The Food and Drug Administration has approved a subcutaneous formulation of trastuzumab – trastuzumab and hyaluronidase-oysk (Herceptin Hylecta) – for the treatment of patients with HER2-overexpressing breast cancer.
Approval of the subcutaneous formulation is based on results from two clinical studies in HER2-positive early breast cancer – HannaH and SafeHER, the FDA said in a press release.
In the phase 3 HannaH study (NCT00950300), researchers compared neoadjuvant and adjuvant trastuzumab and hyaluronidase-oysk with intravenous trastuzumab, both in combination with chemotherapy. Trastuzumab and hyaluronidase-oysk proved noninferior to intravenous trastuzumab in this trial (Lancet Oncol. 2012 Sep;13[9]:869-78).
In the phase 3 SafeHER study (NCT01566721), the safety profile of trastuzumab and hyaluronidase-oysk was deemed consistent with the known safety profiles of intravenous trastuzumab and trastuzumab and hyaluronidase-oysk (Eur J Cancer. 2017 Sep;82:237-246).
The most common adverse reactions observed in patients receiving the subcutaneous formulation were fatigue, arthralgia, diarrhea, injection-site reaction, upper respiratory tract infection, rash, myalgia, nausea, headache, edema, flushing, pyrexia, cough, and pain in extremity, the FDA said.
Trastuzumab plus hyaluronidase-oysk was approved with a black box warning detailing the risk of cardiomyopathy, pulmonary toxicity, and embryo-fetal toxicity associated with the product.
The recommended dose is 600 mg/10,000 units (600 mg trastuzumab and 10,000 units hyaluronidase) administered subcutaneously over approximately 2-5 minutes once every 3 weeks.
Additional details can be found in the prescribing information.