Currently in Orlando Florida the 2013 American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium is in progress. There are a number of very interesting abstracts that pertain to those of us who have advanced prostate cancer. In the course of the next few days I will be reviewing a number of these that I believe are of special interest to us survivors of advanced prostate cancer.

Today’s review includes two abstracts about Provenge (Sipuleucel-T).

Because of the number of recently approved new treatments for advanced prostate cancer we are now wrestling with the issue how to sequence (in what order should the drugs be taken) and which drugs should be combined (in the manner we currently use treatments for AIDES).

The first is Abstract (#34) speaks to the sequencing of two FDA approved treatments, specifically Provenge and hormone therapy (ADT) in men with biochemically recurrent prostate cancer (BRPC or a PSA only recurrence). The data presented came from a Randomized Phase II Trial.

In the trial, Provenge was either followed by ADT or ADT was administered followed by Provenge. The results showed a prime-boost immune response effect based on antigen presenting cell activation patterns, and an analysis off serum samples indicated that there were no differences between the arms in cellular or serum immune responses. Bottom line, the order of the sequencing had no difference in the immune response of the men.

This study did not evaluate survival differences. Additionally, they found that the adverse events for each treatment were consistent with what was seen in pivotal trials.

The results of Abstract #114 were more surprising to me. It was a Randomized Phase II, Open-Label Study of Provenge with Concurrent (at the same time) or Sequential Abiraterone Acetate with prednisone (AA +P) in men with Metastatic Castrate–Resistant Prostate Cancer (mCCRPC). The trial demonstrated no significant differences in median cumulative CD54 up-regulation (31.6 vs. 36.6), or the measure of antigen presenting cell activation, and CCD54+ count (1.9 vs. 2.1) between the two arms, suggesting that Provenge can be administered during treatment with AA + P therapy. Adverse events for each treatment were consistent with what was seen in pivotal trials.

See a video about these finds from Malecare’s partner Patient Power by clicking HERE

This result was surprising because current thinking is that taking a steroid like prednisone would work against the development of a strong immune response. Currently, most oncologists delay the use of AA + P to provide time for the immune system do develop a robust response.

Joel T. Nowak, M.A., M.S.W.