Inotuzumab ozogamicin (Besponsa) is an antibody-drug conjugate (ADC) targeting CD22. It achieves targeted elimination of cancer cells by precisely acting on the CD22 antigen expressed on the surface of B cells.

What is Inotuzumab ozogamicin (Besponsa)?

Core Components

Humanized IgG4 antibody: Specifically recognizes and binds to the CD22 antigen.

Cytotoxic component: N-acetyl-γ-calicheamicin, which can induce DNA double-strand breaks.

Acid-labile linker: Connects the antibody to the cytotoxic component via a cleavable bond.

Mechanism of Action

The antibody portion binds to the CD22 antigen on the surface of CD22-positive tumor cells.

The ADC-CD22 complex is internalized into the cell.

Calicheamicin derivatives are released through hydrolysis within the cell.

Induces cell cycle arrest and programmed cell death (apoptosis).

Specifications and Properties of Inotuzumab ozogamicin (Besponsa)

Dosage Form and Specifications

Injection: 0.9 mg lyophilized powder in a single-dose vial.

Concentration after reconstitution: 0.25 mg/mL (reconstituted with 4 mL of sterile water for injection).

Physical Characteristics

Appearance: White to off-white lyophilized powder.

Reconstituted solution: Clear to opalescent, colorless to slightly yellow.

Osmolality: Equivalent to 0.9% sodium chloride injection.

Excipient Composition

Polysorbate 80 (0.36 mg).

Sodium chloride (2.16 mg).

Sucrose (180 mg).

Tromethamine (8.64 mg).

pH value: Approximately 8.0 after reconstitution.

Storage Conditions for Inotuzumab ozogamicin (Besponsa)

Storage of Unopened Medication

Temperature: Refrigerate at 2°C to 8°C.

Light protection: Store in the original packaging to protect from light.

Contraindications: Do not freeze or subject to vigorous shaking.

Post-Reconstitution Management

Refrigerated storage (2°C-8°C): Use within 4 hours.

Reconstitute only with sterile water for injection.

Do not use diluents containing preservatives.

Storage of Diluted Solution

Room temperature storage (20°C-25°C): Use within 6 hours.

Refrigerated storage (2°C-8°C): Use within 6 hours (equilibrate to room temperature for 1 hour before use).

Key Time Points

The total time from reconstitution to the end of administration must not exceed 8 hours, with the time from reconstitution to dilution not exceeding 4 hours.