ADC Wins Accelerated Approval for TNBC

— A third of patients with previously treated disease responded to sacituzumab govitecan

MedicalToday
sacituzumab govitecan-hziy (Trodelvy) over a computer rendering of breast cancer above FDA APPROVED

WASHINGTON -- The FDA granted accelerated approval to the antibody-drug conjugate (ADC) sacituzumab govitecan (Trodelvy) for previously treated metastatic triple-negative breast cancer (TNBC).

Sacituzumab govitecan consists of a monoclonal antibody directed against trophoblast cell-surface antigen (Trop)-2 -- a protein associated with poor prognosis -- linked to a topoisomerase inhibitor chemotherapeutic agent. The drug is the first ADC to receive an approved indication for TNBC and is limited to patients who have received at least two prior therapies for metastatic disease.

"Chemotherapy has been the mainstay of treatment for triple-negative breast cancer," Richard Pazdur, MD, of the FDA Office of Oncologic Diseases, . "The approval of Trodelvy today represents a new targeted therapy for patients living with this aggressive malignancy. There is intense interest in finding new medications to help treat metastatic triple-negative breast cancer. Today's approval provides patients who've already tried two prior therapies with a new option."

Support for the approval came primarily from a involving 108 patients with metastatic TNBC treated with at least two prior therapies for metastatic disease. The trial had a primary efficacy endpoint of objective response rate, and a third of the patients met that endpoint. Responses had a median duration of 7.7 months.

Prescribing information for sacituzumab govitecan includes a boxed warning about a risk of severe neutropenia. The FDA statement also cautioned healthcare professionals to monitor treated patients for diarrhea and to provide fluid, electrolytes, and supportive medications as needed.

The most commonly reported side effects associated with sacituzumab govitecan were nausea, neutropenia, diarrhea, fatigue, anemia, vomiting, alopecia, constipation, decreased appetite, rash, and abdominal pain.

An accelerated approval requires additional clinical trial data to confirm the initial findings. Immunomedics announced earlier this month that a phase III trial of sacituzumab govitecan ended early after an interim data analysis revealed "compelling efficacy" in favor of the ADC.

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    Charles Bankhead is senior editor for oncology and also covers urology, dermatology, and ophthalmology. He joined in 2007.