Efgartigimod (Vyvgart, argenx) led to statistically significant improvements in symptoms of ocular myasthenia gravis (MG) in the phase 3 ADAPT OCULUS trial, according to topline results released by the company. 

The trial met its primary efficacy endpoint (P = .012), with patients treated with efgartigimod demonstrating a statistically significant improvement from baseline in Myasthenia Gravis Impairment Index (MGII) patient-reported outcome (PRO) ocular scores at week 4 compared with placebo, the company said. 

Patients treated with efgartigimod had a mean 4.04-point improvement in MGII PRO ocular scores compared with a mean improvement of 1.99 on this measure in patients treated with placebo. 

Improvements included marked reductions in diplopia (double vision) and ptosis (eyelid droop), the company said. 

Efgartigimod was generally well tolerated, with a safety profile consistent with prior studies and no new safety concerns identified.

The phase 3 ADAPT OCULUS trial enrolled 141 adult patients with ocular MG across North America, Europe, and Asia-Pacific. In part A, participants were randomly allocated to receive four once-weekly subcutaneous injections of efgartigimod or placebo followed by a 4-week follow-up. 

In part B, open-label extension, they received two cycles of four once-weekly efgartigimod injections with a 4-week interval between cycles. Additional cycles from cycle 3 onward could start ≥ 1 week after the last administration of the previous cycle, based on clinical status.

The company said the topline results support argenx’s plan to submit a supplemental biologics license application to the FDA seeking to expand the indication for efgartigimod to include the ocular MG patient population. 

The FDA approved efgartigimod in 2021 for adults with generalized MG who test positive for the anti-acetylcholine receptor antibody. 

Filling a Treatment Gap

Ocular MG is a debilitating form of MG that primarily affects the muscles controlling the eyes and currently has no approved targeted therapies.

“Ocular myasthenia gravis significantly impacts patients’ daily lives, affecting vision, independence, and the ability to do routine tasks, such as work or drive a car. Yet today, there are no approved targeted medicines for this disease,” Carolina Barnett-Tapia, MD, PhD, associate professor of neurology at the University of Toronto, Canada, said in a company news release. 

“The improvements observed with Vyvgart in the OCULUS trial offer hope to the thousands of myasthenia gravis patients with ocular involvement,” Barnett-Tapia added. 

The company reported that data from the ADAPT OCULUS study will be presented at an upcoming medical conference.