Six fire engines and around 40 firefighters tackled a fire at a semi-detached house on New Road in Dagenham.
Part of the ground floor was damaged by the fire. Three people left the building before the Brigade arrived and were taken to hospital by London Ambulance Service.
Control Officers took the first of three calls regarding the fire at 0116 and mobilised crews from Dagenham and Barking fire stations to the scene. The incident was over for firefighters at 0217.
The cause of the fire is under investigation.