English to French Medical Medical: Pharmaceuticals protocol synopsis - clinical trial on lung cancer

This is a standard clinical trial on lung cancer comparing a drug A to a [drug B + carboplatine or cisplatine].

I fail to understand the meaning of "crossover" in the following context:
"Given the toxicities associated with platinum-based chemotherapies (neutropenia, anemia) and the requirement for pre-medications, this will be an open-label study. No **crossover** will be allowed from the control arm (carboplatin/cisplatin + B) to the experimental arm (drug A)."

This is the one and only occurrence of the term crossover. Nothing simliar was discussed earlier in the synopsis, unfortunately.

I suspect it has to do with "crossover" like in "crossover" study (thus "croisement" would do) but I would need confirmation of this.
Thank you!