Phase 1b/2 Trial Launches Evaluating Polyamine Pathway Inhibition in Metastatic Melanoma and Breast Cancer

Aminex Therapeutics recently announced that it has initiated a multicenter phase 1b/2 clinical trial evaluating the investigational agent AMXT 1501 in combination with difluoromethylornithine (DFMO) in patients with metastatic melanoma or advanced breast cancer. The study (NCT07287917) will assess safety, tolerability, and preliminary efficacy of the oral combination therapy administered alongside standard of care.¹

For dermatologists, the inclusion of metastatic melanoma highlights continued interest in targeting tumor-intrinsic metabolic pathways that may complement existing immuno-oncology strategies. AMXT 1501 is a novel polyamine transport inhibitor designed to block cellular uptake of polyamines, which are critical for tumor growth, survival, and immune evasion. DFMO, a polyamine biosynthesis inhibitor, is intended to work synergistically with AMXT 1501 to comprehensively suppress polyamine metabolism.

"Initiating this study is an important milestone for Aminex and for patients facing advanced cancers with limited treatment options," said Mark Burns, PhD, chief scientific officer and president of Aminex, in the news release. "This trial builds on our foundation of pre- and early clinical data demonstrating the potential of AMXT 1501 plus DFMO to block the polyamine metabolism—a pathway that drives tumor growth and suppresses immune responses. We are advancing this program, in collaboration with leading investigators and pediatric oncologists, targeting eight tumor types."

According to Aminex, preclinical and early clinical data suggest that dual inhibition of polyamine synthesis and transport may limit tumor proliferation while also mitigating immunosuppressive effects within the tumor microenvironment. This mechanistic rationale is particularly relevant in melanoma, where metabolic adaptation has been implicated in treatment resistance and disease progression.

The open-label trial will enroll patients with metastatic melanoma as well as pre- and postmenopausal women with ER-positive, HER2-negative breast cancer who have progressed following prior therapies. The study includes initial safety cohorts followed by dose-expansion phases to further characterize tolerability and early signals of activity.

Beyond adult oncology, Aminex is also advancing AMXT 1501 plus DFMO in pediatric oncology through a randomized phase 1/2 trial in collaboration with The Beat Childhood Cancer Consortium at Penn State College of Medicine. Tumor types include neuroblastoma, diffuse intrinsic pontine glioma, and several rare sarcomas. Notably, the FDA has granted Orphan Drug Designation for the combination in neuroblastoma.²

While clinical efficacy data are still expected, this trial demonstrates a growing interest in metabolic targets as a complementary approach in advanced melanoma, an area dermatologists continue to encounter in multidisciplinary oncology care.

References

1. Aminex Therapeutics announces multiple sites activated for phase 1b/2 clinical trial of novel investigational cancer treatment AMXT 1501 and DFMO in patients with solid tumors including primarily breast cancer and melanoma. News release. Aminex Therapeutics. February 4, 2026. Accessed February 4, 2026. https://aminextx.com/wp-content/uploads/2026/02/FINAL-Aminex-Phase-1_2-Trial-Initiation-PR_.pdf
2. 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 February 4, 2026. https://aminextx.com/wp-content/uploads/2025/10/Aminex-ODD-Press-Release-Final-10_2_25.pdf