talazoparib + temozolomide

Talazoparib + temozolomide is a combination therapy under clinical investigation for cancer, particularly pediatric, adolescent, and adult solid tumors such as recurrent or refractory Ewing sarcoma, malignant glioma, and metastatic castration-resistant prostate cancer. Talazoparib is a potent inhibitor of poly(ADP-ribose) polymerase (PARP) 1 and 2, causing inhibition of PARylation and trapping PARP-DNA complexes, which prevents DNA single-strand break repair and results in cytotoxic DNA damage. Temozolomide is an oral alkylating agent that induces DNA damage by methylating DNA, particularly at the O6 and N7 positions of guanine, leading to single-strand DNA breaks and cell death. The rationale for the combination is synergy: temozolomide increases DNA damage, while talazoparib impairs the cell’s ability to repair that damage, thereby increasing tumor cell death. The combination has been studied in phase 1/2 clinical trials in pediatric solid tumors and metastatic castration-resistant prostate cancer. Hematologic toxicity (neutropenia, thrombocytopenia, anemia) is the main dose-limiting toxicity observed, and clinical responses have included prolonged stable disease and occasional partial responses[1][3].