NEW YORK – The US Food and Drug Administration on Thursday approved Pfizer's crizotinib (Xalkori) for pediatric patients with relapsed or refractory systemic anaplastic large-cell lymphoma (ALCL) that is ALK-positive.
The approval makes crizotinib the first biomarker-guided precision oncology treatment for young ALCL patients. The agency approved the drug based on results from a Phase I/II trial with 121 patients, 26 of whom had ALK-positive ALCL between the ages of one and 21. Among those patients, the objective response rate was 88 percent, with 81 percent achieving a complete remission. Of the 23 patients who responded, 39 percent maintained their response for at least six months and 22 percent did so for at least one year.
The single-arm trial enrolled pediatric ALCL patients with confirmed ALK fusion proteins, ALK mutations, ALK amplification, or with MET mutations or amplification. Patients had to be tested for these biomarkers by a CLIA-certified lab.
"With increased attention being placed on the development of targeted agents and the importance of ALK in pediatric patients with ALCL, the approval of [crizotinib] is a significant victory in our ongoing fight against these cancers that provides an outpatient oral medication with the real possibility of robust and sustained responses," Yael Mossé, principal investigator of the pivotal study run through the Children's Oncology Group, said in a statement. "ALK fusions play an important role in the pathology of ALCL, and it's exciting that [crizotinib] is able to leverage this dependence to provide a treatment option for young people faced with ALCL disease progression."
ALCL is a rare form of non-Hodgkin lymphoma. In young patients, approximately 90 percent of ALCL cases are ALK-positive. "The safety and efficacy of crizotinib have not been established in older adults with relapsed or refractory, systemic ALK-positive ALCL," the FDA said in a statement announcing the drug's approval.
Crizotinib received breakthrough therapy designation from the FDA for this indication in 2018. Pfizer is also working with the European Medicines Agency (EMA) on a Pediatric Investigational Plan (PIP) for crizotinib in this same ALCL indication, which would provide a path to approval in the EU.
Crizotinib is already approved in the US for ROS1- and ALK-rearranged metastatic non-small cell lung cancer. The drug also has received breakthrough therapy designation for NSCLC with MET exon 14 alterations. Pfizer published research on the drug's activity in MET-altered NSCLC last year.