NEW YORK – Aadi Bioscience said on Tuesday it is stopping the Phase II PRECISION1 trial evaluating its mTOR inhibitor Fyarro (nab-sirolimus) in patients with solid tumors harboring TSC1 or TSC2 inactivating alterations.
The Los Angeles-based firm also said in a filing with the US Securities and Exchange Commission on Wednesday that it will lay off 22 employees, approximately 32 percent of its workforce, including 80 percent of its R&D staff.
The tumor-agnostic PRECISION1 trial, which began in 2022, was expected to enroll 120 patients at least 12 years old with solid tumors characterized by TSC1 and TSC2 inactivating mutations. The US Food and Drug Administration previously granted fast-track designation to Fyarro in this setting.
Aadi said that an analysis by an independent data monitoring committee showed the study was unlikely to exceed an efficacy threshold necessary to support Fyarro's accelerated approval. The firm will publish a full analysis of the trial data in the future. Aadi said about 25 patients in the PRECISION1 trial who are benefiting from the drug will be able to access it through an expanded access protocol.
The firm will also stop enrolling patients in two other Phase II trials, one of Fyarro plus letrozole in advanced or recurrent endometrioid-type endometrial cancer and one of Fyarro monotherapy in neuroendocrine tumors. Patients already enrolled in these studies will continue to receive treatment, and Aadi said both studies have enrolled enough patients to assess initial efficacy signals.
Fyarro was approved in the US in 2021 for the treatment of patients with locally advanced unresectable or metastatic malignant perivascular epithelioid cell tumor (PEComa), a rare type of sarcoma commonly associated with TSC1 and TSC2 mutations.
In a statement announcing the changes, Aadi said it will focus on commercializing Fyarro in its approved indication and conduct a comprehensive strategic review to maximize shareholder value. With these layoffs and trial pauses, Aadi expects to extend its cash runway into the second half of 2026.