Stem Cell Harvesting after Bortezomib-Based Reinduction for Myeloma Relapsing after Autologous Transplantation: Results from the British Society of Blood and Marrow Transplantation/United Kingdom Myeloma Forum Myeloma X (Intensive) Trial.

The phase III British Society of Blood and Marrow Transplantation/United Kingdom Myeloma Forum Myeloma X trial (MMX) demonstrated prospectively, for the first time, superiority of salvage autologous stem cell transplantation over chemotherapy maintenance for multiple myeloma (MM) in first relapse after previous ASCT. However, many patients have stored insufficient stem cells (PBSC) for second ASCT and robust evidence for remobilization after first ASCT is lacking. We report the feasibility, safety, and efficacy of remobilization after bortezomib-doxorubicin-dexamethasone reinduction in MMX and outcomes of second ASCT with these cells. One hundred ten patients underwent ≥1 remobilization with 32 and 4, undergoing second and third attempts, respectively. Toxicities of remobilization were similar to those seen in first-line mobilization. After all attempts, 52% of those with insufficient previously stored PBSC had harvested a sufficient quantity to proceed to second ASCT. Median PBSC doses infused, neutrophil engraftment, and time to discharge after second ASCT were similar regardless of stem cell source, as were the toxicities of second ASCT. No significant differences between PBSC sources were noted in depth of response to ASCT or time to progression. Harvesting after bortezomib-doxorubicin-dexamethasone reinduction for MM at first relapse is safe and feasible and yields a reliable cell product for second ASCT. The study is registered with ClinicalTrials.gov (NCT00747877) and EudraCT (2006-005890-24).

Copy number evolution and its relationship with patient outcome-an analysis of 178 matched presentation-relapse tumor pairs from the Myeloma XI trial.

Structural chromosomal changes including copy number aberrations (CNAs) are a major feature of multiple myeloma (MM), however their evolution in context of modern biological therapy is not well characterized. To investigate acquisition of CNAs and their prognostic relevance in context of first-line therapy, we profiled tumor diagnosis-relapse pairs from 178 NCRI Myeloma XI (ISRCTN49407852) trial patients using digital multiplex ligation-dependent probe amplification. CNA profiles acquired at relapse differed substantially between MM subtypes: hyperdiploid (HRD) tumors evolved predominantly in branching pattern vs. linear pattern in t(4;14) vs. stable pattern in t(11;14). CNA acquisition also differed between subtypes based on CCND expression, with a marked enrichment of acquired del(17p) in CCND2 over CCND1 tumors. Acquired CNAs were not influenced by high-dose melphalan or lenalidomide maintenance randomization. A branching evolution pattern was significantly associated with inferior overall survival (OS; hazard ratio (HR) 2.61, P = 0.0048). As an individual lesion, acquisition of gain(1q) at relapse was associated with shorter OS, independent of other risk markers or time of relapse (HR = 2.00; P = 0.021). There is an increasing need for rational therapy sequencing in MM. Our data supports the value of repeat molecular profiling to characterize disease evolution and inform management of MM relapse.

The effect of salvage autologous stem-cell transplantation on overall survival in patients with relapsed multiple myeloma (final results from BSBMT/UKMF Myeloma X Relapse [Intensive]): a randomised, open-label, phase 3 trial.

BACKGROUND: The Myeloma X trial previously reported improved durability of response (time to disease progression) in patients with relapsed multiple myeloma with salvage autologous stem-cell transplantation (ASCT) compared with oral cyclophosphamide in patients with multiple myeloma relapsing after a first ASCT. We report the final overall survival results of the trial. METHODS: BSBMT/UKMF Myeloma X was a multicentre, randomised, open-label, phase 3 trial done at 51 centres in the UK. Eligible patients with multiple myeloma relapsing after a previous ASCT were re-induced with intravenous bortezomib (1·3 mg/m(2) on days 1, 4, 8, 11), intravenous doxorubicin (9 mg/m(2) per day on days 1-4), and oral dexamethasone (40 mg/day on days 1-4, 8-11, and 15-18 during cycle 1 and days 1-4 during cycles 2-4), with supportive care as per local institutional protocols before randomisation in a 1:1 ratio to either high-dose melphalan (200 mg/m(2)) and salvage ASCT or weekly oral cyclophosphamide (400 mg/m(2) per week for 12 weeks). Randomisation was by permuted blocks stratified by length of first remission and response to re-induction treatment. The primary endpoint was time to disease progression; the study was also powered to detect a difference in the secondary endpoint, overall survival. Further secondary endpoints were the proportion of patients achieving an objective response, progression-free survival, overall survival, toxic effects and safety, pain, and quality of life. Prespecified exploratory endpoints included time to second objective disease progression (PFS2). Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00747877, and the European Clinical Trials Database, number 2006-005890-24, and is now in long-term follow-up. FINDINGS: Between April 16, 2008, and Nov 19, 2012, 297 patients were registered into the study and 174 were randomly assigned to receive either high-dose melphalan and salvage ASCT (n=89) or oral weekly cyclophosphamide (n=85). 173 (58%) of 297 patients relapsed after more than 24 months from first ASCT. 75 (43%) of 174 randomised patients had died at follow-up: salvage ASCT (n=31 [35%]) versus oral weekly cyclophosphamide (n=44 [52%]). Updated time to disease progression shows continued advantage in the salvage ASCT group compared with the weekly cyclophosphamide group (19 months [95% CI 16-26] vs 11 months [9-12]; hazard ratio [HR] 0·45 [95% CI 0·31-0·64] log-rank p<0·0001). Median overall survival was superior in the salvage ASCT group compared with weekly cyclophosphamide group (67 months [95% CI 55-not estimable] vs 52 months [42-60]; log-rank p=0·022; HR 0·56 [0·35-0·90], p=0·0169). Time to second objective disease progression was superior in the salvage ASCT group compared with the weekly cyclophosphamide group (67 months [52-not estimable] vs 35 months [31-43]; HR 0·37 [0·24-0·57], log-rank p<0·0001). During extended follow-up, no further treatment-related or treatment-unrelated adverse events were reported. 15 second primary malignancies were reported in 12 patients (salvage ASCT [n=7] vs oral weekly cyclophosphamide [n=5]). The cumulative incidence of second primary malignancies at 60 months after trial entry was 5·2% (2·1-8·2). INTERPRETATION: Salvage ASCT increases overall survival during consolidation of re-induction treatment in patients with multiple myeloma at first relapse after a first ASCT. The delay of salvage ASCT to third-line treatment or later might not confer the same degree of advantage as seen with salvage ASCT at first relapse. FUNDING: Cancer Research UK, Janssen-Cilag, and Chugai Pharma UK.