Thalidomide maintenance treatment increases progression-free but not overall survival in elderly patients with myeloma

Background Thalidomide maintenance therapy after stem cell transplantation resulted in increased progression-free survival and overall survival in a few trials, but its role in non-transplant eligible patients with multiple myeloma remains unclear. This study assessed the impact of thalidomide-interferon in comparison to interferon maintenance therapy in elderly patients with multiple myeloma. Design and Methods Of 289 elderly patients with multiple myeloma who were randomized to thalidomide-dexamethasone or melphalan-prednisolone induction therapy, 137 finally completed 9 cycles of induction therapy with stable disease or better and thereby qualified for maintenance treatment. Of these, 128 have been randomized to either thalidomide-interferon or interferon alone. Primary study endpoints were progression-free survival and response rates; secondary endpoints were overall survival, toxicity and quality of life. Results Thalidomide-interferon maintenance therapy led to a significantly longer progression-free survival compared to interferon (27.7 vs. 13.2 months, P=0.0068), but overall survival was similar in both groups (52.6 vs. 51.4 months, P=0.81) and did not differ between patients aged 75 years or older, or younger patients (P=0.39). Survival after disease progression tended to be shorter in patients on thalidomide-interferon maintenance therapy (P=0.056). Progression-free survival and overall survival tended to be shorter in patients with adverse cytogenetic (FISH) findings compared to the standard risk group but differences were not significant (P=0.084 and P=0.082, respectively). Patients on thalidomide-interferon presented with more neuropathy (P=0.0015), constipation (P=0.0004), skin toxicity (P=0.0041) and elevated creatinine (P=0.026). Conclusions Thalidomide plus interferon maintenance therapy increased progression-free survival but not overall survival and was associated with slightly more toxicity than maintenance with interferon alone.