Charles Ryan, MD: The Efficacy of Abiraterone Plus Prednisone in an Elderly Patient Population

What is the efficacy of abiraterone plus prednisone in an elderly patient population?

So the elderly patient population, for the purposes of our analysis on the outcome of the COU-AA-302 study, was patients who were 75 years or older, and I personally know many men who are 75 or older who are quite young in terms of their physical health, but that was the definition. Now, with regards to the outcome, a couple of things are worth pointing out. One is that this was an analysis that was done post hoc after the study was enrolled, and there are really two comparisons to look at. One is radiographic progression-free survival and the other is overall survival.

Now, in both the elderly and the overall patient population, there was a benefit from the use of abiraterone compared to prednisone alone. In the elderly, however, the hazard ratio for survival was 0.81 compared to 0.71 in the younger patient population. It might be a little bit different because of the risk of other causes of death in older patients. But, in both cases there was a statistically significant, and I think meaningful, clinically significant improvement in the overall survival.

Radiographic progression-free survival is basically measuring how well does abiraterone plus prednisone, compared to prednisone alone, delay the progression of the disease in the bone and elsewhere. And, in that setting as well, the elderly enjoyed a benefit over the placebo arm that was statistically significant.

However, the outcomes were a little bit worse than they were for the younger patients. The elderly patients had a slightly greater risk of progressing, which is I think important to point out. But, again, when it comes to the final conclusion of this elderly analysis, it should be stated that abiraterone is a perfectly appropriate therapy for elderly patients. We did not see any toxicity that was specific to the elderly patient population that would lead us to think that we should avoid this drug in patients above 75. Personally, I’ve treated patients even in their 90s with this drug with reasonably good safety and good results.

CASE: Metastatic Prostate Cancer (Part 1)

Stanley S is an 83-year-old Caucasian male whose past medical history includes diagnosis of adenocarcinoma of the prostate in 2012 with no evidence of metastasis. At the time, he was started on bicalutamide and his serum PSA levels subsequently decreased to 1.2 ng/ml.

During his most recent follow-up exam, the patient complained of intermittent back pain and increasing fatigue.

• His serum PSA level is 56.9 ng/ml and his alkaline phosphatase is 258 U/L
• CT scan shows enlarged lumbar bone metastasis with associated soft tissue component, as well as symptomatic nodes with lumbar bone metastases
• Biopsies of the prostate and transrectal ultrasound reveal the prostate is 42 grams
• Ten of 14 cores are positive for prostate cancer for a Gleason score of 8 (4 + 4)
• His ECOG performance status score is a 2