The FDA granted priority review for inotuzumab ozogamicin, an anti-CD22 monoclonal antibody, for the treatment of adult patients with relapsed/refractory B-cell precursor acute lymphocytic leukemia (ALL).
The decision was based on results of the phase III INO-VATE 1022 trial comparing inotuzumab ozogamicin with standard-of-care chemotherapy in 326 patients with relapsed/refractory B-cell ALL. A total of 218 patients (61% were <55 years; all were CD22-positive) were selected for primary analysis: 109 patients received inotuzumab ozogamicin 1.8 mg/m2 and 109 patients received physicians’ choice of fludarabine plus cytarabine with granulocyte colony-stimulating factor, high-dose cytarabine, or cytarabine plus mitoxantrone.
The risk of disease progression or death was reduced by 55 percent in patients treated with inotuzumab ozogamicin versus standard therapy (hazard ratio [HR] = 0.45; 97.5% CI 0.43-0.61; p<0.001). Overall survival also improved with inotuzumab ozogamicin, although it was not statistically significant (HR=0.77; 97.5% CI 0.58-1.03; p=0.04).
Inotuzumab ozogamicin led to a complete response (CR) or CR with incomplete platelet recovery rate of 80.7 percent, compared with 29.4 percent with chemotherapy (p<0.001).
AEs were assessed in all patients who received at least one dose of inotuzumab ozogamicin (n=139) or chemotherapy (n=120). The most common grade ≥3 AEs in both groups were cytopenias. Any-grade veno-occlusive liver disease occurred in 15 patients (13 were grade ≥3) in the inotuzumab ozogamicin group, compared with just one in the chemotherapy cohort. Two deaths were associated with veno-occlusive liver disease in the inotuzumab ozogamicin arm.
Source: Pfizer press release, February 21, 2017.