Study of PRA-216 in Healthy Participants and Participants With Mild-to-Moderate Asthma

Phase 1 of this study will consist of 2 parts * Part 1 will evaluate the safety, tolerability, pharmacokinetics and immunogenicity of PRA-216 in healthy volunteers through single ascending dose administered by either intravenous (IV) or subcutaneous (SC). * Part 2 will evaluate the safety, tolerability, pharmacokinetics (PK) and immunogenicity of PRA-216 in healthy volunteers with repeat doses of multiple ascending dose administered subcutaneously. Phase 2a of this study is a randomized, double-blind, placebo-controlled study to investigate the efficacy, safety and immunogenicity of PRA-216 in participants with mild to moderate asthma. The dose of PRA-216 for this phase was determined from Phase 1.