Heptares Therapeutics, the wholly-owned subsidiary of Sosei Group Corporation, announces that the first healthy subject has been dosed with the first-in-class, selective muscarinic M4 receptor agonist HTL0016878 in a phase 1 clinical study. The phase 1 study dosing triggers a US$15 million milestone payment by Allergan to Heptares under a global R&D and commercialisation partnership announced in April 2016.

Heptares and Allergan are developing HTL0016878, an orally available, small molecule drug candidate with potential to treat certain neurobehavioural symptoms of Alzheimer’s disease. The compound stimulates M4 receptor activity in the brain with high selectivity, and offers the possibility for an improved safety profile over previous muscarinic receptor agonists, which have been associated with  adverse effects   elsewhere in the body leading to safety and tolerability issues.

HTL0016878 was designed by Heptares using its proprietary structure-based drug design platform and is the first compound, selected from a series of selective M4 agonists, to progress into clinical studies. 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. Preliminary results are expected in the first half of 2018.

Tim Tasker, Heptares’ chief medical officer, said: “The start of this new clinical trial marks the progression of the fourth compound designed by Heptares into clinical studies and follows the advancing clinical studies with selective M1 agonists under our partnership with Allergan. 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. 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.”

Under the terms of the 2016 global R&D and commercialisation partnership, Allergan licensed exclusive global rights to Heptares’ broad portfolio of novel subtype-selective muscarinic receptor agonists (M1, M4 and dual M1/M4 agonists) for the treatment of major neurological disorders, including Alzheimer’s disease. In addition to the new clinical programme with HTL0016878, a selective M4 agonist, announced today, the companies are advancing a programme evaluating selective M1 agonists through clinical studies as a potential treatment for symptomatic cognitive deficits in Alzheimer’s patients; and are assessing the potential of dual M1/M4 agonists with potential to treat both cognitive and neurobehavioural symptoms through preclinical studies.