One of the constant complaints I hear fro men with advanced prostate cancer that has become castrate resistant about Provenge (sipuleucel-T) is that the anticipated increase in overall survival is only 4.1 months and given the cost of $93,000 for the three infusions many men feel that cost does not justify the survival benefit.
My initial response to this issue came in my posts:
Provenge, It Isn’t Over Priced, Its Actually A Bargain Basement Product and
Can Our Society Find Its Way To An Honest Dialogue About The Price Of A Human Life?.
Since that time I have expanded my argument because the actual survival advantage might be even longer than the numbers used to obtain the FDA approval. I wrote about the “crossover” when men who had been in the control group went on to receive a frozen version of Provenge (also known as APC8015F or Frovenge), but were still considered to be in the control group or as if they had not received Provenge.
At the AUA Meeting – Does Provenge Provide Better Survival Numbers?
Also not often discussed is what seems to be an extraordinary survival advantage gained by African American men
African American Men With Advanced Prostate Cancer May Gain Significant Benefit From Provenge (Sipuleucel-T)
Now, researchers at the European Society for Medical Oncology meetings reported in a paper that 145 of the 249 men who were in the control groups of the three randomized controlled trials of Provenge were offered and completed three treatments with APC8015F. These men in the control group were given APC8015F at an average of 5.2 months after they were randomized to their control group.
The findings 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 survival 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.
So, I ask again, is Provenge a good economic value? I thought so before, now I know so.
Joel T Nowak, M.A., M.S.W.
Good work on getting the word out. There’s no question that the evidence continues to mount: Provenge extends life with minimal to no impact on the patients quality of live.
That said, a lot of people simply don’t understand the math involved in talking about trial results. This is especially true of the popular media, the members of which collectively must have failed 6th grade math!
Instead of talking about a 4.1-month MEDIAN—not average—survival advantage demonstrated in the pivotal, 512-patient Phase 3 IMPACT study (which, admittedly, some people find difficult to understand because of the statistics involved), perhaps it would be better simply to talk about a 38% improvement in 3-year survival (31.7% survival rate at three years on the treatment arm compared to 23% for the control arm) and/or a 22.5% improvement in risk of dying. Put another way, the odds of a patient treated with Sipuleucel-T, which is the generic name for Provenge, surviving at 3 years was about one in three comparing to the odds of about one in five for an untreated patient. Think about it this way: If you are a man 70 years old or older with metastatic prostate cancer, would you consider a treatment that would give you a chance of one in three to live 3 years longer instead of doing nothing and taking a chance of one in five or even less of living that long? I know what my answer would be!