BioPharma

Lilly opens Phase III trial of highly targeted Loxo drug in thyroid cancer

The trial is the second Phase III study of the RET inhibitor selpercatinib, which Lilly acquired when it bought Loxo Oncology at the beginning of this year for $8 billion.

T-cells attacking cancer cell illustration of microscopic photosT-cells attacking cancer cell illustration of microscopic photos

Drugmaker Eli Lilly has opened a randomized clinical trial of a drug in thyroid cancer patients who carry a mutation that is rare but highly susceptible to targeted therapy.

The Indianapolis-based company said Monday that it had opened the Phase III LIBRETTO-531 trial of selpercatinib in previously untreated patients with medullary thyroid cancer (MTC) whose tumors carry genetic anomalies known as RET fusions. According to the announcement, RET fusions occur in about 60% of patients with MTC. Overall, the mutations tend to be rare: A 2017 study that used next-generation sequencing on the tumors of 4,871 patients with a variety of tumor types found the mutations in 88.

“This Phase III trial of selpercatinib in patients advanced or metastatic RET-mutant MTC seeks to confirm a new standard of care that we hope will provide a more effective treatment option for this patient population,” said Dr. Lori Wirth, director of the Center for Head and Neck Cancer at Boston’s Massachusetts General Hospital Cancer Center, in a statement for Lilly.

Another Phase III trial, LIBRETTO-431, is testing the drug – also known as LOXO-292 – in RET fusion-positive non-small cell lung cancer. Both trials are designed to enroll 400 patients, and each is taking place at more than 100 sites across North America, South America, Australia, Europe, Asia and the Middle East.

The thyroid cancer trial is randomizing patients to receive selpercatinib or either Exelixis’ Cabometyx (cabozantinib) or Sanofi’s Caprelsa (vandetinib).

Selpercatinib is one of the investigational compounds that Lilly took control of when it acquired Loxo Oncology earlier this year for $8 billion.

It is one of several drugs that represent an increasingly popular approach to oncology treatment, which is to target not the tumors themselves but biomarkers that are genetic drivers of the disease. And it’s an approach to which the Food and Drug Administration has been receptive. In 2017, it approved Merck’s PD-1 checkpoint inhibitor, Keytruda (pembrolizumab), for any solid tumor that displays a biomarker known as microsatellite instability-high/mismatch repair deficiency (MSI-H/dMMR). In 2008, it approved Loxo’s Vitrakvi (larotrectinib) for NTRK fusion-positive cancers, on the basis of a clinical trial that enrolled any solid tumor patient whose cancer exhibited the fusion, making it the first drug to be approved solely on the basis of a tumor-agnostic indication. Following the Lilly deal, Loxo handed rights to Vitrakvi off to development partner Bayer, which is now responsible for its development and marketing.

Another RET inhibitor is Blueprint Medicines’ pralsetinib, or BLU-667, which is in Phase I/II development.

Photo: royaltystockphoto, Getty Images

Shares0
Shares0