Natera (NASDAQ:NTRA) announced a significant clinical breakthrough today, revealing that its pivotal Phase III ALTAIR trial successfully reached statistical significance following a reclassification of patient data.
The findings, to be presented at the 2026 ASCO Gastrointestinal Cancers Symposium (ASCO GI) on January 8–10, demonstrate that treating patients based on "molecular recurrence" (TOMR) can meaningfully delay the return of colorectal cancer (CRC).
The new analysis utilized a post-hoc blinded central radiographic review, which reclassified a subset of cases.
This adjustment shifted the study from a previously reported numerical trend to a statistically significant disease-free survival (DFS) benefit.
In Signatera-positive patients across stages I–IV, those treated with trifluridine/tipiracil (FTD/TPI) achieved a median DFS of 9.23 months compared to just 5.55 months for the placebo group (HR: 0.75, p=0.0406).
Beyond the ALTAIR results, Natera is introducing "Signatera velocity" as a new prognostic metric.
A large-scale study being presented alongside the trial data shows that patients whose circulating tumor DNA (ctDNA) levels doubled in one month or less faced a 40% shorter recurrence-free survival.
This rate of increase remained a significant predictor of relapse regardless of whether patients received adjuvant chemotherapy, highlighting the ability of ctDNA dynamics to provide real-time biological insight into tumor aggressiveness.