Merck & Co. has nixed the phase 2 study of a potential Alzheimer’s disease medicine after the drug underwhelmed in an interim analysis, marking another blow for the pharma’s struggling partner Neuphoria Therapeutics.
Merck stopped the 349-patient study after the small molecule MK-1167 “did not meet the necessary efficacy criteria to warrant further investigation,” a company spokesperson told Fierce Biotech. The trial was testing the ability of MK-1167, a modulator of the alpha-7 nicotinic acetylcholine receptor, to improve Alzheimer’s dementia symptoms when paired with a standard acetylcholinesterase inhibitor.
The trial was not terminated for any safety reasons, the spokesperson added.
MK-1167 isn’t currently being evaluated in any other clinical trials, but the Neuphoria collaboration still stands, according to the Merck spokesperson.
Neuphoria has been a longtime partner of Merck, with the two first pairing up back in 2014 when Neuphoria was still based in Australia and known as Bionomics. The biotech rebranded and moved to the U.S. in 2024.
Merck launched the phase 2 trial of MK-1167 in February 2025, which triggered a $15 million milestone payment for Neuphoria. That payment was a bright spot in an otherwise difficult year for the neuro outfit; in October, the company’s social anxiety candidate failed a phase 3 trial, sparking a strategic review and an attempted buyout by an investor that ultimately didn’t go through.
Just two days ago, London-based Scancell Holdings proposed a merger with Neuphoria that the latter is now considering.
That failed social anxiety candidate, BNC210 or soclenicant, is a negative modulator that tunes down the alpha-7 receptor. MK-1167 is instead a positive allosteric modulator (PAM), meaning it binds to the receptor and amps up its activity.
With the MK-1167 trial sidelined, that leaves just one other Alzheimer’s candidate in Merck’s pipeline, according to its website. That drug, a monoclonal antibody targeting tau called MK-2214, is currently in a phase 2 trial set to wrap up in 2029. The antibody was developed by Japan’s Teijin Pharma and licensed by Merck in 2017.