`
`www.medscape.com
`Phase 3 Trial of Immunotherapy for Metastatic Prostate Cancer
`Terminated
`October 17, 2008
`Nick Mulcahy
`October 17, 2008 — A phase 3 clinical trial of an immunotherapy in patients with asymptomatic metastatic hormone-
`refractory prostate cancer has been terminated by its corporate sponsor, Cell Genesys, Inc, of South San Francisco,
`California, because of a lack of effect on survival, the company announced.
`
`The trial was fully enrolled in 2007 with 626 patients and compared GVAX immunotherapy with docetaxel (Taxotere,
`Sanofi-Aventis) chemotherapy plus prednisone.
`
`"I have not lost my conviction that immunotherapy will play a role in the treatment of this disease," said Stephen A.
`Sherwin, MD, chair and chief executive officer of Cell Genesys, in a press conference call with reporters. "There's a
`huge amount of preclinical and early clinical data suggesting the activity of this platform [GVAX ], and that's why I
`remain optimistic."
`
`In speculating about the failure of trial, Dr. Sherwin said: "Perhaps metastatic prostate cancer, even though it's less
`aggressive than other cancers, is simply just too tough a target for a slow-acting immunotherapy such as GVAX."
`
`Dr. Sherwin also wondered if the company had "raised the bar too high in these phase 3 trials when we put GVAX
`up against an active chemotherapy drug."
`
`The company ended the trial based on the results of an unplanned futility analysis conducted by the study's
`Independent Data Monitoring Committee (IDMC), which indicated that the trial had less than a 30% chance of
`meeting its prespecified primary end point of an improvement in survival.
`
`The termination of the VITAL-1 phase 3 clinical trial of GVAX immunotherapy follows the termination, on August 27,
`2008, of VITAL-2, another phase 3 trial involving the therapy.
`
`In contrast to the VITAL-1 study, the VITAL-2 study was conducted in patients with symptomatic metastatic
`hormone-refractory prostate cancer and compared the combination of GVAX immunotherapy plus docetaxel to
`docetaxel plus prednisone (the control group).
`
`When the VITAL-2 study was terminated, the IDMC reported an imbalance in deaths between the 2 treatment
`groups that was observed during a routine safety-monitoring meeting of the committee. Of 114 deaths at the time of
`the IDMC review, 67 occurred in the group receiving GVAX immunotherapy plus docetaxel, and 47 occurred in the
`group receiving docetaxel plus prednisone. A total of 408 patients had been enrolled in the study up to that point.
`
`Cell Genesys has now conducted an initial analysis of the incomplete VITAL-2 dataset that was reviewed by the
`IDMC in August, and Dr. Sherwin provided an update during the press conference. The analysis has revealed no
`imbalance in patient baseline characteristics with respect to demographic and disease prognostic factors. In
`addition, no significant toxicities were observed with GVAX immunotherapy plus docetaxel that could explain the
`imbalance in deaths. The vast majority of deaths in both treatment groups were reported as being due to the
`progression of prostate cancer.
`
`Notably, fewer treatment cycles with docetaxel were administered to patients receiving GVAX immunotherapy than
`to those receiving prednisone, said Dr. Sherwin, and the difference was statistically significant.
`
`GVAX immunotherapy, an intradermal injection administered on an outpatient basis for prostate cancer, is
`comprised of 2 prostate tumor cell lines that have been modified to secrete granulocyte-macrophage colony-
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`http://www.medscape.com/viewarticle/582220_print
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`4/17/2015
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`JANSSEN EXHIBIT 2082
`Amerigen v. Janssen IPR2016-00286
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`stimulating factor (GM-CSF), an immune-stimulatory cytokine that plays a key role in stimulating the body's immune
`response, and then irradiated for safety. Dr. Sherwin called GM-CSF a "powerful cytokine," and noted that it is used
`"across the board in immunotherapy trials as an adjunctive therapy" because of its potency.
`
`Cell Genesys has put on hold the further development of GVAX immunotherapy for prostate cancer pending a
`review of the program with its collaborator, Takeda Pharmaceutical Co. Ltd.
`
`Dr. Sherwin thanked the patients in the study during his press conference. "On behalf of the Cell Genesys
`management team, I would like to express my deep gratitude to the courageous patients who participated in this
`study, as well as to our committed clinical-trial investigators and their teams."
`
`As a result of the terminated clinical trials, Cell Genesys will reduce its staff of 290 by approximately 75% by year-
`end, with further reductions anticipated in the first half of 2009 as additional activities are phased out, according to
`Dr. Sherwin.
`
`Medscape Medical News © 2008
`
`Cite this article: Nick Mulcahy. Phase 3 Trial of Immunotherapy for Metastatic Prostate Cancer
`Terminated. Medscape. Oct 17, 2008.
`
`http://www.medscape.com/viewarticle/582220_print
`
`4/17/2015