Talquetamab is a CD3 T-cell bispecific antibody targeting GPRC5D, indicated for the treatment of relapsed or refractory multiple myeloma. As a novel immunotherapy, its administration methods and precautions are crucial for ensuring treatment efficacy.

How to Administer Talquetamab

Preparation Before Administration

Before initiating Talquetamab treatment, the patient’s baseline examination results (including complete blood count, liver function, etc.) must be obtained.

After receiving each dose in the "stepwise dosing regimen," the patient should be hospitalized for 48-hour observation to monitor the potential risks of Cytokine Release Syndrome (CRS) and neurotoxicity.

1–3 hours before each dose, premedication is required, including corticosteroids (16 mg dexamethasone or equivalent), antihistamines (50 mg diphenhydramine or equivalent), and antipyretics (650–1000 mg acetaminophen or equivalent).

Weekly Dosing Regimen

Stepwise Dose 1 (Day 1): 0.01 mg/kg

Stepwise Dose 2 (Day 4): 0.06 mg/kg

First Therapeutic Dose (Day 7): 0.4 mg/kg

Subsequent Therapeutic Doses: 0.4 mg/kg once weekly

Biweekly Dosing Regimen

Stepwise Dose 1 (Day 1): 0.01 mg/kg

Stepwise Dose 2 (Day 4): 0.06 mg/kg

Stepwise Dose 3 (Day 7): 0.4 mg/kg

First Therapeutic Dose (Day 10): 0.8 mg/kg

Subsequent Therapeutic Doses: 0.8 mg/kg once every two weeks

The interval between each dose must be at least 6 days (for the weekly regimen) or 12 days (for the biweekly regimen). If a dose is missed, the stepwise dosing regimen must be restarted based on the duration of the delay.

Dose Adjustment of Talquetamab

Dose Adjustment Based on CRS

Graded management of CRS:

Grade 1 (Body temperature ≥ 38°C): Suspend administration until CRS resolves.

Grade 2 (Body temperature ≥ 38°C accompanied by hypotension or requirement for low-flow oxygen): Suspend administration until CRS resolves.

Grade 3 (Requirement for vasopressors or high-flow oxygen): Suspend administration until CRS resolves.

Grade 4 (Requirement for multiple vasopressors or invasive ventilation): Discontinue administration permanently.

Dose Adjustment Based on Neurotoxicity

Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS):

Grade 1: Suspend administration until symptoms resolve.

Grade 2: Suspend administration and administer 10 mg dexamethasone intravenously every 6 hours.

First occurrence of Grade 3: Suspend administration and administer dexamethasone.

Recurrent Grade 3 or Grade 4: Discontinue administration permanently.

Administration of Talquetamab in Special Populations

Patients with Hepatic Impairment

No dose adjustment is required for patients with mild to moderate hepatic impairment.

Data on patients with severe hepatic impairment are limited; the risk-benefit ratio should be carefully evaluated.

Patients with Renal Impairment

No dose adjustment is required for patients with mild to moderate renal impairment (creatinine clearance: 30–89 mL/min).

Experience with the use of Talquetamab in patients with severe renal impairment (creatinine clearance < 30 mL/min) is limited.

Pregnant and Lactating Women

May cause fetal harm. Women of childbearing potential should confirm they are not pregnant within 7 days before treatment, and use effective contraceptive measures during treatment and for 3 months after discontinuing treatment.

Contraindicated during lactation; breastfeeding should be avoided during treatment and for 3 months after the last dose.