TREATMENT OF CANCER-RELATED THROMBOCYTOPENIA BY LOW-DOSE SUBCUTANEOUSINTERLEUKIN-2 PLUS THE PINEAL HORMONE MELATONIN - A BIOLOGICAL PHASE-II STUDY

Despite the platelet production in response to IL-2, cancer immunother apy with IL-2 tends to induce thrombocytopenia, which probably depends on an enhanced peripheral destruction. On the basis of our previous s tudies, this effect may be neutralized by a concomitant administration of the pineal hormone melatonin (MLT). This study was performed to in vestigate the influence of an immunotherapeutic combination with low-d ose IL-2 and MLT on platelet number in advanced cancer patients showin g persistent thrombocytopenia. The study included 14 advanced solid tu mor patients, affected by thrombocytopenia due to different causes (po rtal hypertension: 9; previous chemotherapies: 3 DIC: 2). IL-2 was inj ected at 3 million IU/day subcutaneously for 6 days/week for 4 weeks, in association with MLT (40 mg/day orally). A normalization of platele t number occurred in 10/14 (71%) patients, and platelet mean number si gnificantly increased on treatment. No important therapy-related toxic ity was observed This preliminary study would suggest that the concomi tant administration of MLT is able not only to neutralize IL-2-induced thrombocytopenia, but also to increase platelet number in thrombocyto penic cancer patients.