Talazoparib in Metastatic Castration-Resistant Prostate Cancer
Posted: Friday, April 10, 2020
The first interim analysis of the phase II TALAPRO-1 study of the PARP inhibitor talazoparib demonstrated antitumor activity in docetaxel-pretreated patients with metastatic castration-resistant prostate cancer, especially those with a BRCA1/2 mutation. The study, presented at the 2020 Genitourinary (GU) Cancers Symposium (Abstract 119) in San Francisco, was conducted by Johann S. De Bono, FRCP, MB, MD, PhD, of the Institute of Cancer Research, London, and colleagues.
“Talazoparib is unique in that it also traps polymerase inhibitors on DNA, interfering with cancer cell replication. This novel treatment works against prostate cancer cells, while selectively sparing normal cells in metastatic castration-resistant prostate cancer,” according to a press release from the American Society of Clinical Oncology.
A total of 81 patients with metastatic castration-resistant prostate cancer and DNA damage repair mutations received oral talazoparib at 1 mg/day. Patients were assessed until radiographic disease progression, unacceptable toxicity, or consent withdrawal. For the primary endpoint of objective response rate, there were 43 evaluable patients; of note, 20 had BRCA1/2 mutation, and 14 had ATM mutation.
The overall objective response rate was 25.6%. For patients with BRCA1/2 mutations, the objective response rate was 50%, compared with 7% for patients with ATM mutations. The median progression-free survival was 5.6 months overall. For patients with BRCA1/2 mutations, the progression-free survival was 8.2 months, compared with 3.5 months for patients with ATM mutations.
The investigators reported that talazoparib monotherapy “was generally well tolerated.” The most common treatment-emergent adverse events were anemia, nausea, asthenia, decreased appetite, constipation, and decreased platelet count.
Disclosure: The authors’ disclosure information can be found at coi.asco.org.
