NEW YORK – The US Food and Drug Administration on Thursday approved Pfizer's Xalkori (crizotinib) for adult and pediatric patients with unresectable, recurrent, or refractory ALK-positive inflammatory myofibroblastic tumors.
The approval was based on results from two clinical trials of the drug that included 14 pediatric and seven adult patients. In the pediatric trial, 12 of the 14 patients (86 percent) experienced an objective response, while in the adult study five out of seven patients (71 percent) responded to treatment with Xalkori.
Inflammatory myofibroblastic tumors are rare, typically benign soft tissue sarcomas that occur most often in children and young adults. They can form in mucosal tissues, most often in the lungs, and mesentery tissues, which connect organs including the bladder, uterus, larynx, stomach, liver, or intestine. The typical treatment for these tumors is surgery.
A review published last year said about half of inflammatory myofibroblastic tumors harbor ALK gene rearrangements, and these tumors have also shown to harbor fusions involving ROS1, PDGFR-beta, RET, and NTRK.
This is Xalkori's fourth indication approved in the US. Xalkori is also approved by the FDA for ALK- or ROS1-positive metastatic non-small cell lung cancer and ALK-positive relapsed or refractory systemic anaplastic large cell lymphoma in young adults and children.