On 14 December 2018, the US Food and Drug Administration (FDA) approved trastuzumab-pkrb (Herzuma, Celltrion Inc.) as a biosimilar to trastuzumab (Herceptin, Genentech Inc.) for patients with HER2-overexpressing breast cancer.
Herzuma is a HER2/neu receptor antagonist indicated for the treatment of HER2-overexpressing breast cancer. The recommended dosage and administration is as follows:
Adjuvant treatment of HER2-overexpressing breast cancer:
- Initial dose of 4 mg/kg over 90-minute i.v. infusion, then 2 mg/kg over 30-minute i.v. infusion weekly for 12 weeks (with paclitaxel or docetaxel) or 18 weeks (with docetaxel and carboplatin). One week after the last weekly dose of Herzuma, administer 6 mg/kg as an i.v. infusion over 30−90 minutes every three weeks to complete a total of 52 weeks of therapy.
Metastatic HER2-overexpressing breast cancer:
- Initial dose of 4 mg/kg as a 90-minute i.v. infusion followed by subsequent weekly doses of 2 mg/kg as 30-minute i.v. infusions.
Healthcare professionals should review the prescribing information in the labelling for detailed information about the approved uses.
Full prescribing information for Herzuma is available here.
The approval was based on comparisons of extensive structural and functional product characterisation, animal data, human pharmacokinetic, clinical immunogenicity, and other clinical data demonstrating that Herzuma is biosimilar to US Herceptin. Herzuma has been approved as a biosimilar, not as an interchangeable product.
Common expected side effects of Herzuma for the treatment of HER2-positive breast cancer include headache, diarrhoea, nausea, chills, fever, infection, congestive heart failure, insomnia, cough, and rash. Serious expected side effects of Herzuma include worsening of chemotherapy-induced neutropenia.
Like Herceptin, the labelling for Herzuma contains a Boxed Warning to alert health care professionals and patients about increased risks of cardiomyopathy, infusion reactions, pulmonary toxicity, and embryo-foetal toxicity.
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.