What are the precautions for trastuzumab injection (subcutaneous injection) (Herceptin Hylecta)?

In clinical studies of trastuzumab injection (subcutaneous ) (Herceptin Hylecta), warnings and precautions such as cardiomyopathy, embryo-fetal toxicity, pulmonary toxicity, chemotherapy-induced exacerbation of neutropenia, allergies, and administration-related reactions have emerged.

1. Cardiomyopathy: Trastuzumab injection (subcutaneous injection) can cause left ventricular dysfunction, arrhythmia, hypertension, disabling heart failure, cardiomyopathy and cardiac death. It can also cause asymptomatic decrease in left ventricular ejection fraction (LVEF). The incidence of symptomatic myocardial dysfunction was increased 4- to 6-fold in patients who received trastuzumab alone or in combination compared with patients who did not receive trastuzumab.

Trastuzumab injection (subcutaneous injection) is refused when the absolute decrease in LVEF from the pre-treatment value is ≥16% or the LVEF value is lower than the normal institutional limit and the absolute decrease in LVEF from the pre-treatment value is ≥10%. LVEF measurements were performed every 3 months during and after treatment. If trastuzumab injection (subcutaneous) is discontinued due to severe left ventricular dysfunction, repeat LVEF measurements every 4 weeks. After completion of trastuzumab injection (subcutaneous ) as a component of adjuvant therapy, perform LVEF measurements every 6 months for at least 2 years.

2. Embryo-Fetotoxicity: Trastuzumab injection (subcutaneous injection) taken by pregnant women may cause harm to the fetus. In postmarketing reports, trastuzumab use during pregnancy resulted in a series of cases of oligohydramnios and oligohydramnios, manifesting as pulmonary hypoplasia, skeletal abnormalities, and neonatal death. Verify pregnancy status in females of reproductive potential before initiating trastuzumab injection (subcutaneous) . Inform pregnant women and females of reproductive potential that exposure to trastuzumab injection (subcutaneous injection) during pregnancy or within 7 months before conception may cause fetal harm. Advise females of childbearing potential to use effective contraception during treatment and for 7 months after the last dose.

3. Pulmonary toxicity: Trastuzumab injection (subcutaneous injection) can cause severe and fatal pulmonary toxicity. Pulmonary toxicities include dyspnea, interstitial pneumonitis, pulmonary infiltrates, pleural effusion, noncardiogenic pulmonary edema, pulmonary insufficiency and hypoxia, acute respiratory distress syndrome, and pulmonary fibrosis. Patients with symptomatic intrinsic lung disease or extensive tumor involvement of the lung causing dyspnea at rest appear to have more severe toxicity.

4. Exacerbation of neutropenia caused by chemotherapy: In a randomized controlled clinical trial of intravenous trastuzumab, patients who received trastuzumab combined with myelosuppressive chemotherapyThe per capita incidence of NCI-CTC grade 3-4 neutropenia and febrile neutropenia was higher in patients receiving chemotherapy alone. The incidence of infectious death was similar in patients who received trastuzumab and those who did not.

5. Allergic and administration-related reactions: Including hypersensitivity reactions and anaphylaxis, patients with dyspnea at rest due to complications from advanced malignancies and comorbidities may be at increased risk of severe or fatal cardiac arrest. Monitor patients closely for systemic allergic reactions, especially during the first dose. Patients who experience anaphylaxis or a severe allergic reaction should permanently discontinue trastuzumab injection (subcutaneous injection). For patients who experience a reversible grade 1 or 2 allergic reaction, consider taking an analgesic, fever reducer, or antihistamine before taking the drug again.