Loxo Oncology TRK Inhibitor LOXO-101 Shows Promising Clinical Activity

(RTTNews) - Loxo Oncology Inc. (LOXO) announced new results from its Phase 1 open-label, dose-escalation trial of LOXO-101, a selective inhibitor of tropomyosin receptor kinase (TRK) signaling molecules, and the first preclinical data for its RET and FGFR programs.

Providing a LOXO-101 Phase 1 update, study investigators reported that, as of the October 20, 2015 data cutoff date, 30 patients with solid tumors refractory to standard therapy had been enrolled and treated, including six patients with cancers harboring TRK fusions. Three of the six patients with TRK fusion cancers had been on study sufficiently long for their first efficacy assessment, and all three had achieved an objective response at the first response assessment, as defined by standard RECIST criteria. All three of these patients remain in response and on study.

The other three patients with TRK fusion cancers were recently enrolled and thus had not yet been evaluated for response as of the data cutoff date, though they all remain on study. In addition, LOXO-101 has been well tolerated, including the 100 mg twice-daily dose, which has been selected for Phase 2 study and has shown efficacy in TRK fusion patients.

The majority of adverse events reported by investigators have been mild to moderate. A maximum tolerated dose (MTD) has not been defined, though near-term Phase 1 enrollment will focus on further characterizing the pharmacokinetics and safety of the 100 mg twice-daily dose dosing.