Abbisko Therapeutics Co., Ltd. announced that Merck has exercised the global commercialization option for pimicotinib (ABSK021), with an option exercise fee of USD85.0 million, under the licensing agreement signed in December 2023. The development represents further deepening of the collaboration, underscoring the unwavering commitment and confidence that both parties possess for the ongoing advancement of pimicotinib.

In December 2023, Abbisko Therapeutics entered into an exclusive licensing agreement (the "Agreement") with Merck regarding pimicotinib, a CSF-1R inhibitor. Under the terms of the Agreement, Merck initially had an exclusive license to commercialize pimicotinib for all indications in the Chinese mainland, Hong Kong, Macau and Taiwan with an exclusive option for global commercial rights of pimicotinib. Merck now has exercised such option and has the exclusive license to commercialize pimicotinib worldwide. Abbisko Therapeutics has already received the one-time, non-refundable upfront payment of USD70.0 million in February 2024, and is now entitled to receive the additional option exercise fee of USD85.0 million. Additionally, Merck has the option to co-develop pimicotinib for additional indications under certain conditions. In total, Abbisko Therapeutics is eligible to receive up to USD605.5 million in payments, including upfront, development, and commercial milestones, as well as double-digit percentage royalties on annual net sales.

Pimicotinib is a novel, orally administered, highly selective, and potent small molecule CSF-1R inhibitor, independently developed by Abbisko Therapeutics. Pimicotinib's positive topline results from the Global Phase III MANEUVER Study in tenosynovial giant cell tumor ("TGCT") were successfully released in November 2024, where MANEUVER met the primary endpoint with an objective response rate ("ORR") at Week 25 of 54.0% for pimicotinib compared with 3.2% for placebo (p<0.0001), and treatment with oral, once-daily pimicotinib was well-tolerated with very low rates of discontinuation due to treatment-related adverse events, and with no evidence of cholestatic hepatotoxicity.

Yao-Chang Xu, Chairman and CEO of Abbisko Therapeutics, said, "Pimicotinib represents a key advancement within the emerging class of CSF-1R inhibitors, demonstrating a meaningful clinical efficacy and safety profile that positions it as an innovative treatment option for worldwide TGCT patients. We look forward to deepening our collaboration with the Merck team to expedite the registration process of pimicotinib to bring benefits to patients as quickly as possible."

"Today marks a significant milestone in our partnership with Abbisko as we work together to deliver a potentially best-in-class therapy for patients with TGCT around the world," said Andrew Paterson, Chief Marketing Officer for the Healthcare business sector of Merck. "This collaboration underscores our commitment to advancing new treatment options in rare oncology for patients who need them. With this important step forward, we aim to transform the treatment landscape and offer hope to those living with TGCT, who today have very limited treatment options."