FRIDAY, Feb. 17, 2023 (HealthDay News) -- For patients with metastatic castration-resistant prostate cancer (mCRPC), treatment with talazoparib (TALA) plus enzalutamide (ENZA) is better than placebo (PBO) plus ENZA, according to a study presented at the American Society of Clinical Oncology annual Genitourinary Cancers Symposium, held from Feb. 16 to 18 in San Francisco.
Neeraj Agarwal, M.D., from the University of Utah in Salt Lake City, and colleagues randomly assigned patients with mildly symptomatic or asymptomatic mCRPC, with disease progression and receiving androgen deprivation therapy and no prior life-prolonging therapy for CRPC, to receive TALA + ENZA or PBO + ENZA as first-line treatment (402 and 403 patients, respectively).
The researchers found that the median imaging-based progression-free survival (ibPFS) was significantly improved in the TALA + ENZA arm compared with the PBO + ENZA arm (not reached versus 21.9 months; hazard ratio, 0.63). In homologous recombination repair (HRR)-deficient, HRR-nondeficient or unknown, and HRR-nondeficient patients, ibPFS was improved significantly in the TALA + ENZA versus PBO + ENZA arm (hazard ratios, 0.46, 0.70, and 0.66, respectively). Overall survival data were immature. The TALA + ENZA arm was significantly favored for objective response rates, prostate-specific antigen (PSA) response ≥50 percent and time to PSA progression, and use of subsequent cytotoxic chemotherapy and antineoplastic therapy.
"Not only did the combination therapy delay disease progression, it also significantly delayed progression of PSA readings and the time until chemotherapy was needed compared to the control group," Agarwal said in a statement.
The study was partially funded by Pfizer, the manufacturer of talazoparib; Astellas Pharma provided enzalutamide.