Shares of Mersana Therapeutics, a clinical-stage biopharmaceutical company, plunged more than 60% in premarket trading on Thursday. The significant drop came after the company's lead product candidate, upifitamab rilsodotin (UpRi), failed to meet its primary endpoint in a late-stage study involving patients with platinum-resistant ovarian cancer.
The stock, which closed at $3.91 the previous day, was trading at $1.55 in premarket hours. This represents a year-to-date decline of approximately 33%.
Mersana, headquartered in Cambridge, Massachusetts, had previously stated that positive results from the study could lead to a filing with the U.S. Food and Drug Administration by the end of 2023. However, following the setback, the company has announced a comprehensive restructuring plan. This approach aims to wind down UpRi-related development activities and reduce its workforce by 50%. By doing so, Mersana intends to extend its cash runway, allowing it to assess the clinical potential of its other promising product candidates.
With approximately 150 employees, as reported by FactSet, Mersana had a total cash balance of around $286.6 million, inclusive of cash, equivalents, and marketable securities as of June 30.