In short
Rimonabant is an investigational chemical substance that blocks the cannabinoid type-1 (CB1) receptor. It has no marketing authorisation and is currently being studied in four authorised clinical trials involving 248 participants across three conditions: stroke, spinal cord injury and post-COVID-19 syndrome.
Rimonabant is an investigational chemical substance that acts as a selective cannabinoid type-1 (CB1) receptor antagonist. It is also known by the development code SR141716A and was previously marketed under the trade name Acomplia. The product records in the EU Clinical Trials Information System (CTIS) list no marketing authorisation, meaning it remains an investigational substance supplied by SINFATIN, S.L.
Key points
- Rimonabant is a CB1 receptor antagonist with no marketing authorisation — an investigational substance.
- Four authorised trials are listed, covering stroke, spinal cord injury and post-COVID-19 syndrome.
- Two trials are Phase 2 in stroke, one Phase 2 in post-COVID-19 syndrome, and one Phase 1 in spinal cord injury.
- Enrolment ranges from 8 participants (spinal cord injury) to 80 participants in each Phase 2 trial.
- The spinal cord injury trial measures hand function with the GRASSP scale.
- Rimonabant is given as oral tablets at 2.5 mg or 5 mg in these trials.
What is rimonabant?
Rimonabant is a chemically synthesised pyrazole and piperidine derivative that acts as a selective CB1 receptor antagonist. Its ATC code is A08AX01, a class used for anti-obesity preparations, though the trials listed here investigate it in neurological conditions. The substance is also referred to as SR141716A and Acomplia. No marketing authorisation is recorded in the CTIS product records.
How does rimonabant work?
Rimonabant blocks the CB1 receptor, which is part of the endocannabinoid system. It also inhibits the proliferation and maturation of adipocytes (fat cells). Blocking this receptor is thought to influence neurological recovery processes, which is why the current trials are studying it in conditions affecting the brain and spinal cord.
Which conditions is rimonabant being studied for?
- Stroke — two Phase 2 trials are testing whether rimonabant improves functional independence and walking ability after stroke.
- Spinal cord injury — one Phase 1 trial is evaluating hand motor function in patients with cervical spinal cord injury.
- Post-COVID-19 syndrome — one Phase 2 trial is testing cognitive performance compared with placebo.
How is rimonabant given?
In the CTIS product records, rimonabant is formulated as tablets for oral use. The trials use 2.5 mg tablets and 5 mg orodispersible tablets (ODT).
What do the clinical trials show?
The four authorised trials are all interventional and cover three conditions. Two Phase 2 trials enrol 80 participants each in stroke: one in the subacute phase measuring functional independence with the Barthel Index, and one in the chronic phase measuring walking capacity with the six-minute walking test (6MWT). A third Phase 2 trial enrols 80 participants with post-COVID-19 syndrome and measures cognitive performance with the Symbol Digit Modalities Test (SDMT). The Phase 1 trial enrols 8 participants with spinal cord injury and measures hand function with the GRASSP scale.
All four trials are currently in Authorised status, meaning they have been approved but may not yet be recruiting.–[4]
What side effects are known?
A systematic review of 18 clinical trials found that rimonabant 20 mg produced significantly more overall adverse events, psychiatric events and gastrointestinal adverse events than placebo. Gastrointestinal events such as diarrhoea were more common with rimonabant (odds ratio 2.05). Psychiatric events were also more frequent (odds ratio 1.79). These findings come from earlier trials using a 20 mg dose, which is higher than the doses used in the current CTIS trials.