Four fire engines and 21 firefighters and officers were called to a fire at a shop with flats above in Green Lane in Dagenham.
Part of the first floor was damaged by fire.
Two people left the property before the arrival of the Brigade.
Three people were led to safety from the first floor by firefighters and two people were rescued by ladder from the loft conversion. They were treated at the scene for smoke inhalation by London Ambulance Service crews.
The Brigade was called at 0716 and the fire was under control at 0826. Fire crews from Dagenham and Ilford fire stations attended the scene.
The cause of the fire is under investigation.