Addition of thalidomide to oral melphalan/prednisone in patients with multiple myeloma not eligible for transplantation: Results of a randomized trial from the Turkish Myeloma Study Group

Abstract

The combination of melphalan-prednisone-thalidomide (MPT) has been investigated in several clinical studies that differed significantly with regard to patient characteristics and treatment schedules. This prospective trial differs from previous melphalan-prednisone (MP) vs. MPT trials by treatment dosing, duration, routine anticoagulation, and permission for a crossover. Newly diagnosed patients with multiple myeloma (MM) (n = 122) aged greater than 55 yr, not eligible for transplantation were randomized to receive 8 cycles of M (9 mg/m2/d) and P (60 mg/m2/d) for 4 d every 6 wk (n = 62) or MP and thalidomide (100 mg/d) continuously (n = 60). Primary endpoint was treatment response and toxicities following 4 and 8 cycles of therapy. Secondary endpoints were disease-free (DFS) and overall survival (OS). Overall, MPT-treated patients were younger (median 69 yr vs. 72 yr; P = 0.016) and had a higher incidence of renal impairment (RI, 19% vs. 7%, respectively; P = 0.057). After 4 cycles of treatment (n = 115), there were more partial responses or better in the MPT arm than in the MP arm (57.9% vs. 37.5%; P = 0.030). However, DFS and OS were not significantly different between the arms after a median of 23 months follow-up (median OS 26.0 vs. 28.0 months, P = 0.655; DFS 21.0 vs. 14.0 months, P = 0.342, respectively). Crossover to MPT was required in 11 patients, 57% of whom responded to treatment. A higher rate of grade 3-4 infections was observed in the MPT arm compared with the MP arm (22.4% vs. 7.0%; P = 0.033). However, none of these infections were associated with febrile neutropenia. Death within the first 3 months was observed more frequently in the MP arm (n = 8, 14.0%) than in the MPT arm (n = 2, 3.4%; P = 0.053). Long-term discontinuation and dose reduction rates were also analyzed (MPT: 15.5% vs. MP: 5.3%; P = 0.072). Although patients treated with MPT were relatively younger and had more frequent RI, better responses and less early mortality were observed in all age groups despite more frequent discontinuation.