Prostate Cancer Provenge Strong in Trial
Treatment Vaccine Improved Survival in Men With Advanced Prostate Cancer
Provenge Patients Lived Longer continued...
Penson also revealed that:
- Provenge improved three-year survival by 38%, with about 31% of patients who got the immunotherapy surviving this long, compared to 23% of the placebo-treated patients.
- Average survival among patients who got the active vaccine was slightly less than 26 months, compared to 22 months among patients in the placebo arm.
- The survival advantage seen among the Provenge-treated patients was similar to that reported in two smaller, company-sponsored trials comparing the immunotherapy to placebo. Patients in the three trials lived, on average, between 3.3 and 4.5 months longer than the placebo-treated patients.
- There was no statistically significant difference in disease progression between the two treatment groups. The two previous trials also failed to show that Provenge slows the progression of disease.
Dendreon plans to seek approval of the immunotherapy drug later this year, Gold said.
FDA Move Prompted Protests
The FDA considered, and rejected, such a request two years ago in a move that angered prostate cancer patients and patient advocates.
Considering evidence from the first two trials, an FDA board concluded that Dendreon had failed to prove that Provenge was both safe and effective.
The decision reportedly led to protests outside FDA headquarters by patients and company investors, and to death threats directed at board members who voted against approval.
It also led to the newly published trial, which Brawley says addresses many of the concerns about Provenge, if, as he says, “the results hold up to scrutiny.”
“I do believe this is the trial that needed to be completed in order to approve this treatment,” he says. “If it had been approved after the last FDA hearing there would have been a lot of questions that never would have been answered. I have seen the harm done when a bad drug is approved without adequate evaluation.”
Biostatician Donald Berry, MD, of Houston’s University of Texas M.D. Anderson Cancer Center, tells WebMD that the three studies together suggest that patients do benefit from the novel treatment. But he characterized the benefits as “marginal.”
“This is not the magic bullet that we had hoped for to cure cancer,” he says. “It is not a panacea.”