This article was adapted from an OncLive story posted on May 21, 2012.
Leonard G. Gomella, M.D, chair of the Department of Urology at Thomas Jefferson University Hospital and director of Clinical Affairs, Jefferson’s Kimmel Cancer Center, was part of the team to present new findings from the IMPACT trial looking at the immunotherapy sipuleucel-T (Provenge) in men with advanced prostate cancer.
The abstract was presented at the American Urological Association (AUA) Annual Meeting in Atlanta.
Results from the exploratory, multi-institutional analysis provides important insight into how the cross-over design of the IMPACT trial may have affected the overall survival findings, and supports a greater treatment effect of sipuleucel-T than previously reported.
In the study, researchers administered the vaccine APC8015F to a group of patients from the control arm of three randomized, Phase 3 clinical trials evaluating sipuleucel-T, a similar, FDA-approved cancer vaccine for metastatic castrate resistant prostate cancer.
APC8015F is made from immune system cells taken from a patient with prostate cancer; however, unlike sipuleucel-T, which is never frozen, APC8015F is cryopreserved at a time before the disease progressed.
Of the 249 men in the control arm, 155 received APC8015F. Those receiving APC8015F demonstrated similar benefits to those receiving sipuleucel-T. However, these patients were grouped with the placebo arm, when the benefits were calculated.
Removing the patients that received APC8015F and comparing just the patients that received placebo alone to those receiving sipuleucel-T alone more than doubles the 4.1-month median survival benefit found in the IMPACT trial.
“From my viewpoint, the benefit of sipuleucel-T has been understated because many of the patients who received the frozen product on the control actually enjoyed a longer survival, decreasing the difference between the control arm and the treatment arm,” Dr. Gomella tells OncLive.
“In fact, if you look at our analysis of the patients who received the frozen product on the control arm and those that did not receive it, there was a significant survival advantage to those patients who did receive the frozen product. So it actually made a difference between the control arm and treatment arm much closer. And if you actually take those patients out who did not receive the frozen product on the control arm, that survival difference actually approaches 10 to 11 months.”
Watch the full interview here: http://www.onclive.com/onclive-tv/Dr-Gomella-on-the-IMPACT-Trial-Survival-Benefit