crizotinib

crizotinib is an antineoplastic agent used in the treatment of certain cancers driven by specific genetic alterations. It is a tyrosine kinase inhibitor that primarily targets anaplastic lymphoma kinase (ALK) and ROS1 receptors. Developed by Pfizer, it received its initial FDA approval in 2011 for ALK-positive non-small cell lung cancer.

Medical uses

crizotinib is indicated for the treatment of patients with metastatic non-small cell lung cancer whose tumors are ALK-positive as detected by an FDA-approved test. Following clinical trials such as PROFILE 1001 and PROFILE 1007, its approval was expanded to include tumors that are ROS1-positive. The National Comprehensive Cancer Network guidelines recommend it as a first-line therapy for these patient populations. Its use is contingent upon confirmation of these specific biomarkers through companion diagnostic assays like the Vysis ALK Break Apart FISH Probe Kit.

Adverse effects

Common adverse effects include visual disturbances, nausea, diarrhea, edema, and constipation. More serious risks involve hepatotoxicity, which requires monitoring of liver function tests, interstitial lung disease, and QT interval prolongation. Cases of severe pneumonitis have been reported in clinical studies like PROFILE 1005. Patients may also experience bradycardia and renal cyst formation. Management often involves dose modifications as outlined in the prescribing information from Pfizer.

Pharmacology

crizotinib functions as a competitive inhibitor of adenosine triphosphate binding within the kinase domain of anaplastic lymphoma kinase and ROS1. This inhibition blocks downstream signaling pathways such as the PI3K/AKT/mTOR pathway and the JAK/STAT pathway, leading to reduced cell proliferation and apoptosis in tumor cells. It is metabolized primarily by the cytochrome P450 enzyme CYP3A4, and its pharmacokinetics can be significantly affected by concomitant use of strong CYP3A inhibitors or inducers like ketoconazole or rifampin.

History

The discovery of crizotinib originated from research at Pfizer's La Jolla laboratories, targeting the MET proto-oncogene. Its development shifted following the 2007 discovery of ALK fusions in non-small cell lung cancer by Hiroyuki Mano and colleagues. The pivotal PROFILE 1001 trial, led by investigators like Yung-Jue Bang, demonstrated remarkable efficacy, leading to an accelerated approval by the FDA in August 2011. This marked one of the first successful examples of a companion diagnostic paired with a targeted therapy in oncology.

Society and culture

Marketed under the trade name Xalkori, crizotinib has been cited as a landmark in precision medicine. Its high cost has been a subject of debate within healthcare systems like the National Health Service in the United Kingdom. The drug's development story was featured in publications such as The New England Journal of Medicine and has been discussed in the context of orphan drug status and accelerated approval pathways. Patient advocacy groups, including the Lung Cancer Foundation of America, have highlighted access issues.

Category:Antineoplastic drugs Category:Pfizer Category:Tyrosine kinase inhibitors