The combination therapy yielded greater tumor suppression and longer median survival in mice, with increased HMOX1 and decreased GPX4 in tumor tissues and no extra toxicity observed.

Bioinformatic analysis linked high HMOX1 expression in patient plasma cells to significantly better overall survival (HR=0.51), suggesting a biomarker-guided approach for IRX4204-based combinations.

Further data imply that high HMOX1 in patient plasma cells may serve as a prognostic biomarker supporting IRX4204-based therapeutic strategies.

IRX4204 protects CAR-T cells from exhaustion and ferroptotic death by suppressing CHAC1-driven ferroptosis and promoting mitophagy via PINK1/PARK2, improving CAR-T persistence and tumor control in vivo.

By dampening CHAC1-driven ferroptosis and activating PINK1/PARK2-mediated mitophagy, IRX4204 helps CAR-T cells endure and perform better against tumors in xenograft models.

Io Therapeutics reported preclinical results at the American Society of Hematology meeting showing IRX4204, an RXR agonist, enhances the efficacy of BCMA CAR-T cells and lenalidomide against human multiple myeloma in vitro and in vivo.

Led by Dr. Yubin Kang at Duke University, the work points to a druggable ferroptosis pathway in multiple myeloma and suggests potential biomarker-guided therapy selection.

The studies indicate IRX4204 activates the PPARα/RXRα–HMOX1 axis to induce ferroptosis in myeloma plasma cells while dampening GPX4/SLC7A11 antioxidant defenses, showing synergy with lenalidomide in cells and animal models.

Analyses of tumors from treated subjects showed higher HMOX1 and lower GPX4 in combination-treated tumors.

In mice, the IRX4204–lenalidomide combination reduced tumor growth compared with lenalidomide alone and extended median survival without additional systemic toxicity.