Upstream Bio, Inc. is a clinical-stage biotech firm pioneering verekitug, a highly potent monoclonal antibody antagonizing the TSLP receptor, targeting upstream inflammatory pathways in severe respiratory diseases including asthma, CRSwNP, and COPD. The company reported positive Phase 2 results for severe asthma and CRSwNP and plans Phase 3 initiation in early 2027 focused on extended dosing intervals and at-home administration. Despite these clinical advances, Upstream Bio’s financials reflect deepening net losses and negative operating cash flows in 2025, highlighting funding pressures as it invests heavily in R&D and clinical development. Dependence on third-party manufacturing and the competitive biologics landscape remain notable operational risks.