Disc Medicine's Bitopertin Meets APOLLO Endpoints

The Tip Desk · November 7, 2026 · 3 min read

The company plans an NDA resubmission by year-end after an October raise that it said extends cash into 2030.

Disc Medicine (IRON), a clinical-stage biopharmaceutical company focused on hematologic diseases, said its pivotal Phase 3 APOLLO trial of bitopertin in erythropoietic protoporphyria met both co-primary endpoints, clearing the way for a planned New Drug Application resubmission by the end of 2026 and an FDA decision anticipated by mid-2027.

The GlyT1 inhibitor reduced whole-blood metal-free PPIX by 41.4% versus placebo (p<0.0001) and increased average monthly total time in light without pain by 12.2 hours during month 6 (p=0.0010). The company said all secondary endpoints were positive and statistically significant, including reductions in phototoxic reactions and improvements in light tolerance, with exploratory quality-of-life measures also significant. Bitopertin was generally well-tolerated; dizziness was the most common treatment-emergent adverse event at 50% in the bitopertin group, mild or moderate and generally transient, with no treatment-emergent adverse events above Grade 3.

President and Chief Executive Officer John Quisel called APOLLO the company’s first pivotal trial readout and said the results add to bitopertin’s clinical data package. In the second quarter, Disc had completed a Type A meeting with the FDA and aligned that APOLLO, if successful, could serve as the basis for a complete-response-letter response.

For the three months ended September 30, 2026, net loss was $59.5 million, or $1.53 a share, compared with $62.3 million, or $1.77 a share, a year earlier. Research and development expenses were $44.1 million, down from $50.3 million, which the company attributed primarily to a $10.0 million milestone payment and drug manufacturing in the comparative period that did not recur, partially offset by higher personnel-related costs. Selling, general and administrative expenses were $20.1 million, up from $17.4 million, primarily due to increased headcount.

Cash, cash equivalents, and marketable securities were $682.8 million as of September 30, 2026, versus $791.2 million at December 31, 2025. In October 2026, Disc completed a public offering with net proceeds of approximately $485.9 million after announcing a proposed $350 million offering, plus a $52.5 million underwriter option, in late October. The company said that, together with those proceeds, cash would be sufficient to fund current operating and capital expenditure plans and debt service into 2030.

Pipeline work continued on two other programs. Initial Phase 2 RESTORE-PV results for DISC-3405 in polycythemia vera, presented at the SOHO Annual Meeting, covered the Q2W (every-two-weeks) dosed cohort and showed increased hepcidin, lower serum iron, controlled hematocrit, reduced phlebotomy, and improved symptoms, with adverse events consistent with underlying disease and a low rate of mild, self-limited injection-site reactions. Enrollment had been completed in the second quarter, with initial data expected in the third. Updated RESTORE-PV data, including the Q4W (every-four-weeks) cohort, and initial Phase 1b data in sickle cell disease are slated for the American Society of Hematology meeting in December.

For selcodebart in anemia of myelofibrosis, Disc said feedback from an end-of-Phase 2 FDA meeting and plans for pivotal development would be announced by year-end, with updated RALLY-MF data also to be presented at ASH. A Phase 2 study in inflammatory bowel disease is progressing, with initial data expected in 2027. Quisel said the company is well positioned to support an anticipated bitopertin launch and advance two additional programs toward pivotal-stage development in 2027.