Superluminal Medicines announced Thursday September 3, 2026 an oversubscribed $60 million Series B financing round led by BVF Partners with participation from Deep Track Capital, Perceptive Advisors, RA Capital Management, Insight Partners, NVIDIA, Catalio Capital Management, Eli Lilly and Company, Cooley, and Gaingels. Proceeds will advance the company's lead clinical program (a selective, biased MC4R agonist) into Phase 1 for rare genetic forms of obesity including Bardet-Biedl syndrome (BBS) and hypothalamic obesity, targeting Phase 1 initiation by end of 2026. Superluminal's technology platform uses AI plus GPCR-structural chemistry to design biased agonists with reduced off-target signaling. The MC4R agonist positioning is directly against Rhythm Pharmaceuticals's Imcivree (setmelanotide, the currently-approved MC4R agonist peptide for BBS and hypothalamic obesity) — a small-molecule alternative would have oral bioavailability advantages plus different tolerability profile. Eli Lilly's investor participation extends Lilly's obesity-adjacent equity portfolio.
Rhythm Pharmaceuticals (NASDAQ: RYTM) reported on the August 4, 2026 Q2 2026 earnings call that the US launch of IMCIVREE (setmelanotide) in the newly-approved acquired hypothalamic obesity indication has recorded more than 400 patient start forms since FDA approval in late June 2026. Setmelanotide is a synthetic alpha-melanocyte-stimulating hormone (alpha-MSH) analog peptide that activates the melanocortin-4 receptor (MC4R) to produce appetite suppression; the peptide is administered as a daily subcutaneous injection. The launch ranks among the stronger rare-disease peptide launches of the year to date and extends the melanocortin-agonist franchise beyond the original rare genetic obesity syndromes (POMC, LEPR, PCSK1 deficiency) that IMCIVREE was initially approved for in 2020. The acquired hypothalamic obesity indication addresses patients with hypothalamic damage from brain tumors (particularly craniopharyngioma), radiation therapy, surgery, or trauma that disrupts normal melanocortin signaling and leads to severe obesity with dysfunctional appetite regulation. The therapeutic story is mechanistically adjacent to but distinct from the alpha-MSH gray-market use of melanotan II (which activates the same broader melanocortin receptor family for tanning and appetite suppression); setmelanotide has substantially more selectivity for MC4R specifically, an established safety monitoring program, and full FDA approval under the rare-disease pathway. IMCIVREE full-year 2026 revenue guidance is expected to reflect the acquired hypothalamic obesity launch trajectory.