The company didn’t share specific data for the molecule, gefurulimab, but said it hit all endpoints in the Phase III PREVAIL trial and promised to share more at an upcoming scientific meeting.
AstraZeneca’s investigational myasthenia gravis treatment gefurulimab cleared a Phase III trial, meeting all primary and secondary endpoints, the company announced Thursday.
The company did not release specific numerical data, only noting that gefurulimab “demonstrated a statistically significant and clinically meaningful improvement from baseline” using the Myasthenia Gravis Activities of Daily Living (MG-ADL) scale, a validated measurement tool for symptoms of myasthenia gravis.
Analysts at William Blair said in a note Thursday morning on the news that investors should keep in mind “the minimal clinically important difference on the MG-ADL scale is considered to be ≥2 points from baseline.” A comparable approved daily treatment, UCB’s Zilbrysq, got a 4.39-point reduction using that scale in its Phase III trial, the group wrote.
Gefurulimab is a complement C5 inhibiting nanobody, a fragment of a normal antibody. The molecule is being tested in the Phase III PREVAIL trial in adults with anti-acetylcholine receptor (AChR) antibody-positive (Ab+) generalized myasthenia gravis, an autoimmune condition that breaks down communications between the brain and muscles. According to AstraZeneca, 85% of patients with myasthenia gravis have this version of the disease.
More detailed information will be presented at a future medical meeting, according to AstraZeneca. The William Blair analysts speculated that that presentation could be at the Myasthenia Gravis Foundation of America (MFGA)’s sessions at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) Annual Meeting on Oct. 29.
Zilbrysq is the only FDA-approved subcutaneous treatment for gMG. Gefurulimab could compete with Zilbrysq given that it is a self-administered weekly drug. However, the William Blair analysts cautioned that argenx’s Vyvgart still leads in the $20 billion myasthenia gravis market, given its two-year head-start, having received FDA approval in June 2023.
Both AstraZeneca’s and argenx’s stock prices were up about 1.2% in morning trading following the news.
The PREVAIL announcement follows a week of newsmaking for AstraZeneca. The company stumbled last week in another rare disease setting after its antibody anselamimab failed to improve survival or hospitalization in patients with amyloidosis. Earlier this week the company also announced a new $50 billion manufacturing push in the U.S., led by a plant in Virginia that will create the company’s metabolic drugs aimed at cardiovascular conditions and obesity.
