Herzuma

Herzuma is a prescription monoclonal antibody whose active ingredient is trastuzumab, supplied as a sterile solution for injection. It is marketed in the European Union and is classified as an antineoplastic agent. The product is administered intravenously and targets HER2‑positive cancers. As a biosimilar of reference trastuzumab, Herzuma is used for HER2‑positive breast and gastric cancers after specialist evaluation.

Herzuma is prescribed for patients whose tumors overexpress the human epidermal growth factor receptor 2 (HER2). The drug is used in both early and advanced disease settings across several cancer types. - HER2‑positive metastatic breast cancer, in combination with chemotherapy. - HER2‑positive early breast cancer, as adjuvant or neoadjuvant therapy. - HER2‑positive gastric or gastro‑esophageal junction adenocarcinoma, together with chemotherapy. - HER2‑positive locally advanced or unresectable breast cancer, when surgery is not feasible. - HER2‑positive disease in patients who have completed prior trastuzumab‑containing regimens, as per clinical guidance.

Adverse reactions to Herzuma vary in frequency and severity, reflecting its immunologic and vascular effects. Common: - Infusion‑related reactions such as fever, chills, flushing, or hypotension. - Nausea, vomiting, or mild gastrointestinal upset including abdominal discomfort. - Fatigue, headache, dizziness, or mild skin rash at the injection site. Serious: - Cardiac dysfunction, including reduced left ventricular ejection fraction or congestive heart failure. - Severe hypersensitivity or anaphylactic reactions, potentially requiring emergency treatment. - Thromboembolic events such as deep‑vein thrombosis, pulmonary embolism, or arterial occlusion.

Before initiating Herzuma, clinicians should evaluate several patient‑specific factors to minimize risk and ensure appropriate monitoring. - Assess baseline cardiac function with echocardiography or MUGA scan, and repeat periodically. - Review history of hypersensitivity reactions to monoclonal antibodies or trastuzumab‑containing products. - Evaluate hepatic and renal function, adjusting treatment if significant impairment is present. - Monitor for signs of infusion‑related reactions during and after each administration. - Use caution in patients with uncontrolled hypertension or active infections. - Discuss contraception and potential fetal risks, as safety in pregnancy has not been established.

Herzuma may interact with other medicines that affect cardiac function, immune response, or drug clearance. Avoid: - Concurrent use of anthracyclines (e.g., doxorubicin) due to increased risk of cardiotoxicity. - Live vaccines during treatment, because immune suppression may reduce vaccine efficacy and increase infection risk. Use with caution: - Chemotherapeutic agents that also cause myelosuppression, requiring close blood count monitoring. - Medications that prolong QT interval, as cardiac monitoring is already indicated. - Hormonal therapies (e.g., tamoxifen) that may have additive cardiac effects.