AZ trumpets results for new injectable C5 drug for myasthenia gravis

 AstraZeneca has reported the first phase 3 data with its next-generation complement C5 inhibitor, gefurulimab, which could give patients with generalised myasthenia gravis (gMG) a treatment option they can self-administer at home.

The results of the PREVAIL study showed that gefurulimab – a nanobody developed by AZ's Alexion unit - achieved a statistically significant improvement from baseline in gMG symptoms, measured using the MG-ADL scale, over 26 weeks.

There was a 1.6-point improvement in MG-ADL scores compared to placebo, which AZ said was "clinically meaningful." The drug also hit all its secondary objectives, including a 1.8-point improvement in the QMG scale total score at week four and a 2.1-point improvement at week 26.

AZ is already a major presence in gMG treatment with its current antibody-based anti-C5 drugs – Soliris (eculizumab) and Ultomiris (ravulizumab) – which are dosed by intravenous infusion every two and eight weeks, respectively, meaning that patients with the rare but debilitating autoimmune disease have to have frequent clinic visits.

Aside from offering greater convenience for patients, gefurulimab also gives AZ and Alexion a way to defend their C5 business as Soliris started to feel the effects of biosimilar competition, having now lost its patent protection in most major markets.

gMG causes muscle weakness, breathing troubles, difficulty swallowing, and impaired speech and vision, and affects approximately 200 people per 1 million globally. PREVAIL recruited 260 adult patients with anti-acetylcholine receptor (AChR) antibody-positive (Ab+) gMG, a group that makes up around 85% of all people living with the disease.

Principal investigator Kelly Gwathmey of Virginia Commonwealth University in the US said that results show "early and lasting benefits" of gefurulimab and support its potential "to offer an efficacious and convenient self-administered treatment option that may help address the unpredictability of this disease."

AZ hasn't revealed its plans for regulatory filings for gefurulimab, but has previously suggested the drug could make peak sales of $1 billion to $3 billion a year.

There are a couple of subcutaneous treatment options for gMG already on the market, including ArgenX's Vyvgart Hytrulo (efgartigimod alfa) and UCB's Rystiggo (rozanolixizumab) and Zilbrysq (zilucoplan). Of those, only Zilbrysq can be self-administered, and it needs to be injected once daily.

Meanwhile, other IV competitors are on or near the market for gMG, including Amgen's anti-CD19 antibody Uplizna (inebilizumab), which cleared the phase 3 MINT trial earlier this year, and Johnson & Johnson's recently approved FcRn blocker Imaavy (nipocalimab).

https://pharmaphorum.com/news/az-trumpets-results-new-injectable-c5-drug-gmg