Oral Melphalan, Prednisone and Thalidomide for Multiple Myeloma.

In newly diagnosed multiple myeloma (MM) patients, the combination melphalan, prednisone and thalidomide (MPT) induces a fast tumor response with a high response rate, but evidence that this translate into improved outcome is limited. This multicenter trial compared the efficacy and the toxicity of oral MPT with oral melphalan and prednisone (MP) in previously untreated patients. From January 2002 to December 2004, we randomised 255 patients, who were older than 65 years of age (median age 72). Data analysis was performed on July 2005. The MPT regimen included oral melphalan (4 mg/m² for 7 days) and prednisone (40 mg/m² 7 days) for six four week cycles plus thalidomide (100 mg per day continuously until any sign of relapse or progressive disease) The MP regimen was as MPT without thalidomide. Patients who were not assigned to receive thalidomide were permitted to cross over to receive thalidomide after relapse or disease progression. Patients treated with MPT experienced higher response rates and a longer time to progression (primary end points) than patients who did not receive thalidomide. The overall response rate was 76% for MPT and 48% for MP alone (P<0.0001), and the near complete response rates were 28% and 7%, respectively (P<0.0001). Median progression free survival in the MPT and in the MP groups was 33 months and 14 months, respectively (hazard ratio, 0.47; P<0.001). MPT increase median progression free survival by almost 19 months. The 2-yr survival rate was 82% in MPT patients and 65% in MP patients (hazard ratio, 0.68; P=0.2). In MPT group, 33 patients did not complete the 6 courses because of progression disease (9), toxicity (16), death (2), and withdrawal of consent or lost to follow-up (6). In MP group, 32 patients did not complete the 6 courses because of progression disease (19), toxicity (3), death (3), and withdrawal of consent or lost to follow-up (7). By looking at those patients who completed the assigned 6 cycles in both arms, the 2-yr survival rate was 90% in MPT patients and 71% in MP patients, the difference was statistically significant (hazard ratio, 0.39; P<0.01). Grade 3 or 4 adverse events were reported in 49% of patients treated with MPT and in 25% of those treated with MP: they included thromboembolism (12% versus 2% of patients), infections (10% versus 1%), peripheral neuropathy (10% versus 1%), and hematologic toxicity (22% versus 25%) respectively. In the first 64 patients who received MPT, grade 3–4 adverse events were reported in 58% of patients. In the last 65 MPT patients, the incidence of grade 3–4 adverse events was 40%. By comparing the first cohort with the second one, thromboembolism dropped from 22% to 3% (P<0.01) and neurotoxicity from 13% to 8% (P=NS), respectively. The oral MPT was superior to the standard MP in patients with newly diagnosed myeloma. The adequate mangement of side effects reduced toxicity.