Toxicity-Benefit analysis of advanced prostate cancer trials using weighted toxicity scoring

Background The weighted toxicity score (WTS) is a metric suitable for comparing the toxicity burden in experimental versus control arms of randomized controlled trials (RCTs). When paired with clinical endpoints, the WTS offers a framework to evaluate the toxicity-benefit profile of anti-cancer agents. This study applied the WTS to phase III advanced prostate cancer (PC) clinical trials. Methods Select phase III PC RCTs with adverse event (AE) data were compiled. The WTS was calculated for each arm using two approaches: (1) all AEs (A-WTS) and (2) symptomatic AEs (S-WTS). Percent change in WTS between trial arms quantified the toxicity burden, while hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) were used to assess efficacy. Results Seventeen RCTs were analyzed (investigational agents: androgen-receptor signaling inhibitors [ARSi, n = 4], poly (ADP-ribose) polymerase inhibitor monotherapy [PARPi, n = 2], ARSi + PARPi [n = 3], ARSi + ARSi [n = 3], triplet therapy [n = 3], and docetaxel as well as Lutetium-177 (177Lu)–PSMA-617) [n = 1 each]). Overall, toxicity and efficacy were greater among experimental than control arms (median A-WTS 6.62 vs 4.10; median S-WTS 3.91 vs 3.08; median HR for OS 0.75, median HR for PFS 0.61). ARSi + PARPi studies observed the highest average A-WTS increase (78%), whereas ARSi + ARSi and triplet therapy trials noted the lowest average A-WTS increases (31% and 32%, respectively) with favorable clinical outcomes. Conclusions RCTs demonstrated increased toxicity in experimental arms relative to controls, with both toxicity and survival outcomes varying across therapeutic strategies.