AMXT 1501 and DFMO Combination Achieve FDA Orphan Drug Designation

The FDA has granted orphan drug designation (ODD) to AMXT 1501 in combination with difluoromethylornithine (Iwilfin; DFMO) for the treatment of patients with neuroblastoma.¹

AMXT 1501 is a novel polyamine transport inhibitor designed to block the uptake of polyamines, therefore working to stop the growth and survival of tumors. DFMO is an irreversible inhibitor of ornithine decarboxylase, and in combination with AMXT 1501, is meant to suppress polyamine metabolism and tumor growth.¹

“Neuroblastoma is a rare childhood cancer that, unfortunately, accounts for 12-15% of all pediatric cancer deaths in the United States,” said Giselle Sholler, MD, founder and chair of the Beat Childhood Cancer Research Consortium, in a news release.¹ “We believe this combination has the potential to build upon the FDA approval of DFMO to further improve clinical outcomes for children with neuroblastoma and other rare childhood cancers.”

Sholler is also the director of Pediatric Oncology Research, professor of Pediatrics and Neuroscience at Penn State College of Medicine, and chief of the division of Pediatric Hematology and Oncology at Penn State Health Children’s Hospital.

The Beat Childhood Cancer Research Consortium at Penn State College of Medicine is currently conducting a phase 1/2 (NCT06465199)²clinical trial in pediatric patients with neuroblastoma, central nervous system (CNS) tumors, and sarcomas to evaluate the efficacy of the combination AMXT 1501 and DFMO. The clinical study has an estimated enrollment of 289. Eligible patients had to be no older than 21 at the time of their diagnosis.

Aminex Therapeutics initiated their first clinical trial with the combination of AMXT 1501 and DFMO in patients with a broad range of advanced solid tumor cancers in 2018. They have seen the combination of drugs through target discovery, patenting, preclinical research, and clinical development.³

Patients with high-risk neuroblastoma who have been treated through multimodal therapy have survival rates of less than 50%. Patients who relapse after being treated with standard of care therapies have a long-term survival rate of less than 10%.⁴

“Receiving orphan drug designation for AMXT 1501 in combination with DFMO represents an important milestone in our mission to develop innovative therapies for children with life-threatening cancers,” said Mark Burns, PhD, chief scientific officer and president of Aminex Therapeutics, in a press release.¹ “We are committed to working closely with regulators, investigators, and patient advocacy groups, to accelerate the clinical development efforts for AMXT 1501 in combination with DFMO for the treatment of neuroblastoma and other childhood and adult tumor types in collaboration with the Beat Childhood Cancer Research Consortium.”

Aminex Therapeutics is currently planning clinical trials to assess the safety and efficacy of the combination of AMXT 1501 with DFMO in patients with metastatic melanoma and patients with breast cancer.¹

REFERENCES:

1. Aminex Therapeutics Announces FDA Orphan Drug Designation Granted to AMXT 1501 in Combination with DFMO for the Treatment of Neuroblastoma. News release. Aminex Therapeutics. October 2, 2025. Accessed October 3, 2025. https://tinyurl.com/5n88mxhk

2. Eflorithine (DFMO) and AMXT 1501 for Neuroblastoma, CNS Tumors, and Sarcomas. ClinicalTrials.gov. Updated September 10, 2025. Accessed October 3, 2025. https://clinicaltrials.gov/study/NCT06465199

3. Aminex Therapeutics Initiates First Clinical Trial of Novel Immunotherapy AMXT 1501 + DFMO in Cancer Patients. News release. Aminex Therapeutics. June 20, 2018. Accessed October 3, 2025. https://tinyurl.com/y2j2sn63

4. Saulnier Sholler GL, Ferguson W, Bergendahl G, et al. Survival outcomes in patients with high-risk neuroblastoma (HRNB) in remission after relapsed or refractory treatment receiving eflornithine (DFMO) maintenance. J Clin Oncol 42, 10060-10060(2024). doi:10.1200/JCO.2024.42.16_suppl.10060