Faculty Bibliography

IgD myeloma is a subtype often considered to have adverse features and inferior survival but there is a paucity of data from large clinical studies. We compare the clinical characteristics and outcomes of IgD myeloma patients from UK Phase III myeloma trials analysed in two groups; old (1980-2002) and recent (2002-2016) clinical trials, based on the time of adoption of novel myeloma therapies. IgD myeloma patients comprised 44/2789 (1.6%) and 70/5773 (1.2%) of the old and recent trials respectively. Overall, IgD myeloma was associated with male predominance, low-level paraproteinemia (<10g/l) and lambda light chain preference. The frequency of ultra-high risk cytogenetics was similar in IgD myeloma compared with other subtypes (4.3% vs 5.3%, p>0.99). Despite the old trial series being a younger group (median age: 59 years vs 63 years, p=0.015), there was a higher frequency of bone lesions, advanced stage at diagnosis, worse performance status and severe renal impairment compared with the recent trials. Furthermore, the early mortality rate was significantly higher for the old trial series (20% vs 4%, p=0.01). The overall response rate following induction therapy was significantly higher in the recent trials (89% vs 43%, p<0.0001) and this was consistent with improved median overall survival (48 months; 95% CI 35-67 months vs 22 months, 95% CI 16-29 months). Survival outcomes for IgD myeloma have significantly improved and are now comparable to other myeloma types due to earlier diagnosis, novel therapies and improved supportive care. (Myeloma IX International Standard Randomised Controlled Trial Number: 68454111, Myeloma XI International Standard Randomised Controlled Trial Number: 49407852).

Deciphering Multiple Myeloma evolution in the whole bone marrow is key to inform curative strategies. Here, we perform spatial-longitudinal whole-exome sequencing, including 140 samples collected from 24 Multiple Myeloma patients during up to 14 years. Applying imaging-guided sampling we observe three evolutionary patterns, including relapse driven by a single-cell expansion, competing/co-existing sub-clones, and unique sub-clones at distinct locations. While we do not find the unique relapse sub-clone in the baseline focal lesion(s), we show a close phylogenetic relationship between baseline focal lesions and relapse disease, highlighting focal lesions as hotspots of tumor evolution. In patients with ≥3 focal lesions on positron-emission-tomography at diagnosis, relapse is driven by multiple distinct sub-clones, whereas in other patients, a single-cell expansion is typically seen (p < 0.01). Notably, we observe resistant sub-clones that can be hidden over years, suggesting that a prerequisite for curative therapies would be to overcome not only tumor heterogeneity but also dormancy.

The multiple myeloma treatment landscape has changed dramatically. This change, paralleled by an increase in scientific knowledge, has resulted in significant improvement in survival. However, heterogeneity remains in clinical outcomes, with a proportion of patients not benefiting from current approaches and continuing to have a poor prognosis. A significant proportion of the variability in outcome can be predicted on the basis of clinical and biochemical parameters and tumor-acquired genetic variants, allowing for risk stratification and a more personalized approach to therapy. This article discusses the principles that can enable the rational and effective development of therapeutic approaches for high-risk multiple myeloma.

PURPOSE/OBJECTIVE:We designed a comprehensive multiple myeloma (MM) targeted sequencing panel to identify common genomic abnormalities in a single assay and validated it against known standards. EXPERIMENTAL DESIGN/METHODS:The panel comprised 228 genes/exons for mutations, 6 regions for translocations, and 56 regions for copy number abnormalities (CNAs). Toward panel validation, targeted sequencing was conducted on 233 patient samples and further validated using clinical fluorescence in situ hybridization (FISH) (translocations), multiplex ligation probe analysis (MLPA) (CNAs), whole genome sequencing (WGS) (CNAs, mutations, translocations) or droplet digital PCR (ddPCR) of known standards (mutations). RESULTS:Canonical IgH translocations were detected in 43.2% of patients by sequencing, and aligned with FISH except for one patient. CNAs determined by sequencing and MLPA for 22 regions were comparable in 103 samples and concordance between platforms was R2=0.969. VAFs for 74 mutations were compared between sequencing and ddPCR with concordance of R2=0.9849. CONCLUSIONS:In summary, we have developed a targeted sequencing panel that is as robust or superior to FISH and WGS. This molecular panel is cost effective, comprehensive, clinically actionable and can be routinely deployed to assist risk stratification at diagnosis or post-treatment to guide sequencing of therapies.

Chromosomal translocations are important drivers of hematological malignancies whereby proto-oncogenes are activated by juxtaposition with super-enhancers, often called enhancer hijacking. We analysed the epigenomic consequences of rearrangements between the super-enhancers of the immunoglobulin heavy locus (IGH) and proto-oncogene CCND1 that are common in B cell malignancies. By integrating BLUEPRINT epigenomic data with DNA breakpoint detection, we characterised the normal chromatin landscape of the human IGH locus and its dynamics after pathological genomic rearrangement. We detected an H3K4me3 broad domain (BD) within the IGH locus of healthy B cells that was absent in samples with IGH-CCND1 translocations. The appearance of H3K4me3-BD over CCND1 in the latter was associated with overexpression and extensive chromatin accessibility of its gene body. We observed similar cancer-specific H3K4me3-BDs associated with super-enhancer hijacking of other common oncogenes in B cell (MAF, MYC and FGFR3/NSD2) and in T-cell malignancies (LMO2, TLX3 and TAL1). Our analysis suggests that H3K4me3-BDs can be created by super-enhancers and supports the new concept of epigenomic translocation, where the relocation of H3K4me3-BDs from cell identity genes to oncogenes accompanies the translocation of super-enhancers.

Smoldering multiple myeloma (SMM) is a precursor condition of multiple myeloma (MM) with significant heterogeneity in disease progression. Existing clinical models of progression risk do not fully capture this heterogeneity. Here we integrate 42 genetic alterations from 214 SMM patients using unsupervised binary matrix factorization (BMF) clustering and identify six distinct genetic subtypes. These subtypes are differentially associated with established MM-related RNA signatures, oncogenic and immune transcriptional profiles, and evolving clinical biomarkers. Three genetic subtypes are associated with increased risk of progression to active MM in both the primary and validation cohorts, indicating they can be used to better predict high and low-risk patients within the currently used clinical risk stratification models.

Deciphering genomic architecture is key to identifying novel disease drivers and understanding the mechanisms underlying myeloma initiation and progression. In this work, using the CoMMpass dataset, we show that structural variants (SV) occur in a nonrandom fashion throughout the genome with an increased frequency in the t(4;14), RB1, or TP53 mutated cases and reduced frequency in t(11;14) cases. By mapping sites of chromosomal rearrangements to topologically associated domains and identifying significantly upregulated genes by RNAseq we identify both predicted and novel putative driver genes. These data highlight the heterogeneity of transcriptional dysregulation occurring as a consequence of both the canonical and novel structural variants. Further, it shows that the complex rearrangements chromoplexy, chromothripsis and templated insertions are common in MM with each variant having its own distinct frequency and impact on clinical outcome. Chromothripsis is associated with a significant independent negative impact on clinical outcome in newly diagnosed cases consistent with its use alongside other clinical and genetic risk factors to identify prognosis.

PURPOSE/OBJECTIVE:Minimal residual disease (MRD) can predict outcomes in patients with multiple myeloma, but limited data are available on the prognostic impact of MRD when assessed at serial time points in the context of maintenance therapy after autologous stem-cell transplant (ASCT) and the interaction between MRD and molecular risk. METHODS:Data from a large phase III trial (Myeloma XI) were examined to determine the relationship between MRD status, progression-free survival (PFS), and overall survival (OS) in post-ASCT patients randomly assigned to lenalidomide maintenance or no maintenance at 3 months after ASCT. MRD status was assessed by flow cytometry (median sensitivity 0.004%) before maintenance random assignment (ASCT + 3) and 6 months later (ASCT + 9). RESULTS:= .0077). The findings were very similar when restricted to patients with complete response/near complete response. Sustained MRD negativity from ASCT + 3 to ASCT + 9 or the conversion to MRD negativity by ASCT + 9 was associated with the longest PFS/OS. Patients randomly assigned to lenalidomide maintenance were more likely to convert from being MRD-positive before maintenance random assignment to MRD-negative 6 months later (lenalidomide 30%, observation 17%). High-risk molecular features had an adverse effect on PFS and OS even for those patients achieving MRD-negative status. On multivariable analysis of MRD status, maintenance therapy and molecular risk maintained prognostic impact at both ASCT + 3 and ASCT + 9. CONCLUSION/CONCLUSIONS:In patients with multiple myeloma, MRD status at both ASCT + 3 and ASCT + 9 is a powerful predictor of PFS and OS.

The all-oral combination of ixazomib, cyclophosphamide, and dexamethasone (ICD) is well tolerated and effective in newly diagnosed and relapsed multiple myeloma (MM). We carried out MUKeight, a randomised, controlled, open, parallel group, multi-centre phase II trial in patients with relapsed MM after prior treatment with thalidomide, lenalidomide, and a proteasome inhibitor (ISRCTN58227268), with the primary objective to test whether ICD has improved clinical activity compared to cyclophosphamide and dexamethasone (CD) in terms of progression-free survival (PFS). Between January 2016 and December 2018, 112 participants were randomised between ICD (n = 58) and CD (n = 54) in 33 UK centres. Patients had a median age of 70 years and had received a median of four prior lines of therapy. 74% were classed as frail. Median PFS in the ICD arm was 5.6 months, compared to 6.7 months with CD (hazard ratio (HR) = 1.21, 80% CI 0.9-1.6, p = 0.3634). Response rates and overall survival were not significantly different between ICD and CD. Dose modifications or omissions, and serious adverse events (SAEs), occurred more often in the ICD arm. In summary, the addition of ixazomib to cyclophosphamide and dexamethasone did not improve outcomes in the comparatively frail patients enroled in the MUKeight trial.