Investigational Drug Shows Promise in Patients with RET-Altered Cancers

Patients with RET-fusion-positive non-small cell lung cancer (NSCLC) had a high response to LOXO-292 (selpercatinib), according to findings from the largest clinical trial of patients with RET-altered cancers.

The oral investigational medication was examined in 105 patients who had a median of three prior treatment regimens. LOXO-292 showed a 68% objective response rate, meaning their tumors shrunk by at least 30%.

“In this large cohort, selpercatinib’s response rate, durability, robust CNS (central nervous system) activity and safety show promise,” Dr. Alexander Drilon, the lead investigator and a medical oncologist at Memorial Sloan Kettering Cancer Center in New York City, said in a press release. “Furthermore, this continues to confirm that RET fusions are clinically targetable alterations, placing them in the company of activating EGFR/ALK/ROS1 alterations.”

RET fusions, rare genetic alterations of NSCLC, occur in roughly 2% of NSCLC cases. Up to 50% of these cancers can spread to the brain.

LOXO-292 was well-tolerated by patients. A safety analysis that included all 531 patients enrolled in the trial showed that nine patients stopped treatment because of a therapy-related side effect. The most common side effects included dry mouth, diarrhea, hypertension, increased liver enzymes, fatigue, constipation and headache.