Impact of early response to sequential high-dose chemotherapy on outcome of patients with advanced myeloma and poor prognostic features

We report the results of a dose-intense chemotherapy regimen designed to rapidly induce remissions in patients with advanced multiple myeloma (MM). Patients received VAD for 3-6 cycles depending on response kinetics. This was followed by three sequential cycles of cyclophosphamide (CTX) at 3 g/m² every 15 days with G-CSF support. 71% of these patients had stage IIIa, 23% had renal failure. The median age was 58, median β-2 microglobulin 4.6 and median albumin was 3.5, indicating poor prognosis. Of 35 patients, 66% achieved a complete response (CR) (SWOG). Six patients (18%) had a partial response. Fifty percent of the patients with renal failure recovered their kidney function. High-dose CTX contributed to tumor-mass reduction particularly in patients presenting with high-tumor burden. Tumor-mass reduction following three pulses of dexamethasone (4 days each) is significantly higher than with one pulse (p < 0.005). While high β-2 microglobulin and LDH levels (p < 0.05) were associated with poor outcome, patients who responded faster to chemotherapy had a longer survival (p = 0.005). We conclude that this regimen is safe and effective. A rapid response may be useful in selecting patients who may benefit from further high dose chemotherapy and stem cell support.