Loxo Oncology reports positive results from Phase I study of larotrectinib to treat TRK fusion cancers


US-based biopharmaceutical company Loxo Oncology has reported positive results from its Phase I study of larotrectinib (LOXO-101) to treat tropomyosin receptor kinase (TRK) fusion cancers.

Larotrectinib has been developed as a potent, orally administered and selective investigational new drug, which is under development to treat patients with cancers exhibiting abnormalities involving the tropomyosin receptor kinases (TRKs).

It directly targets TRK, inhibiting the signalling pathway that leads to the progression of TRK fusion cancers.

The open-label, dose-escalation Phase I trial was being conducted to evaluate efficacy of larotrectinib while examining 59 adult patients with advanced cancer, including eight patients with TRK Fusion cancer who were administered with six dose levels of larotrectinib.

Results suggested that six of the patients with TRK fusion cancers confirmed partial response determined on the basis of standard RECIST criteria.

"The depth of responses and durability data with larotrectinib in patients with TRK fusion cancers are among the most promising that we see in oncology Phase I clinical trials."

Additionally, larotrectinib was also well tolerated at doses that include and exceed the recommended Phase II dose of 100mg BID with mild-to-moderate adverse events.

Sarah Cannon Research Institute drug development and principal investigator associate director Todd Bauer said: “The depth of responses and durability data with larotrectinib in patients with TRK fusion cancers are among the most promising that we see in oncology Phase I clinical trials.

“We believe our patients would benefit from the addition of larotrectinib to the armamentarium of matched targeted therapies for our patients, as our continued utilisation of molecular testing in clinical practice will naturally lead to the identification of patients with TRK fusions.”

The company is planning to conduct the Phase II Navigate study to test larotrectinib in adults with TRK fusion cancers and Phase I/II Scout study to evaluate larotrectinib in children.