Randomized, open-label phase II study of brigatinib and carboplatin plus pemetrexed and brigatinib alone for chemotherapy-naive patients with ALK-rearranged non-squamous non-small cell lung cancer: treatment rationale and protocol design of the B-DASH study (WJOG 14720 L)

BACKGROUND: The ALTA-1L study compared brigatinib with crizotinib in untreated ALK-rearranged non-small cell lung cancer (NSCLC) patients, demonstrating the efficacy of brigatinib. Although the median progression-free survival (PFS) of brigatinib group was 24.0 months, the one-year PFS rate was 70%. In the NEJ009 study, patients with EGFR mutations showed improved outcomes with gefitinib plus chemotherapy compared with gefitinib monotherapy. To evaluate the efficacy of the combination of brigatinib with chemotherapy for patients with ALK-rearranged NSCLC, we designed B-DASH study (WJOG 14720L). METHODS: B-DASH study is a multicenter, two-arm, phase II study. Eligible patients have untreated stage IIIB, stage IIIC, stage IV, or postoperative relapse ALK-rearranged nonsquamous NSCLC. Patients will be randomized in a 1:1 ratio to receive brigatinib (180 mg once daily with a 7-day lead-in period at 90 mg) monotherapy or carboplatin (area under the curve = 5 on day 1) plus pemetrexed (500 mg/m(2) on day 1) and brigatinib in a 3-week cycle for up to four cycles, followed by pemetrexed and brigatinib as maintenance therapy. The target hazard ratio of 0.62 is set based on the NEJ009 study. With one-sided alpha = 0.20 and power = 0.8, the sample size for the B-DASH study was calculated to be 110, considering the possibility of patients dropping out. The primary endpoint is PFS. The key secondary endpoints are the overall response rate and overall survival. We will evaluate tumor-derived DNA from plasma specimens before treatment, 42 days after administering the study drug, and on the day of progressive disease. Recruitment began in November 2021 and is ongoing. DISCUSSION: The efficacy of combination therapy with tyrosine kinase inhibitors and cytotoxic chemotherapy was demonstrated in patients with EGFR mutations but remains unclear in patients with ALK-rearranged NSCLC. The B-DASH study is the only trial of brigatinib combined with chemotherapy in patients with untreated ALK-rearranged NSCLC. TRIAL REGISTRATION: jRCT identifier: jRCTs041210103.