Loxo Oncology Updates Results From Adult Phase 1 Trial Of Larotrectinib

(RTTNews) - Loxo Oncology Inc. (LOXO) announced updated results from its adult Phase 1 open-label, dose-escalation trial of larotrectinib (LOXO-101), a selective inhibitor of tropomyosin receptor kinase (TRK). The data were presented today at the 2016 European Society for Medical Oncology (ESMO) Asia Congress in Singapore.

As of a November 10, 2016 data cutoff, 59 patients with refractory solid tumors had been enrolled and treated with single agent larotrectinib, including eight patients with cancers harboring TRK fusions. Seven patients with TRK fusion cancers were on study sufficiently long for an efficacy assessment, while an eighth TRK fusion patient had been recently enrolled and was not yet evaluated for response. Six of the seven efficacy evaluable patients achieved a confirmed partial response, as defined by standard RECIST criteria. The seventh patient, as previously reported, demonstrated clear radiographic tumor regressions, including in the central nervous system, and remains on study, but had not met the threshold required for a RECIST response. All responders remained in response, with one patient in cycle 22, one patient in cycle 19, one patient in cycle 18, two patients in cycle 15 and one patient in cycle 11. Each cycle is 28 days, or approximately one month.

Larotrectinib has been well tolerated at doses that include and exceed the recommended Phase 2 dose of 100 mg BID. A maximum tolerated dose (MTD) has not been defined. The majority of adverse events reported by the investigators have been mild to moderate.

On Monday, December 19, 2016, Loxo Oncology plans to file a Form 8-K with the U.S. Securities and Exchange Commission (SEC) containing the larotrectinib materials presented at the ESMO Asia meeting.