“With the positive feedback from EMA, we can now plan the design of the Phase III program for mesdopetam to meet regulatory requirements in both the U.S. and Europe. This significantly enhances the value of the project and is a crucial part in our discussions with potential collaborators for the final development stages and a possible commercialization of our unique drug candidate,” said IRLAB’s CEO, Kristina Torfgård.

Following the successful dialogue with EMA and the company’s prior End-of-Phase 2 meeting with the U.S. Food and Drug Administration (FDA), IRLAB has reached a consensus with both European and US regulatory authorities on the remaining clinical development plan for mesdopetam. This agreement includes the program required for the approval of mesdopetam as a treatment for levodopa-induced dyskinesia (LIDs) in patients with Parkinson’s disease.

EMA has reviewed the comprehensive data package provided by IRLAB and has given feedback on all aspects of the mesdopetam development plan, including the design of the Phase III studies.

The agency has responded positively and accepts the setup of the Phase III program, including the following key components:

• The patient population will be the same as in previous clinical studies within the mesdopetam program.
• The primary efficacy endpoint will be UDysRS parts 1+3+4.
• Secondary efficacy endpoints will be based on elements of UDysRS, MDS-UPDRS, and 24-hour diaries.
• The estimated number of participants required to demonstrate efficacy in Phase III is approximately 250–270 patients, distributed across two parallel studies (both with a 1:1 randomization between active treatment and placebo) with a treatment duration of three months.
• The dose to be evaluated in the Phase III program will be 7.5 mg twice daily.
• The required safety documentation will include a population of at least 100 patients treated with a clinically relevant dose of mesdopetam during one year in the safety extension of the phase III program. The safety population in the program will be adjusted to ensure sufficient overall exposure to mesdopetam required for registration across different markets.

Importantly, efficacy on the planned primary endpoint in the Phase III program, UDysRS part 1+3+4, was prespecified and evaluated in the Phase IIb study of mesdopetam. Using this specific assessment scale for dyskinesia, the Phase IIb study demonstrated a clinically meaningful and nominally significant and anti-dyskinetic effect of mesdopetam at 7.5 mg twice daily as compared to placebo (ITT analysis, p=0.026).