IRLAB Therapeutics (IRLAB) Study Update summary

Phase IIb study design

• Randomized, double-blind, placebo-controlled, 12-week dose-finding study in Parkinson’s disease levodopa-induced dyskinesia; compared mesdopetam 2.5, 5 and 7.5 mg twice daily with placebo.

• Primary objective: assess dose response and select a Phase III dose; primary efficacy measure was daily good ON-time from Hauser diaries.

• Full Analysis Set used randomized doses; protocol-compliant adjusted-dose analyses reflected doses actually received, with diary results scaled to 16 awake hours.

Efficacy findings

• Protocol-compliant adjusted-dose analysis showed 1.75 hours more good ON-time vs placebo at 7.5 mg twice daily; p=0.049.

• In the adjusted-dose set, OFF-time fell 1.27 hours vs placebo at 7.5 mg twice daily; p=0.051.

• UDysRS parts 1, 3 and 4 improved vs placebo by 9.2 points in the adjusted-dose set at 7.5 mg twice daily; p=0.011; Full Analysis Set difference was 6.2 points, p=0.026.

• Study conclusions cited dose-response anti-dyskinetic efficacy, improved good ON-time and reduced OFF-time, without increased parkinsonism or adverse effects on normal motor function.

Safety and pharmacokinetics

• Withdrawal rates were reported as comparable to placebo across all mesdopetam doses; 4, 3 and 2 early withdrawals due to adverse events at 2.5, 5 and 7.5 mg, respectively, versus 4 on placebo.

• Treatment-related adverse-event incidence was 4.3% across mesdopetam arms vs 10.3% on placebo for parkinsonism, and 5.2% vs 7.7% for dyskinesia.

• Phase IIb findings included predictable, linear, dose-dependent plasma exposure; the selected Phase III dose was 7.5 mg twice daily.

• Ipsen’s three Phase I studies found similar pharmacokinetics in Asian and non-Asian populations, low drug-interaction risk and no signs of accumulation; results indicated predictable exposure and simple dosing.