Eli Lilly and Co’s LOXO-292, a experimental cancer drug the company acquired in January as part of its $8 billion takeover of Loxo Oncology, shrank tumors in nearly 70% of advanced lung cancer patients whose tumors carried specific abnormalities in the RET gene.
The results, presented at the World Lung Conference on Lung Cancer in Barcelona, will support Lilly’s application for U.S. Food and Drug Administration approval later this year.
“At the beginning of this year, we put a bet on Loxo,” Dr. Daniel Skovronsky, Lilly’s chief scientific officer, said in a telephone interview. “The result today certainly validates that vet and exceeds what many people expected.”
Lilly’s drug, now called selpercatinib, is intended for patients with rare RET abnormalities. RET abnormailities occur in about 2% of non-small cell lung cancers. They also occur in 10 to 20% of papillary thyroid cancers and about 60% of medullary thyroid cancers. The first 105 patients with RET-fusion positive non-small cell lung cancers who had been previously treated with chemotherapy are included in the study. Many had tried and failed to respond to several other treatments as well.
As of the cut-off date of June 17, 2019, 68% of treated patients had significant tumor shrinkage. Significant shrinkage is defined as 30% or more. In 11 patients whose cancers had spread to the brain, 91% saw significant tumor shrinkage of 30% or more.
In a safety analysis of the whole study population of 531 individuals, nine patients, stopped the treatment. Drug-related side effects cited as reason. Dry mouth, diarrhea, high blood pressure, increased liver enzymes, fatigue, constipation and headache are the most common side effects..
The company also released preliminary data on 34 patients with RET-fusion positive lung cancer patients who had received no prior treatment. In this group, which has only been followed for about four months, 85% saw significant tumor shrinkage.
RET drug and ESMO
Lilly plans to present data on patients with two kinds of thyroid cancers that carry RET alterations at the European Society for Medical Oncology meeting later this month. The company will file for FDA-approval of the drug in all three indications by the end of this year.
Blueprint Medicines is developing a lung cancer drug targeting RET alterations. They plan to file for FDA approval in the first quarter of 2020.