Precautions for use of Retifanlimab

Retifanlimab - Zynyz is a monoclonal antibody directed against programmed death receptor-1 (PD-1) and is used to treat a variety of malignancies, such as Merkel cell carcinoma (MCC). In clinical studies, it was found that this drug may cause serious and fatal immune-mediated adverse reactions, infusion-related reactions, complications of allogeneic hematopoietic stem cell transplantation (HSCT), and embryo-fetal toxicity. Therefore, special attention should be paid to the following points during use:

1. Serious and fatal immune-mediated adverse reactions: Immune-mediated adverse reactions are the most common and potentially fatal conditions during the use of retivarimab. This type of reaction can affect any organ system, including the lungs, liver, endocrine glands, and skin, and may manifest as immune-mediated pneumonia, colitis, hepatitis, and various endocrine diseases. Although these reactions usually occur while taking the drug, they may also occur after the drug is stopped. Therefore, when an immune-mediated adverse reaction is detected, the medication should be discontinued immediately and systemic corticosteroid therapy should be given until improvement.

2. Infusion-related reactions: During treatment with retivarimab, patients may experience severe infusion-related reactions. In this regard, it is recommended to carefully monitor the patient's vital signs before infusion and to provide preventive treatment, such as antipyretics and antihistamines, in patients with a history of allergies to reduce the risk of adverse reactions.

3. AllogeneicComplications of HSCT: For patients who have received allogeneic hematopoietic stem cell transplantation, the use of retifalimab may lead to fatal and other serious complications, such as hyperacute graft-versus-host disease (GVHD), acute and chronic GVHD, etc. Therefore, when deciding whether to use this drug before or after HSCT, the possible risks should be weighed against the benefits and the patient's condition should be monitored closely.

4. Embryo-Fetal Toxicity: Retifalimab may cause damage to the fetus when used by pregnant women. Animal studies have shown that inhibiting the PD-1/PD-L1 pathway may lead to fetal immune rejection and increase the risk of fetal death. Therefore, female patients must be informed of the potential risks and females of childbearing potential should be advised to use effective contraception during treatment and for four months after the last dose.

Reference materials:https://www.drugs.com/mtm/retifanlimab.html