Natera (NTRA) has received a Category 1 recommendation from the National Comprehensive Cancer Network for Signatera-guided adjuvant atezolizumab treatment in patients with muscle-invasive bladder cancer, the company said Tuesday.

The company said the NCCN updated its Clinical Practice Guidelines in Oncology for Bladder Cancer to include tumor-informed multiplex PCR-NGS circulating tumor DNA-based molecular residual disease testing in the treatment algorithm for patients with muscle-invasive bladder cancer.

The recommendation follows the US Food and Drug Administration approval of Signatera CDx as a companion diagnostic to identify patients with muscle-invasive bladder cancer who are ctDNA-MRD positive and may benefit from adjuvant immunotherapy treatment in May, Natera said.

Shares of Natera were down more than 1% in Tuesday pre-bell activity.