1086P - Aggregated Analysis of Reported Efficacy for Salvage Autologous Stem-Cell Transplantation for Myeloma

Abstract

ABSTRACT The rate of complete response (CR) achieved soon after autologous stem cell transplantation (ASCT) is often used as a measure of relative success when comparing interventions in similar or randomized identical settings. New therapies are often tried in salvage and rescue settings early on in development and some of these therapies may electively or necessarily be combined with ASCT also in the rescue/salvage setting. Response rates in such settings are anecdotally low however few studies exist and many variables confound their understanding not least of which is the small numbers of patients involved. Methods A pubmed/medline/googlescholar search strategy along with hand-searching key haematology and oncology journal archives and key paper bibliographies was adopted. 13 published cohorts were identified that reported CR as an outcome from second/salvage ASCT across a total of 1064 patients ( table 1 ). Reported data that included patients who did not have measurable disease (i.e. already in CR) going into the second transplant were excluded as the intent was to observe salvage ASCT effects in measurable disease. Complete response rate (CR), Event free survival/Progression free survival (EFS ∼ PFS were considered heuristically similar) and overall survival (OS) were aggregated. Weighted mean estimates (WME) of efficacy were derived for each setting adjusted according to the number of patients associated with each CR rate. Table: 1086P . CR rate % Number of patients PFS/EFS Months OS Months Krishnan 2011 35 295 Olin 2007 5 41 8.5 20.7 N Shah 2011 11 44 12.3 31.7 Simpson 2007 33 45 12.5 30.6 Jiminez 2011 7 81 Mehta 1998 33 42 12.5 32 Qazilbash 2006 21.4 14 6.8 29 Elice 2006 3.8 26 14.8 38.1 Giaccone 2011 17.4 46 Cavo 2007 19.4 103 Sirohi 2002 31.3 94 10.5 15 Rosinol 2012 11 85 Cook 2011 26 148 Sum 1064 Weighted Average 23.8 11.3 20.8 Results The WME CR rate after a second ASCT was calculated to be ∼24%. Aggregated WME of EFS was 11.2 months and OS 20.8 months. Conclusions Complete responses can be expected in approximately 1 in 4 patients who are selected for clinical trials and given a second transplant for relapsed or non-responding disease. Variability in reported rates is considerable.CR rate Percent Number of Patients PFS/EFS months OS months Disclosure D.P. Smethurst: Full time employee of Immunocore Ltd. and Consultant to Adaptimmmune Ltd. Share options in Immunocore Ltd. and Adaptimmune Ltd.