LOXO-292 is a highly selective RET inhibitor that has shown efficacy in preclinical models. This phase 1 trial included RET fusion/mutations patients with advanced or metastatic solid tumors refractory to or intolerant of standard treatment. At the April 2018 data cutoff, the overall response rate (ORR) was 77% for patients with RET fusion–positive cancers, 77% for patients with RET fusion-positive non–small cell lung cancer (NSCLC), and 78% for patients with other RET fusion–positive cancers. In patients with RET-mutated medullary thyroid cancer (MTC), the ORR was 45%. In patients without a known activating RET alteration, no responses were seen. Additionally, responses were seen across RET fusion partners in NSCLC patients. For those with the most common partner, KIF5B (n = 16), the ORR was 81%. For those with non-KIF5B partners, the ORR was 82%. Overall, LOXO-292 shows promising efficacy across solid tumors with RET alterations.
Source: J Clin Oncol. 2018;36 (suppl; abstr 102)