The present invention relates to a method for determining a subject's resistance to treatment with 2,2-dimethyl-N-((S)-6-oxo-6,7-dihydro-5H-dibenzo[b,d]azepin-7-yl)-N′-(2,2,3,3,3-pentafluoro-propyl)-malonamide by measuring the levels a biomarker or biomarkers present in a biological sample obtained from the subject, the biomarker being IL6 and/or IL8. The present invention also relates to a combination therapy for a patient suffering from a proliferative disorder comprising administering to the patient 2,2-Dimethyl-N-((S)-6-oxo-6,7-dihydro-5H-dibenzo[b,d]azepin-7-yl)-N′-(2,2,3,3,3-pentafluoro-propyl)-malonamide and an anti-IL6 and/or an anti-IL8 agent.