Moleculin Biotech, Inc.

MIRACLE Trial Progress and Next Steps

The MIRACLE study (derived from Moleculin R/R AML AnnAraC Clinical Evaluation) is a Phase 2/3, global multi-center, randomized, double-blind, placebo-controlled, adaptive-design clinical trial whereby data from the Phase 2 (Part A) portion will be combined with the Phase 3 (Part B) portion for purposes of measuring its primary efficacy endpoint. Part A of the MIRACLE trial is designed to evaluate the effectiveness of Annamycin in two dosing arms (190 mg/m² and 230 mg/m²) in combination with cytarabine (also referred to as Ara-C) as compared to a control arm of cytarabine plus placebo. The protocol for the MIRACLE trial allows for the limited unblinding of preliminary primary efficacy data (Complete Remission, or “CR”) of the three arms at 45 subjects in Part A, in addition to an expanded data set including primary, secondary and exploratory endpoints at the conclusion of Part A (at 90 total subjects).

The MIRACLE trial is being offered only to AML patients who have had a single prior induction therapy (2nd-line patients, or 2L). The currently enrolled subjects, including those who have been treated but not yet evaluated for efficacy, are from sites across seven countries, providing a diverse base of subjects. 33 sites in the US, the European Union, and elsewhere in Europe have had site initiation visits as the Company targets at least 45 sites for Part B. The Company is focused on improving recruitment in the US, as recruitment in Europe has been the dominant contributor to date.

The unblinding of the first 45 subjects in Part A with efficacy data occurred at the end of Q2 2026, as scheduled. The Company expects to reach final recruitment and treatment of the 90 subjects in Part A in September and the final readout in the December 2026 to February 2027 timeframe. As such, these preliminary data may differ from the final locked efficacy and safety results. Unblinding for the full 90 subjects in Part A will require more time than for the first 45, as it involves more data to support the transition from Part A to Part B.

The data reported herein were as of July 18, 2026.

For more information about the MIRACLE trial, visit clinicaltrials.gov and reference identifier NCT06788756. Additionally, the clinical trial in the EU can be found on euclinicaltrials.eu and the reference identifier is 2024-518359-47-00.

Annamycin, also known by its non-proprietary name of naxtarubicin, currently has Fast Track Status and Orphan Drug Designation from the FDA for the treatment of relapsed or refractory acute myeloid leukemia, in addition to Orphan Drug Designation for the treatment of soft tissue sarcoma. Annamycin also benefits from composition-of-matter patent protection through 2040, with the potential to extend that protection as far as 2045. Furthermore, Annamycin has Orphan Drug Designation for the treatment of relapsed or refractory acute myeloid leukemia from the EMA.