The present invention relates to a combination for the treatment of cancer wherein the combination exhibits a synergistic effect. The combination comprises radiation and at least one cyclin dependent kinase (CDK) inhibitor selected from the compounds of formula I or a pharmaceutically acceptable salt or a solvate thereof. The present invention also relates to a method for the treatment of cancer, which method comprises administering to a patient in need of such a treatment, a therapeutically effective amount of the combination. The present invention also relates to the use of a CDK inhibitor selected from the compounds of formula I as a radiosensitizer that enhances the efficacy of radiotherapy for the treatment of cancer, particularly head and neck cancer.
