Ibrutinib in combination with nab-paclitaxel and gemcitabine for first-line treatment of patients with metastatic pancreatic adenocarcinoma: phase III RESOLVE study

Background: First-line treatment of metastatic pancreatic ductal adenocarcinoma (PDAC) includes nab-paclitaxel/gemcitabine. Ibrutinib, a Bruton's tyrosine kinase inhibitor, exhibits antitumor activity through tumor microenvironment modulation. The safety and efficacy of first-line ibrutinib plus nab-paclitaxel/gemcitabine treatment in patients with PDAC were evaluated. Patients and methods: RESOLVE (NCT02436668) was a phase III, randomized, double-blind, placebo-controlled study. Patients (histologically-confirmed PDAC; stage IV diagnosis >6 weeks of randomization; Karnofsky performance score >70) were randomized to once-daily oral ibrutinib (560 mg) or placebo plus nab-paclitaxel (125 mg/m(2)) and gemcitabine (1000 mg/m(2)). Primary endpoints were overall survival (OS) and investigator-assessed progression-free survival (PFS); overall response rate and safety were assessed. Results: In total, 424 patients were randomized (ibrutinib arm, n = 211; placebo arm, n = 213). Baseline characteristics were balanced across arms. After a median follow-up of 25 months, there was no significant difference in OS between ibrutinib plus nab-paclitaxel/gemcitabine versus placebo plus nab-paclitaxel/gemcitabine (median of 9.7 versus 10.8 months; P = 0.3225). PFS was shorter for ibrutinib plus nab-paclitaxel/gemcitabine compared with placebo plus nab-paclitaxel/gemcitabine (median 5.3 versus 6.0 months; P < 0.0001). Overall response rates were 29% and 42%, respectively (P = 0.0058). Patients in the ibrutinib arm had less time on treatment and received lower cumulative doses for all agents compared with the placebo arm. The most common grade >3 adverse events for ibrutinib versus placebo arms included neutropenia (24% versus 35%), peripheral sensory neuropathy (17% versus 8%), and anemia (16% versus 17%). Primary reasons for any treatment discontinuation were disease progression and adverse events. Conclusions: Ibrutinib plus nab-paclitaxel/gemcitabine did not improve OS or PFS for patients with PDAC. Safety was consistent with known profiles for these agents.