Aminex to Initiate Phase 1/2 Clinical Trial (NCT06465199) of AMXT 1501 + DFMO in 289 Pediatric Cancer Patients
Clinical Design and Patient Population
This Phase 1/2 clinical trial (NCT06465199), co-designed by the Beat Childhood Cancer Research Consortium and Aminex Therapeutics, plans to enroll a total of 289 pediatric patients. Phase 1 will explore the optimal dose of AMXT 1501 in combination with oral DFMO (eflornithine), and Phase 2 will adopt a randomized, controlled design to compare the progression-free survival (PFS) of the AMXT 1501 combination group versus the DFMO monotherapy group. The target diseases include neuroblastoma, central nervous system tumors (including DIPG), and sarcomas (including Ewing sarcoma), encompassing high-risk pediatric cancer patients who are refractory to or have relapsed after prior treatment. The expected primary completion date is February 2033, and the final completion date is February 2035.
Drug Mechanism and Differentiation
AMXT 1501 is a polyamine transport inhibitor that blocks the uptake of extracellular polyamines by cancer cells, while DFMO is an irreversible inhibitor of ornithine decarboxylase (ODC), which blocks polyamine biosynthesis. The combination of these two drugs simultaneously blocks polyamine supply through both synthesis and transport, inhibiting cancer cell proliferation and reducing bone marrow-derived suppressor cells (MDSCs) in the tumor microenvironment, thereby activating anti-tumor immune responses. Unlike existing GD2 antibodies (dinutuximab, naxitamab) or chemotherapy, this approach offers both convenience of administration and mechanistic differentiation as an orally administered combination therapy based on an immune-modulatory mechanism.
Preclinical Evidence and Regulatory Achievements
A previous Phase 1 trial (NCT03536728, to be published in ESMO Open 2025) in adult solid tumors involved 56 patients, and the recommended Phase 2 dose (RP2D) was determined to be AMXT 1501 600mg BID + DFMO 500mg BID. There were no Grade 4 or 5 adverse events or treatment-related deaths, and the main adverse events were diarrhea (39.3%), nausea (37.5%), and vomiting (33.9%), which were manageable. In a patient population with a median of 10 or more prior lines of therapy, the clinical benefit rate (CBR) was 49%. The FDA has granted Orphan Drug Designation (ODD) for this combination therapy for neuroblastoma (October 2025) and malignant glioma/DIPG (March 2026), securing 7 years of market exclusivity and tax benefits.
Competitive Landscape and Unmet Needs
High-risk neuroblastoma accounts for 12-15% of pediatric cancer deaths, and even after standard multi-modality treatment, the 5-year survival rate is less than 50%. Currently, the only FDA-approved drug for maintenance therapy is US WorldMeds' Iwilfin (eflornithine, approved in December 2023), and the GD2 immunotherapies include United Therapeutics' dinutuximab (Unituxin) and Y-mAbs Therapeutics' naxitamab (DANYELZA). In the pivotal trial for Iwilfin approval, the 4-year event-free survival (EFS) in the DFMO group was 84%, and in the non-administered group, it was 72% (HR 0.48), demonstrating the clinical efficacy of polyamine blockade. The AMXT 1501 combination aims to surpass these results by employing a strategy that also blocks the transport pathway, targeting a pediatric neuroblastoma market of approximately $2-3 billion (2025).
If the novel immune-modulatory mechanism of dual polyamine synthesis and transport inhibition demonstrates clinical efficacy in pediatric high-risk cancers, it will bring about a meaningful change in the current treatment paradigm centered on GD2 antibodies and chemotherapy. The 49% clinical benefit rate and favorable safety profile (Grade 4-5 adverse events: 0) observed in adult Phase 1 trials provide a solid foundation for the transition to pediatric indications, and the two FDA Orphan Drug Designations (neuroblastoma and DIPG) strengthen the development economics of Aminex, a non-listed biotech company, by securing 7 years of market exclusivity and tax benefits. If the standard of care for pediatric neuroblastoma shifts from DFMO monotherapy (Iwilfin) to AMXT 1501 combination therapy in the $2-3 billion pediatric neuroblastoma market, a significant revaluation of Aminex's corporate value is expected. Simultaneously, the ongoing adult solid tumor Phase 1b/2 trials (melanoma and breast cancer, NCT07287917) are structured to validate the potential for expanding the indications of the polyamine platform in parallel, making it noteworthy from a pipeline diversification perspective.
Source: ClinicalTrials.gov (api_ct)