Ontruzant (Trastuzumab)

Trastuzumab, the active ingredient in Ontruzant, is a monoclonal antibody presented as an intravenous formulation for intravenous use. It targets HER2‑positive malignancies, primarily breast and gastric cancers, in adult patients. GNH USA supplies Ontruzant as a licensed, GDP‑compliant international pharmaceutical supplier serving oncology centres worldwide.

Ontruzant is a monoclonal antibody that acts on the HER2 signaling pathway in several solid tumours. - HER2‑positive metastatic breast cancer: improves overall survival when combined with chemotherapy. - HER2‑positive early‑stage breast cancer (adjuvant setting): reduces risk of disease recurrence after surgery. - HER2‑positive gastric or gastro‑esophageal adenocarcinoma: enhances response rates when used with chemotherapy.

Adverse reactions may occur with trastuzumab therapy and are monitored closely.

Common Side Effects: - Fever or chills during infusion - Nausea or vomiting - Diarrhoea - Fatigue - Headache - Rash or mild skin reactions

Serious or Rare Side Effects: - Cardiac dysfunction or heart failure - Severe infusion‑related reactions (anaphylaxis, bronchospasm) - Pulmonary toxicity (interstitial lung disease) - Hepatotoxicity (elevated liver enzymes) - Thrombocytopenia or neutropenia - Severe skin reactions (Stevens‑Johnson syndrome).

Trastuzumab requires careful clinical monitoring to minimise risks. - Cardiac assessment: baseline and periodic ejection fraction evaluation is recommended. - Infusion monitoring: observe patients for signs of hypersensitivity during and after administration. - Pregnancy: avoid use; potential fetal harm has been reported. - Breastfeeding: discontinue therapy; drug may be present in milk. - Concomitant cardiotoxic agents: use with caution and monitor cardiac function closely. Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Trastuzumab may interact with other agents, influencing safety or efficacy.

Major Interactions (Avoid): - Anthracycline chemotherapy (e.g., doxorubicin): increased risk of cardiotoxicity. - Concurrent use with other HER2‑targeted antibodies without clinical justification.

Moderate Interactions (Monitor Closely): - Paclitaxel or other taxanes: may enhance infusion‑related reactions. - CYP450 inducers or inhibitors: generally minimal effect but monitor for unexpected toxicity. - Vaccines: live attenuated vaccines should be avoided during treatment.