Background Ruxolitinib, a Janus kinase 1 (JAK1)/JAK2 inhibitor, plus capecitabine improved overall survival (OS) vs capecitabine in a subgroup analysis of patients with metastatic pancreatic cancer and systemic inflammation (C-reactive protein [CRP] >13 mg/dL) in the randomized phase II RECAP study. We report results from two randomized phase III studies, JANUS 1 (NCT02117479) and JANUS 2 (NCT02119663). Patients and Methods Adults with advanced/metastatic pancreatic cancer, one prior chemotherapy regimen and CRP >10 mg/L were randomized 1:1 (stratified by modified Glasgow Prognostic Score [1 vs 2] and Eastern Cooperative Oncology Group performance status [0/1 vs 2]) to 21-day cycles of ruxolitinib 15 mg twice daily plus capecitabine 2000 mg/m2/day (Days 1-14) or placebo plus capecitabine. The primary endpoint was OS. Results Both studies were terminated following a planned interim futility/efficacy analysis of JANUS 1. Overall, 321 and 86 patients were randomized in JANUS 1 (ruxolitinib: n = 161; placebo: n = 160) and JANUS 2 (ruxolitinib: n = 43; placebo: n = 43). There was no significant difference in OS or progression-free survival (PFS) between treatments in JANUS 1 (OS: hazard ratio [HR], 0.969, 95% confidence interval [CI], 0.747-1.256; PFS: HR, 1.056; 95% CI, 0.827-1.348) or JANUS 2 (OS: HR, 1.584; 95% CI, 0.886-2.830; PFS: HR, 1.166; 95% CI, 0.687-1.978). The most common hematologic adverse event was anemia. No new safety signals with ruxolitinib or capecitabine were identified. Conclusions Ruxolitinib plus capecitabine was well tolerated in refractory pancreatic cancer patients; this combination did not improve survival.