Annamycin (MB-106) in combination with Cytarabine - (Ara-C, MIRACLE)

June 30, 2026: Moleculin Biotech, Inc. (NASDAQ: MBRX) reported positive preliminary unblinded interim efficacy results from the first 45 patients in Part A of its pivotal Phase 2/3 MIRACLE trial (MB-108) of L-Annamycin (naxtarubicin) plus high-dose cytarabine (HiDAC) vs placebo plus HiDAC for remission induction in adults with relapsed/refractory acute myeloid leukemia (R/R AML). On a full intent-to-treat basis with no exclusions, complete remission (CR; primary endpoint) was 43% (Annamycin 190 mg/m² + HiDAC) and 36% (230 mg/m² + HiDAC) vs 12% for control; composite CR (CRc) was 50% and 57% vs 29% for control. Responses reflect outcomes after a single treatment cycle per protocol.

The independent Data Monitoring Committee unanimously recommended continuing the study; while no statistical significance was reached at this early interim look, it cited a strong numeric trend favoring both experimental arms and did not support dropping either dose.

Enrollment continues: 67 of 90 planned Part A subjects enrolled (~74%). After Part A dose selection, the chosen arm advances to Part B, with Part A efficacy data carried forward into the pivotal analysis (~282 total subjects planned). Other Part A data remain subject to final database review/readout.