Overview Phase 4 COPD and Suboptimal Inspiratory Flow Rate Status: Not yet recruiting Trial end date: 2022-09-01 Target enrollment: Participant gender: Summary Study is a randomized, double-blind, double-dummy, parallel-group study evaluating efficacy and safety of revefenacin vs. tiotropium in adults with severe to very severe COPD and suboptimal PIFR. Phase: Phase 4 Details Lead Sponsor: Theravance BiopharmaCollaborator: Mylan Inc.Treatments: Tiotropium Bromide