Expert Analyzes Efficacy/Safety Data for Apalutamide and ADT in Prostate Cancer

Vitaly Margulis, MD, professor of urology at UT Southwestern Medical Center, reflects on the secondary end points findings and safety data from the Apa-RP study (NCT04523207) which evaluated adjuvant treatment with apalutamide and androgen deprivation therapy (ADT) in patients with high-risk localized prostate cancer.

According to Margulis, the serum testosterone recovery event rate was 76.4% (95% CI, 65.0-84.5) at 12 months after the completion of treatment completion.

The safety profile of the combination was fairly mild, however, treatment-emergent adverse events (TEAEs) were seen in 99.1% (n = 107) patients during the study, 22.2% (n = 24) of which were grade 3 or 4. A total of 14.8% (n = 16) of these TEAEs were serious AEs, and 13.0% (n = 14) required treatment dose reduction or interruption. Further, 10.2% (n = 11) of patients discontinued treatment due to their AEs.

Transcription:

0:09 | The downside of this particular treatment is that it is essentially a chemical castration for these patients for the duration of the treatment. And the question is, what happens when patients discontinue treatment? It is always a concern that patients or some patients may never recover, for example, their testosterone levels and remain castrate for their lifetime. Certainly this study indicates that, at least when the data was assessed, 75% of patients were able to recover their testosterone levels. So again, indicating that there is recovery, recovery happens for the majority of the patients, and I suspect that the recovery will continue to happen with the various data points.

0:58 | So first of all, apalutamide and ADT is a combination that has been studied in multiple clinical trials. Thousands of patients have been treated with this particular combination, and there is no signal here that we have not seen before. The [adverse] effect profile was fairly mild. I think less than 50% of the patients required treatment interruption or discontinuation, meaning that most patients were able to tolerate the treatment very well. And again, there was nothing unusual. There were [adverse] effects that have not been seen with the utilization of this combination before.