The Food and Drug Administration (FDA) has accepted for Priority Review the New Drug Application (NDA) for Fyarro™, an investigational nanoparticle albumin-bound sirolimus, for the treatment of advanced malignant perivascular epithelioid cell tumor (PEComa), a rare subset of soft-tissue sarcomas.

Nab-sirolimus is an mTOR inhibitor bound to human albumin. In preclinical studies, the product was associated with significantly higher tumor accumulation, greater mTOR target suppression, and increased tumor growth inhibition compared with other mTOR inhibitors.

The NDA submission is supported by data from the multicenter phase 2 AMPECT study ( Identifier: NCT02494570), which evaluated the efficacy of nab-sirolimus in 34 adults aged 18 years and older with advanced malignant PEComa. Patients received nab-sirolimus intravenously weekly until disease progression or unacceptable toxicity. The primary endpoint was overall response rate (ORR) up to 32 months. Findings showed that among 31 evaluable patients, the confirmed ORR was 39% (n=12/31; 95% CI, 22-58), with 1 complete response and 11 partial responses.

The FDA previously granted Orphan Drug, Fast Track, and Breakthrough designations to nab-sirolimus for advanced malignant PEComa. “If approved, Fyarro will be the first FDA-approved therapy for the treatment of patients with this disease,” said Neil Desai, PhD, Founder, CEO and President of Aadi.

A Prescription Drug User Fee Act (PDUFA) target date of November 26, 2021 has been set for the application.


  1. Aadi Bioscience announces FDA acceptance and Priority Review for the New Drug Application of Fyarro™ for the treatment of advanced malignant PEComa. News release. Aadi Bioscience, Inc. Accessed July 26, 2021.
  2. Wagner AJ, Ravi V, Riedel RF, et al. Long-term follow-up for duration of response (DoR) after weekly nab-sirolimus in patients with advanced malignant perivascular epithelioid cell tumors (PEComa): Results from a registrational open-label phase II trial, AMPECT. Journal of Clinical Oncology. Published online May 25, 2020. doi: 10.1200/JCO.2020.38.15_suppl.11516