Moleculin Biotech has reported preliminary blinded data from Part A of its ongoing pivotal Phase II/III MIRACLE trial assessing Annamycin combined with cytarabine (AnnAraC) in adult patients with relapsed or refractory acute myeloid leukaemia (r/r AML).

Among 62 evaluable patients, the complete remission (CR) rate was 24% and the composite complete remission (CRc) rate was 37%.

Of these subjects, 30 had previously failed a first-line venetoclax-based regimen, a group in which published salvage remission rates are about 13% and median survival is estimated at 2.4 months.

A total of 74 out of a planned 90 subjects have been enrolled so far, and the company expects final Part A treatment to conclude in September 2026, targeting comprehensive unblinded results between December 2026 and February 2027.

According to the protocol, Part A examines two dosing regimens of Annamycin plus cytarabine compared with cytarabine plus placebo, with all patients receiving only one cycle of therapy.

The MIRACLE study is being conducted at sites in the EU, the US, and additional European countries. The trial is open to AML patients who have received a single prior induction therapy.

Moleculin chairman and CEO Walter Klemp said: “Because this analysis is still blinded and includes control-arm subjects, we would expect it to sit below the unblinded Annamycin-arm results we reported in June. That it has held in a narrow band while the population became measurably harder to treat is what gives us added confidence as we approach the completion of Part A.

“Just as importantly, based on reported ejection fractions and adverse events, we continue to observe no evidence of cardiotoxicity, one of the defining characteristics that differentiates Annamycin from conventional anthracyclines.” 

In April 2025, Moleculin Biotech begun dosing subjects in its Phase III MIRACLE trial of Annamycin with cytarabine for treating AML.