Gemtuzumab is an antibody drug conjugate targeting CD33, used to treat CD33 positive acute myeloid leukemia. In clinical applications, it is important to focus on the three major risks of liver toxicity, infusion reactions, and bone marrow suppression. The following are systematic precautions.

1、 Monitoring and Management of Hepatotoxicity

1.1 Risk Characteristics

The hepatotoxicity of cetuximab is mainly manifested as elevated transaminase levels, hyperbilirubinemia, and in severe cases, it can lead to hepatic sinus obstruction syndrome (SOS/VOD), especially when used before hematopoietic stem cell transplantation or high-dose regimens.

1.2 Monitoring points

Baseline assessment: ALT, AST, total bilirubin, and alkaline phosphatase were tested before treatment.

Dynamic monitoring: Re check liver function before each administration and on the 3rd and 7th day after administration; Increase to twice a week when abnormalities occur.

SOS warning: Pay attention to signs such as sudden weight gain, upper right abdominal pain, ascites, jaundice, etc.

1.3 Processing Strategy

Elevation of transaminase to>5 × ULN: Suspend medication and evaluate whether to reduce or stop medication after it returns to ≤ 2.5 × ULN.

Diagnosed with SOS: Immediately and permanently discontinue medication, and receive standard treatment with fibrinogen.

Avoid combination therapy with hepatotoxic drugs: Use other hepatotoxic drugs (such as azole antifungal drugs and acetaminophen) with caution during treatment.

2、 Prevention and treatment of infusion reactions

2.1 High risk period and performance

Infusion reactions are more common during the first administration or dose escalation stage, and can manifest as fever, chills, hypotension, difficulty breathing, rash, and in severe cases, allergic shock.

2.2 Preventive measures

Pre treatment before administration: 30-60 minutes before each infusion, administer:

Antihistamines (such as diphenhydramine 25-50mg)

Corticosteroids (such as methylprednisolone 50-100mg or hydrocortisone 100mg)

Antipyretic and analgesic drugs (such as acetaminophen 650mg)

Infusion duration: The first infusion should last for no less than 2 hours, and subsequent infusions should last for no less than 1 hour.

2.3 Acute Reaction Management

Mild to moderate reactions: Suspend infusion, administer fluid replacement and intravenous antihistamines/hormones; After the symptoms subside, restart at 50% of the original rate.

Severe reactions/anaphylactic shock: Immediately stop infusion, administer adrenaline, fluid resuscitation, and airway support, and prohibit the use of cetuximab again in the future.