Läkemedelsföretaget Roche har under fem års tid genomfört kliniska studier med personer som har Downs syndrom av ett ämne (RG1662 / Basmisanil) som blockerar vissa GABA-receptorer i hjärnans nervceller. Syftet var att förbättra personernas kognition genom en bättre balans mellan excitation och hämning i nervcellernas synapser. Den största delstudien CLEMATIS omfattade vuxna (18-30 år) och ungdomar (12-17 år) i tio länder.
Den 28 juni meddelade Roche att effekterna av behandlingen i CLEMATIS visat sig sakna signifikans och att man därför avbryter den nu pågående studien för barn (6-11 år) i USA.
Lärdomarna från studien kommer att presenteras på en medicinsk konferens och resultaten kommer också att publiceras på clinicaltrials.gov.
Roche Statement on CLEMATIS trial:
June 28, 2016
The CLEMATIS trial was a Phase II study investigating the efficacy and safety of basmisanil (RG1662) in adults and adolescents with Down syndrome. It was a 26 week, multi-centre, randomized, double-blind, three arm, parallel-group, placebo-controlled study.
This phase II study did not meet its primary and secondary endpoints on improvement in cognition and function. There was no difference observed between adults (18-30 years old) and adolescent (12-17 years old) in the study. In addition, there was no significant difference between those who took the drug and those that took the placebo.
Given the lack of efficacy seen in the CLEMATIS trial, Roche has decided to discontinue the ongoing clinical trial (WP28760) in children (6-11 years old) with Down syndrome. This paediatric study is not being discontinued for safety reasons as basmisanil was well tolerated and no relevant safety signals were observed with basmisanil when compared to placebo and previous trials.
We are disappointed by the lack of efficacy seen in the CLEMATIS trial. We have learnt a lot from people with Down syndrome and their families over the past few years and we are very grateful for their willingness to participate in this clinical trial programme.
We are committed to sharing our learnings with the community and the results of the CLEMATIS trial will be presented at an upcoming medical congress as well as being posted on clinicaltrials.gov.
A randomized, double-blind, placebo-controlled phase II trial to explore the effects of a GABA A-α5 NAM (basmisanil) on intellectual disability associated with Down syndrome (2022 Feb: Celia Goeldner, Priya S Kishnani, Brian G Skotko, Julian Lirio Casero, Joerg F Hipp, Michael Derks, Maria-Clemencia Hernandez, Omar Khwaja, Sian Lennon-Chrimes, Jana Noeldeke, Sabine Pellicer, Lisa Squassante, Jeannie Visootsak, Christoph Wandel, Paulo Fontoura, Xavier Liogier d’Ardhuy, Clematis Study Group.) PMID35123401, DOI:10.1186/s11689-022-09418-0