2 lights, as shown.
It's not the lights that are the most important thing. It's how you control them. Small soft boxes might do it, better would be hoods with a scrim over them. The one on the right might of been further up to the girls left, just a quick illustration.
The most vital element is the lack of bounce. so surrounding the whole thing there needs to be something to adsorb light, including the ceiling. Otherwise the light bounces around and the effect of the shadows are lost.
If you notice there's more light at the girls feet than her head, so the 2 sources of light will be around 4-5 feet off the ground.
Who ever shot this might of done 20 or more test shots to get it right, in the old days they would of been on Polaroid and driven us to despair getting it right.