2011 ASCO: Exelixis Reports Expanded Cabozantinib (XL184) Phase II Data For Advanced Ovarian Cancer; Six Deaths Reported

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

Exelixis, Inc. reported expanded Phase 2 study data with respect to cabozantinib (XL184) use in advanced ovarian cancer patients at the 2011 American Society of Clinical Oncology (ASCO) Annual Meeting . The overall solid tumor Phase 2 safety and tolerability data refers to six deaths, including two ovarian cancer patients.

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 efficacy endpoint 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 histologic characteristics 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 Eventsgrade 3 or 4 adverse 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).

To access the cabozantinib clinical study data information, please visit www.exelixis.com/sites/default/files/pdf/ASCO_2011-XL184-Ovarian.pdf

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

Sources: 

Cabozantinib (XL184) Clinical Trial Information
Related Libby’s H*O*P*E*™ Postings
Related Libby’s H*O*P*E*™ Videos

2011 ASCO: Additional Phase III Study Data Support the Potential Role of Avastin in Newly-Diagnosed & Recurrent Ovarian Cancer

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.

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.

About Bevacizumab (Avastin®)

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.

The primary endpoint of the OCEANS study was progression free survival. The secondary endpoints of the study included overall survival, objective response, duration of response and safety profile.

  • OCEANS Study Data

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.”

References:

1/Rudlowski C, Pickart AK, Fuhljahn C, et. al. Prognostic significance of vascular endothelial growth factor expression in ovarian cancer patients: a long-term follow-up. Int J Gynecol Cancer. 2006 Jan-Feb;16 Suppl 1:183-9. PubMed PMID: 16515588.

2/Cooper BC, Ritchie JM, Broghammer CL, et. al. Preoperative serum vascular endothelial growth factor levels: significance in ovarian cancer. Clin Cancer Res. 2002 Oct;8(10):3193-7.  PMID: 12374688

3/Aghajanian C, Finkler NJ, Rutherford T, et. alOCEANS: A randomized, double-blinded, placebo-controlled phase III trial of chemotherapy with or without bevacizumab (BEV) in patients with platinum-sensitive recurrent epithelial ovarian (EOC), primary peritoneal (PPC), or fallopian tube cancer (FTC)J Clin Oncol 29: 2011 (suppl; abstr LBA5007)[2011 American Society of Clinical Oncology Annual Meeting].

4/ Burger RA, Brady MF, Bookman MA, et. alPhase III trial of bevacizumab in the primary treatment of advanced epithelial ovarian cancer (EOC), primary peritoneal cancer (PPC), or fallopian tube cancer (FTC): a Gynecologic Oncology Group study [GOG 218 Abstract]J Clin Oncol 28:18s, 2010 (suppl; abstr LBA1).

5/Kristensen G, Perren T, Qian W., et. alResult of interim analysis of overall survival in the GCIG ICON7 phase III randomized trial of bevacizumab in women with newly diagnosed ovarian cancerJ Clin Oncol 29: 2011 (suppl; abstr LBA5006) [2011 American Society of Clinical Oncology Annual Meeting].

Additional Sources & Helpful Information:

Bevacizumab (Avastin®) Clinical Trial Information

Related WORD of HOPE Ovarian Cancer Podcast™

Related Libby’s H*O*P*E*™ Postings

Related Libby’s H*O*P*E*™ Videos

  • To view videos regarding bevacizumab (Avastin®), click here.


2009 ASCO Annual Meeting Highlights: Ovarian Cancer & Select General Issues

The 2009 American Society of Clinical Oncology (ASCO) Annual Meeting was held in Orlando, Florida from May 29 through June 2, 2009.  We provide below select highlights from the 2009 ASCO Annual Meeting that relate to ovarian cancer and other general issues.

The 2009 American Society of Clinical Oncology (ASCO) Annual Meeting was held in Orlando, Florida from May 29 through June 2, 2009.  We provide below select highlights from the 2009 ASCO Annual Meeting that relate to ovarian cancer and other general issues. Learn more about How to Read a Medical Abstract in a Research Study.

Development Time of Cancer Clinical Trials Linked to Accrual Goals.

Physicians Need to Address Prescription Costs With Patients Who Participate In Clinical Trials.

Availability of Experimental Therapy Outside of Randomized Clinical Trials In Oncology.

ASCO Fertility Preservation Guidelines For Cancer Patients Not Widely Followed By Oncologists.

Ginger (Zindol®) Quells Cancer Patients’ Chemotherapy-Related Nausea.

Early Treatment of Recurrent Ovarian Cancer Based Upon Rising CA-125 Levels Does Not Increase Survival.

Body Mass Index (BMI) Should Be Taken Into Account When Assessing A Cancer Patient’s Vitamin D Status.

Extreme Drug Resistance (EDR) Assay Results Do Not Independently Predict Or Alter The Outcomes of Patients With Epithelial Ovarian Cancer Who Are Treated With Optimal Cytoreductive Surgery Followed By Platinum & Taxane Combination Chemotherapy in Either a Primary or Recurrent Setting.

Systematic Review Of Past Study Results For Use of Cytoreductive Surgery Combined With Hyperthermic Intraperitoneal Chemotherapy (HIPEC).

Preliminary Results From Phase II Study of Oxaliplatin+Docetaxel+Bevacizumab As First Line Treatment of Advanced Ovarian Cancer Show 62% Overall Response Rate & 70% One-Year Progression Free Survival.

Combined Weekly Docetaxel + Gemcitabine In Relapsed Ovarian Cancer & Peritoneal Cancer Produces 59% Overall Response Rate.

A Phase II Trial of Irinotecan & Oral Etoposide Chemotherapy in Recurrent Ovarian Cancer Patients Produces 47% Overall Response Rate & 81% Clinical Benefit Rate.

Weekly Bevacizumab & Pegylated Liposomal Doxorubicin Produce 55% Clinical Benefit Rate In Progressing/Recurrent Ovarian Cancer Patients.

Phase II Study of Belotecan (CKD-602)+ Carboplatin Demonstrates 53% Overall Response Rate in Recurrent Ovarian Cancer Patients.

Single Agent Voreloxin Produces 11% Overall Response Rate & 52% Disease Control Rate in Phase II Study Involving Women with Platinum-Resistant Ovarian Cancer.

A Phase II Study of Patupilone In Patients With Platinum Refractory/Resistant Ovarian, Primary Fallopian, or Peritoneal Cancer Produces 48% Clinical Benefit Rate.

Trabectedin (Yondelis®) + Pegylated Liposomal Doxorubicin (PLD) Produces Better Response Than PLD Alone.

M.D. Anderson Cancer Center Finds Anti-VEGF Therapy Is Highly Effective In Patients With Ovarian Granulosa Cell Tumors.

M.D. Anderson Cancer Center Finds That Increased Angiogenesis Is A Significant Predictor Of Poor Clinical Outcome In Patients With Sex-Cord Stromal Tumors; Suggests Anti-Angiogenesis Therapy is Warranted For This Subtype of Ovarian Cancer.

ZYBRESTAT™ (Combretastatin A-4 phosphate) Produces 32% Confirmed Partial Response Rate (RR) in Evaluable Patients With Platinum Resistant Ovarian Cancer (25% RR if total enrolled patients used as denominator).

ASSIST-5 Trial of TELCYTA® + Pegylated Liposomal Doxorubicin Produces 12% Response Rate (With One Complete Response) in Patients With Platinum Refractory and Resistant Ovarian Cancer.

Two Studies Provide Contradictory Data for Use of Carboplatin + Pegylated Liposomal Doxorubicin in Ovarian Cancer

OGX-427 Treatment Demonstrates Safety, Evidence of Declines in Circulating Tumor Cells and Reductions in Tumor Markers in a Phase I Cancer Trial, Including 60% Response Rate (Based Upon Declining CA125) For Ovarian Cancer Patients.

Maintenance BIBF 1120 Could Delay Disease Progression in Recurrent Ovarian Cancer.

Oral PARP Inhibitor Olaparib (AZD2281) Effective Against BRCA-Deficient Advanced Ovarian Cancer.

Carfilzomib (PX-171-007) Produces Stable Disease For 4+ Months In One Ovarian Cancer Patient Who Failed Under Four Previous Treatment Lines – Phase II Solid Tumor Trial.

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About The American Society of Clinical Oncology

The American Society of Clinical Oncology is a non-profit organization founded in 1964 with the overarching goals of improving cancer care and prevention. More than 27,000 oncology practitioners belong to ASCO, representing all oncology disciplines and subspecialties. Members include physicians and health-care professionals in all levels of the practice of oncology. To view 2009 ASCO Annual Meeting presentation abstracts, click here.  To view 2009 ASCO Annual Meeting presentation abstracts regarding ovarian cancer, click here.  To view ASCO ovarian cancer information, click here.

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Cancer.Net, formerly People Living With Cancer (PLWC), brings the expertise and resources of the American Society of Clinical Oncology (ASCO), the voice of the world’s cancer physicians, to people living with cancer and those who care for and care about them. ASCO is composed of more than 27,000 oncologists globally who are the leaders in advancing cancer care. All the information and content on Cancer.Net was developed and approved by the cancer doctors who are members of ASCO, making Cancer.Net the most up-to-date and trusted resource for cancer information on the Internet. Cancer.Net is made possible by The ASCO Cancer Foundation, which provides support for cutting-edge cancer research, professional education, and patient information.

Cancer.Net provides timely, oncologist-approved information to help patients and families make informed health-care decisions. All content is subject to a formal peer-review process by the Cancer.Net Editorial Board, composed of more than 150 medical, surgical, radiation, and pediatric oncologists, oncology nurses, social workers, and patient advocates. In addition, ASCO editorial staff reviews the content for easy readability. Cancer.Net content is reviewed on an annual basis or as needed.

To view Cancer.Net ovarian cancer information, click here.

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Sometimes More Is Less: Evaluation of Experimental Platinum-Based Treatment Regimens in Advanced-Stage Ovarian Cancer; A Phase III Trial of the Gynecologic Cancer InterGroup

“… Compared with standard paclitaxel and carboplatin, addition of a third cytotoxic agent [gemcitibine, liposomal doxorubicin or topotecan] provided no benefit in PFS [progression-free survival] or OS [overall survival] after optimal or suboptimal cytoreduction. Dual-stage, multiarm, phase III trials can efficiently evaluate multiple experimental regimens against a single reference arm. The development of new interventions beyond surgery and conventional platinum-based chemotherapy is required to additionally improve outcomes for women with advanced EOC.”

“Michael A. Bookman,* Mark F. Brady, William P. McGuire, Peter G. Harper, David S. Alberts, Michael Friedlander, Nicoletta Colombo, Jeffrey M. Fowler, Peter A. Argenta, Koen De Geest, David G. Mutch, Robert A. Burger, Ann Marie Swart, Edward L. Trimble, Chrisann Accario-Winslow, and Lawrence M. Roth

From the Fox Chase Cancer Center, Philadelphia, PA; Gynecologic Oncology Group Statistical and Data Center, Buffalo, NY; Franklin Square Hospital; Baltimore, MD; Guy’s Hospital, London, United Kingdom; Arizona Cancer Center, Tucson, AZ; Australia New Zealand Gynaecological Oncology Group, Camperdown, Australia; European Institute of Cancer Research, Milano, Italy; Ohio State University, Columbus, OH; University of Minnesota School of Medicine, Minneapolis, MN; University of Iowa Hospitals and Clinics, Iowa City, IA; Washington University School of Medicine, St. Louis, MO; University of California, Irvine Medical Center, Orange, CA; University College London and Medical Research Council Clinical Trials Unit, London, United Kingdom; National Cancer Institute, Bethesda, MD; and Indiana University School of Medicine, Indianapolis, IN.

* To whom correspondence should be addressed. E-mail: michael.bookman@fccc.edu

Purpose: To determine if incorporation of an additional cytotoxic agent improves overall survival (OS) and progression-free survival (PFS) for women with advanced-stage epithelial ovarian carcinoma (EOC) and primary peritoneal carcinoma who receive carboplatin and paclitaxel.

Patients and Methods: Women with stages III to IV disease were stratified by coordinating center, maximal diameter of residual tumor, and intent for interval cytoreduction and were then randomly assigned among five arms that incorporated gemcitabine, methoxypolyethylene glycosylated liposomal doxorubicin, or topotecan compared with carboplatin and paclitaxel. The primary end point was OS and was determined by pairwise comparison to the reference arm, with a 90% chance of detecting a true hazard ratio of 1.33 that limited type I error to 5% (two-tail) for the four comparisons.

Results: Accrual exceeded 1,200 patients per year. An event-triggered interim analysis occurred after 272 events on the reference arm, and the study closed with 4,312 women enrolled. Arms were well balanced for demographic and prognostic factors, and 79% of patients completed eight cycles of therapy. There were no improvements in either PFS or OS associated with any experimental regimen. Survival analyses of groups defined by size of residual disease also failed to show experimental benefit in any subgroup.

Conclusion: Compared with standard paclitaxel and carboplatin, addition of a third cytotoxic agent provided no benefit in PFS or OS after optimal or suboptimal cytoreduction. Dual-stage, multiarm, phase III trials can efficiently evaluate multiple experimental regimens against a single reference arm. The development of new interventions beyond surgery and conventional platinum-based chemotherapy is required to additionally improve outcomes for women with advanced EOC.”

Quoted Source Evaluation of New Platinum-Based Treatment Regimens in Advanced-Stage Ovarian Cancer: A Phase III Trial of the Gynecologic Cancer InterGroup; Bookman MA et. al., J Clin Oncol. 2009 Feb 17. [Epub ahead of print].

Non-Platinum Topotecan Drug Combination Therapy Provides No Survival Advantage Over Topotecan Monotherapy

“In women with recurrent ovarian cancer, treatment with topotecan along with etoposide or gemcitabine offers no survival advantage over topotecan monotherapy, German and Austrian researchers report in the July 1st issue of the Journal of Clinical Oncology.”

“In women with recurrent ovarian cancer, treatment with topotecan along with etoposide or gemcitabine offers no survival advantage over topotecan monotherapy, German and Austrian researchers report in the July 1st issue of the Journal of Clinical Oncology.

‘Combination therapies,’ lead investigator Dr. Jalid Sehouli told Reuters Health, ‘were associated with higher toxicity, but progression-free survival and overall survival were not significantly different.’

Dr. Sehouli, of Humboldt University in Berlin, and colleagues explain in their paper that although topotecan monotherapy is an established treatment, there was evidence to suggest that combination therapy may provide better results.

To investigate further, the researchers studied 502 women in whom ovarian cancer recurred following primary surgery and platinum-based chemotherapy. They were randomized to receive either topotecan alone or in combination with etoposide or gemcitabine.

Median overall survival was not significantly different among the groups: 17.2 months with topotecan alone, 17.8 months with the etoposide combination and 15.2 months with the gemcitabine combination. There were no differences in either median progression-free survival or objective response rates.

The researchers note that the incidence of thrombocytopenia was lower with monotherapy (13.5%) than with the etoposide combination (21.5%) or gemcitabine combination (31.3%), and they conclude that combination therapy increases toxicity and does not provide a survival advantage.

‘Based on our results,’ Dr. Sehouli warns, ‘physicians should not harm their patients with such combination regimens.’”

Quoted Source: Topotecan Combo No Extra Help in Ovarian Cancer, by David Douglas, Matria Healthcare News, July 28, 2008 (summarizing the findings of Nonplatinum topotecan combinations versus topotecan alone for recurrent ovarian cancer: results of a phase III study of the North-Eastern German Society of Gynecological Oncology Ovarian Cancer Study Group; Sehouli J et. al., J Clin Oncol. 2008 July;26(19):3176-82.

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