Momenta Reports Positive Topline Results from Interim Analysis of Study of Therapy for Generalized Myasthenia Gravis

Momenta Pharmaceuticals reported positive topline data from an interim analysis of its phase 2 Vivacity-MG study of its experimental therapy nipocalimab in generalized myasthenia gravis, a rare autoimmune condition.

Myasthenia gravis (MG) is a chronic neuromuscular disease that affects skeletal muscles responsible for eye movements, breathing, and body motion, causing muscle weakness and fatigue. Myasthenia gravis can be restricted to eye muscles or may affect other muscle besides eye muscles (generalized myasthenia gravis). In gMG, the immune system mistakenly attacks muscle receptors, preventing signals from transferring from nerves to muscles.

Over time, this may lead to symptoms, such as limb weakness, drooping eyelids, double vision, as well as cause difficulties with chewing, swallowing, speech, and breathing. Although gMG may be managed with current therapies, Momenta said research is needed to develop new treatments for those who may not respond well enough to or tolerate current therapies.

Nipocalimab is an antibody in development to treat patients with gMG. It is expected to improve nerve-to-muscle signals and muscle function, alleviating the clinical signs and symptoms of gMG. It is also in clinical studies as a potential treatment for warm autoimmune hemolytic anemia, an indication for which the U.S. Food and Drug Administration has awarded it Fast Track and Orphan Drug designations.

The Vivacity-MG study is a phase 2, multicenter, randomized, double-blind, placebo-controlled study evaluating the safety, efficacy, pharmacokinetics and pharmacodynamics of nipocalimab in 68 patients with moderate-to-severe gMG. The eight-week treatment period included four active arms and one placebo arm. The primary endpoint of the study was to reach statistically significant change from the baseline score of the myasthenia gravis activities of daily living score.

The interim results showed all four treatment arms in the study showed efficacy in the myasthenia gravis activities of daily living (MG-ADL) score, the primary endpoint. Additionally, all dosing arms showed strong safety and tolerability profiles. It showed 52 percent of patients who received nipocalimab had rapid, significant, and durable reductions in MG-ADL scores (at least a 2-point reduction from baseline for at least four consecutive weeks) across all four dosing arms, versus 15 percent of placebo treated patients. There were no severe or serious nipocalimab-related adverse events and most adverse events were characterized as mild. The company said the findings support continued clinical development in gMG and subcutaneous formulation dose selection.

“For patients with myasthenia gravis, current treatment options include medications such as acetylcholinesterase inhibitors, corticosteroids and immunosuppressants that may provide improvement in muscle strength; however, many patients fail to respond, have substantial side effects or have uncontrolled disease symptoms that limit their daily function and quality of life,” said Jeffrey Guptill, principal investigator. “The promise of nipocalimab to reduce pathogenic autoantibodies in a dose dependent manner, brings me great hope in providing these patients with a new treatment option. The correlation between IgG reduction and symptom control across all doses in the nipocalimab trial may provide physicians the ability to optimally adjust patient dosing.”

Based on the data, the company has begun preparations to conduct end of phase 2 meetings with regulatory agencies before the end of 2020.

“The knowledge we have gained from this multi-arm dosing study serves as a roadmap to design a phase 3 study focused on dosing precision and flexibility, and ultimately for physicians to better understand the onset of action and duration of effect for their gMG patients.” said Santiago Arroyo, chief medical officer of Momenta Pharmaceuticals.

Photo: Santiago Arroyo, chief medical officer of Momenta Pharmaceuticals

Author: Rare Daily Staff