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Highlights

  • MBRX receives FDA agreement for single pediatric approval study of Annamycin with Cytarabine
  • The company continues MIRACLE Phase 3 adult trial for Annamycin in R/R AML; data expected H2 2025
  • Moleculin to revise and resubmit pediatric trial plan, targeting study launch in H2 2027

Moleculin Biotech, Inc. (NASDAQ: MBRX) is a Houston-based clinical-stage pharmaceutical company focused on the development of oncology therapeutics. Its lead candidates include Annamycin (in development for AML and other cancers), WP1066 (targeting glioblastoma and brain metastases), and other molecules designed to exploit tumor-specific pathways. The company is advancing its pipeline across multiple indications and regulatory jurisdictions.

The company announced it has received formal written feedback from the U.S. Food and Drug Administration (FDA) concerning its proposed initial pediatric study plan (iPSP) for Annamycin, a next-generation anthracycline being developed for the treatment of relapsed or refractory acute myeloid leukemia (R/R AML).

The FDA has indicated support for a single pediatric approval study, which will evaluate Annamycin in combination with Cytarabine as a second-line therapy for children with R/R AML. Moleculin plans to revise the proposed study plan in alignment with the agency’s guidance and submit the updated version later in the current quarter. If accepted, this will form the basis for a regulatory path forward to investigate Annamycin’s potential in pediatric populations.

The pediatric study is expected to begin in the second half of 2027, following the necessary revisions, approvals, and preparatory work. The planned trial would mark a significant step in Moleculin’s broader efforts to address unmet medical needs in leukemia, especially among pediatric patients for whom treatment options are limited.

Annamycin is a liposomal formulation of anthracycline that is designed to overcome known resistance mechanisms and reduce cardiotoxicity typically associated with conventional anthracyclines. It is currently being evaluated in adult patients through a Phase 3 clinical trial, known as MIRACLE, which pairs Annamycin with Cytarabine in the treatment of R/R AML. The company expects initial readout from the adult MIRACLE trial in the second half of 2025.

Moleculin's Chairman and CEO, Walter Klemp, stated that the agency’s guidance provides clarity as the company advances its pediatric development program and prepares for the future study. Moleculin also noted that the pediatric trial plan aligns with regulatory pathways under the FDA’s Pediatric Research Equity Act (PREA), which requires pediatric assessments for certain new drug applications. Gaining early feedback and alignment with the FDA is considered a critical procedural milestone in advancing pediatric trials under this framework.

In addition to AML, Moleculin is exploring Annamycin in other indications including soft tissue sarcoma lung metastases and has multiple early-stage and preclinical compounds in development focused on immuno-oncology, metabolism, and antiviral activity.