Dendreon (DNDN) Shares Rise After Approval of Provenge

Thanks for posting Amy. If I can add a correction,

"In studies of men with advanced prostate cancer, this drug showed to extend lives by an average of about four months."

this is misinformation that is going around. Some patients have lived longer than 7 years after taking Provenge. The media is constantly mixing up the mean and the median.

This is from a lawsuit filed by CareToLive. Keep in mind that is from before the Impact trial results were in, which confirmed the survival benefit.

Appellee attempts to underwhelm the Court by stressing a 4.5 month “average” extension in survival to Provenge patients. That understates the effectiveness. Average is different from median. It’s an important distinction because misuse of the term "median survival" is one of the deceptive arguments used by those who are against Provenge approval (FDA). When anti-Provenge forces use the "average" terminology and attribute it to the median, they are undercutting the total Provenge beneficial effect. At the time of the committee meeting it is estimated that the actual average survival benefit in the 9901 trial was in the 10-12 month range, judging from the likely survival through Feb/Mar 2007 of 20 out of the 28 three-year survivors from 10/04. These 20 Provenge arm survivors would have lived anywhere from 5.5 to 7 years after their randomization between 1/00 and 10/01.
 All trials show that Provenge is efficacious by extending survival (D9901
and D9902a). Triple the survival after 3 years. All six clinical studies following PC patients after Provenge treatment have all demonstrated the effectiveness of Provenge. The Provenge arm had a median survival advantage of 4.5 months vs.the 21 control arm. The median survival is calculated from each arm by taking the survival time of the person in each arm at the 50th percentile. It does not reflect the true long term benefit of a treatment. The Appellee stresses that result because the layman tends to misinterpret it. Numerous patients are doing well on an ongoing basis at 5, 6 and even 7 years since receiving Provenge, whereupon the men who were randomized to placebo in these trials are nearly all dead. For example, say for two treatments, “a” and “b”, the median is a month. After a year all patients in group “a” are dead yet all remain alive in group “b”. The median stays the same in spite of the fact that many patients are still alive in “b”. The more stunning figure is the 34% survival after three years in the Provenge arm, vs 11% in the control arm. This is a disease stage where the typical survival was 16-19 months, so a 34% three-year survival is very impressive. Also, we knew that in March 2007, only 8 of the 28 three-year survivors in the 9901 trial had died (the calculations for the trial ended in Sept 2004). Therefore, this means that as of 3/07, 20 out of 82 men survived between 5.5 and 7.1 years (the enrollment period for 9901 was 1/00 to 9/01).
 03/05/08 Reply Brief of Appellant