THURSDAY, June 8, 2023 (HealthDay News) -- For patients with metastatic castration-resistant prostate cancer (mCRPC), talazoparib plus enzalutamide results in improvement in radiographic progression-free survival (rPFS), according to a study published online June 4 in The Lancet to coincide with the annual meeting of the American Society of Clinical Oncology, held from June 2 to 6 in Chicago.
Neeraj Agarwal, M.D., from the University of Utah in Salt Lake City, and colleagues conducted a randomized phase 3 trial of talazoparib plus enzalutamide versus placebo plus enzalutamide as first-line therapy for men with asymptomatic or mildly symptomatic mCRPC receiving ongoing androgen deprivation therapy from 223 hospitals, cancer centers, and medical centers in 26 countries. Patients were prospectively assessed for homologous recombination repair gene alterations in tumor tissue and randomly assigned to once daily talazoparib or placebo (402 and 203 patients, respectively).
The researchers found that the median rPFS was not reached for talazoparib plus enzalutamide and was 21.9 months for placebo plus enzalutamide at the planned primary analysis (hazard ratio, 0.63). The most common treatment-emergent adverse events were anemia, neutropenia, and fatigue in the talazoparib group; anemia was the most common grade 3 to 4 event (46 percent of patients), which improved after dose reduction and resulted in discontinuation in 8 percent of patients. No patients in the talazoparib group and two in the placebo group (<1 percent) had treatment-related deaths.
"Results from the primary analysis of the all-comers population of the TALAPRO-2 trial support the consideration of talazoparib plus enzalutamide as a first-line treatment option in patients with mCRPC," the authors write.
Several authors disclosed ties to pharmaceutical companies, including Pfizer, which manufactures talazoparib and enzalutamide and funded the study.