Four fire engines and around 20 firefighters and officers were called to a fire at a block of maisonettes in Anglo Road in Bow.
Part of a maisonette on the first floor was damaged by fire.
A man, a woman and two children left the property before the arrival of the Brigade. One man was treated at the scene for smoke inhalation by London Ambulance Service crews. Two further adults were assisted from a maisonette on the third floor by firefighters wearing breathing apparatus.
The Brigade was called at 0810 and the fire was under control at 0946. Fire crews from Bethnal Green, Homerton and Stratford fire stations attended the scene.
The cause of the fire is under investigation.