This is a Phase 2, multicenter, randomized, double-blind, placebo-controlled, dose-ranging study to evaluate the safety, tolerability, efficacy and pharmacokinetics of WIN378 in adult participants with moderate to severe asthma. Participants will continue their standard background asthma therapy according to GINA Steps 3-5. Eligible participants will be randomized to receive WIN378 or placebo administered subcutaneously over a 48-week treatment period, followed by a 12-week safety follow-up.