A substantial discount would be needed to meet cost-effectiveness thresholds.
Soliris (eculizumab) and efgartigimod improve function and quality of life for patients with myasthenia gravis, a rare neuromuscular disorder. But at Soliris' current price, its estimated cost-effectiveness is well above typical thresholds, and a substantial discount would be needed to meet commonly used thresholds, according to a draft report from the Institute for Clinical and Economic Review (ICER).
The cost-effectiveness of efgartigimod will depend on its eventual price, as it is not yet available, ICER officials said. But even at a projected price, this is also likely to be above cost-effectiveness thresholds.
Based on an annual cost of $470,200, the incremental cost/quality-adjusted life-year (QALY) and incremental cost/equal value of life years gained (evLYG) for Soliris were estimated to be $3,746,000. For efgartigimod, using a placeholder price of $286,100, the incremental cost/QALY and incremental cost/evLYG were estimated to be $1,426,000.
Soliris is a monoclonal antibody developed by Alexion Pharmaceuticals. (AstraZeneca completed its acquisition of Alexion on July 21, 2021.) The FDA approved Soliris in October 2017 for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-AChR antibody positive.
Efgartigimod, developed by Argenx, is an immunoglobulin fragment that targets the neonatal Fc receptor. It is currently being reviewed by the FDA, and a decision is expected in December 2021.
ICER evaluated the cost-effectiveness of Soliris plus conventional therapy versus conventional therapy alone in patients with refractory anti-AChR antibody positive gMG, as well as efgartigimod plus conventional therapy versus conventional therapy alone in the patients with gMG.
Myasthenia gravis is a neuromuscular disorder primarily characterized by muscle weakness and muscle fatigue. It is caused by an antibody-mediated autoimmune response) in which the antibodies inappropriately attack certain proteins in muscles that receive nerve impulses. Autoimmune myasthenia gravis has a prevalence of about 14 to 40 per 100,000 people in the United States, according to the National Organization for Rare Disorders.