Moleculin Reports 40% Response Rate in Pivotal AML Trial, Unblinding Expected Q1 2026

Moleculin Biotech, Inc. (Nasdaq: MBRX) announced on February 18, 2026 that it is approaching the first unblinding of data in its pivotal Phase 2B/3 "MIRACLE" study of Annamycin in combination with cytarabine for the treatment of adult patients with acute myeloid leukemia (AML) who are refractory to or relapsed after induction therapy. The company reported a preliminary composite complete remission (CRc) rate of 40% in the MIRACLE trial's first 30 subjects treated, comprised of a complete remission (CR) rate of 30% and complete remission with partial hematological recovery (CRh) of 10%.

The company has treated 35 subjects to date with another 11 in screening or identified. Additional subjects continue to be identified by site investigators. The targeted number for the first unblinding of data is 45 subjects with the company believing it is on track to treat the 45th subject in Q1 2026 with unblinding of data thereafter. This update is as of February 10, 2026, as treatment, identification and recruitment are ongoing.

The preliminary, blinded results include the control arm of cytarabine plus placebo. The current blinded CR rate is 67% in excess of the historical response rates seen in two recent HiDAC trials with cytarabine alone, which were around 17-18% CR, and also 50% greater than the median CR rate used for approval of all currently prescribed therapies for second line AML patients.

Of particular note, roughly 35% of the subjects treated to date are relapsed or refractory from a venetoclax regimen, a subject population that is generally considered among the most challenging to address with 2nd line therapies. The subjects treated to date presented with a high degree of genetic markers that are considered predictive of poor treatment response. The efficacy rates have been observed across six countries to date in MIRACLE.

Safety data from 90 total subjects in prior clinical trials demonstrate Annamycin's lack of cardiotoxicity. The company stated that the continued absence of cardiotoxicity and high efficacy are expected to position Annamycin as a "significant advancement" in AML treatment.

The MIRACLE study is a Phase 2B/3, global multi-center, randomized, double-blind, placebo-controlled, adaptive designed clinical trial whereby data from the 2B (Part A) portion will be combined with the Phase 3 (Part B) portion for purposes of measuring its primary efficacy endpoint.

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. Furthermore, Annamycin has Orphan Drug Designation for the treatment of relapsed or refractory acute myeloid leukemia from the EMA.