FDA Approves Genentech’s Enspryng for Neuromyelitis Optica Spectrum Disorder
The U.S. Food and Drug Administration (FDA) approved Genentech’s Enspryng (satralizumab-mwge) as a subcutaneous treatment for adults with anti-aquaporin-4 (AQP4) antibody positive neuromyelitis optica spectrum disorder (NMOSD).
NMOSD, also known as Devic disease, is a chronic disorder of the brain and spinal cord. It is marked by inflammation of the optic nerve and inflammation of the spinal cord. The first symptom is typically inflammation of the optic nerve that leads to pain inside the eye which is quickly followed by loss of clear vision. It sometimes is preceded by a prodromal upper respiratory infection. The other primary symptom is inflammation of the spinal cord, and tends to affect some or all of the motor, sensory and autonomic functions, such as bladder and bowel, below a specific level of the body, although symptoms may be confined to one side of the body.
The disease is often associated with pathogenic antibodies (AQP4) that target and damage astrocytes, which are neural support cells. The antibodies are found in the blood of about 70 to 80% of NMOSD patients. Although the disease can be confirmed via diagnostic tests, it is often misdiagnosed with multiple sclerosis, because of overlapping characteristics, including a higher prevalence in women.
“Today’s FDA approval of Enspryng, the first subcutaneous NMOSD treatment using novel recycling antibody technology, builds upon the work we’ve done in multiple sclerosis with Ocrevus to develop first-in-class medicines and further the scientific understanding of neuroimmunological diseases,” said Levi Garraway, Genentech’s chief medical officer and head of Global Product Development. “We thank the NMOSD community, including patients and investigators who participated in Enspryng clinical trials.”
Enspryng is a humanized monoclonal antibody. It is the only therapy approved for NMOSD that targets and inhibits interleukin-6 (IL-6) receptor activity, which researchers believe plays a central role in NMOSD-associated inflammation. The drug can be self-administered in the home or by a caregiver after training from a healthcare provider. The therapy is administered every four weeks after an initial loading dose.
“For people with NMOSD, relapses can cause devastating, irreversible and disabling neurological effects,” said Jeffrey Bennett, investigator for the Enspryng pivotal clinical trials and professor at the University of Colorado Neurology & Ophthalmology. “Having an approved therapy that can be administered subcutaneously in the home and has demonstrated an impact on the frequency of relapses is an important advancement for patients.”
The approval was based on data from two randomized controlled Phase III trials, SAkuraStar and SAkuraSky. In both, Enspryng demonstrated robust and sustained efficacy and a favorable safety status in adults with AQP4 antibody positive NMOSD. The improvement was sustained over 96 weeks and significantly decreased the risk of relapse compared to placebo as a monotherapy and when used together with baseline immunosuppressant therapy (IST).
The most common side effects, with an incidence of less than 15%, were nasopharyngitis, headache, upper respiratory tract infection, gastritis, rash, arthralgia, extremity pain, fatigue and nausea.
Enspryng was designed by Chugai, a member of the Roche group. The drug is approved for NMOSD in Canada, Japan and Switzerland, and is under review in the European Union and China. It has been designated an orphan drug int eh U.S., Europe and Japan.
Genentech expects to make the drug available in the U.S. in two weeks.
“We are very optimistic the addition of this new approved treatment option will make a meaningful difference for those living with NMOSD, those who love and support them and the doctors who treat them,” said Victoria Jackson, founder, The Guthy-Jackson Charitable Foundation. “When my daughter was diagnosed with NMOSD in 2008, there were no approved treatment options, and a critical lack of resources and understanding for people living with this disabling disorder. After years of dedicated effort and collaboration, the FDA approval of Enspryng exemplifies how patients, industry, and academia can find solutions together.”