A year ago, we reported that Japanese pharma Daiichi Sankyo and partner Plexxikon had suspended a trial of its rare cancer candidate on safety advice from a data monitoring committee.
The phase 3 study was designed to test the investigational oral CSF-1R inhibitor pexidartinib (aka PLX3397) in patients with a tumor of pigmented villonodular synovitis, or giant cell tumor of the tendon sheath, for whom surgical removal of the tumor would cause more harm than good.
But last fall the DMC recommended that new patients not be taken on after two reported cases of nonfatal, serious liver toxicity. The companies decided to suspend enrollment.
The company told FierceBiotech last October: “At the time of the suspension 121 patients had been randomized, just five short of the 126 planned. The DMC also recommended measures to address these safety concerns while maintaining the blinded nature of the study.”
“As a result, ENLIVEN will continue to completion in order to evaluate its efficacy and safety endpoints. These measures were reviewed and agreed on by the U.S. Food and Drug Administration, and all regulatory authorities involved in the ENLIVEN study have been notified.”
Today, they posted some very top-line results, saying only that pexidartinib “met its primary endpoint of tumor response as measured by tumor size reduction in patients with symptomatic tenosynovial giant cell tumor (TGCT) where surgical resection is potentially associated with worsening functional limitation or severe morbidity.” No data were shared.
It added that a “comprehensive evaluation of the benefit/risk for TGCT based on the totality of the pexidartinib program is now underway and will guide next steps.” On the ClinicalTrials.gov site, it has guided March next year as the month when final data collection will be ready, and it expects to have its primary outcome measure.
Daiichi, when contacted by FierceBiotech, gave no extra information about the suspension or the data.