Moleculin Biotech Inc. (NASDAQ: MBRX) announced that preliminary data from its ongoing MIRACLE trial show a complete remission rate of approximately 30% for the first 45 subjects, representing what the company describes as a 67% improvement compared to standard care.

The Houston-based pharmaceutical company expects to unblind data from the first 45 subjects in its Phase 2B/3 trial before June 30, 2026. The trial evaluates Annamycin combined with cytarabine for treating patients with relapsed or refractory acute myeloid leukemia.

The study compares two doses of Annamycin (190 mg/m² and 230 mg/m²) plus cytarabine against a control group receiving cytarabine with placebo. Historical complete remission rates for cytarabine alone in similar patient populations range from 17-18%, according to the company.

As of May 1, 56 subjects have been recruited for the trial, with the company targeting 90 subjects for Part A by the third quarter of 2026. The median age of enrolled subjects is in the mid-60s, with over 30% having become relapsed or refractory to prior venetoclax treatment.

"The data coming from MIRACLE is encouraging," said Walter Klemp, Chairman and CEO of Moleculin. "For decades, cytarabine monotherapy regimens, although one of the current standards of care, have set a relatively low bar in relapsed or refractory AML."

Annamycin has received Fast Track Status and Orphan Drug Designation from the FDA for treating relapsed or refractory acute myeloid leukemia. The drug also has composition of matter patent protection through 2040, with potential extension to 2045.

The trial protocol allows for unblinding preliminary efficacy data at 45 subjects and again at the conclusion of Part A with 90 total subjects. Recruitment of the second group of 45 subjects will continue while the first group's data is being unblinded.