Allergan and Sosei temporary setback for Alzheimer compound

Allergan and Sosei have taken the precaution of voluntarily halting clinical development of their Alzheimer compound HTL0018318 due to results from a single animal toxicology study in non-human primates. HTL0018318 is a selective small molecule muscarinic M1 receptor agonist that researchers hope will be a new symptomatic treatment for cognitive impairment in patients with Alzheimer’s disease and dementia with Lewy bodies. Allergan are sponsoring the Phase I clinical development in the US, and it is also in a Phase II clinical study in Japan in patients with DLB.

Human clinical trials so far have been conducted on around 310 people from the EU and the US with mild, moderate or no Alzheimer’s and these trials have shown good tolerance and no serious adverse effect at the tested doses for up to 28 days. The study in question was looking at various dosing levels over a nine-month period and the findings (neoplastic, rare tumor) were observed at doses and durations above those used in human clinical trials so far, and no serious safety findings were observed in any species in any other animal toxicology studies with the drug extending as long as six months.

Sosei’s chief medical officer, Dr Tim Tasker, said: “We were very surprised to see these results given the safety profile HTL0018318 has exhibited across all previous animal and clinical studies. We have taken these steps in the best interests of patient safety, which is our number one priority. We are committed to working with clinical investigators, R&D teams and regulatory authorities to understand better the reason for the findings from this animal toxicology study and so enable the human clinical development program with HTL0018318 to continue as soon as possible.”