
The US Food and Drug Administration (FDA) has placed a partial clinical hold pausing enrolment of new patients in Mersana Therapeutics’ ongoing UP-NEXT and UPGRADE-A clinical trials of UpRi in platinum-sensitive ovarian cancer.
The partial hold is based on the serious bleeding events reported in the safety analysis of nearly 560 patients dosed with UpRi.
Most of the bleeding cases were low-grade while five (<1%) Grade 5 (fatal) bleeding events were observed.
The causes of bleeding events are being investigated.
Mersana Therapeutics president and CEO Anna Protopapas said: “Patient safety is always at the forefront for us, and work is now underway to compile further analyses that may inform FDA.
“Additionally, with UPLIFT top-line data on the near-term horizon, we will soon have a much more complete assessment of both the efficacy and safety profile for UpRi in platinum-resistant ovarian cancer.”
UPLIFT is Mersana’s ongoing study of UpRi which completed patient enrolment in October 2022. Patients will continue to receive UpRi in these trials.
Mersana plans to submit the UPLIFT efficacy and safety data once available, to the FDA.
It is also planning to seek alignment with the FDA to lift the clinical hold and resume enrolment in both UpRi trials.
In 2022, Mersana initiated the dosing of subjects in its Phase I study of XMT-1660 to treat patients with solid tumours including ovarian, endometrial, and breast cancers.
Investigator-evaluated objective response rate and duration of response were the primary endpoints of the dose expansion portion of the trial.