A new drug to treat lung cancer caused by a specific genetic mutation has been approved by the US Food and Drug Administration. Lumakras (sotorasib) has been authorised for patients with non-small cell lung cancer whose tumours have a KRAS G12C mutation and who have received at least one prior systemic therapy. This is the first approved targeted therapy for tumours with any KRAS mutation. KRAS G12C mutations represent about 13% of all mutations in non-small cell lung cancers.