Trethera wins FDA Fast Track for TRE-515 in KRAS G12C NSCLC

Trethera Corporation has received FDA Fast Track designation for TRE-515 in combination with KRAS G12C inhibitors for the treatment of G12C mutation-positive non-small cell lung cancer in patients previously treated with an anti-PD-(L)1 antibody and platinum-based chemotherapy. The privately held Los Angeles biotech said the designation reflects the unmet need in a patient population where response to KRAS inhibitor monotherapy remains incomplete and short-lived.

TRE-515 is an orally administered inhibitor of deoxycytidine kinase (dCK), the rate-limiting enzyme in the nucleoside salvage pathway. Trethera's hypothesis is that tumours treated with KRAS inhibitors may upregulate this pathway as a metabolic escape mechanism. In preclinical mouse models, fluorinated PET imaging showed persistent dCK activity in tumours following KRAS inhibitor treatment; subsequent TRE-515 dosing was reported to fully block that activity, providing a pharmacodynamic read-out for the biological rationale behind the combination.

Clinical and regulatory context

TRE-515 is currently in a first-in-human clinical trial, and the company said the compound has shown a favourable safety profile and early antitumour activity in that study, without releasing detailed data. The new Fast Track designation is the second Trethera has received for TRE-515: the FDA previously granted the same status for its use in metastatic castration-resistant prostate cancer. The compound also holds Orphan Drug designation for two autoimmune neurological conditions, suggesting the company is pursuing a broad metabolic-targeting strategy across oncology and immunology.

The designation follows a 2025 NIH grant of $2.7 million awarded to support preclinical evaluation of TRE-515 in combination with KRAS inhibitors. Fast Track status facilitates more frequent agency interaction and creates potential eligibility for Accelerated Approval and Priority Review, though neither is guaranteed.

Ken Schultz, chairman and chief executive, said the designation "further validates our strategy of combining dCK inhibition with targeted cancer therapies," adding that KRAS G12C inhibitors had transformed the NSCLC landscape while leaving resistance and incomplete responses as persistent clinical challenges.

Market landscape

NSCLC is one of the most intensely contested spaces in oncology. The KRAS G12C inhibitors sotorasib (Lumakras, Amgen) and adagrasib (Krazati, Mirati/Bristol Myers Squibb) are already approved, and a pipeline of next-generation KRAS inhibitors and combination regimens is in active development. Resistance to first-generation KRAS inhibitors is well documented, creating commercial and scientific appetite for agents that can prolong or deepen responses.

The metabolic-vulnerability approach Trethera is pursuing is less crowded than the signalling-pathway field, though a number of academic groups and early-stage companies are exploring nucleotide metabolism as a therapeutic target in solid tumours. Trethera's UCLA co-founder base gives it access to translational imaging expertise that underpins the PET biomarker strategy, which could differentiate its combination rationale if the first-in-human data hold up in larger cohorts.

Full clinical data from the ongoing trial, including response rates and any dose-expansion cohorts in the KRAS G12C population, will be the critical near-term catalysts for external validation. The company has not disclosed a timeline for Phase 2 initiation or a partnering strategy.