FDA places partial clinical hold on Mersana’s ovarian cancer trials

The US Food and Drug Administration (FDA) has issued a partial clinical hold pausing new patient enrolment in Mersana’s ongoing ovarian cancer trials.

UPLIFT, Mersana’s ongoing clinical trial of UpRi in platinum-resistant ovarian cancer, completed enrolment in October 2022.

The partial clinical hold is based on the serious bleeding events reported in the safety analysis of nearly 560 patients dosed with UpRi.

Although data on the background rate of bleeding in platinum-resistant ovarian cancer are limited, Mersana’s recent assessment determined that serious bleeding events appear to occur at a higher rate than background.

While most bleeding cases in this aggregate safety analysis were low-grade, five (<one per cent) Grade 5 (fatal) bleeding events were observed. The causes of bleeding events remain under investigation.

Mersana says patients who are already enrolled in these trials may continue receiving UpRi. The biopharma company expects to lock its UPLIFT clinical trial database and disclose UPLIFT data by early August.

Anna Protopapas, president and Mersana Therapeutics CEO, 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.”

The company is awaiting the FDA’s written correspondence regarding the partial clinical hold and expects the FDA will request a comprehensive assessment of UpRi safety data, inclusive of bleeding events.

Mersana plans to submit to the FDA the UPLIFT safety and efficacy data once available. The company says it plans to seek alignment with the FDA to lift the partial clinical hold and resume enrolment in UP-NEXT and UPGRADE-A.