RATIONALE

1. RATIONALE METHODS Although extreme free light chains ratio (eFLCr: < 0.03 or > 32) and ISS have been found to be prognostic factors for survival in newly diagnosed multiple myeloma (MM), their usefulness in relapsed/refractory myeloma have not been explored so far. We explored the impact of age, ISS stage, eFLCr, cytogenetics and duration of first remission on survival parameters in 87 patients with relapsed/refractory MM treated within controlled trials with regimens including: CHARACTERISTICS OF 87 PATIENTS RESPONSE TO THERAPY ACCORDING TO FLCr Age PS ≥ 2 ISS 2-3 Free light chain monoclonality k l FLC ratio value Extreme FLC ratio Renal failure Unfavourable cytogenetics b2 microglobulin (mg/l)  3.5 Albumin (g/dl)  3.5 g/dl Disease status relapse refractory Prior chemotherapy lines > 2 Prior PSCT First remission duration < 12 months No (%) 31 (36) 60 (69) 56 (64) 31 (36) 42 (48) 8 (9) 24 (54) 42 (52) 36 (46) 68 (78) 19 (22) 28 (32) 51 (59) 38 (44) Median (range) 65 (31-82) 8.3 (0-14200) 3.6 (0.2-21.5) 3.6 (2.4-4.5) Response CR  VGPR  PR FLCr <0.03 or >32 No (%) 5 (12) 20 (47.5) 24 (57) FLCr 0.03-32 No (%) 13 (29.5) 20 (45.5) 28 (62) UNIVARIATE ANALYSIS FOR PFS Age > 65 (HR=1.5; p=0.433) ISS stage 2-3 (HR=1.7; p= 0.078) eFLCr (HR=2.0; p= 0.020) Unfavorable FISH (HR=1.3; p= 0.345) First remission < 12 months (HR=1.6; p=0.083) MULTIVARIATE ANALYSIS FOR PFS eFLCr: HR= 1.9 (95%CI= 1.2-3.4); p= 0.030) p= 0.030 PFS FLCr 0.03-32 median = NR OS FLCr< 0.03 or >32 median = 17 months EXTREME SERUM FREE LIGHT CHAINS RATIO IS AN INDEPENDENT PROGNOSTIC FACTOR FOR PROGRESSION IN RELAPSE/REFRACTORY MULTIPLE MYELOMA M. Offidani1, L. Corvatta2, S. Gentili1, A. Savini1, C. Polloni1, M. Brunori2, M. Catarini2, G. Visani2, F.Alesiani2, A. Samori2, M. Ferranti2, P. Fraticelli2, B. Amoroso3, P. Leoni1 1Clinica di Ematologia Azienda Ospedaliero-Universitaria, Ospedali Riuniti Ancona; 2Marche Multiple Myeloma Network, GEMaMM, Italy and 3Scientific Director Freelite Italy, The Binding Site, Birmingham, UK ThaDD (8%) ThaDD-V (36%) EDA-V (40%) RD (16%) FLCr 0.03-32 No (%) 13 (29.5) 20 (45.5%) 28 (62) p 0.028 0.468 0.542 FLCr 0.03-32 median = 22 months p= 0.019 FLCr< 0.03 or >32 median = 10 months • CONCLUSIONS • As well as patients with newly diagnosed MM, those with advanced disease can be usefully stratified according to eFLCr • The FLCr should be included in the work-up of patients with relapsed/refractory disease since it seems helpful in tailoring treatment