Progress report on the L-serine HSAN1 Trial
by Florian Eichler, M.D.
There are 18 subjects currently enrolled in the two-year, double-blind, placebo-controlled trial studying the efficacy of L-serine in patients with HSAN1. This is lower than our original recruitment aim of 20. However, at the last meeting of the Data Safety Monitoring Board (DSMB) it was discussed that if two additional subjects could not be identified, then enrollment should be closed. Of the 18 subjects enrolled, all have completed their 48-week visit.
The study was initially randomized to placebo versus study drug, and both the participants and the investigators were blinded as to who was on placebo and who was on the study drug. At week 48 all participants were switched over to L-serine, regardless of their randomization from the previous year. The investigators are blinded until the end of the study, so they currently cannot assess whether L-serine is more effective than placebo.
To date no adverse events have been deemed related to the study drug. To ensure data integrity and compliance with the study protocol, for which we receive our funding, we have regular DSMB meetings scheduled. During the last DSMB meeting the investigators also discussed an open label extension until the DSMB meeting following the last study visit. We are in the process of discussing this with the Massachusetts General Hospital Institutional Review Board as well as with the Food and Drug Administration, who provided funding. In an open label extension, at the conclusion of a randomized, placebo-controlled trial, all participants are invited to take the active study drug, regardless of whether they were on the active study drug or placebo. Researchers continue to gather information from participants during the open-label phase. If a drug is shown to be ineffective or unsafe, the open-label extension is closed. We also had the Partners Human Research Quality Improvement Program complete an internal audit on our trial, and have been in close contact with their team to ensure Good Clinical Practice compliance. All of these oversight programs insure the integrity of the study.