Four fire engines and around 25 firefighters were called to a fire at a residential property on Vine Gardens in Ilford.
Half of the ground floor and part of the first floor was damaged by fire.
One man was rescued from a first-floor window by firefighters via a short extension ladder. A second man was rescued by firefighters wearing breathing apparatus from the ground floor. They were both taken to hospital along with three further people to be treated for smoke inhalation.
The Brigade received the first of six calls at 1448 and Control Officers mobilised crews from Ilford, Dagenham and Plaistow fire stations to the scene. The fire was extinguished by 1620.
The cause of the fire is under investigation.