Enspryng Approved to Treat Rare Autoimmune Disorder

August 17, 2020 – The U.S. FDA has approved EnspryngTM (satralizumab-mwge), manufactured by Genentech, to treat neuromyelitis optica spectrum disorder (NMOSD) in adult patients who are anti-aquaporin-4 (AQP4) antibody positive. Enspryng is the third treatment for NMOSD to receive FDA approval.

NMOSD is a rare, potentially life-threatening disease in which the immune system mistakenly attacks healthy cells and proteins in the body. Patients diagnosed with NMOSD experience periods of relapse and remission. Damage to the optic nerves and spinal cord accumulates over time and can lead to vision loss, muscle weakness, and paralysis. In many cases, NMOSD is associated with AQP4 antibodies that target and harm a specific type of cell known as astrocytes, which are part of the central nervous system.

In clinical studies, 76.5% of AQP4 antibody positive patients treated with Enspryng were relapse-free at 96 weeks, compared to 41.1% of patients who received a placebo. Ninety-one percent of patients who received Enspryng concurrently with baseline immunosuppressant therapy, a current standard of care, were relapse-free at 96 weeks, compared to 56.8% of patients on placebo.

Recommended dosing requires a 120mg loading dose at Weeks 0, 2, and 4, followed by a maintenance dosage of 120mg every four weeks. Enspryng is administered via subcutaneous injection and can be administered at home by a caregiver or the patient. Hepatitis B virus, tuberculosis, and liver transaminase screening is required before the first dose. Patient’s should consult their healthcare professional prior to taking Enspryng if they may have an active infection, including localized infections. Enspryng should be delayed if the patient currently has an active infection.

Genentech has launched the product at a wholesale acquisition cost (WAC) of $14,615.39 per syringe.