08/25/2026 | Millie Hoe | BioXconomy

https://www.bioxconomy.com/modalities/regeneron-terminates-mab-eye-therapy-trial-amid-safety-concerns 

The one-patient study was evaluating a T cell-targeting monoclonal antibody drug for noninfectious uveitis.

Large pharmaceutical company Regeneron has terminated the early Phase I/IIa TITAN clinical trial (NCT07218770) for its new monoclonal antibody therapy targeting noninfectious uveitis. According to the study’s online filing, the trial was terminated early due to an unfavorable risk versus benefit assessment.

“Regeneron voluntarily terminated the Phase I/IIa TITAN study investigating REGN7041, prompted by a thorough review of a safety event observed in the trial,” a Regeneron spokesperson told BioXconomy.

“An investigation into this event has been conducted, and the underlying cause has not been identified.”

The TITAN study had only enrolled a single adult patient before its early termination. The anti-CD3 monoclonal antibody treatment was designed to address noninfectious uveitis, an inflammatory eye disorder that can cause significant vision damage. Current treatments rely on immunosuppression regimens, including steroid injections into the eye.

The CD3 complex is an integral receptor on the surface of T cells that helps facilitate an inflammatory immune response. Many monoclonal antibody therapies have been developed to target the CD3 receptor for immune modulation, including teplizumab for the treatment of type I diabetes.

The exact cause of the clinical trial’s closure has not yet been stated publicly.

Unfortunately, TITAN’s early trial termination isn’t the only setback antibodies have recently faced. Bristol Myers Squibb’s antibody combination approach failed to outperform chemotherapy in its Phase III clinical trial for the treatment of advanced colorectal cancer.

Regeneron has also suffered similar setbacks, including the failure of an interleukin-33 blocker for chronic obstructive pulmonary disease (COPD). Its investigational melanoma therapy also failed to outdo competitors.

“Patient safety is Regeneron's top priority,” the spokesperson said. “We will continue to evaluate the data from this study.”

Quotes have been lightly edited for clarity. Header image depicts drawings of the eye by A. Vandenhoeck circa 1743.