Alliance Foundation Trials (AFT) and Natera, Inc. (NASDAQ: NTRA) announced the launch of AFT-70 NAVIGATE, a randomized phase III clinical trial evaluating a molecular residual disease (MRD)-guided treatment strategy for patients with intermediate and high-risk ER-positive/HER2-negative early breast cancer.

The trial is sponsored and led by AFT, with collaboration and co-funding from Natera and Genentech, a member of the Roche Group. It will use Natera's Signatera Genome MRD test, paired with giredestrant, Genentech's investigational oral selective estrogen receptor degrader (SERD), to guide decisions about CDK4/6 inhibitor use.

AFT expects to enroll more than 2,000 patients with stage II-III ER-positive/HER2-negative breast cancer across approximately 200 sites in the U.S. and internationally. Patients with no detectable MRD after completing standard-of-care treatment will be randomly assigned to one of two arms: a control arm receiving standard endocrine therapy plus upfront CDK4/6 inhibition, or an investigational arm receiving giredestrant monotherapy with CDK4/6 inhibition added only if Signatera becomes positive. The primary endpoint is non-inferiority in four-year distant recurrence-free survival.

Giredestrant was selected as the endocrine therapy backbone based on results from the phase III lidERA trial, which showed a statistically significant improvement in invasive disease-free survival compared with standard endocrine monotherapy. Signatera was selected based on clinical evidence from the AFT-05 PALLAS and MonarchE trials, and its analytical sensitivity below 1 parts per million.

"By using MRD technology to guide treatment decisions, this trial has the potential to transform care for eligible breast cancer patients and individualize treatment intensity," said Evanthia Galanis, M.D., D.Sc., president of Alliance Foundation Trials.

The trial aims to determine whether MRD-guided monitoring can identify patients who may safely forgo CDK4/6 inhibitor therapy, potentially reducing treatment-related side effects for those patients.