Pokoradi, Alida

Abstract One potential approach to improve the results of autologous stem cell transplantation (ASCT) in multiple myeloma (MM) involves the use of more potent induction regimens; the achievement of deeper remission pre-ASCT should translate into longer progression-free (PFS) and overall survival (OS). To evaluate this hypothesis, we assessed the influence of the percent reduction in serum monoclonal protein (M protein) pre-ASCT in patients (pts) treated with dexamethasone-based regimens (most often VAD) on the best response, PFS and OS achieved after ASCT. Between 2000–2006, 376 pts with IgG (267) or IgA (109) non-progressive MM underwent ASCT. Median age was 59 (21–73) yrs; 60% were male. The median hemoglobin at diagnosis was 103 g/L, creatinine 98 μmol/L, β2-microglobulin 241 nmol/L and albumin 35 g/L. Maintenance therapy was given to 84 (22%) after ASCT and consisted of corticosteroids in 29, thalidomide in 10, both in 41 and other regimens in 4 pts. Patients were divided into 4 groups based on the per cent reduction in M protein after induction therapy: group A, ≥ 99%; group B, 90–98%; group C, 50–89%; group D, < 50%. Post-ASCT responses included complete remission (CR), very good partial remission (VGPR) (≥ 90% reduction in M protein), PR (≥ 50% reduction) and stable disease (SD). Median follow-up from diagnosis is 37.4 mos and from ASCT 24.1 mos. For all pts, the median OS from diagnosis is 90.8 mos (95% CI 73.9–129.1 mos) and from ASCT 63.9 mos (95% CI 50.8–69.4 mos), while the median PFS from ASCT is 21.3 mos (95% CI 19.1–23.3 mos). Maintenance therapy had no significant effect on PFS (p=0.49) or OS (p=0.59). The post-ASCT results in evaluable patients according to the percent reduction in M protein after induction therapy are summarized below. We conclude: High-grade remissions after dexamethasone-based induction therapy are uncommon, with only 2% achieving ≥ 99% and 13% achieving 90–98% reduction in serum M protein; post-ASCT CR and VGPR rates were higher in these 2 groups; there was no significant difference in PFS or OS-based on protein response prior to transplant; whether newer induction regimens, which incorporate novel agents and which produce more CRs and VGPRs before ASCT, will confer better PFS and OS post-ASCT will be of great interest. Table 1 Group N CR (%)1 VGPR (%)1 PR (%)1 SD (%)1 Median PFS (mo)2 Median OS (mo)3 1p<0.001;2p=0.77;3p=0.79 A 7 50 50 Not reached Not reached B 47 19 64 17 23.3 Not reached C 232 14 17 68 1 20.7 59.1 D 87 11 7 54 28 21.1 69.4 Figure Figure Figure Figure