FDA Approves Soliris for Particular Type of Myasthenia Gravis

The U.S. Food and Drug Administration has approved Soliris (eculizumab) as a treatment for adults with a particular type of generalized myasthenia gravis (gMG) — the first time in more than 60 years that it has authorized a therapy for the disease.

Alexion Pharmaceuticals, which developed Solaris, said the approval covers gMG patients who have acetylcholine receptor (AchR) antibodies. Myasthenia gravis is a chronic neuromuscular disorder.  AchR antibodies inhibit acetylcholine, a neurotransmitter that sends messages between nerve cells, leading to loss of muscle function.

Soliris targets the underlying cause of gMG by preventing the immune system from becoming activated in an uncontrolled manner. The uncontrolled form of what scientists call the complement cascade not only plays a role in the development of gMG but in the development of other neuromuscular diseases as well.

The FDA based its approval of Soliris on the results of the Phase 3 REGAIN clinical trial (NCT01997229) and from an ongoing extension trial (NCT02301624).

Ninety-four percent of the patients who completed the 26-week REGAIN trial — or 117 out of 125 — took part in the 52-week extension study as well. Fifty-six patients who received Soliris in the REGAIN trial continued to receive it in the extension, and 61 who received a placebo in the initial study were switched to Soliris in the second one.

Interim results showed that both groups had better muscle strength and function, and improved quality of life, during the extension trial. The bottom line is that Soliris helped gMG patients with AchR antibodies who had previously failed immunosuppressive treatment and continued to have problems walking, seeing, talking, swallowing, and breathing.

The study also confirmed the safety profile that the drug displayed in the Phase 3 trial. Alexion plans to finish the extension study in January 2019.

“It is exciting that patients who have not responded adequately to existing therapies will now have a new treatment option that was shown in clinical studies to improve patients’ symptoms, their ability to carry out activities of daily living, and their quality of life,” Dr. James F. Howard, lead investigator of the clinical trials, said in a press release.

“This is a landmark day for the members of the U.S. myasthenia gravis community, who have not seen a therapy approved for generalized myasthenia gravis in more than 60 years,” said Nancy Law, chief executive officer of the Myasthenia Gravis Foundation of America. “It is particularly significant that this approval of Soliris will provide a new option for those with gMG and especially for those who do not respond adequately to or cannot tolerate standard treatment options.”

The European Union approved Solaris in August 2017 after the European Medicines Agency’s Committee for Medicinal Products for Human Use recommended the approval in July. The EU approval covers Soliris as a treatment of gMG in adults with AchR antibodies who have failed to respond to other treatments.

Japan’s Ministry of Health, Labor and Welfare will be considering a new drug application for Soliris in coming months. This application also covers Soliris as a treatment for patients with AchR antibodies who failed to respond to other therapies.