Apalutamide benefit sustained in mCSPC regardless of next therapy

SAN FRANCISCO – Early use of the androgen receptor antagonist apalutamide for metastatic castration-sensitive prostate cancer has a sustained carry-over benefit regardless of subsequent therapy, an exploratory analysis of the TITAN trial suggests.

^{Susan London/MDedge News}

Dr. Neeraj Agarwal

Previous trial results for all 1,052 men randomized showed significant improvements in radiographic progression-free survival and overall survival from adding apalutamide versus placebo to androgen deprivation therapy (N Engl J Med. 2019;381:13-24), leading to recent Food and Drug Administration approval of the drug for metastatic castration-sensitive prostate cancer.

In the new analysis, investigators assessed progression-free survival 2 (PFS2), measured from time of randomization to investigator-determined disease progression or death, among the 277 men who went on to receive a subsequent life-prolonging therapy after progression on their trial therapy.

Results reported at the 2020 Genitourinary Cancers Symposium showed that the risk of PFS2 events was similarly reduced for patients who had initially received apalutamide vs. placebo regardless of whether their next therapy was a new hormonal therapy (32% reduction in risk) or a taxane (37% reduction in risk).

“The PFS2 benefit is an indicator of effective early intensification of treatment, is consistent with the overall survival benefit we have seen with this agent, and together shows totality of the treatment trajectory,” reported Neeraj Agarwal, MD, the study’s lead investigator. “These results may assist with counseling of patients with metastatic castration-sensitive prostate cancer who are contemplating various treatment options.”

The analysis was performed post hoc, and the subsequent therapy was left up to the treating clinicians, acknowledged Dr. Agarwal, professor of medicine and director of the genitourinary oncology program at the Huntsman Cancer Institute, University of Utah, Salt Lake City.

“A small number of events on subsequent therapy and the nonrandomized treatment decision preclude determination of best subsequent therapy based on these data,” he said. “We need further events and for data to mature more in order to pursue additional in-depth analysis.”