Natera Announces Successful Readout of Randomized, Phase III CALGB (Alliance) / SWOG 80702 Clinical Trial in Colorectal Cancer

Readout of ~1K patients at ASCO GI 2025 demonstrates that Signatera™ positive patients treated with both chemotherapy and celecoxib had a 40% improvement in overall survival versus chemotherapy alone

Additional ASCO GI poster highlights data from the ALTAIR clinical trial, showing significant clinical benefit in patients with stage IV colorectal cancer who were treated with Trifluridine/Tipiracil (FTD/TPI)

AUSTIN, Texas,--(BUSINESS WIRE)-- Natera, Inc. (NASDAQ: NTRA), a global leader in cell-free DNA and genetic testing, announced new data from the randomized, Phase III CALGB (Alliance) / SWOG 80702 study. The study will be presented today, Jan. 25, 2025 as a late-breaking oral presentation at the 2025 American Society of Clinical Oncology’s Gastrointestinal Cancers Symposium (ASCO GI) in San Francisco, CA.

This first-of-its-kind study evaluated whether Signatera-positive patients benefit from an escalation in adjuvant treatment. In the trial, Signatera was used to evaluate the benefit of adding celecoxib, a non-steroidal anti-inflammatory drug (NSAID), to standard of care (SOC) adjuvant chemotherapy with FOLFOX in the management of stage III colorectal cancer (CRC). The pre-specified analysis included approximately 1,000 patients with available post-surgical plasma samples, who were randomized to receive FOLFOX (+/-) celecoxib.

Key findings included:

• Signatera-positivity after surgery was predictive of a disease-free survival (DFS) and overall survival (OS) benefit with the addition of celecoxib to adjuvant FOLFOX. The addition of celecoxib to SOC chemotherapy significantly improved DFS compared to placebo (HR 0.55, 95% CI 0.39-0.80; p=0.001) among Signatera-positive patients with a three-year DFS of 44.1% versus 26.6%. Similar results were seen for OS (HR 0.58, 95% CI 0.38-0.90; p=0.013). No survival benefit was seen by adding celecoxib to chemotherapy in Signatera-negative patients.
• Signatera status after surgery and prior to starting adjuvant therapy was highly predictive of recurrence. Signatera-positivity was significantly associated with worse DFS (HR 7.14, 95% CI: 5.54-9.21; p