Moleculin reports consistent blinded remission rates with Annamycin plus cytarabine in the Phase 2/3 MIRACLE trial for relapsed or refractory AML, including patients with prior venetoclax failure.
Written By: Meghana Jinka, PharmD
Reviewed By: Pharmacally Editorial Team
Moleculin Biotech has reported updated preliminary blinded findings from Part A of the pivotal Phase 2/3 MIRACLE (MB-108) trial evaluating Annamycin (naxtarubicin) in combination with cytarabine for adults with relapsed or refractory acute myeloid leukemia (R/R AML). Based on data available as of July 18, 2026, the analysis showed a blinded complete remission (CR) rate of 24% and a composite complete remission (CRc) rate of 37% among 62 evaluable patients. Continued enrollment and the absence of cardiotoxicity support progress toward the trial’s next major milestone.
Scientific and Clinical Context
Annamycin is a next-generation anthracycline developed to overcome multidrug resistance while reducing the cardiac toxicity associated with conventional anthracycline chemotherapy. The investigational therapy is being studied in combination with cytarabine for patients whose AML has relapsed or failed to respond after initial induction therapy.
Venetoclax-based regimens have become a standard first-line treatment for older or chemotherapy-ineligible patients with AML, yet outcomes after treatment failure remain poor. Published retrospective data have reported salvage remission rates of approximately 13% and a median overall survival of only 2.4 months following frontline venetoclax failure, highlighting the need for more effective second-line therapies.
MIRACLE Trial Continues to Show Stable Blinded Activity
The global, randomized, double-blind, placebo-controlled Phase 2/3 MIRACLE study (NCT06788756) has enrolled patients across seven countries. Part A compares two doses of Annamycin (190 mg/m² and 230 mg/m²) plus cytarabine with cytarabine plus placebo, with remission assessed after a single treatment cycle, unlike several historical AML studies that permitted multiple treatment cycles.
Among the 62 evaluable participants, 30 patients (48%) had previously received venetoclax-based treatment. Within this subgroup, blinded CR and CRc rates were 23% and 37%, respectively, closely matching outcomes observed across the overall evaluable population. These findings suggest that prior venetoclax exposure has not adversely affected remission rates, although the analysis remains blinded and includes patients from both treatment and control arms.
The company also noted that blinded CRc rates have remained stable across successive analyses involving 30, 45, and 62 evaluable patients despite an increasing proportion of harder-to-treat patients with prior venetoclax failure. In the June 2026 interim unblinded analysis, the 190 mg/m² and 230 mg/m² Annamycin plus cytarabine treatment arms achieved CRc rates of 50% and 57%, respectively, compared with 29% for the cytarabine plus placebo control arm after one treatment cycle. Because the current analysis remains blinded, the two datasets are not directly comparable.
Investigators also continue to report no evidence of cardiotoxicity based on adverse event monitoring and cardiac ejection fraction assessments, reinforcing one of Annamycin’s key differentiating features compared with conventional anthracyclines.
Executive Perspective
Chairman and Chief Executive Officer Walter Klemp said the consistent remission rates observed among patients who previously failed venetoclax therapy strengthen confidence in the investigational treatment as Part A approaches completion. He also highlighted the continued absence of cardiotoxicity alongside encouraging efficacy findings, supporting Annamycin’s differentiated clinical profile.
Future Development
Enrollment in Part A has reached 74 of the planned 90 patients, with treatment of the final participant expected in September 2026. Comprehensive unblinded Part A data remain on schedule for release between December 2026 and February 2027.
The adaptive Phase 2/3 MIRACLE trial will combine efficacy data from Parts A and B to support its primary endpoint. If the upcoming analysis confirms the interim findings, it could support advancement into Part B, strengthen regulatory discussions, and expand strategic partnering opportunities.
Annamycin currently holds FDA Fast Track designation and Orphan Drug designation for relapsed or refractory AML, along with Orphan Drug designation from the European Medicines Agency. The investigational therapy is also protected by composition-of-matter patents through 2040, with the potential for extension to 2045.
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About the Writer
Meghana Jinka (LinkedIn) is a PharmD graduate with a strong interest in clinical pharmacy, clinical research, pharmacovigilance, and medical writing. She has developed expertise in evaluating scientific literature, interpreting clinical data, and communicating complex medical information in a clear and accessible manner. Through clinical training, patient counseling, and healthcare awareness activities, she has gained practical experience in evidence-based medicine and patient-centered care. Passionate about healthcare communication, Meghana is committed to developing accurate, engaging, and evidence-based healthcare documents that support healthcare professionals and the wider community.