Executive Summary

Interleukin-11 (IL-11) is increasingly viewed as a key driver of tissue fibrosis, prompting development of IL-11-targeting therapies. As of 2026, the only approved IL-11-related drug is oprelvekin (Neumega), a recombinant IL-11 analog used to prevent chemotherapy-induced thrombocytopenia. By contrast, IL-11 pathway inhibitors are entirely experimental. Several pharmaceutical companies have entered this space: Boehringer Ingelheim, Lassen Therapeutics, and Mabwell are developing IL-11 or IL-11 receptor antibodies for conditions like idiopathic pulmonary fibrosis (IPF), thyroid eye disease, and pathological skin scarring. Preclinical research indicates IL-11 blockade can halt or reverse fibrosis and may even influence aging biology. This report reviews the approved products, pipeline candidates, clinical trials, safety signals, and commercial context of IL-11 therapies.