Natera, Inc. and Exelixis, Inc. have entered into a partnership that will embed Natera’s Signatera™ circulating tumor DNA assay into the Phase 3 STELLAR‑316 trial of Exelixis’s oral kinase inhibitor zanzalintinib for patients with resected stage II/III colorectal cancer. The collaboration will use Signatera to identify patients who are molecular‑residual‑disease (MRD) positive after definitive therapy and to monitor treatment response, allowing the trial to begin enrollment in mid‑2026.
The Signatera assay is a tumor‑informed ctDNA test that has been validated in colorectal cancer, most notably in the CALGB/SWOG 80702 study where MRD‑positive patients benefited from adjuvant therapy. By leveraging this technology, the partnership offers a precision‑guided therapeutic strategy for a patient group that currently has no approved post‑surgery treatment options, potentially transforming the standard of care for high‑risk colorectal cancer patients.
For Exelixis, the partnership accelerates the development of zanzalintinib in a new indication. The STELLAR‑316 design enrolls patients who are already receiving commercial Signatera testing, streamlining patient identification and expediting enrollment. The trial’s primary endpoint is disease‑free survival, with longitudinal ctDNA monitoring to assess early treatment response and guide clinical decisions.
The collaboration expands Natera’s clinical trial footprint and positions its assay as a key companion diagnostic in a major oncology indication, while giving Exelixis a faster path to market for zanzalintinib in colorectal cancer. Together, the companies aim to address an unmet need in a high‑risk population, potentially creating a new therapeutic paradigm and opening significant revenue opportunities for both firms.
"Patients with colorectal cancer who are MRD‑positive following definitive therapy face a high risk of recurrence, underscoring the urgent need for new treatment options that can help prevent clinical metastatic progression," said Dana T. Aftab, Ph.D., Executive Vice President of Research and Development at Exelixis. "STELLAR‑316 is our second pivotal trial of zanzalintinib in patients with CRC and represents our continued commitment to addressing unmet needs in this patient population by conducting rigorous trials with the potential to improve standards of care."
"We are excited to collaborate with Natera on STELLAR‑316, which, if successful, could make zanzalintinib the first MRD‑guided treatment for these patients. Leveraging Signatera to inform trial enrollment will help identify high‑risk patients earlier, enabling intervention when disease burden is lower and potentially improving clinical outcomes," added John Simmons, Ph.D., Global Vice President of Biopharma at Natera.
The content on BeyondSPX is for informational purposes only and should not be construed as financial or investment advice. We are not financial advisors. Consult with a qualified professional before making any investment decisions. Any actions you take based on information from this site are solely at your own risk.