Dr. Hadaschik on Treatment After Apalutamide Progression in SPARTAN Trial

Boris A. Hadaschik, MD, is director, chair, the Department of Urology, Essen University Hospital, University of Duisburg-Essen, Essen, Germany, vice director, the West German Cancer Center Consortium, discusses a post-hoc analysis of subsequent therapies received by patients with prostate cancer treated with apalutamide (Erleada) during the phase 3 SPARTAN trial (NCT01946204).

The study originally evaluated the efficacy and safety of apalutamide in adult men with high-risk non-metastatic castration-resistant prostate cancer (CRPC). In a post-hoc analysis presented at the 2023 Genitourinary Cancers Symposium, investigators explored the efficacy of subsequent treatment for patients who progressed to mCRPC following treatment with apalutamide and androgen deprivation therapy (ADT). Findings showed that patients experienced comparable overall survival and progression-free survival in first-line mCRPC, irrespective of subsequent treatment choice.

In this post-hoc analysis, investigators examined patients who received subsequent treatment with abiraterone acetate (Zytiga), docetaxel, enzalutamide (Xtandi), or other agents. Since treatment with one androgen receptor (AR)–targeted therapy failed for the patients who progressed, some physicians may have been hesitant to use another AR inhibitor in the first-line setting for mCRPC, prompting them to switch to chemotherapy or another treatment, Hadaschik starts. Notably, these subsequent treatments were given before the era of combining treatments within AR-targeted agents and PARP inhibition, as well as the emergence of lutetium Lu 177 vipivotide tetraxetan (Pluvicto; formerly 177Lu-PSMA-617); therefore, investigators limited the post-hoc analysis to comparing AR-targeted agents and chemotherapy, Hadaschik explains.

In this population of patients who were high risk and had poor prognostic disease, there was not a big difference between chemotherapy and abiraterone as a subsequent therapy, Hadaschik says, adding that it supports an earlier observation looking at genetic changes caused by apalutamide. Additionally, clinicians did not see an accumulation of high-risk features.

Overall, these data a reassuring that when beginning with apalutamide in the non-metastatic setting, clinicians can have different therapy choices in the metastatic setting. Investigators are continuing a similar post-hoc analysis for the phase 3 TITAN trial (NCT02489318), which investigated apalutamide plus ADT vs ADT alone patients with metastatic hormone-sensitive prostate cancer, Hadaschik concludes.