Annamycin-Cytarabine Combination Shows Promising Remission Rates in Relapsed AML Trial

Moleculin Biotech reported preliminary blinded data from its Phase 2B/3 MIRACLE trial showing that the investigational drug Annamycin in combination with cytarabine achieved a complete remission rate of approximately 30% in patients with relapsed or refractory acute myeloid leukemia, with a composite complete remission rate exceeding 40%.

The global, randomized, double-blind, placebo-controlled trial evaluates Annamycin at two dose levels (190 mg/m² and 230 mg/m²) combined with cytarabine against a control arm of cytarabine plus placebo. In the first 45 subjects, the composite complete remission rate of over 40% includes a 30% complete remission rate and a 10% rate of complete remission with partial blood count recovery. This represents a roughly 67% improvement compared to historical rates of 17-18% observed with cytarabine alone in similar populations.

Among the 56 subjects enrolled as of May 1, over 30% have disease that failed a venetoclax-based regimen as first-line therapy, a subgroup often associated with difficult-to-treat leukemia. The median age of participants is in the mid-60s. Across approximately 90 patients treated in earlier studies, Annamycin, designed as a next-generation anthracycline, showed no evidence of cardiotoxicity, a common issue with older drugs in this class.

Annamycin holds Fast Track Status and Orphan Drug Designation from the U.S. Food and Drug Administration for relapsed or refractory AML. The trial is limited to adults who have received only one prior induction therapy, defining a second-line treatment population.

The first unblinding of data from the initial 45 subjects is expected before June 30, 2026, including approximately 30 subjects treated with Annamycin plus cytarabine and 15 on the control arm. Recruitment of the second group of 45 subjects will continue during the unblinding process, with full unblinding anticipated later in 2026. The trial aims to enroll a total of 90 subjects for Part A, with completion targeted in the third quarter of 2026.

Enrollment is ongoing across multiple countries, with strong participation in Europe and efforts underway to expand recruitment in the United States. The adaptive trial design combines data from phase 2B and phase 3 portions to assess complete remission as the main endpoint.