Eliem Therapeutics’ would-be challenger to Biogen and Sage Therapeutics’ zuranolone is moving into a phase 2a clinical trial. The transatlantic biotech greenlighted the study after a pharmacokinetic study cleared up drug exposure concerns raised in another clinical trial.
Like zuranolone, Eliem’s ETX-155 is a GABAA receptor positive allosteric modulator that is designed to treat conditions including major depressive (MDD) order. While Eliem has ceded a big head start to Biogen and Sage’s candidate, it is betting that its prospect’s apparent lack of a clinically meaningful food effect and longer half-life will translate into improved efficacy, tolerability, compliance and durability.
Eliem is now preparing for the most rigorous test of its hypothesis yet. In the first quarter of next year, the biotech will start a phase 2a trial of either a 60 mg or 75 mg dose of ETX-155 in MDD. Eliem will decide the dose after assessing the effect of repeat 75 mg doses on healthy volunteers in a phase 1 trial.
ETX-155 is moving into phase 2 after coming through a trial designed to clear up a concern identified in another study. Specifically, Eliem saw lower-than-expected drug exposure levels in the three subjects evaluated in a phase 1b photosensitive epilepsy trial, leading it to test single and repeat doses in healthy volunteers to confirm the pharmacokinetic profile.
Eliem found no meaningful difference between the exposures at the 60 mg dose in its pharmacokinetic trial and its earlier phase 1 studies. The biotech said the low exposures seen in its other trial were within “the range of previously reported moderate variability,” adding that it saw no irregularities or differences in the chemistry, manufacturing and controls associated with the drug product and the drug substance.
The 60 mg data, and the fact that a single 75 mg shot was well-tolerated, has persuaded Eliem to test the effect of giving the higher dose repeatedly before deciding on which dose to trial in the phase 2a. If the phase 2a starts on time, Eliem expects to report top-line data around the middle of 2024. The biotech’s $130 million cash runway is scheduled to run into 2025.