Biotechnology company Genentech, a member of the Roche Group (SIX: RO, ROG) (OTCQX: RHHBY), announced on Friday that the US Food and Drug Administration (FDA) has approved Tecentriq (atezolizumab) and Tecentriq Hybreza (atezolizumab and hyaluronidase-tqjs) in combination with fluoropyrimidine and oxaliplatin chemotherapy for the adjuvant treatment of stage III deficient mismatch repair (dMMR) colon cancer.

The approval, Tecentriq's 12th indication in the United States, is based on the Phase III ATOMIC study published in The New England Journal of Medicine, which found that adding Tecentriq to modified FOLFOX6 chemotherapy reduced the risk of disease recurrence or death by 50% compared with chemotherapy alone.

At 36 months, disease-free survival reached 86% among patients receiving the combination therapy, compared with 76% for those treated with chemotherapy alone. The safety profile was consistent with previous studies.

This approval establishes the first approved adjuvant immunotherapy regimen for stage III dMMR colon cancer, addressing a patient population with a higher tumour mutation rate and potential responsiveness to immunotherapy.

Nearly 25% of colon cancers are diagnosed at stage III, and approximately 30% of patients at this stage experience recurrence within five years. Around 15% of colon cancer patients have dMMR or microsatellite instability-high tumours.