A University of Colorado Cancer Center study published today in the International Journal of Radiation Oncology Biology and Physics shows that patients taking crizotinib for ALK+ non-small cell lung cancer may safely and durably use up to three courses of targeted radiation therapy to eradicate pockets of drug-resistant disease. Eliminating these pockets of resistant disease allows patients to continue treating the overall condition with crizotinib, leading to improved 2-year survival rates compared with patients forced to discontinue the drug sooner.
ALK+ lung cancers are caused by the aberrant reactivation of the ALK gene, and comprise about 3-5 percent of all cases of non-small cell lung cancer. In these cases, clinical studies have shown that the drug crizotinib is highly effective and the drug was rapidly approved by the FDA in 2011. Unfortunately, at around 8 10 months after the initiation of treatment, the cancer tends to acquire resistance to crizotinib. Earlier work at CU Cancer Center and elsewhere showed that resistance occurs through a change in the biology of the cancer. At this point, patients have generally been switched to another drug.
However, it may not be the entire cancer that develops resistance to the drug. Instead, as the change in biology is an evolutionary event only pockets of the cancer may become immune. Previous work from the CU Cancer Center described the use of a single course of radiotherapeutic local ablative therapy to eliminate these isolated pockets of resistant disease.
"The traditional paradigm for cancer patients has been to switch your systemic therapy to another agent if you progress, even though a majority of your cancer may still be controlled by the original drug. But what if we could use targeted radiation therapy to eliminate those sites of errant disease so a person could stay on a specific drug longer?" says Gregory Gan, MD, PhD, a chief resident in the University of Colorado Sc
|Contact: Garth Sundem|
University of Colorado Denver