OBJECTIVES: In nmCRPC and mCSPC, treatment with APA+ADT demonstrated significant clinical benefit versus placebo + ADT (ADT alone) in the SPARTAN and TITAN trials. APA+ADT was shown to be generally well tolerated with a safety profile similar to that of ADT alone. It is important to understand the impact of apalutamide on MRU; therefore, this analysis aimed to assess this across both studies.

METHODS: MRU data collected from SPARTAN and TITAN based on first interim analyses were obtained and analyzed. MRU types included emergency department and outpatient visits, hospitalizations, and others beyond those mandated within the trials. The median follow-up was slightly different for each study (20.3 months in SPARTAN and 22.7 months in TITAN). To correct for the different treatment durations across both groups, MRU types were analyzed by treatment cycle. A maximum of 45 cycles were available for the analysis in SPARTAN, and 13 cycles for TITAN.

RESULTS: In SPARTAN, there were 803 and 398 evaluable patients at baseline, and 4 and 0 evaluable patients at cycle 45 for APA+ADT and ADT alone, respectively. In TITAN, there were 524 and 527 evaluable patients at baseline, decreasing to 433 and 386 patients at cycle 13 for APA+ADT and ADT alone, respectively. MRU was low in all trial groups over the treatment cycles with no apparent differences seen between the APA+ADT and ADT alone groups in either study. In SPARTAN, the average probability of being hospitalized over all cycles was 3.3% for APA+ADT and 5.2% for ADT alone. The probability of hospitalizations in TITAN was 0.9% for both groups. Average emergency department visits in both groups was less than 1.3% in SPARTAN and less than 0.5% in TITAN.

CONCLUSIONS: The addition of APA to ADT does not increase MRU, indicating that this addition does not impact tolerability of the treatment regimen.