Some patients with non-small cell lung cancer (NSCLC) have tumor mutations called “RET fusions.” RET fusions are especially common in patients who have adenocarcinoma, never smoked, and/or have no mutations in other genes commonly associated with NSCLC. In an ongoing phase II clinical trial, three patients with adenocarcinoma and RET fusions appeared to respond well to the drug cabozantinib (Cometriq). The tumors of two of the patients shrank during Cometriq treatment, while the third experienced stable disease. Further studies are needed, but these results suggest that Cometriq may be an effective treatment for NSCLC patients with RET fusions.
“The discovery of RET fusions in lung cancers has uncovered a new therapeutic target for patients whose tumors harbor these changes. In an unselected population of non-small cell lung cancers (NSCLCs), RET fusions are present in 1-2% of cases. This incidence rises substantially, however, in never-smokers with lung adenocarcinomas that lack other known driver oncogenes. While pre-clinical data provide experimental support for the use of RET inhibitors in the treatment of RET fusion-positive tumors, clinical data on response are lacking. We report preliminary data for the first three patients treated with the RET inhibitor cabozantinib on a prospective phase 2 trial for patients with RET fusion-positive NSCLCs (NCT01639508)…”