Such bends are possible with a maximum diameter of 42 mm

IMPORTANT:
If the handrail is curved lengthwise, as in landings of spiral staircases, it must be bent using curved templates! To prevent spring-back´s after removal from the template, brackets must be placed at the beginning and end of the horizontal handrail part.

ALTERNATIVELY, there are stable, curved solutions without cuts at the transitions.
See the following link: Double curved handrails for intermediate platforms