On 28 February 2019, the FDA approved the subcutaneous formulation trastuzumab/hyaluronidase-oysk (Herceptin Hylecta®, Genentech) for the treatment of human epidermal growth factor receptor 2 (HER2)‑overexpressing breast cancer.¹FDA website

HannaH

The open-label multicentre HannaH (NCT00950300) trial randomised 596 HER2-positive breast cancer patients with operable disease, including inflammatory breast cancer, to undergo eight cycles of subcutaneous (SC) trastuzumab/hyaluronidase-oysk vs intravenous (IV) trastuzumab concurrently with neoadjuvant chemotherapy, followed by surgery. All participants then received an additional ten cycles of adjuvant SC trastuzumab/hyaluronidase-oysk or IV trastuzumab. The co-primary endpoints were the pathologic complete response pCR) and the pharmacokinetics.

The HannaH trial demonstrated that SC trastuzumab/hyaluronidase-oysk was comparable to IV trastuzumab. A pCR was observed in 118 patients (45.4%) receiving the subcutaneous formulation vs 107 patients (40.7%) receiving intravenous trastuzumab (95% CI: -4.0-13.4).

SafeHER and Safety

The prospective, two-cohort, non-randomised, multinational, open-label SafeHER (NCT01566721) trial investigated the safety and tolerability of SC trastuzumab/hyaluronidase-oysk plus chemotherapy in 1,864 HER2-positive breast cancer patients. All participants received a fixed 600 mg dose of SC trastuzumab/hyaluronidase-oysk every three weeks over an 18-cycles study period. The investigational agent was administered either concurrently or sequentially with adjuvant chemotherapy or without adjuvant chemotherapy, or concurrently with neoadjuvant chemotherapy followed by trastuzumab.

Common adverse reactions of SC trastuzumab/hyaluronidase-oysk occurring in ≥10% of patients included fatigue, arthralgia, diarrhoea, injection site reaction, upper respiratory tract infection, rash, myalgia, nausea, headache, oedema, flushing, pyrexia, cough, and pain in extremity.

Full prescribing information Herceptin Hylecta®.