FDA Approves First LEMS Drug for Children and Adds New Wrinkle to Pricing Controversy

The U.S. Food and Drug Administration (FDA) granted approval to Jacobus Pharmaceuticals’ Ruzurgi, the first approved treatment for patients age six to 16 with Lambert-Eaton myasthenic syndrome (LEMS), a rare autoimmune condition.

Ruzurgi, developed by Jacobus Pharmaceutical, a family-run firm, had been available for free for many years under an FDA-approved compassionate use program. When Catalyst Pharmaceuticals’ won FDA approval in November 2018 for Firdapse for use in adults with LEMS, it ignited a politically-charged controversy over the price of the drug.

Catalyst priced its newly approved formulation of Amifampridine, the active compound in the drug, at an annual list price of $375,000. Senator Bernie Sanders, D-Vermont, demanded to know why it set such a high price, calling it “egregious” and an “immoral exploitation of patients who need this medication.”

While Jacobus has yet to confirm a price for Ruzurgi, there is speculation that the FDA may have dampened the pricing controversy with its approval of a competing treatment. Although Ruzurgi is approved for use in children with LEMS, there is nothing to stop doctors from prescribing it for adults.

Writing about the recent developments, Piper Jaffray senior research analyst Joseph Catanzaro questioned whether Catalyst would be able to maintain its orphan drug price and noted that there might be a legal issue on whether Ruzurgi infringes on Firdapse’s orphan drug exclusivity in LEMS.

“We see this approval by the FDA simply as a way to combat the pricing rhetoric that has surrounded Firdapse since its approval late last year and bring a potential competitor to the market,” he wrote.

In LEMS, the immune system attacks the areas where the nerves and muscles connect, affecting the way they communicate and making it difficult to move the muscles normally. It can occur at any age, but more commonly occurs in patients with cancer, where its onset precedes or coincides with the diagnosis of cancer. Prevalence of LEMS is estimated to be three per million individuals worldwide.

The FDA approved Ruzurgi based on a randomized, double-blind, placebo-controlled withdrawal study of 32 adult patients in which patients were taking Ruzurgi for at least three months prior to entering the study. The study compared patients continuing on Ruzurgi to patients switched to a placebo and found that patients who continued on Ruzurgi experienced less impairment than those on a placebo. Its use in pediatrics was supported by evidence from studies of the drug in adults with LEMS, pharmacokinetic data in adult patients, pharmacokinetic modeling and simulation to identify the dosing regimen in pediatric patients, and safety data from pediatric patients age six to 16.

“This approval will provide a much-needed treatment option for pediatric patients with LEMS who have significant weakness and fatigue that can often cause great difficulties with daily activities,” said Billy Dunn, director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research.