London, UK-based Heptares Therapeutics says the first healthy subject has now been dosed with its first-in-class, selective muscarinic M4 receptor agonist HTL0016878 in a Phase I clinical study.

The move triggers a $15 million milestone payment from Allergan under a global R&D and commercialisation partnership signed in April last year, under which Allergan licensed exclusive global rights to Heptares’ broad portfolio of novel subtype-selective muscarinic receptor agonists for the treatment of major neurological disorders.

The companies are now developing the experimental orally available, small molecule drug candidate with potential to treat certain neurobehavioural symptoms of Alzheimer’s disease.

HTL0016878 was designed by Heptares using its structure-based drug design platform and is the first compound, selected from a series of selective M4 agonists, to progress into clinical studies.

“The target selectivity we can build into molecules increasingly highlights the potential of our approach to create new medicines with significantly improved clinical profiles for addressing a range of diseases,” commented Tim Tasker, Heptares’ chief medical officer.

“In creating the first selective M4 agonist to enter human studies, we are a step closer to our goal of developing a new therapeutic approach to ease the considerable burden and distress caused by diseases such as Alzheimer’s.”

The double-blind, randomised first-in-human study is being conducted in the UK by Heptares and will assess safety, tolerability and pharmacokinetics of single and multiple oral doses of HTL0016878 in up to 106 healthy subjects, with a preliminary read out expected in the first half of next year.