Inotuzumab ozogamicin (Besponsa) is an antibody-drug conjugate targeting CD22, specifically indicated for the treatment of relapsed or refractory CD22-positive B-cell precursor acute lymphoblastic leukemia.
How to Use Inotuzumab ozogamicin (Besponsa)
General Administration Principles
Inotuzumab ozogamicin must be administered via intravenous infusion.
Routine premedication with corticosteroids, antipyretic analgesics, and antihistamines is required before each dose.
For patients with circulating lymphoblasts, cytoreductive therapy with hydroxyurea, steroids, and/or vincristine should be administered prior to the first dose to reduce the peripheral blood blast count to ≤10,000/mm³.
Dosage Regimen
Cycle 1: The recommended total dose for all patients is 1.8 mg/m², divided into three administrations: 0.8 mg/m² on Day 1, 0.5 mg/m² on Day 8, and 0.5 mg/m² on Day 15.
The cycle length is 21 days. If the patient achieves complete remission (CR) or complete remission with incomplete hematologic recovery (CRi), and/or to allow recovery from toxicity, the cycle may be extended to 28 days.
Subsequent Cycles
Patients who achieved CR or CRi: The recommended total dose is 1.5 mg/m², administered as 0.5 mg/m² on Days 1, 8, and 15, with a cycle length of 28 days.
Patients who did not achieve CR or CRi: The recommended total dose is 1.8 mg/m², divided into 0.8 mg/m² on Day 1 and 0.5 mg/m² on Days 8 and 15, with a cycle length of 28 days.
Treatment Cycle Planning
For patients planned to undergo hematopoietic stem cell transplantation (HSCT), the recommended duration of treatment is 2 cycles.
For patients not undergoing HSCT, a maximum of 6 cycles of treatment may be administered.
Dosage Adjustments for Inotuzumab ozogamicin (Besponsa)
Thrombocytopenia Adjustment Plan
If the platelet count is ≥50×10⁹/L before treatment: Interrupt the next cycle when the platelet count decreases, and resume treatment only when the platelet count recovers to ≥50×10⁹/L.
If severe thrombocytopenia persists for more than 28 days and is considered related to inotuzumab ozogamicin, discontinue the drug permanently.
Neutropenia Adjustment Plan
If the absolute neutrophil count (ANC) is ≥1×10⁹/L before treatment: Interrupt the next cycle when ANC decreases, and resume treatment only when ANC recovers to ≥1×10⁹/L.
If severe neutropenia persists for more than 28 days and is considered drug-related, discontinue the drug permanently.
Special Populations for Inotuzumab ozogamicin (Besponsa)
Patients with Hepatic Impairment
Patients with mild hepatic impairment (total bilirubin ≤ upper limit of normal [ULN] and AST > ULN, or total bilirubin >1.0-1.5×ULN) do not require initial dose adjustment.
Data on patients with moderate to severe hepatic impairment are limited; use with caution.
Patients with Renal Impairment
Patients with mild to moderate renal impairment (creatinine clearance 15-89 mL/min) do not require dose adjustment.
The safety of use in patients with end-stage renal disease has not been established.
Women of Childbearing Age and Pregnant Women
Contraception requirements: Effective contraception must be used during treatment and for 8 months after the last dose.
Male contraception: Effective contraception must be used during treatment and for 5 months after the last dose.
Pregnancy risk: May cause fetal harm; contraindicated during pregnancy.
Lactation: Breastfeeding is not recommended during treatment and for 2 months after the last dose.
