FDA approved Fyarro (nab-sirolimus) for Malignant PEComaFDA approved new drug Fyarro for rare soft tissue cancer PEComa

Fyarro (nab-sirolimus) is an mTOR inhibitor. It binds to and inhibits the mechanistic target of rapamycin (mTOR) kinase, thereby reducing cell proliferation and angiogenesis. The nanoparticle albumin-bound formulation may enhance delivery to tumors.

Fyarro is indicated for the treatment of adult patients with locally advanced unresectable or metastatic malignant perivascular epithelioid cell tumor (PEComa).

The recommended dosage is 100 mg/m² administered as an intravenous infusion over 30 minutes on Days 1 and 8 of each 21-day cycle until disease progression or unacceptable toxicity. Dose reductions for adverse reactions are specified: first reduction to 75 mg/m², second to 56 mg/m², third to 45 mg/m²; permanently discontinue if unable to tolerate after three reductions. For moderate or weak CYP3A4 inhibitors, reduce dose to 56 mg/m². For mild hepatic impairment (total bilirubin ≤ULN with AST >ULN, or total bilirubin >1 to 1.5×ULN any AST), dose is 75 mg/m²; for moderate hepatic impairment (total bilirubin >1.5 to 3.0×ULN any AST), dose is 56 mg/m². Avoid use in severe hepatic impairment. Fyarro is a hazardous drug; follow special handling and disposal procedures.

Trial data not available in label.

Warnings include stomatitis, myelosuppression (anemia, thrombocytopenia, neutropenia), infections, hypokalemia, hyperglycemia, interstitial lung disease/non-infectious pneumonitis, and hemorrhage. Dosage modifications for these adverse reactions are detailed in the label. Avoid concomitant use with strong CYP3A4 and/or P-gp inhibitors and inducers, and with grapefruit products. No contraindications are listed in the label.

Fyarro is the first FDA-approved treatment specifically for malignant PEComa, a rare sarcoma with limited options. As an mTOR inhibitor, it targets a key pathway in this tumor type. It is indicated for locally advanced unresectable or metastatic disease. Clinicians should consider its use in appropriate patients, with careful monitoring for adverse effects.