A bit more complicated, but here I go.
The subject is placed in front of the camera with subject in front of background. Ground ground may have been digitally inserted, having used a green screen, or it may have been the original background, but would have been a paper that was intented to look that way (meaning the camera's plane of focus has nothing to do with the blur.) The background was equally and fully lit.
A small specular, spotlight was placed above the subject, slightly behind (facing downward angel) with a blue gel to cool the subject.
A flash was placed at 2 p.m., again above the subject, (downward angel towards subject) with a diffuser over it or a translucent sheet in front of it to soften the light. A gel of soft blue hue may have been used.
The main source of light was placed at 7 p.m. above the subject, but lower than the previous two. Again, a diffuser or translucent was used as a "go-bo" Note, the intensity of this light and the one placed at 2 p.m. were probably at equal intensity, if not one stop different (this one would have been the greater)
A fill-light was used at the 7 p.m. position, but dropped below the subject (clam shell lighting) to be used as a fill. Harsh lighting was avoided and this source is less intense than the main source, by 1 or two stops (if not placed further from subject.)
A white bounce may have been used directly to the right of the camera as a fill.