US major Pfizer (NYSE: PFE) has announced the first prescriptions for its leukemia therapy Besponsa (inotuzumab ozogamicin) in multiple cities in China. This marks the official application of the world’s first antibody drug conjugate (ADC) in relapsed or refractory precursor B-cell ALL (R/R B-ALL).
Mechanism of Action
Besponsa targets CD22, which is expressed in more than 90% of B-ALL cases. When Besponsa binds to the CD22 antigen on B cells, it is internalized by the cells, which then release the cytotoxic drug calicheamicin to kill tumor cells.
Regulatory Milestones
The drug was awarded breakthrough therapy designation (BTD) status in the US in ALL in October 2015 and received accelerated approval in both the US and European Union in 2017. The market approval for Besponsa to treat R/R B-ALL patients in China was granted in December of last year.-Fineline Info & Tech
