Annamycin Plus Cytarabine Shows Early Remission Signals in AML

Early findings from the ongoing MIRACLE clinical trial suggest that the investigational drug annamycin, given with cytarabine, may help more patients with relapsed or refractory acute myeloid leukemia (AML) achieve remission, according to a news release from Moleculin Biotech, Inc.

In the first 30 treated participants, researchers reported a preliminary composite complete remission (CRc) rate of 40%, including a 30% complete remission rate and a 10% rate of complete remission with partial blood count recovery. Notably, approximately 35% of patients enrolled so far had disease that had already failed a Venclexta (venetoclax)–based regimen, a group often associated with particularly difficult-to-treat leukemia.

Although the data remain blinded (meaning researchers do not yet know which patients received annamycin versus placebo) the remission rate appears higher than historical response rates seen with cytarabine alone.

Why these early findings matter for patients

These results are considered encouraging because outcomes for patients whose AML returns after initial treatment are typically poor, and treatment options remain limited.

If confirmed after the trial is unblinded, the results could represent a meaningful advance for people with second-line AML. Historically, complete remission rates with high-dose cytarabine alone have been approximately 17% to 18%. The current blinded remission rate is reported to be substantially higher than those benchmarks.

Investigators also noted that many enrolled patients had genetic features linked with poor prognosis. Seeing responses in this higher-risk population adds to the potential significance of the findings.

Another important aspect for patients is safety. Annamycin is designed as a next-generation anthracycline that aims to avoid the heart-related toxicity commonly associated with older drugs in this class. Across approximately 90 patients treated in earlier studies, researchers reported no evidence of cardiotoxicity, an issue that often limits the use of standard anthracyclines.

Understanding relapsed or refractory AML and treatment needs

AML is an aggressive blood cancer that often requires intensive initial treatment known as induction therapy. Unfortunately, many patients either do not respond to first-line treatment or experience relapse. Outcomes in this setting are generally poor, and newer therapies are urgently needed.

Patients whose disease returns after Venclexta-based regimens represent an especially challenging subgroup, with limited effective second-line options. Clinical trials remain a key pathway to accessing investigational therapies that may improve remission rates and survival.

How the MIRACLE trial is designed

The MIRACLE study is a global, randomized, double-blind, placebo-controlled trial evaluating annamycin in combination with cytarabine. Patients are assigned to receive one of two annamycin dose levels plus cytarabine or cytarabine with placebo.

The trial uses an adaptive design and will combine data from its phase 2B and phase 3 portions to assess its main endpoint: complete remission. An early analysis will occur after 45 patients are treated, with approximately two-thirds expected to receive annamycin and one-third assigned to the control arm.

Enrollment is ongoing across multiple countries, and investigators report strong participation in Europe, with efforts underway to expand recruitment in the United States.

The trial is limited to adults with relapsed or refractory AML who have received only one prior induction therapy, meaning they are in the second-line setting. This design helps ensure that results reflect outcomes in a clearly defined treatment population.

To date, dozens of patients have consented to participate, although many did not qualify because they had received more than one prior induction regimen. Researchers view this as a sign of the substantial unmet need in this patient community.

Additional findings and what comes next

Researchers expect to reach the first unblinding milestone after 45 patients complete treatment and evaluation, which is anticipated in 2026 following data verification and analysis. A second group of 45 patients will then complete the first portion of the study.

Annamycin has received fast track and orphan drug designations from the U.S. Food and Drug Administration for relapsed or refractory AML, reflecting the need for new treatment options in this setting.

Although these early results are preliminary and must be confirmed after unblinding, the combination of higher-than-expected remission rates, activity in Venclexta-exposed disease, and a favorable cardiac safety profile suggests that annamycin could become an important investigational option for patients facing relapsed AML.

Editor's note: This article is for informational purposes only and is not a substitute for professional medical advice, as your own experience will be unique. Use this article to guide discussions with your oncologist. Content was generated with AI and reviewed by a human editor.

References

1. “Moleculin MIRACLE Trial Delivers 40% Preliminary Blinded CRc Rate (n=30),” by Moleculin Biotech, Inc. News release; Feb. 18, 2026.

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