Ropinirole

K Pharma is a small Tokyo-listed company spun out of Keio University, which holds the ALS use patents and licenses them to K Pharma. K Pharma has licensed the Japanese rights to Alfresa Pharma, which developed a new slow-release granule form (code KA-2301) and will run the Japanese Phase 3 trial. K Pharma is looking for partners outside Japan.

Ropinirole mimics dopamine and is approved for Parkinson's disease and restless legs. In nerve cells made from ALS patients' stem cells it reduced cell death and harmful stress, and the Keio team reported that it acts partly by dampening cholesterol production inside nerve cells. A 2025 lab study suggested much of this protection does not depend on its dopamine action, so exactly how it might work in ALS is still being studied.

The ROPALS Phase 1/2a trial at Keio is finished and was published in June 2023. In 2025 Alfresa ran a study in healthy volunteers to compare the new granule form with the original tablets; it finished in December 2025. In August 2026 K Pharma said Alfresa plans to start the Phase 3 trial in Japan during fiscal year 2026, which ends in March 2027. As of early November 2026 no start has been announced.

ROPALS had 20 people with sporadic ALS (13 on ropinirole, 7 on placebo); its main goal was safety. During the 24-week placebo-controlled period, the ALS functional score (ALSFRS-R) did not differ between groups (1.46 points, a gap too small to rule out chance). In the open-label extension that followed, people who had taken ropinirole from the start went about 27.9 weeks longer before their disease worsened. But 6 of 7 placebo patients and 6 of 13 ropinirole patients left the trial, and an independent expert said the extension is open to bias and the trial too small to judge benefit.

This is the most favourable result reported. See all key studies for the full picture.

The Keio trial enrolled people with sporadic (non-inherited) ALS. It used once-daily slow-release Parkinson's tablets (ReQuip CR). Because many people with ALS have trouble swallowing large tablets, Alfresa developed slow-release granules (KA-2301) for the Phase 3 trial.

At its August 2026 results briefing K Pharma said Alfresa plans to start Phase 3 in Japan within fiscal year 2026 (April 2026 to March 2027). An analyst report from March 2026 estimated a trial of about 200 people lasting two to two and a half years. In the US, K Pharma received FDA written feedback in January 2026 but has not started a trial there.

No trial is currently enrolling people with ALS. The Phase 3 trial is expected to recruit in Japan only. Ropinirole itself is a widely available Parkinson's drug, but it is not approved for ALS and the dose and form used in ALS trials differ; talk to a neurologist before considering it.

• ROPALS (Phase 1/2a) (UMIN000034954) completed · Japan (Keio University Hospital)
• KA-2301 granule study in healthy volunteers (jRCT2051250084) completed · Japan