Sirolimus, Trastuzumab Well-Tolerated in Breast Cancer Progression with Prior Therapy

Combination sirolimus and trastuzumab is well-tolerated in patients with metastatic human epidermal growth factor receptor  (HER2)-positive breast cancer after disease progression with prior trastuzumab therapy, according to a study published in Breast Cancer Research and Treatment.

In a phase II trial, researchers led by Carlos Acevedo-Gadea, MD, of the Yale University School of Medicine administered sirolimus 6 mg oral daily along with a standard dose of trastuzumab weekly or every three weeks.

In total, eleven patients were evaluated for safety, and nine were evaluated for response assessment.

They found that five patients who were treated for 101 weeks had achieved stable disease as best response, while one patient who received eight cycles achieved a partial response.

Overall response rate amounted to 11 percent while clinical benefit rate was 44%.

“Sirolimus 6 mg administered daily with trastuzumab appears to be well-tolerated in patients with metastatic HER2-positive breast cancer following disease progression on prior trastuzumab therapy, with evidence of disease activity,” the authors concluded.

Reference

1. Acevedo-Gadea, Carlos. “Sirolimus and trastuzumab combination therapy for HER2-positive metastatic breast cancer after progression on prior trastuzumab therapy.” Breast Cancer Research and Treatment. DOI: 10.1007/s10549-015-3292-8. February 17, 2015.