Besponsa mechanism of action?

How does Besponsa (inotuzumab ozogamicin) work?

Besponsa is an antibody-drug conjugate. It targets the CD22 protein on the surface of B cells. After the drug binds to CD22, the compound is taken into the cell, where the attached cytotoxic agent is released to damage DNA and trigger cell death [1].

What is the “antibody + payload” part of the mechanism?

Besponsa combines:
- A monoclonal antibody component that recognizes CD22, and
- A cytotoxic payload (a DNA-damaging agent) that is delivered to CD22-positive cells after binding and internalization [1].

Why does targeting CD22 matter in cancer cells?

Many B-cell malignancies express CD22, so using CD22 as a target concentrates the cytotoxic effect on cancer cells (those with CD22) rather than relying only on broadly acting chemotherapy [1].

What happens at the cellular level after binding to CD22?

Once Besponsa binds CD22 on the cell surface, it is internalized. Inside the cell, the payload is released and interferes with DNA function, leading to apoptosis (cell death) [1].

Safety-related connection: how the mechanism relates to risks?

Because the drug delivers a DNA-damaging payload into cells that express CD22, the same class of mechanism is one reason Besponsa can cause serious side effects tied to effects on normal tissues and the liver—events that clinicians watch closely during treatment [1].

References

1. Besponsa (inotuzumab ozogamicin) prescribing information – mechanism of action