Terns Pharmaceuticals Inc. (NASDAQ:TERN) announced on Monday that the U.S. Food and Drug Administration has granted Breakthrough Therapy Designation to TERN-701 for the treatment of adult patients with chronic myeloid leukemia (CML) in the chronic phase who do not carry the T315I mutation and who have been treated previously with two or more tyrosine kinase inhibitors (TKIs).
TERN-701 is described by the company as an oral allosteric inhibitor of BCR::ABL1. The FDA designation was awarded on the basis of interim results from the ongoing Phase 1/2 CARDINAL clinical trial. CARDINAL enrolled patients with chronic phase CML who had been treated with at least one prior TKI and who experienced either treatment failure, a suboptimal response, or intolerance to prior therapy.
According to the trial data cited by Terns, the study showed both major molecular response (MMR) and deep molecular response (DMR) rates at the 24-week assessment. Responses were observed in patients who had a high disease burden at baseline and among individuals who had already received multiple lines of prior therapy.
On safety, the company reported that the majority of treatment-emergent adverse events (TEAEs) observed in the CARDINAL trial were low grade. There was a low incidence of severe adverse events and a low rate of treatment discontinuations attributed to adverse effects.
The Breakthrough Therapy Designation is a regulatory pathway intended to expedite the development and FDA review of medicines that target serious conditions or address unmet medical needs. The designation is intended to facilitate more intensive guidance from the FDA and potentially faster development timelines for qualifying therapies.
Terns' announcement focuses on the specific adult CML population without the T315I mutation who have previously been exposed to multiple TKIs, and it ties the regulatory recognition directly to the interim CARDINAL data showing molecular responses at week 24 alongside a generally manageable safety profile.