Four fire engines and around 25 firefighters were called to a flat fire on Vandome Close in Canning Town.
Half of a three-roomed flat on the ground floor of the building was damaged by fire. There were no reports of any injuries.
The Brigade was called at 0311 and the fire was under control by 0348. Fire crews from Plaistow, Poplar and Stratford fire stations attended the scene.
The cause of the fire is under investigation.