Boston-based Superluminal Medicines has closed an oversubscribed USD 60 million Series B financing round to advance its lead small-molecule melanocortin-4 receptor (MC4R) agonist into Phase I clinical trials for rare genetic forms of obesity and hypothalamic obesity, with the trial expected to begin before the end of 2026.
BVF Partners, L.P. led the round, with new investors Deep Track Capital and Perceptive Advisors joining existing backers RA Capital Management, Insight Partners, NVentures (NVIDIA’s venture capital arm), Catalio Capital Management, Eli Lilly and Company, Cooley, and Gaingels. Proceeds will also support continued expansion of the company's G protein-coupled receptor (GPCR)-focused discovery platform and additional pipeline programs. The raise marks Superluminal's third equity round since its 2023 founding, following a USD 33 million seed round led by RA Capital and a USD 120 million Series A closed in September 2024. Eli Lilly, which joined as an equity investor in the Series A, subsequently entered into a strategic collaboration with Superluminal in August 2025 valued at up to USD 1.3 billion to discover small-molecule GPCR therapeutics for cardiometabolic diseases and obesity, and participates again in this Series B.
Superluminal's lead asset is a selective, biased MC4R agonist — a small molecule designed to activate only the MC4R signalling pathways governing energy homeostasis and appetite, while avoiding pathways associated with cardiovascular and sexual side effects that contributed to the failure of earlier MC4R programs. The candidate completed IND-enabling studies in July 2025 and is being developed initially for rare genetic conditions including Bardet-Biedl syndrome (BBS) and hypothalamic obesity, with potential future applications in Prader-Willi syndrome and as a combination partner for GLP-1 therapies. In preclinical studies, the company said the candidate demonstrated high selectivity and a favorable safety profile.