How does Besponsa work to treat Acute Lymphoblastic Leukemia (ALL)?

Besponsa (inotuzumab ozogamicin) works to treat relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL) by binding to B-cell ALL cancer cells that express the CD22 antigen to block the growth of cancerous cells.

B-cell acute lymphoblastic leukemia (B-ALL) is an aggressive type of leukemia in which the bone marrow makes too many B-cell lymphocytes. It can be fatal within a matter of months if left untreated. Almost all B-ALL patients have cancer cells that express the CD22 antigen.

Besponsa is an antibody-drug conjugate (ADC) composed of a monoclonal antibody (mAb) that targets the CD22 antigen linked to a cytotoxic agent. When Besponsa binds to the CD22 antigen on B-cells, it is internalized into the cell, where the cytotoxic agent calicheamicin is released causing cell death.

Besponsa is administered as a one-hour intravenous infusion.

The prescribing information for Besponsa includes a boxed warning for severe liver damage (hepatotoxicity). Serious side effects include a decrease in blood cell and platelet production (myelosuppression), infusion-related reactions and problems with the heart’s electrical pulses (QT interval prolongation).

Common side effects of Besponsa include low levels of platelets (thrombocytopenia), low levels of certain white blood cells (neutropenia, leukopenia), infection, low levels of red blood cells (anemia), fatigue, severe bleeding (hemorrhage), fever (pyrexia), nausea, headache, low levels of white blood cells with fever (febrile neutropenia), liver damage (transaminases and/or gamma-glutamyltransferase increased), abdominal pain and high levels of bilirubin in the blood (hyperbilirubinemia).