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PURPOSE Pyrotinib, an irreversible pan-ErbB inhibitor, showed promising antitumor activity and acceptable tolerability in a phase I trial. We assessed the efficacy and tolerability of pyrotinib versus lapatinib, both in combination with capecitabine, in women with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer in an open-label, multicenter, randomized phase II study. PATIENTS AND METHODS Chinese patients with HER2-positive relapsed or metastatic breast cancer previously treated with taxanes, anthracyclines, and/or trastuzumab were assigned (1:1) to receive 400 mg pyrotinib or lapatinib 1,250 mg orally once per day for 21-day cycles in combination with capecitabine (1,000 mg/m2 orally twice per day on days 1 to 14). The primary end point was investigator-assessed overall response rate per Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1. RESULTS Between May 29, 2015, and March 15, 2016, 128 eligible patients were randomly assigned to the pyrotinib (n = 65) or lapatinib (n = 63) treatment groups. The overall response rate was 78.5% (95% CI, 68.5% to 88.5%) with pyrotinib and 57.1% (95% CI, 44.9% to 69.4%) with lapatinib (treatment difference, 21.3%; 95% CI, 4.0% to 38.7%; P = .01). The median progression-free survival was 18.1 months (95% CI, 13.9 months to not reached) with pyrotinib and 7.0 months (95% CI, 5.6 to 9.8 months) with lapatinib (adjusted hazard ratio, 0.36; 95% CI, 0.23 to 0.58; P < .001). The most frequent grade 3 to 4 adverse events were hand-foot syndrome in 16 of 65 patients (24.6%) in the pyrotinib group versus 13 of 63 (20.6%) in the lapatinib group; diarrhea in 10 patients (15.4%) versus three patients (4.8%), respectively; and decreased neutrophil count in six patients (9.2%) versus two patients (3.2%), respectively. CONCLUSION In women with HER2-positive metastatic breast cancer previously treated with taxanes, anthracyclines, and/or trastuzumab, pyrotinib plus capecitabine yielded statistically significant better overall response rate and progression-free survival than lapatinib plus capecitabine in this randomized phase II trial.

PURPOSE Targeted therapies against non–small-cell lung cancer (NSCLC) harboring HER2 mutations remain an unmet need. In this study, we assessed the efficacy and safety of pyrotinib in patients with HER2-mutant advanced NSCLC in a prospective, multicenter, open-label, single-arm, phase II study. PATIENTS AND METHODS Patients with stage IIIB or IV HER2-mutant lung adenocarcinoma who were previously treated with platinum-based chemotherapy were enrolled to receive pyrotinib at a dose of 400 mg/d for 21-day cycles. The primary end point was objective response rate per independent review committee (IRC). RESULTS Between October 20, 2016, and December 10, 2018, 60 patients received pyrotinib monotherapy. At baseline, 58 (96.7%) were stage IV, and 25 (41.7%) received at least 2 lines of prior chemotherapy. As of data cutoff on June 20, 2019, IRC-assessed objective response rate was 30.0% (95% CI, 18.8% to 43.2%). All subgroups of patients with different HER2 mutation types showed a favorable objective response rate. The objective response rates were similar between patients with and without brain metastases (25.0% v 31.3%). The median duration of response was 6.9 months (95% CI, 4.9 to 11.1 months). The median progression-free survival was 6.9 months (95% CI, 5.5 to 8.3 months) per IRC. The median overall survival was 14.4 months (95% CI, 12.3 to 21.3 months). Treatment-related adverse events of grade 3 or 4 occurred in 28.3% of patients, with the most common being diarrhea (20.0%; all grade 3). No treatment-related deaths were reported. CONCLUSION Pyrotinib showed promising antitumor activity and an acceptable safety profile in chemotherapy-treated patients with HER2-mutant NSCLC.

Triple-negative breast cancer (TNBC) is a highly heterogeneous disease, and molecular subtyping may result in improved diagnostic precision and targeted therapies. Our previous study classified TNBCs into four subtypes with putative therapeutic targets. Here, we conducted the FUTURE trial (ClinicalTrials.gov identifier: NCT03805399), a phase Ib/II subtyping-based and genomic biomarkerguided umbrella trial, to evaluate the efficacy of these targets. Patients with refractory metastatic TNBC were enrolled and stratified by TNBC subtypes and genomic biomarkers, and assigned to one of these seven arms: (A) pyrotinib with capecitabine, (B) androgen receptor inhibitor with CDK4/6 inhibitor, (C) anti PD-1 with nab-paclitaxel, (D) PARP inhibitor included, (E) and (F) anti-VEGFR included, or (G) mTOR inhibitor with nab-paclitaxel. The primary end point was the objective response rate (ORR). We enrolled 69 refractory metastatic TNBC patients with a median of three previous lines of therapy (range, 1-8). Objective response was achieved in 20 (29.0%, 95% confidence interval (CI): 18.7%-41.2%) of the 69 intention-to-treat (ITT) patients. Our results showed that immunotherapy (arm C), in particular, achieved the highest ORR (52.6%, 95% CI: 28.9%-75.6%) in the ITT population. Arm E demonstrated favorable ORR (26.1%, 95% CI: 10.2%-48.4% in the ITT population) but with more high grade (≥ 3) adverse events. Somatic mutations of TOP2A and CD8 immunohistochemical score may have the potential to predict immunotherapy response in the immunomodulatory subtype of TNBC. In conclusion, the phase Ib/II FUTURE trial suggested a new concept for TNBC treatment, demonstrating the clinical benefit of subtyping-based targeted therapy for refractory metastatic TNBC.

Background: Pyrotinib is an irreversible pan-ErbB inhibitor targeting epidermal growth factor receptor, human epidermal growth factor receptor 2 (HER2), and HER4. This randomized, double-blinded phase 3 study evaluated the efficacy and safety of pyrotinib plus capecitabine for HER2-positive local relapsed or metastatic breast cancer.Methods: Patients who had been treated with trastuzumab and taxanes were randomized (2:1) to receive either oral pyrotinib or placebo (400 mg, qd) plus capecitabine (1,000 mg/m 2 , bid on days 1-14) for 21-day cycles, using stratified block randomization. The primary endpoint was progression-free survival (PFS) per independent review committee. Patients who progressed on placebo plus capecitabine received subsequent pyrotinib monotherapy. This study is registered with ClinicalTrials.gov (NCT02973737), enrollment is closed.