Modified high-dose melphalan and autologous SCT for AL amyloidosis or high-risk myeloma: analysis of SWOG trial S0115

In multiple myeloma, combination chemotherapy with melphalan plus prednisone is still regarded as the standard of care in elderly patients. We assessed whether the addition of thalidomide to this combination, or reduced-intensity stem cell transplantation, would improve survival. Between May 22, 2000, and Aug 8, 2005, 447 previously untreated patients with multiple myeloma, who were aged between 65 and 75 years, were randomly assigned to receive either melphalan and prednisone (MP; n=196), melphalan and prednisone plus thalidomide (MPT; n=125), or reduced-intensity stem cell transplantation using melphalan 100 mg/m2 (MEL100; n=126). The primary endpoint was overall survival. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00367185. After a median follow-up of 51.5 months (IQR 34.4-63.2), median overall survival times were 33.2 months (13.8-54.8) for MP, 51.6 months (26.6-not reached) for MPT, and 38.3 months (13.0-61.6) for MEL100. The MPT regimen was associated with a significantly better overall survival than was the MP regimen (hazard ratio 0.59, 95% CI 0.46-0.81, p=0.0006) or MEL100 regimen (0.69, 0.49-0.96, p=0.027). No difference was seen for MEL100 versus MP (0.86, 0.65-1.15, p=0.32). The results of our trial provide strong evidence to indicate that the use of thalidomide in combination with melphalan and prednisone should, at present, be the reference treatment for previously untreated elderly patients with multiple myeloma.

The role of maintenance therapy in multiple myeloma is controversial. Recent studies have shown an improvement in both progression-free and overall survival for patients receiving maintenance treatment with a combination of interferon and glucocorticoids, compared with interferon alone. The role of glucocorticoids alone as maintenance therapy has not been previously addressed. We compared alternate-day, oral prednisone at 2 different dose levels (10 mg versus 50 mg) for remission maintenance among previously untreated myeloma patients following a response to induction with standard-dose vincristine, doxorubicin, and dexamethasone with prednisone (VAD-P) or VAD-P plus quinine (VAD-P/Q). There were 250 eligible patients registered on Southwest Oncology Group study 9210 and randomized to receive VAD-P or VAD-P/Q. There were 125 patients achieving at least a 25% tumor reduction following induction therapy who were randomized to either physiologic (10 mg) or pharmacologic (50 mg) doses of alternate-day, oral prednisone until disease progression. At the time of study entry, patient characteristics were similar in VAD-P and VAD-P/Q patients and in the 2 arms randomized to maintenance therapy. After a median follow-up of 53 months, there was no difference in either progression-free or overall survival between the 2 induction regimens. However, from the time of maintenance randomization, both progression-free (14 versus 5 months; P =.003) and overall survival (37 versus 26 months; P =.05) were significantly improved in patients receiving 50 mg as compared with 10 mg alternate-day prednisone. There was no difference in treatment-related adverse events between the groups. Thus, 50 mg, oral, alternate-day prednisone is effective maintenance treatment for multiple myeloma patients who achieve a response to induction chemotherapy. (Blood. 2002;99:3163-3168)

The feasibility and efficacy of autologous stem cell transplantation (auto-SCT) in patients aged > or = 70 years was analysed. Newly diagnosed (n = 34) and refractory multiple myeloma (n = 36) patients were studied. The median age was 72 years (range: 70-82.6). CD34+ cells were mobilized with chemotherapy and granulocyte colony-stimulating factor (G-CSF) (n = 35) or G-CSF alone (n = 35), yielding medians of 11.8 x 10(6) versus 8 x 10(6) cells/kg respectively (P = 0.007). Because of excessive mortality (16%) in the first 25 patients who received melphalan 200 mg/m2 (MEL-200), the dose was subsequently decreased to 140 mg/m2 (MEL-140). Median times to absolute neutrophil count (ANC) > 0.5 x 10(9)/l and to platelets > 20 x 10(9)/l were 11 and 13 d respectively. Thirty-one patients (44%) received tandem auto-SCT. Complete remission (CR) was 20% after the first SCT and 27% after tandem SCT. Median CR duration was 1.5 years and was significantly longer for patients with < or = 12 months of prior chemotherapy (2.6 versus 1.0 years, P = 0.0008). The 3-year event-free survival (EFS) and overall survival (OS) (+ standard error, SE) were projected at 20% + 9% and 31% + 10% respectively. Tandem SCTs positively affected EFS (4.0 versus 0.7 years; P = 0.003) and OS (4.0 versus 1.4 years; P = 0.02) compared with single auto-SCT. In conclusion, MEL-140 is less toxic and appears equally as efficacious as MEL-200 in elderly patients. The benefits of tandem SCT in this patient population need further evaluation in a randomized trial.