Moleculin reports interim MIRACLE data showing higher remission with Annamycin

Moleculin Biotech announced on June 30, 2026 preliminary unblinded efficacy results from the first 45 patients enrolled in Part A of its pivotal Phase 2/3 MIRACLE trial, analyzed on a full intent-to-treat basis with no patient exclusions.¹ The trial is testing Annamycin, also called naxtarubicin, in relapsed or refractory acute myeloid leukemia.

The interim analysis compared two Annamycin doses, 190 mg/m² plus HiDAC and 230 mg/m² plus HiDAC, against a HiDAC control arm. Complete remission reached 43% and 36% in the two Annamycin cohorts versus 12% for control, while composite complete remission reached 50% and 57% versus 29% for control.¹ The company noted these numbers reflect outcomes measured after only a single cycle of therapy, as specified by the MIRACLE protocol.¹

The trial's Independent Data Monitoring Committee reviewed the data and found that for the primary efficacy endpoint of CR rates, there was no statistical significance, but the committee saw a numeric trend pointing toward the Annamycin arms outperforming the control arm.¹ The committee found enough evidence to support continuing the trial, said the data did not support dropping either Annamycin dose arm because results between them were too similar, and Moleculin accepted the recommendation to proceed with MIRACLE as planned.¹

The company explained that under the trial's statistical plan, MIRACLE spreads its statistical significance threshold across three planned analyses using an O'Brien-Fleming spending function, which sets a high bar for significance at an early look and saves most of the statistical power for the final analysis of roughly 282 subjects.¹

On enrollment, 67 of the targeted 90 patients for Part A have been enrolled, representing approximately 74% of the planned enrollment.¹ Once Part A finishes, the chosen dose arm is expected to move into Part B, carrying Part A efficacy data into the pivotal analysis.¹