Provenge survival rates, also referred to as the overall survival benefit, have been reported as 4.1 months. This is the Provenge survival rates data upon which the Food and Drug Administration (FDA) granted its approval of Provenge for prostate cancer treatment. However, that figure may be low–by about twofold and possibly more. How could this be?
For men who have been reading or following information about Provenge (sipuleucel-T), the immunotherapy for men with asymptomatic or minimally symptomatic metastatic prostate cancer that has not responded to hormone therapy, the following news about overall Provenge survival rates should be of interest. According to an article at SeekingAlpha.com, data from the Provenge trial were “corrupted” because some of the men in the three placebos arms of the three trials crossed over and took Frovenge (also known as APC8015F), which is a frozen form of Provenge.
In a nutshell, this is what researchers found, as reported in a paper presented during the first week of October 2012 at the European Society for Medical Oncology meetings. The investigators reported that 145 of the 249 men who were in the control groups of the three randomized controlled trials of sipuleucel-T were offered and completed three treatments with APC8015F, which was made from the frozen (cryopreserved) cells collected from the men at the time they were chosen as controls. The patients were given these infusions at an average of 5.2 months after they were randomized to their control group.
The findings concerning Provenge survival rates were as follows:
- Median overall survival for the 488 men treated with Provenge was 25.4 months
- Median overall survival for the 249 controls was 21.5 months
- Therefore, the overall survival advantage associated with Provenge was 4.1 months
- Among the 145 (165 recruited and 145 completed) men in the control groups who were subsequently given frozen Provenge, median overall survival was 23.6 months versus 12.7 months for men who did not receive frozen Provenge
After using a rank-preserving structural failure time model to adjust the findings, the authors reported “an 8.1 month median increase in OS [overall survival] with sipuleucel-T,” and a possibility it may be as high as 12.7 months.
Therefore, the 4.1 month increase in overall Provenge survival rates reported in the study that accompanied approval of Provenge by the FDA appears to be low by a factor of at least two and possibly three.
If you wonder whether Provenge is right for you, consult your healthcare provider and ask about the results of these and other studies of this unique immunotherapy for prostate cancer. And stay tuned: who knows what research findings will turn up next!
Read more in our Prostate Cancer Health Center.