Experimental Drug LOXO-292 Shrinks RET-Positive Tumors

The experimental drug LOXO-292 (now called selpercatinib) shrank tumors in nearly 70% of lung tumors with the RET mutation, according to data from the drug’s manufacturer Eli Lilly and Co., that was presented at the World Conference on Lung Cancer in Barcelona, Spain.

The drug is intended for patients with RET abnormalities, which occur in about 2% of non-small cell lung cancers (NSCLCs), 10% to 20% of papillary thyroid cancers, and 60% of medullary thyroid cancers.

The data included the first 105 patients with RET-positive NSCLC who were previously treated with chemotherapy.

Significant tumor shrinkage observed

As of June 17, 68% of patients who received LOXO-292 saw a reduction in tumor size of 30% or more. In 11 patients whose cancers had spread to the brain, 91% experienced tumor shrinkage of 30% or more.

In a safety analysis of 531 patients, nine (1.7%) discontinued therapy due to treatment-related adverse events (AEs). The most common AEs were dry mouth, diarrhea, high blood pressure, increased liver enzymes, fatigue, constipation, and headache.

Preliminary data from 34 patients with RET-positive lung cancer who had not received prior treatment showed that 85% had significant tumor shrinkage.

Eli Lilly and Co., plans to file for Food and Drug Administration approval later this year.