A cutting tool assembly includes a tool body and a clamping mechanism for releasably clamping a cutting insert to the tool body. The clamping mechanism includes a rotatable cam member, a coupling member, a biasing spring and a clamping element. The rotation of the rotatable cam member in opposite senses results in the adjustment of the position of the coupling member in opposite directions, which results in a displacement of the clamping element, and therefore changing the locking position to a releasing position and vice versa.