FirST-4-LEMS Study Seeks Participants

Researchers are looking for people with Lambert-Eaton myasthenic syndrome (LEMS) to participate in a phase 3 clinical trial, being conducted by Catalyst Pharmaceuticals, to test the investigational drug amifampridine phosphate.

The Firdapse Strength Trial for LEMS, or FirST-4-LEMS, study is designed to evaluate the effectiveness of amifampridine phosphate in controlling, reducing and/or eliminating symptoms of LEMS.

Amifampridine phosphate is a potassium channel inhibitor designed to prolong signals released from nerves and allow greater stimulation of muscles. The drug currently is under clinical investigation as a symptomatic therapy to treat LEMS and some forms of myasthenia gravis. It also is under investigation as a treatment for adults and children with congenital myasthenic syndrome.

The study, which will last at least five and up to 12 days, will evaluate the effects of withdrawing amifampridine phosphate treatment from people with LEMS. One half of trial participants will receive the drug, and the other half will receive placebo for four consecutive days. Participants will undergo a clinical evaluation in which they will complete strength and walking tests, answer questions about how they are feeling, and provide urine samples.

Trial sites are located in Miami and Los Angeles. All treatment and participation costs (travel, hotel, meals, etc.) are covered, and participants will have 24/7 access to expert medical care for the duration of the study.

Participants must be 18 years or older, have a confirmed diagnosis of LEMS, currently be receiving treatment with amifampridine phosphate and meet additional criteria.

MDA has supported previous studies of amifampridine phosphate in children with CMS.

For additional information on this trial, including complete eligibility criteria, visit and enter NCT02970162 into the search box. If you are interested in participating in the study, call 844-347-3277.