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# FDA Partial Hold on Mersana Trials
- URL: https://www.fdaweb.com/fda-partial-hold-on-mersana-trials/
- Published: 2023-06-15T12:00:00.000Z
- Updated: 2026-09-14T18:39:18.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5154702

FDA has issued a partial clinical hold against Mersana Therapeutics’ clinical trials of UpRi (upifitamab rilsodotin) in platinum-sensitive ovarian cancer after the company submitted a safety report that evaluated bleeding events. The hold affects the UP-NEXT and UPGRADE-A clinical trials, and patients who are already enrolled may continue receiving UpRi, according to the company.

“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,” the company says. “While most bleeding cases in this aggregate safety analysis were low-grade, five (less than 1%) Grade 5 (fatal) bleeding events were observed among the approximately 560 patients dosed to date. The causes of bleeding events remain under investigation.” Additionally, Mersana says UPLIFT top-line data will be available shortly, which will provide a more complete assessment of both the efficacy and safety profile for UpRi in platinum-resistant ovarian cancer.