FDA Approves Besponsa for Relapsed/Refractory Acute Lymphoblastic Leukemia

The FDA has approved Besponsa (inotuzumab ozogamicin) for treating adults with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL), a cancer that occurs when the bone marrow makes too many B-cell lymphocytes, an immature type of white blood cell.

ALL is a rapidly progressing type of cancer: the National Cancer Institute estimates that approximately 5970 people in the United states will be diagnosed with ALL in 2017, while 1440 will die as a result of the disease. Besponsa is intended to lower these odds by targeting and binding to B-cell ALL cancer cells that have the CD22 antigen and therefore restricting cancerous cells from growing.

“For adult patients with B-cell ALL whose cancer has not responded to initial treatment or has returned after treatment, life expectancy is typically low,” Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, said in a statement announcing the approval.

Besponsa was studied in a randomized trial of 326 patients who had relapsed or refractory B-cell ALL and had received 1 or 2 treatments before the study. The researchers then randomly selected patients to receive Besponsa for treatment or an alternative chemotherapy in order to measure the percentage of patients who demonstrated no evidence of disease and to calculate which patients had a full recovery of blood counts after treatment.

Of the total patients in the trial, 35.8% of those treated with Besponsa reached complete remission for a median 8 months, while of the patients who received chemotherapy, only 17.4% reached complete remission for a median of 4.9 months.

Despite Besponsa’s established efficacy, the treatment causes certain common side effects, including low levels of platelets, low levels of certain white blood cells, infection, anemia, fatigue, and fever.

“These patients have few treatments available and today’s approval provides a new, targeted treatment option,” Pazdur concluded.