The fire was reported at 4:25 a.m. in the 2600 block of North Broad Street.
Firefighters say they arrived to find flames coming from the fourth floor of the building.
A number of people had to be evacuated.
One of the victims injured was burned, while the other was injured in a fall. Both were reported to be in stable condition.
Traffic was being detoured while firefighters remained on the scene.
There was no immediate word on a cause of the fire.