Sosei has become the latest victim of AbbVie’s post-Allergan merger clear-out as the new suitor has decided to dump its former partner.
The original deal goes back nearly five years, when then-independent Allergan penned a pact with U.K.- and Japan-based Sosei, and it also came about after a near buyout from Pfizer.
In fact, that deal came just hours after Allergan backed away from a $160 billion merger with the Big Pharma, signing a $3.3 billion licensing deal for global rights to a portfolio of drugs for neurological disorders from the U.K.'s Heptares, a subsidiary of Sosei.
Heptares got $125 million upfront, $665 million in milestones for clinical development and up to $2.5 billion in sales milestones.
Aside from double-digit royalties, Allergan also shelled out $50 million for a joint R&D program to get clinical candidates through midstage trials, with the idea being to treat symptoms of Alzheimer's, schizophrenia and other neurological diseases.
The R&D foci of that pact were small-molecule agonists targeting muscarinic M1 and M4 receptors in the brain, including a pair of M1 agonists—HTL9936 and HTL18318—which were in phase 1 when the pact was first signed.
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Those M1 agonists are designed to treat cognitive declines associated with Alzheimer's, while the M4s are directed at neurobehavioral symptoms through a different mechanism of action used by antipsychotics. Each would make natural combinations, provided they work.
While a focus for Allergan in 2016, it certainly isn’t for new parent AbbVie in 2021, which is returning the rights back to Sosei for those muscarinic agonist programs. The Japanese-British biopharma will now seek out a new partner amid a “full internal review,” according to a statement. This review should be done and reported on by mid-February.
This also comes after AbbVie cleared out another unwanted pact from Allergan, sweeping out a series of unwanted gastrointestinal microbiome assets from Assembly Biosciences in the summer.
This isn't the first attempt to use an M1 to go after Alzheimer's. Eli Lilly took a shot in the 1990s, only to back off after side effects derailed the effort, like many other programs for the memory-wasting disease.
Heptares/Sosei has previously said its approach has the kind of target selectivity that could avoid spurring the type of safety issues Lilly experienced. It will now need to convince someone else that this is the case.