July 1, 2019Regulatory
Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease of the central nervous system that mainly affects the optic nerves and spinal cord. In patients with NMOSD, the body's immune system mistakenly attacks healthy cells and proteins in the body, most often in the optic nerves and spinal cord. Individuals with NMOSD typically have attacks of optic neuritis, which causes eye pain and vision loss. Individuals also can have attacks resulting in transverse myelitis, which often causes numbness, weakness, or paralysis of the arms and legs, along with loss of bladder and bowel control. Most attacks occur in clusters, days to months to years apart, followed by partial recovery during periods of remission. Approximately 50% of patients with NMOSD have permanent visual impairment and paralysis caused by NMOSD attacks. According to the National Institutes of Health, women are more often affected by NMOSD than men and African Americans are at greater risk of the disease than Caucasians. Estimates vary, but NMOSD is thought to impact approximately 4,000 to 8,000 patients in the United States.
NMOSD can be associated with antibodies that bind to a protein called aquaporin-4 (AQP4). Binding of the anti-AQP4 antibody appears to activate other components of the immune system, causing inflammation and damage to the central nervous system.
The FDA has approved Soliris (eculizumab) injection for intravenous use for the treatment of NMOSD in adult patients who are anti-aquaporin-4 (AQP4) antibody positive. The effectiveness of Soliris for the treatment of NMOSD was demonstrated in a clinical study of 143 patients with NMOSD who had antibodies against AQP4 (anti-AQP4 positive) who were randomized to receive either Soliris treatment or placebo. Compared to treatment with placebo, the study showed that treatment with Soliris reduced the number of NMOSD relapses by 94% over the 48-week course of the trial. Soliris also reduced the need for hospitalizations and the need for treatment of acute attacks with corticosteroids and plasma exchange.
Soliris has a boxed warning to alert health care professionals and patients that life-threatening and fatal meningococcal infections have occurred in patients treated with Soliris, and that such infections may become rapidly life-threatening or fatal if not recognized and treated early. Patients should be monitored for early signs of meningococcal infections and evaluated immediately if infection is suspected. Use should be discontinued in patients who are being treated for serious meningococcal infections. Health care professionals should use caution when administering Soliris to patients with any other infection. In the NMOSD clinical trial, no cases of meningococcal infection were observed.
Soliris is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS). Prescribers must enroll in the REMS program. Prescribers must counsel patients about the risk of meningococcal infection, provide the patients with the REMS educational materials and ensure patients are vaccinated with meningococcal vaccine(s). The drug must be dispensed with the FDA-approved patient Medication Guide that provides important information about the drug's uses and risks. The most frequently reported adverse reactions reported by patients in the NMOSD clinical trial were: upper respiratory infection, common cold (nasopharyngitis), diarrhea, back pain, dizziness, influenza, joint pain (arthralgia), sore throat (pharyngitis) and contusion.
Soliris was first approved by the FDA in 2007. The drug is approved to reduce destruction of red blood cells in adults with a rare blood disease called paroxysmal nocturnal hemoglobinuria, for the treatment of adults and children with a rare disease that causes abnormal blood clots to form in small blood vessels in the kidneys (atypical hemolytic uremic syndrome to inhibit complement-mediated thrombotic microangiopathy), and for the treatment of adults with Myasthenia Gravis who are anti-acetylcholine receptor antibody positive.
The FDA granted this application Priority Review. The use for NMOSD received Orphan Drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases. The FDA granted the approval of Soliris to Alexion Pharmaceuticals.