THE "NEW" PROSTATE CANCER INFOLINK

There are three major prostate cancer research studies that we expect or hope to hear results from at some time in 2011.

The first of these studies is the Prostate Cancer Intervention Versus Observation Trial or PIVOT, originally initiated in 1994. PIVOT is a randomized trial designed to compare active intervention with radical prostatectomy to “palliative expectant management” in men initially diagnosed with clinically localized prostate cancer. What this actually means is that men were randomized to immediate and potentially curative surgery (followed by aggressive intervention such as radiation therapy for disease recurrence) or to watchful waiting (followed by palliative radiation and hormone therapy as necessary). We know that this trial is “completed,” so it is reasonable to expect that results will be presented at one of the major prostate cancer meetings this year — the first opportunity being the Genitourinary Cancers Symposium in February.

We already know, from an  article by Wilt et al. published back in 2008, that :

• 13,022 men were screened at 52 United States medical centers for potential enrollment.
• 5,023 patients met initial age, comorbidity, and disease eligibility criteria.
• 731 men agreed to participate and were randomized.
• The mean age of enrollees was 67 years.
• Nearly one-third were African-American.
• The median PSA level of the enrollees was 7.8 ng/ml (mean 10.2 ng/ml).

It will be apparent from these data that patient enrollment was a problem, with only 14.5 percent of eligible patients agreeing to participate. (The trial was originally designed to enroll 1,050 participants and take just 7 years to complete.) We also expect the results of this trial to be “politicized” since they will provide data specific to the question of the comparative value of two “standard” forms of management of localized prostate cancer.

The second major trial that we hope to see results from this year is the AFFIRM study — a randomized Phase III clinical trial comparing MDV3100 to placebo in men with metastatic, castration-resistant prostate cancer (mCRPC) who have already received docetaxel-based chemotherapy. We know that this trial was fully enrolled (with 1,199 patients before the end of November 2010). It is therefore very possible, but not certain, that the trial will report results late in 2011.

The third significant study that might report results in 2011 is the randomized Phase III clinical trial comparing abiraterone acetate + prednisone to a placebo + prednisone in men who have chemotherapy-naïve mCRPC. We already know that abiraterone + prednisone was able to extend overall survival compared to a placebo + prednisone by just under 4 months in men with mCRPC who had already been treated with docetaxel-based chemotherapy. The question is whether it is capable of doing better in men who were chemotherapy-naïve at the time of study enrollment.

The trial in question was fully enrolled relatively early in 2010, with about 1,000 patients. It is unclear whether results of this trial will be available in 2011 — for a variety of reasons. Some time in early 2012 may be more likely. We do, however, expect the U.S. Food & Drug Administration to approve abiraterone acetate for the treatment of men with mCRPC who have progressive disease after docetaxel-based chemotherapy. We are optimistic that this will happen within the first 6 months of 2011.

We hope, of course, that there will be other major and positive news items on the prostate cancer front in this new year — but these are the three items we will be watching for specifically.

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