Lilly's RET drug, nabbed in Loxo buyout, hits 68% ORR in lung cancer

BARCELONA—Now within the ownership of Eli Lilly, Loxo Oncology has presented new data at the World Conference on Lung Cancer for its RET inhibitor LOXO-292 as it plots an NDA in the coming months.

The drug, aka selpercatinib, showed a 68% objective response rate (ORR) in heavily pretreated RET fusion-positive non-small cell lung cancer (NSCLC) in the phase 1/2 LIBRETTO-001 trial.

This is compared to data presented at several U.S. cancer congresses last year when the drug (then still owned by Loxo) hit a similar overall response rate, which is impressive, especially given these patients had already been through the ringer with other treatments.

The latest data drop also showed an 85% ORR in treatment-naive RET fusion-positive NSCLC patients for Lilly’s RET signaling inhibitor, which is also in trials for thyroid cancer. Selpercatinib, in addition, hit a central nervous system ORR of 91%, and has a median progression-free survival rate of more than 18 months, Lilly told FierceBiotech ahead of the results presented today in Barcelona, Spain.

In terms of safety, the FDA breakthrough-tagged drug also appeared to perform well, with only nine patients (1.7%) stopping treatment as a result of toxicity out of more than 500 across the study.

RELATED: ASCO: Loxo sees boosted response rates with LOXO-292

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

“We are encouraged by these data as there is currently an unmet need to provide genomically tailored therapy to patients with RET fusion-positive NSCLCs.”

Josh Bilenker, M.D., interim senior vice president of oncology research and early phase development at Lilly and CEO of Loxo Oncology, said these data would form the basis of its NDA with the U.S. regulator, planned before the end of the year.

Lilly/Loxo aren’t the only players in this space, with Blueprint Medicines and Stemline Therapeutics also working on rival RET drugs, namely pralsetinib and SL-1001, respectively. Lilly, though, via its $8 billion Loxo buyout, seems to be ahead of these two, for once at the forefront of oncology R&D.

Lilly's shares were up by more than 2.5% on early trading this morning on the news.