Simon's two-stage optimization method is used to estimate the sample size. The first kind of error α Set to 0.1, type II error β Set to 0.25, P0 to 30%, P1 to 44%. 22 patients were enrolled in the first stage. If the number of effective cases ≤ 6, the trial was terminated. Otherwise, continue to enroll 26 patients in the second stage. If the number of effective cases in the two stages is ≤ 18, there is no need to further study the drug. Assuming an abscission rate of 5%, it is estimated that 50 subjects will be enrolled in the trial.
The incidence of homologous recombination deficiency in metastatic triple negative breast cancer was 52%-59%，PARP plays a key role in sensing DNA damage and converting it into intracellular signals that activate the base excision repair (BER) and single-strand break repair pathways. Treatment with PARP inhibitors could represent a novel opportunity to selectively kill a subset of cancer cells with deficiencies in DNA repair pathways. This is a multicenter, single-arm, phase II study evaluating the efficacy and safety of niraparib in patients with HRD positive metastatic triple negative breast cancer.