On February 28, 2019, the U.S. Food and Drug Administration (FDA) approved a trastuzumab and hyaluronidase-oysk injection, for subcutaneous use (Herceptin Hylecta). The drug is a combination of trastuzumab, a HER2/neu receptor antagonist, and hyaluronidase, an endoglycosidase, for the treatment of HER2‑overexpressing breast cancer.
Approval was based on two randomized trials, HannaH (NCT00950300) and SafeHER (NCT01566721). In HannaH, 596 patients with HER2-positive operable or locally advanced breast cancer, including inflammatory breast cancer, were randomized to receive eight cycles of either the trastuzumab and hyaluronidase-oysk injection or intravenous trastuzumab concurrently with chemotherapy, followed by surgery and continued therapy with either the trastuzumab and hyaluronidase-oysk injection or intravenous trastuzumab, for an additional ten cycles. HannaH demonstrated comparability between the trastuzumab and hyaluronidase-oysk injection and intravenous trastuzumab based on co-primary endpoints of pathologic complete response and pharmacokinetics. Pathological complete response (pCR) was observed in 118 patients (45.4%) on the trastuzumab and hyaluronidase-oysk injection arm and in 107 patients (40.7%) receiving intravenous trastuzumab (95% CI for difference in pCR: -4.0; 13.4).
SafeHER was a prospective, two-cohort, non-randomized, multinational, open-label trial assessing the overall safety and tolerability of the trastuzumab and hyaluronidase-oysk injection with chemotherapy in 1,864 patients with HER2-positive breast cancer. Patients received a fixed dose of 600 mg of the trastuzumab and hyaluronidase-oysk injection every three weeks for 18 cycles. The trastuzumab and hyaluronidase-oysk injection was initiated either sequentially with chemotherapy, concurrently with chemotherapy, or without adjuvant chemotherapy, or in combination with neoadjuvant chemotherapy followed by trastuzumab.
The most common adverse reactions of the trastuzumab and hyaluronidase-oysk injection observed in at least 10% of patients were fatigue, arthralgia, diarrhea, injection site reaction, upper respiratory tract infection, rash, myalgia, nausea, headache, edema, flushing, pyrexia, cough, and pain in extremity.
The recommended trastuzumab and hyaluronidase-oysk injection dose is 600 mg/10,000 units (600 mg trastuzumab and 10,000 units hyaluronidase) administered subcutaneously over approximately 2–5 minutes once every three weeks.
Healthcare professionals should report all serious adverse events suspected to be associated with the use of any medicine and device to FDA’s MedWatch Reporting System or by calling 1-800-FDA-1088.
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