Disc Medicine is a clinical-stage biopharmaceutical company developing treatments for rare hematologic diseases, with no approved products and no revenue. The company's pipeline targets two biological pathways: heme biosynthesis modulation and iron homeostasis modulation via hepcidin regulation. Its lead drug, bitopertin, is an oral pill that reduces toxic porphyrin buildup in patients with erythropoietic porphyrias (EPP and XLP), rare inherited diseases causing severe light sensitivity. Bitopertin received an FDA Complete Response Letter in early 2026 after an NDA filing, with the agency concluding the Phase 2 trials did not clearly link porphyrin reduction to improved sunlight tolerance. Topline data from the Phase 3 APOLLO trial are expected in Q4 2026. DISC-0974 is an injectable antibody that suppresses hepcidin to increase iron availability, targeting anemia in myelofibrosis; Phase 2 data showed strong early responses, with topline results expected in H2 2026. DISC-3405 is an injectable antibody that induces hepcidin to restrict iron and reduce red blood cell overproduction, targeting polycythemia vera and sickle cell disease, with Phase 2 data also expected in H2 2026. All three compounds were in-licensed — bitopertin from Roche, DISC-0974 and a next-generation follow-on from AbbVie, and DISC-3405 from Mabwell — and Disc Medicine owes milestones and royalties to each licensor. Manufacturing is fully outsourced. Disc Medicine funds operations through equity raises and would commercialize through a specialty pharma model, selling high-priced therapies to small rare disease populations.