Moleculin Biotech has received positive feedback from the FDA regarding its Initial Pediatric Study Plan (iPSP) for Annamycin, marking a significant milestone in developing safer cancer treatments for children. The FDA has agreed to a single pediatric approval study evaluating Annamycin in combination with cytarabine (AnnAraC) as second-line therapy for pediatric patients with relapsed/refractory acute myeloid leukemia (R/R AML).
FDA Expands Age Range for Pediatric Trial
The FDA's response exceeded Moleculin's expectations by recommending the inclusion of patients as young as 6 months old, significantly younger than the company's original proposal of 2 to 16 years of age. The regulatory agency specified no minimum number of patients required between 6 months and 2 years old, providing flexibility in enrollment while ensuring comprehensive safety evaluation across age groups.
"We continue to be encouraged by the potential of Annamycin to change the game when it comes to the most prevalent cancer therapies in use today," said Walter Klemp, Chairman and CEO of Moleculin. "This is particularly important in pediatric oncology, where about 60% of children with cancer are treated with anthracyclines that present a high risk of causing heart damage."
Addressing Critical Safety Concerns
Annamycin represents a next-generation anthracycline designed to eliminate the cardiotoxicity commonly associated with current anthracycline treatments. An independent expert's review of study data has shown no cardiotoxicity to date in 84 adult patients treated with Annamycin across five clinical studies conducted in the US and Europe.
The FDA clarified that comparable drug concentration exposure and safety profiles would allow extrapolation from adult efficacy data. Importantly, the agency indicated that Moleculin could initiate the pediatric trial before completing the full two years of follow-up data from the adult trial, potentially accelerating the development timeline.
Current Development Status
The company is currently conducting the pivotal Phase 3 MIRACLE trial (MB-108), a global adaptive design study evaluating AnnAraC in adult patients with R/R AML. The trial includes sites across the US, Europe, and the Middle East, with patient dosing already commenced. Initial data readout remains on track for the second half of 2025.
Moleculin plans to update its iPSP to incorporate FDA recommendations and submit the revised plan later this quarter. The pediatric clinical study is expected to initiate in the second half of 2027.
Regulatory Recognition
Annamycin has received significant regulatory recognition, including FDA Fast Track Status and Orphan Drug Designation for treating relapsed or refractory acute myeloid leukemia, plus an additional Orphan Drug Designation for soft tissue sarcoma. The European Medicines Agency has also granted Orphan Drug Designation for R/R AML treatment.
The company's broader pipeline includes WP1066, an immune/transcription modulator targeting brain tumors and pancreatic cancer, and WP1122, an antimetabolite in development for pathogenic viruses and certain cancer indications.
