Study of the drug, HTL0018318, has been suspended pending the investigation of toxicology findings in non-human primates. While this suspension was not based upon on any results in humans, the drug has been investigated in roughly 310 human subjects in the US and Europe.
Per these studies, the treatment was found to be tolerated for up to 28 days with no serious adverse effects.
The animal toxicology study investigated dosing levels of HTL0018318 over a nine-month period in which neoplastic, rare tumors were observed after doses and durations had exceeded those used in human clinical trials.
The drug in development is a selective small molecule muscarinic M1 receptor agonist for the potential treatment of Alzheimer’s disease (AD) and other dementia’s symptoms. It is currently in Phase I in the US and Phase II in Japan.
The toxicological findings have been reported to the US Food and Drug Administration (FDA) and the Japan Pharmaceutical and Medical Devices Agency (PMDA).
The findings will delay the company’s start of Phase II studies in AD and other dementias by six months at least. The companies report that this will have an impact on revenue.
Allergen was set to award Sosei a milestone payment in 2019 for the AD program. Sosei stated that the voluntary suspension will not immediately affect impairment of assets and goodwill.