EPI-589 Phase 2a

The research record

This is the project's file for this landmark, as written and checked. Sources are listed at the end; anything not yet confirmed is marked "Not yet verified".

Who

Edison Pharmaceuticals is the registered sponsor; the registry title calls the drug PTC-589 (PTC Therapeutics' role is not stated in the record). Sites included Germany and the UK (from registry pages and a DZNE listing; not checked in detail).

What happened

EPI-589 is a small-molecule pill described by its developer as a redox modulator: a drug meant to protect cells from oxidative stress and restore energy balance. The link to Parkinson's runs through Complex I, a part of the mitochondrial energy chain that is weak in the disease (landmark 11), and through glutathione, the antioxidant that falls in the nigra (landmark 129).

NCT02462603 was open-label and single-arm, with a 30-day run-in and an adaptive element to add participants: everyone received the drug. It enrolled 44 people with idiopathic Parkinson's or a mitochondrial genetic subtype; 41 got at least one dose and 40 completed. The dose was 500 mg (two 250 mg tablets) twice daily for up to 3 months (registry arm description). It ran from 17 May 2016 to 8 January 2019. The primary outcome was safety: no participants had a drug-related serious adverse event. Secondary results, as posted:

• The motor examination score (MDS-UPDRS Part III) started at 22.5 on average and changed by −0.6 at month 3 (standard deviation 6.7).
• Non-motor and quality-of-life scales were flat.
• Glutathione was measured in plasma (1.54 µM at month 3), spinal fluid (0.10 µM) and urine; the registry posts only month-3 values with no baseline or comparison group, so no effect can be read from them.

Why it moved us toward a cure

It tested whether the drug could be taken and whether a glutathione signal appeared, a step before any trial that could test slowing. It did not test slowing: no placebo, three months.

Outcome

Open. Finished January 2019; results were posted in May 2022. A ClinicalTrials.gov search (19 Oct 2026) finds no other Parkinson's trial of EPI-589 or PTC-589. The only other registered EPI-589 trial is a sister ALS safety and biomarker study (NCT02460679). No placebo-controlled Parkinson's trial followed, so the idea is unresolved rather than failed.

Sources

• ClinicalTrials.gov NCT02462603 (API, results section, 19 Oct 2026) · NCT02460679 (ALS)
• EU Clinical Trials Register 2015-001786-10
• Not yet verified: the drug's molecular target; PTC's role; whether a peer-reviewed paper exists; why development in Parkinson's stopped.