Balinatunfib: A Clinical Oral Small Molecule TNFα Inhibitor

Abstract

Most diseases are accompanied by an inflammatory response, making effective pharmacological control highly desirable. Tumor necrosis factor alpha (TNFα) is a key cytokine driving inflammatory and autoimmune diseases, such as rheumatoid arthritis and inflammatory bowel disease. Although biological TNFα inhibitors revolutionized treatment, they have drawbacks including lacking blood–brain barrier penetration, parenteral administration, and immunogenicity. Recent studies highlight the potential of small-molecule approaches to target TNFα by stabilizing an asymmetrical, receptor-incompetent trimer conformation. Balinatunfib (also known as SAR441566) is an orally available small molecule designed to exploit this mechanism, thereby preventing TNFα from effectively binding to its receptors. In preclinical models, balinatunfib reduces inflammation comparably to biologic therapies, yet avoids the complexities of large protein therapeutics. This allosteric strategy involves capturing a sampled but distorted state of TNFα, thereby blocking receptor clustering and downstream proinflammatory signaling. The oral route of administration confers practical advantages in terms of patient compliance and could facilitate drug access to sites traditionally less amenable to biologics, such as the central nervous system. By demonstrating that small molecules can achieve high-affinity, conformation-based inhibition of TNFα, balinatunfib, and related compounds may result in a new area of orally administered therapies that advance the management of TNFα-mediated diseases.