ESMO 2021: TALAPRO-3: A Phase 3, Double-blind, Randomized Study of Enzalutamide Plus Talazoparib vs Placebo Plus Enzalutamide in Patients with DDR Gene Mutated Metastatic Castration-sensitive Prostate Cancer (mCSPC)

( Poly (ADP-ribose) polymerase inhibitors provide clinical benefit across multiple cancers with germline or somatic alterations in the BRCA1 and BRCA2 genes, as well as other select genes within the homologous recombination DNA repair pathway. The PARP inhibitors olaparib and rucaparib are approved for use in metastatic castration-resistant prostate cancer (mCRPC) in patients harboring certain genomic alterations in the DNA damage repair pathway. Talazoparib is another PARP inhibitor, which in a phase 2 study (TALAPRO-1) demonstrated anti-tumor activity in men with mCRPC harboring alterations in homologous recombination repair. Interestingly, androgen pathway inhibitors such as enzalutamide have been shown to downregulate the expression of homologous recombination repair genes, resulting in a BRCA-like phenotype in cancer cells. To test the hypothesis that the addition of PARP inhibition to enzalutamide can improve clinical outcomes of enzalutamide alone, Dr. Aggarwal and colleagues presented the TALAPRO-2 trial.

This study is a phase 3, double-blind, randomized clinical trial (NCT04821622) that will compare the combination of enzalutamide +/- talazoparib in patients with metastatic castration sensitive prostate cancer harboring alterations in 12 DNA damage repair genes (ATM, ATR, BRCA1, BRCA2, CDK12, CHEK2, FANCA, MLH1, MRE11A, NBN, PALB2, RAD51C). The primary endpoint is radiographic progression-free survival, with secondary endpoints including overall survival.

Presented by: Neeraj Aggarwal, MD, Huntsman Cancer Institute at the University of Utah, Salt Lake City, Utah

Written by: Alok Tewari, MD, PhD – Genitourinary Medical Oncologist, Instructor in Medicine, Dana-Farber Cancer Institute, Harvard Medical School, Twitter: @aloktewar during the 2021 European Society for Medical Oncology (ESMO) Annual Congress 2021, Thursday, Sep 16, 2021 – Tuesday, Sep 21, 2021.