The investigative agent, inotuzumab ozogamicin, significantly improves progression-free survival and 2-year survival rates among patients with acute lymphoblastic leukemia that has stopped responding to prior therapy. These results were recently published in the New England Journal of Medicine.
Acute lymphoblastic leukemia (ALL) is an aggressive form of leukemia with limited treatment options once it progresses following standard therapies. In ALL, the cancer originates from immune cells, most often B-cells. If ALL relapses, 5-year survival rates are less than 10% with available treatment options. Therefore, researchers continue to evaluate novel ways in which to improve outcomes for patients with this disease.
Inotuzumab ozogamicin is a drug that is referred to as an antibody conjugate. It is comprised of an antibody that has been developed to specifically bind to the CD22 antigen, which is a small molecule found on the surface of B-cells. Attached to the antibody is a chemotherapy agent called calicheamicin. Once the agent is bound to the B-cell, it is internalized into the cell where a chemotherapy agent is released.
Inotuzumab ozogamicin has recently been granted breakthrough status by the United States Food and Drug Administration (FDA) for the treatment of relapsed ALL.
Researchers recently conducted a clinical trial further evaluating inotuzumab ozogamicin among patients with ALL that had progressed, or stopped responding to, prior therapy. The trial, referred to as the INO-VATE ALL Trial, or the Study 1022, was a phase III study that included 326 adults with B-cell ALL that had progressed following prior therapy. The leukemia cells tested positive for the CD22 antigen. Patients were treated with either inotuzumab ozogamicin or standard treatment.
- The median survival time without cancer progression was 5.0 months for patients treated with inotuzumab ozogamicin, compared with only 1.8 months for those treated with standard therapy.
- Survival at 2 years was 23% for patients treated with inotuzumab ozogamicin, compared with 10% for those treated with standard therapy.
- The median overall survival was 7.7 months for patients treated with inotuzumab ozogamicin, compared with 6.7 months for those treated with standard therapy.
- 41% of patients treated with inotuzumab ozogamicin went on to receive a stem cell transplant, compared with only 11% of patients treated with standard therapy.
- Veno-occlusive disease is the most serious side effect associated with inotuzumab ozogamicin.
The researchers concluded that treatment with inotuzumab ozogamicin appears superior to standard therapy for treatment of relapsed ALL, and may provide an important new treatment option for patients with this disease.
Reference: Kantarjian H, DeAngelo D, Steljies M, et al. Inotuzumab ozogamicin versus standard therapy for acute lymphoblastic leukemia. New England Journal of Medicine. 2016; 375:740-753. DOI: 10.1056/NEJMoa1509277. Available at: http://www.nejm.org/doi/full/10.1056/NEJMoa1509277. Accessed August 29, 2016.