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Theseus Pharmaceuticals Laying Off 72 Percent of Workforce

NEW YORK – Theseus Pharmaceuticals said on Monday it is laying off 26 full-time employees, or 72 percent of its workforce.

William Shakespeare, Theseus' president of R&D, will also leave the company but will serve as a consultant through June 2024, according to the firm.

The layoffs come as Theseus is exploring strategic options, including selling the company or its assets, or merging with another firm.

In July, Theseus stopped developing a pan-variant KIT inhibitor, THE-630, in gastrointestinal stromal tumors after patients in a Phase I/II study experienced dose-limiting toxicities at a dosage too low to achieve the target concentration.

The company's pipeline also includes an EGFR inhibitor under development in non-small cell lung cancer and a BCR-ABL-targeted inhibitor being tested in leukemia, along with another discovery-stage KIT inhibitor. Earlier this year, the firm said it planned to file an investigational new drug application for the EGFR inhibitor in Q4 2023.

As of Sept. 30, the Cambridge, Massachusetts-based firm had cash, cash equivalents, and marketable securities of $225.4 million.