Merck KGaA and Abbisko Therapeutics have announced positive results from a late-stage study of pimicotinib in patients with tenosynovial giant cell tumours (TGCTs).
The phase 3 MANEUVER trial has been evaluating the candidate in TGCT patients who are eligible for systemic therapy and have not received prior anti-CSF-1/CSF-1R therapy.
The trial met its primary endpoint, with an objective response rate at week 25 of 54% for pimicotinib versus 3.2% for placebo.
Pimicotinib also provided statistically significant and clinically meaningful improvements in secondary endpoints associated with patient outcomes in TGCT, including stiffness and pain.
The companies added that the drug was found to be well tolerated, and its safety profile was consistent with previously reported data.
TGCT is a rare, benign and locally aggressive disease that originates in the synovial lining of joints, bursae and tendon sheaths.
Patients can experience joint pain, stiffness, swelling and a reduced range of motion, and the disease can cause irreversible damage to bones, joints and surrounding tissues if left untreated or in recurrent cases.
Pimicotinib, being developed by Abbisko, is an orally administered, highly selective and potent small-molecule inhibitor of CSF-1R.
The candidate has already been granted breakthrough therapy designation in the US and China, and priority medicine designation in the EU for TGCT.
Merck and Abbisko entered into an agreement in December last year, giving Merck an exclusive licence to commercialise pimicotinib in mainland China, Hong Kong, Macau and Taiwan, with an option for the rest of the world.
Danny Bar-Zohar, global head of research and development and chief medical officer for the healthcare business sector of Merck, said: “This phase 3 data from MANEUVER confirms results of Abbisko’s phase 1 study, indicating that targeting CSF-1R with pimicotinib has the potential to offer a new treatment option for patients.
“As we work with Abbisko to review the data from this study and prepare to share it with regulators in China, we are focused on our shared goal of bringing pimicotinib to patients in need.”
