US drugmaker Pfizer has reported positive Phase III INO-VATE ALL study results of inotuzumab ozogamicin to treat relapsed or refractory CD22-positive acute lymphoblastic leukemia (ALL).
An investigational antibody-drug conjugate (ADC), inotuzumab ozogamicin, is composed of a monoclonal antibody (mAb), which targets the cell surface antigen, CD22, occurring on cancer cells in almost all B-ALL patients, linked to a cytotoxic agent.
The open-label, randomised, Phase III trial, known as Study 1022, aims at evaluating the safety and efficacy of inotuzumab ozogamicin while comparing it with investigator-choice chemotherapy administered to 326 adults.
Results have exhibited inotuzumab ozogamicin, offering an improved result over chemotherapy on fields including complete hematologic remission and progression-free survival (PFS).
University of Texas MD Anderson Cancer Centre lead study investigator and professor Hagop Kantarjian said: "Relapsed or refractory ALL is an aggressive leukemia in urgent need of new treatment options as about half of adult patients will not respond to chemotherapy or will see their disease return.
"The efficacy results seen in patients treated with inotuzumab ozogamicin in this study are impressive, particularly median progression-free survival, high rates of hematological remission and absence of minimal residual disease.
"These results suggest inotuzumab ozogamicin, if approved, could be a valuable new addition to currently available treatment options for ALL patients, including as a bridge to stem cell transplantation, which is the best chance for a cure at this stage of the disease."
Inotuzumab ozogamicin attaches to the CD22 antigen on malignant B-cells, where the cytotoxic agent calicheamicin is released to destroy the cell.
It has been developed in collaboration with Celltech (now UCB), with Pfizer having sole responsibility for all manufacturing and clinical development activities for this molecule.