Margetuximab (margetuximab) drug instructions and instructions for use

Margetuximab (Margetuximab) is a new type of humanized anti-HER2 monoclonal antibody drug, which is a targeted anti-cancer treatment drug. Its trade name is Margenza, which is an antibody drug developed by MacroGenics. It is mainly used to treat patients with HER2-positive advanced breast cancer. As an improved version of trastuzumab (Trastuzumab), margetuximab not only binds to the HER2 receptor to inhibit the growth of cancer cells, but also enhances the immune system's killing effect on cancer cells, thereby improving the therapeutic effect. The following is a detailed analysis of the drug instructions and clinical use methods.

1. [Indications]

Margetuximab is mainly indicated for the treatment of HER2 -positive advanced or metastatic breast cancer, especially for patients who have received at least two anti-HER2 treatment regimens (including trastuzumab and pertuzumab). If the tumor becomes resistant to previous lines of anti-HER2 treatment or the disease progresses, margituximab, as a later-line treatment drug, provides a new treatment option. Clinical study data show that in patients carrying the CD16A low-affinity allele (F158), margetuximab may be more effective than trastuzumab.

2. [Pharmacological effects and mechanisms]

Margetuximab is similar to trastuzumab, targeting the extracellular structure of the HER2 receptor and inhibiting the proliferation and survival of tumor cells by blocking the HER2 signaling pathway. Not only that, it also engineered the Fc fragment so that it interacts with the Fc on the surface of immune cells (such as NK cells). γRIIIaThe receptor binding ability is enhanced, thereby enhancing the antibody-dependent cell-mediated cytotoxicity (ADCC) and improving the immune clearance effect of the drug. In other words, margetuximab has more therapeutic potential than traditional anti-HER2 monoclonal antibodies in terms of "targeting +immune enhancement".

3. [Usage and Dosage]

Margituximab is administered intravenously. The recommended dose is 15mg per kilogram of body weight, once every three weeks (Q3W), continue treatment until disease progression or intolerable side effects occur. It is recommended that the first infusion be completed within 2 hours. If there are no serious infusion-related reactions, subsequent infusions can be shortened to 30 minutes.

During preparation, the drug needs to be diluted to an appropriate concentration (usually 0.9% sodium chloride injection) and infused through an intravenous infusion pump. Before infusion, the drug solution should be observed for particles or discoloration. To reduce the incidence of infusion reactions, it is recommended to pretreat with antihistamines and antipyretics 30-60 minutes before administration.

4. [Adverse reactions and precautions]

Common adverse reactions include fatigue, nausea, diarrhea, infusion reactions, muscle pain, etc., most of which are mild to moderate. There are few serious adverse events, mainly including allergic reactions, cardiotoxicity (such as decreased left ventricular ejection fraction), immune system reactions, etc.

Cardiotoxicity is a common risk of HER2 targeted therapy. During treatment, it is recommended to regularly evaluate the patient's cardiac function, such as cardiac ultrasound, LVEF measurement, etc. Especially patients with a history of heart disease need to be more cautious. If the patient develops infusion-related reactions, such as fever, chills, and difficulty breathing, the infusion should be stopped immediately and treated accordingly, and the drug should be permanently discontinued if necessary.

In addition, female patients should take effective contraceptive measures during the use of margetuximab and for at least 4 months after stopping the drug, because the drug may cause harm to the fetus. It is also not recommended for lactating women, as it is unclear whether the drug is excreted through breast milk.

5. [Drug Form and Storage]

The common packaging specifications of macituximab are250mg/10ml/ bottles for single dose use. Medicines should be kept refrigerated (2-8°C), avoid freezing, and avoid direct sunlight. Before use, check whether the solution in the bottle is clear and free of impurities. The prepared infusion should be used at room temperature for no more than 24 hours.

6. [Global launch and price]

Margituximab was approved for marketing by the U.S.FDA at the end of 2020 and has become a new generation of HER2 targeted drugs. In China, the drug has recently been approved for marketing, but it has not yet been included in the medical insurance list and is priced relatively high. According to public information, the specifications of the Japanese and European versions of the original drug are250mg/10ml, the price of a single bottle is around 3 more than 10,000 yuan (fluctuated by exchange rates). The cost of treatment for patients is high, and it needs to be used rationally based on the condition and the doctor's advice. Generic drugs are not yet on the market, and there are currently no low-price alternatives.

7. [Clinical Research and Prospects]

The pivotal clinical study of margetuximab isSOPHIA Phase III trial results showed that compared with trastuzumab combined with chemotherapy, the margetuximab group had a slight improvement in progression-free survival (PFS), especially inFCGR3A-158F The effect is more obvious among carriers of the allele, suggesting that the drug has a stronger immune clearance effect on some HER2 positive breast cancer patients. In the future, margetuximab may expand its indications in HER2-positive gastric cancer, esophageal cancer and other fields, and may also be used in combination with immune checkpoint inhibitors to improve the breadth and depth of treatment.

Margetuximab, as a new member in the field of HER2 targeted therapy, not only optimizes the immune clearance effect in terms of mechanism, but also provides a new treatment option for breast cancer patients who are resistant to trastuzumab. Although the price is relatively high and it is not yet covered by medical insurance, its efficacy potential and safety have been recognized. In the future, with the expansion of indications and the launch of generic drugs, margituximab is expected to bring tangible benefits to more HER2-positive patients.

Reference materials:https://www.margenza.com/