China-based Minghui Pharmaceutical has linked its thyroid eye disease treatment to a reduction in eye bulging in a small phase 1b/2 clinical trial.
The study enrolled 30 participants and assessed MHB018A—a VHH-Fc fusion protein delivered via subcutaneous injection—for moderate-to-severe thyroid eye disease (TED), an autoimmune condition also known as Graves' ophthalmopathy.
In the double-blind study, MHB018A was delivered across three dosing regimens: a 300 mg fixed dose once every four weeks for three doses; a 450 mg fixed dose every four weeks for three doses; and a 600 mg loading dose followed by two 300 mg fixed doses every four weeks. Participants in each group were randomly selected in a 4:1 ratio to receive MHB018A or placebo.
The study’s primary endpoint measured the reduction of proptosis, a term for the eyeball protruding from the socket. At week 12, the percentage of participants with a proptosis reduction greater than or equal to 2 mm from baseline was 50% for the 300 mg group; 50% for the 600 mg and 300 mg arm; and 87.5% for the 450 mg group. This compares to a 16.7% response rate seen in the placebo arm.
The group receiving 450 mg demonstrated “rapid, profound and sustained responses,” with 50% (4/8) of patients seeing a 2 mm or more reduction in proptosis at the four-week mark, with an 87.5% response rate (7/8) reported at eight weeks.
MHB018A was generally well-tolerated across all dosing levels, with most adverse events mild in severity and resolved without intervention after treatment, according to an Oct. 22 release from Minghui. The injection, which is designed to target the insulin-like growth factor-1 receptor (IGF-1R), had an overall safety profile consistent with other IGF-1R antibodies, the biotech said.
"While these findings are preliminary and from a small cohort, they offer significant potential,” Minghui CEO Guoqing Cao, Ph.D., said in the release. “A subcutaneous treatment with a great safety profile could represent a major advancement in TED care. Building on these encouraging results, we plan to initiate phase 3 registrational trials in the first half of 2025."