What Is B-Cell Acute Lymphoblastic Leukemia (B-ALL)?
Explore the role of Besponsa in treating B-cell ALL in U.S. patients, including how it works, who it’s for, and what to expect during treatment.
B-cell acute lymphoblastic leukemia (B-ALL) is a fast-growing cancer of the blood and bone marrow, where immature B lymphocytes (a type of white blood cell) multiply uncontrollably. It most commonly affects children but also occurs in adults, particularly those over age 60.
When initial treatments fail or the cancer returns, it is known as relapsed or refractory B-ALL—a particularly challenging form to treat.
What Is Besponsa?
Besponsa® (inotuzumab ozogamicin) is a targeted antibody-drug conjugate approved by the FDA for the treatment of relapsed or refractory B-cell ALL in adults.
It combines:
A monoclonal antibody that targets CD22 (a protein on B cells)
A potent chemotherapy agent (calicheamicin) that kills the cancer cell once internalized
This precision-targeted delivery helps reduce damage to healthy cells while improving outcomes in patients who haven’t responded to standard chemotherapy.
How Does Besponsa Work?
The monoclonal antibody attaches to the CD22 protein oncancerous B cells
The cancer cell absorbs the drug
Calicheamicin is released inside the cell, triggering DNA damage and cell death
This targeted method helps shrink leukemic cell counts and prepare some patients for stem cell transplantation, the only curative option for many.
Who Is Eligible for Besponsa?
Adults with relapsed or refractory B-cell ALL
Patients with CD22-positive leukemia
Those who are candidates for hematopoietic stem cell transplantation (HSCT)
Your oncologist will order specific lab tests to confirm eligibility.
Benefits of Besponsa
Higher complete remission rates compared to traditional chemo
Potential bridge to curative stem cell transplant
Administered through IV infusion on an outpatient basis
Potential Side Effects
While effective, Besponsa may cause:
Fatigue, nausea, fever, and headache
Liver toxicity (VOD)—a serious but rare risk, especially before transplant
Low blood counts, increasing infection and bleeding risks
Close monitoring by a hematology-oncology team is essential throughout treatment.
The Future of Targeted Leukemia Therapy
Besponsa reflects the growing shift toward precision medicine in cancer care. As researchers learn more about genetic markers like CD22, new antibody-drug combinations and immunotherapies are expected to expand treatment options for high-risk leukemia patients in the U.S.