FDA Approves Myrio's PHOX2B PC-CAR T Therapy for Neuroblastoma Trials

The U.S. Food and Drug Administration (FDA) has granted investigational new drug (IND) approval for Myrio Therapeutics' novel PHOX2B peptide-centric chimeric antigen receptor T-cell therapy (PC-CAR T), marking a significant advancement in the treatment of high-risk neuroblastoma. The approval, announced on June 13, 2025, paves the way for the therapy to enter human clinical trials, with the first patient expected to be enrolled by mid-2025.

Neuroblastoma, primarily affecting infants and young children, is the most common tumor of the sympathetic nervous system and accounts for approximately 15% of pediatric cancer-related deaths, according to Dr. John M. Maris, a pediatric oncologist at the Children’s Hospital of Philadelphia and co-head of the Pediatric Cancer Dream Team. Dr. Maris, who led the research team that identified the PHOX2B protein as a target in neuroblastoma cells, emphasized the urgent need for innovative treatment options due to the limited efficacy and significant side effects of existing therapies.

The PHOX2B PC-CAR T therapy is distinguished by its ability to 'break HLA restriction,' a limitation that has hindered the effectiveness of conventional CAR T therapies for solid tumors. Myrio's proprietary ReD™ technology enables the therapy to recognize the PHOX2B peptide presented by various human leukocyte antigen (HLA) allotypes, thus broadening its applicability to a more diverse patient population.

A pivotal 2023 study published in Nature outlines the potential of this approach, revealing that the neuroblastoma immunopeptidome is enriched with peptides from crucial tumorigenesis proteins. The study demonstrated that the PC-CARs could effectively target the unmutated peptide derived from the PHOX2B gene, which is involved in neuroblastoma's development, leading to significant tumor regression in preclinical mouse models.

Graeme Wald, CEO of Myrio Therapeutics, stated, "This is a major step forward for Myrio, culminating years of research in developing bispecific binders to human leukocyte antigens for treating solid tumors." He expressed optimism about the potential impact of the therapy on patients suffering from high-risk neuroblastoma.

As Myrio prepares for the clinical trial phase under Dr. Maris's leadership, the implications of this therapy could be profound, offering hope to families affected by this aggressive cancer. The trial's outcomes may not only influence treatment paradigms for neuroblastoma but also set a precedent for future immunotherapy developments targeting other malignancies.

In summary, the FDA's approval of Myrio's PHOX2B PC-CAR T therapy represents a significant milestone in pediatric oncology, potentially transforming the treatment landscape for high-risk neuroblastoma and paving the way for similar innovative therapies targeting solid tumors. The medical community eagerly anticipates the commencement of these trials and their subsequent results, which could herald a new era in cancer treatment for the youngest patients in need.