HOUSTON, July 31, 2026
Moleculin Biotech, Inc. announced updated positive preliminary blinded interim results from Part A of its pivotal Phase 2/3 MIRACLE trial evaluating Annamycin in combination with cytarabine (AnnAraC) for patients with relapsed or refractory acute myeloid leukemia (R/R AML). Among 62 evaluable patients, the trial reported a preliminary blinded complete remission (CR) rate of 24% and a composite complete remission (CRc) rate of 37%. Notably, nearly half of the evaluable patients had previously failed first-line venetoclax-based therapy, yet the subgroup demonstrated an identical 37% CRc rate, substantially exceeding the approximately 13% historical salvage remission rate reported in published studies for this difficult-to-treat population. The company also reported continued absence of evidence of cardiotoxicity, further differentiating Annamycin from conventional anthracycline chemotherapy as enrollment approaches completion.
Interim Results Show Consistent Remission Despite Prior Venetoclax Failure
The latest blinded analysis included 62 evaluable patients, of whom 30 patients (48%) had previously received and failed a venetoclax-based regimen. Preliminary blinded results showed a 23% complete remission rate and 37% composite complete remission rate within the venetoclax-failure subgroup, matching the overall trial population. According to Moleculin, these findings suggest that previous venetoclax exposure does not appear to reduce treatment response with AnnAraC. Because the analysis remains blinded and includes both treatment and control arms, the reported remission rates are expected to be lower than the previously announced unblinded interim efficacy results. Across three consecutive blinded analyses involving 30, 45, and now 62 evaluable patients, blinded CRc rates have remained consistently between 37% and 40%, providing additional confidence as enrollment continues.
Enrollment Nears Completion While Cardiac Safety Profile Remains Favorable
Enrollment in Part A has now reached 74 of the planned 90 patients, with the company expecting to complete treatment of the final participant during September 2026. Comprehensive unblinded Part A results remain on track for release between December 2026 and February 2027. Throughout the study, Moleculin continues to report no evidence of cardiotoxicity, one of Annamycin’s key differentiating characteristics compared with traditional anthracycline chemotherapy. The pivotal MIRACLE study is evaluating two doses of Annamycin combined with cytarabine against a placebo-controlled cytarabine regimen in adult patients with relapsed or refractory AML following one prior induction therapy. The adaptive Phase 2/3 design is intended to support regulatory development while determining the optimal treatment dose before progressing into Part B.
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Company Positions MIRACLE for Key Regulatory and Development Milestones
Moleculin believes the upcoming completion of Part A represents an important value-inflection point for the company. The anticipated comprehensive unblinded results could validate Annamycin’s efficacy and safety profile in a randomized setting, support advancement into the Phase 3 portion of the trial, strengthen the regulatory pathway, and expand strategic partnering opportunities. Annamycin currently holds FDA Fast Track Designation and Orphan Drug Designation for relapsed or refractory AML, along with EMA Orphan Drug Designation, reinforcing its regulatory potential. If future data continue to demonstrate durable remission rates together with an absence of cardiotoxicity, Annamycin could emerge as a differentiated treatment option for patients with relapsed or refractory acute myeloid leukemia who currently face limited therapeutic alternatives.
Source: Moleculin Biotech press release
