The FDA granted breakthrough therapy designation to LOXO-292, a selective RET inhibitor, for the treatment certain patients with RET-altered non-small cell lung cancer or medullary thyroid cancer, according to the agent’s manufacturer.

The designation includes patients with RET-fusion positive NSCLC who have progressed on platinum-based chemotherapy and a PD-1 or PD-L1 inhibitor, and patients with RET-mutant thyroid cancer who have progressed following prior treatment and have no alternative treatment options.

The FDA based the breakthrough designation of LOXO-292 (Loxo Oncology) on the ongoing phase 1/phase 2 LIBRETTO-001 clinical trial of patients with RET-altered advanced solid tumors.

“We look forward to working with FDA to streamline the development of LOXO-292 in the two patient populations that have comprised the bulk of our initial clinical trial enrollment,” Josh Bilenker, MD, CEO of Loxo Oncology, said in a company-issued press release. “Given the many available therapies for non-small cell lung cancer and medullary thyroid cancer, we are pleased that LOXO-292 has shown encouraging data in refractory patients and hope to demonstrate the full potential of this treatment in additional populations over time.”