Disc Medicine Announces Phase 2 RESTORE-PV Initial Results

What Happened
Disc Medicine, Inc. (IRON) announced initial results from the Phase 2 RESTORE-PV trial of DISC-3405 in patients with polycythemia vera (PV) via a press release on September 9, 2026 (8-K filed September 10, 2026). The multi-center, open-label trial enrolled 40 adults (20 in Cohort A, 20 in Cohort B). At the data cut: all 20 Cohort A patients were dosed (13 completed 26 weeks), and 18 of 20 Cohort B patients were dosed. Disc reported efficacy data for Cohort A and baseline/safety data for both cohorts, including hematocrit control, pharmacokinetics, iron-marker changes, and reduced need for phlebotomy.

Key Details

• Trial design: 4–12 week observation, 12-week dose escalation, then maintenance at 300 mg subcutaneously — every 2 weeks (Cohort A) or every 4 weeks (Cohort B) for 20 weeks, with up to 20 additional weeks possible.
• Cohort A efficacy (n=13 completing 26 weeks): mean phlebotomy events fell from 4.0 in the 26 weeks before treatment to 0.6 in 26 weeks post-Day 1 (p < 0.0001); 61.5% remained entirely phlebotomy-free through 26 weeks.
• Hematocrit: mean hematocrit was maintained stably below 45% through week 26 in Cohort A, with an associated initial improvement in symptom burden.
• Safety/PK: dose-proportional PK, increased hepcidin, reduced serum iron and increased ferritin (Cohort A); generally well tolerated across cohorts, with mainly mild, self-limited injection-site reactions.

Why It Matters
These initial Phase 2 data address key clinical endpoints for PV patients—hematocrit control and reduced need for therapeutic phlebotomy—along with supportive pharmacodynamic and safety signals. For investors, the results provide early evidence of biological activity and tolerability for DISC-3405 in PV, which may inform the program’s development pathway and future clinical milestones. The company filed the press release as Exhibit 99.1 in its 8-K (signed Sept. 10, 2026 by CEO John Quisel).