncology annual meeting by the M.D. Anderson Cancer Center. In patients with end-stage disease, matched patients achieved a 27% response rate, versus 5% in those unmatched.
Apostolia M. Tsimberidou, M.D., Ph.D., Associate Professor, Department of Investigational Cancer Therapeutics, Division of Cancer Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, Texas
Marking the largest scale on which this approach has been examined to date, the study analyzed the results of matching targeted therapies with specific genemutations in patients. The data indicated that this strategy was associated with higher rates of response, survival and failure-free survival than observed in non-matched patients.
Pairing Patient and Treatment
“This preliminary study strongly suggests that molecular analysis is needed to use the right drug for the right patient. Up to this point, we have treated tumor types, but this study shows we cannot treat all patients with a tumor type the same way. We need to take into consideration a number of factors, and this study suggests that a personalized approach is needed to improve clinical outcomes for patients with cancer,” said Tsimberidou.
The identification of pathways involved in carcinogenesis, metastasis and drug resistance; new technologies enabling tumor molecular analysis; and the discovery of targeted therapies have stimulated research focusing on the use of targeted agents as part of a personalized medicine approach, she said.
“Over the past decades, a personalized medicine approach using Gleevec has changed the way we treat chronic myeloid leukemia, as well as survival rates,” said Razelle Kurzrock, M.D., professor and chair of the M.D. Anderson Department of Investigational Cancer Therapeutics. “We wanted to apply a similar approach to solid tumors.”
“Ultimately, to best match treatments to patients and offer the most therapeutic benefit, assessing a patient’s molecular markers has to become the standard at diagnosis. …
This study affirms what we in the cancer community have been talking about for a decade – matching drugs to patients. The time is now. The drugs are here. The technology is here, and with our program at M.D. Anderson we can bring the two together in hopes to offer the most personalized care for our patients. …”
–Razelle Kurzrock, M.D., Professor & Chair, Department of Investigational Cancer Therapeutics, University of Texas M.D. Anderson Cancer Center
Research Methods and Results
In the initial analysis, Tsimberidou analyzed 1,144 patients with metastatic or inoperable cancer who underwent testing for molecular aberrations at M.D. Anderson. Their median age was 58, and the median number of prior treatments was four. Of these patients, 460 had one or more gene aberrations, including:
Patients with gene aberrations were treated on clinical trials with matched targeted agents, when available. Regimens included one or more therapies targeting PIK3CA, mTOR, BRAF, MEK, multikinases, KIT or EGFR. Outcomes of patients with gene aberrations treated with matched therapy were compared with those patients with gene aberrations who were not treated with matched therapy because of issues such as eligibility, study availability; insurance coverage and/or logistical problems with the study calendar.
For the 175 patients with one aberration, the response rate was 27 percent with matched targeted therapy. The response rate was 5 percent in 116 patients when treated with non-matched therapy.
Patients who received matched targeted therapy had median survival of 13.4 months, while median survival for patients treated with unmatched targeted therapy was nine months. Median failure-free survival in patients who received matched targeted therapy was 5.2 months, compared to 2.2 months for patients who received unmatched targeted therapy.
Further Research Needed
These preliminary results merit further investigation and confirmatory, prospective studies are needed, especially because the study was not a randomized study and therefore biases could influence the results.
“M.D. Anderson’s goal is to better understand the biology involved in each patient’s carcinogenesis by testing each tumor for genetic abnormalities driving tumor growth to guide treatment selection. This strategy will lead to the optimization of personalized therapy,” Tsimberidou said.
Another goal is to match targeted therapies to patients earlier in treatment.
“When Gleevec was first introduced, it was tested in patients in blast crisis and the response rate was about 15 percent. In contrast, when tested in the front line setting, and with the introduction of similar but increasingly potent second- and third-generation drugs, patients’ response rate was close to 100 percent, and now their expected survival is 25 years and counting,” said Kurzrock. “Ultimately, to best match treatments to patients and offer the most therapeutic benefit, assessing a patient’s molecular markers has to become the standard at diagnosis.”
About the Phase I Program – The Time is Now
The M.D. Anderson’s Phase I program is the largest of its kind and accounts for the majority – but not all – of the institution’s earliest clinical studies. In 2010, of the 11,000 patients who participated in M.D. Anderson clinical trials, more than 1,150 were enrolled in one of the 120 Phase I trials in the program.
Currently, tumors are tested for up to 12 molecular aberrations, but at the rate technology is rapidly advancing, Kurzrock expects that number to climb to more than 100 in the near future.
Patients treated in the Phase I Program are typically very ill and all other approved therapies have failed them. Yet they are “fighters” who are willing to try anything, including studies not specific to their diagnosis to test the effectiveness of a new drug, drug combination or delivery method, said Kurzrock.
“This study affirms what we in the cancer community have been talking about for a decade – matching drugs to patients,” said Kurzrock. “The time is now. The drugs are here. The technology is here, and with our program at M.D. Anderson we can bring the two together in hopes to offer the most personalized care for our patients.”
In addition to Tsimberidou and Kurzrock, other authors on the all-M.D. Anderson study included N. G. Iskander, David S. Hong, M.D., Jennifer J. Wheler, M.D., Siqing Fu, M.D., Ph.D., Sarina A. Piha-Paul, M.D., Aung Naing, M.D., Gerald Falchook, Filip Janku, M.D., Ph.D., all assistant professors of the Department of Investigational Cancer Therapeutics; Raja Luthra, Ph.D., professor, Department of Hematopathology, Research and Sijin Wen, Ph.D., Division of Quantitative Sciences.
Libby’s H*O*P*E*™ Commentary — Use of Molecular Profiling and Chemosensitivity Testing To Determine Individualized Ovarian Cancer Treatment
It is wonderful that various medical research institutions, including M.D. Anderson, are beginning to match targeted therapies to a patient’s specific molecular tumor characteristics. This approach is generally referred to as “molecular profiling,” and it represents one promising method of matching an individual cancer patient to an effective therapy. As noted in the related Libby’s H*O*P*E*™ postings set forth below, there are several medical and scientific institutions which are pursuing development of molecular profiling for clinical study use. In the most recent related posting listed below, we discuss the molecular profile testing that is commercially available through The Clearity Foundation and Caris Life Sciences.
In the future, it may be helpful to use a form of chemosensitivity testing (e.g., the type of testing provided by Precision Therapeutics, Rational Therapeutics, and the Weisenthal Cancer Group), which is based upon the measurement of actual cancer cell death, as a second method to match a cancer patient to a potential drug or drug combination within the context of a clinical study. In fact, we would like to see a future prospective, randomized ovarian cancer clinical trial in which enrolled women are provided with treatment after assignment to one of three clinical trial arms: (i) treatment based upon the standard of care (e.g., paclitaxel and carboplatin), (ii) treatment based upon molecular profiling, or (iii) treatment based upon chemosensitivity testing. This type of study may uncover additional ovarian cancer treatment insights (both molecular and functional) with respect to the most lethal gynecologic cancer, while ultimately helping women with forms of the disease that may not possess a known molecular characteristic that is potentially “targetable” by an existing clinical trial drug or compound.
This combination of “bottom-up” scientific research (i.e., molecular profiling) performed side-by-side with “top-down” research (i.e., chemosensitivity testing) may represent an effective and efficient approach — albeit provocative — for evaluation of optimal personalized ovarian cancer treatment.
It is important to note that Libby’s H*O*P*E*™ and its founder Paul Cacciatore do not receive financial renumeration or benefit of any kind from the companies referred to in the paragraphs above.
About the University of Texas M.D. Anderson Cancer Center
The University of Texas M.D. Anderson Cancer Center in Houston ranks as one of the world’s most respected centers focused on cancer patient care, research, education and prevention. MD Anderson is one of only 40 comprehensive cancer centers designated by the National Cancer Institute. For seven of the past nine years, including 2010, M.D. Anderson has ranked No. 1 in cancer care in “America’s Best Hospitals,” a survey published annually in U.S. News & World Report.
Eating a low-carbohydrate, high-protein diet may reduce the risk of cancer and slow the growth of tumors already present, according to a study published in Cancer Research, a journal of the American Association for Cancer Research.
Libby's H*O*P*E* 