Faculty Bibliography

PURPOSE/OBJECTIVE:Copy number changes and translocations have been studied extensively in many datasets with long term follow-up. The impact of mutations remains debated given the short time to follow-up of most datasets. METHODS:we performed targeted panel sequencing covering 125 myeloma-specific genes and the loci involved in translocations in 223 newly diagnosed myeloma samples recruited into one of the Total Therapy Trials (TT). RESULTS:As expected, the most commonly mutated genes were NRAS, KRAS, and BRAF making up 44% of patients. Double-Hit, BRAF and DIS3 mutations had an impact on outcome alongside classical risk factors in the context of an intensive treatment approach. We were able to identify both V600E and non-V600E BRAF mutations, 58% of which were predicted to be hypoactive or kinase dead. Interestingly, 44% of the hypoactive/kinase dead BRAF mutated patients showed co-occurring alterations in KRAS, NRAS or activating BRAF mutations suggesting they play a role in the oncogenesis of multiple myeloma (MM) by facilitating MAPK activation and may lead to chemo resistance. CONCLUSION/CONCLUSIONS:Overall, these data highlight the importance of mutational screening to better understand newly diagnosed MM (NDMM) and may lead to patient specific mutation-driven treatment approaches.

As multiple myeloma (MM) treatments evolve, frequent updates are required to monitor the long-term effect of changes in approach. Traditionally, MM is considered an incurable disease, with most patients eventually relapsing. However, improvements in treatments has raised the possibility that MM might be functionally curable. To examine improvements in long-term survival, we followed 4329 patients with newly diagnosed MM treated with autologous stem cell transplantation (ASCT) at the University of Arkansas for Medical Sciences from 1989 through 2018. Overall survival (OS) and progression-free survival (PFS) were evaluated using Kaplan-Meier analysis, Cox proportional hazards models, relative survival analysis, and cure modeling among different time periods, risk groups, and demographic traits. Steady improvements in OS were found, with patients treated in 2014 or later having superior OS (hazard ratio, 0.35; 95% confidence interval [CI], 0.27-0.45) and reduced excess risk for MM death (relative excess risk, 0.30; 95% CI, 0.22-0.41) compared with patients treated in 1997 or earlier. Patients treated during intervening time periods often had intermediate survival, but trends in OS, PFS, and landmarked analyses were inconsistent. Cure models support the potential for cure, ranging from 6.3% to 31.3%, depending on the year of treatment, with 10.0% to 18.6% of patients achieving their normal life expectancy across multiple periods. There was some evidence of reductions in early mortality within 3 years of diagnosis, longer complete response (CR) duration, and reductions in relapse after achieving CR. However, results differed depending on age, risk group, and cytogenetic characteristics.

Disease factors such as tumor burden and molecular risk affect myeloma patient outcomes as well as patient factors that impact the capacity to deliver treatment. How the relative importance of these factors changes with patient age has not previously been investigated comprehensively. We analyzed data from 3894 patients of all ages uniformly treated in a large clinical trial of myeloma patients, Myeloma XI. Even with novel therapeutic approaches progression-free survival (PFS) and overall survival (OS) are affected by age with a stepwise reduction in PFS and OS with each decade increase. Renal function deteriorated with increasing age whilst the frequency of t(4;14) and del(17p) decreased and gain(1q) increased. The relative contribution of performance status, international staging score and molecular risk to progression-free and overall survival varied by age group. Molecular events have a larger effect on outcome in younger patients with their relative contribution diminishing in the elderly. Performance status is important for patient outcome at all ages suggesting that physical frailty may be a more important predictor of outcome than age itself. Significant differences in the factors driving patient outcomes at different ages are important to consider as we design disease segmentation strategies to deliver personalized treatment approaches.

Background: Structural variants are key recurrent molecular features of myeloma (MM) with two types of complex rearrangement, chromoplexy and chromothripsis, having been described recently. The contribution of these to MM prognosis, rapid changes in clinical behavior and punctuated evolution is currently unknown as is the mechanism by which they deregulate gene function. XXMethod(s): We analyzed two sets of newly diagnosed MM data: 85 cases with phased whole genome sequencing; and 812 cases from CoMMpass where long-insert whole-genome sequencing was available. Patient derived xenografts from five MM cases were used to generate epigenetic maps for the histone marks, BRD4, MED1, H3K27Ac, H3K4me1, H3K4me3, H3K9me3, H3K36me3 and H3K27me3. XXResult(s): In the 10X data the median number of structural events per case was 25 (range 1 - 182); with a median of 14 intra-chromosomal events (range 1 - 179; P<0.001) and 7 inter-chromosomal events (range 0 - 29). Structural events were seen most frequently on chromosomes 14 (64%), 8 (53%), 1 (44%) and 6 (42%). Complex chromosomal rearrangements involving 3 or more chromosomal sites were seen in 46%, 4 or more sites in 20%, 5 or more in 10% and 6 or more in 5% of samples. There were significantly more structural events in the t(4;14) subgroup compared to the t(11;14) subgroup. Significantly more events were also seen in the bi-allelically inactivated TP53 cases. Using an elbow test defined cutoff, we identified cases with high structural variant load in 10% of cases. Chromoplexy called by "Chainfinder" was seen in 18% of cases. Chromothripsis called by "Shatterseek" was seen in 9% of cases. Cases with a high structural load alone were not associated with an adverse outcome whereas cases with chromoplexy or chromothripsis were associated with adverse PFS and OS, p=0.001. A new high-risk subgroup comprising approximately 5% of cases was identified with chromoplexy, chromothripsis and a high structural load. Gene set enrichment analysis of cases with chromoplexy and chromothripsis showed an excess of MYC, E2F and G2M targets, and a reduction in RAS signaling. Interferon a and g responses, an excess of TP53 and reduction in TRAF3 mutations was associated predominantly with chromothripsis. How chromoplexy and chromothripsis are tolerated by the cell is unknown and the association with the cGAS/STING response is further being explored. To determine how chromoplexy may deregulate multiple genes we identified the full spectrum of structural variants to the immunoglobulin (Ig) and non-Ig loci. A range of genes are deregulated by Ig loci including MAP3K14 at a frequency of 2% confirming the importance of non-canonical NFkB signaling. A novel intra-chromosomal rearrangement to ZFP36L1 was upregulated in 10% of cases but was not prognostic. Gene upregulation by non-Ig super enhancers is frequent and targets include PAX5, GLI3, CD40, NFKB1, MAP3K14, LRRC37A, LIPG, PHLDA3, ZNF267, CENPF, SLC44A2, MIER1, SOX30, TMEM258, PPIL1, and BUB3. The topologically associating domain (TADs) containing super enhancers bringing about gene deregulation include TXNDC5, FOXO3, FCHSD2, SP2, FAM46C, CACNA1C, TLCD2 and PIK3C2G. These super enhancers frequently contain important MM genes, the coding sequence of which are disrupted by the rearrangement and could contribute to the clinical phenotype. Accurately reconstructing the structure of the complex rearrangements will allow us to identify the mechanism of gene deregulation and to distinguish between either gene stacking, receptor stacking or both. XXConclusion(s): Upregulation of gene expression by super enhancer rearrangement is a major mechanism of gene deregulation in MM and complex structural events contribute significantly to adverse prognosis by a range of mechanisms as well as simple gene overexpression. Disclosures: Boyle: Amgen, Abbvie, Janssen, Takeda, Celgene Corporation: Honoraria; Amgen, Janssen, Takeda, Celgene Corporation: Other: Travel expenses. Walker: Celgene: Research Funding. Thakurta: Celgene: Employment, Equity Ownership. Flynt: Celgene Corporation: Employment, Equity Ownership. Davies: Amgen, Celgene, Janssen, Oncopeptides, Roche, Takeda: Membership on an entity's Board of Directors or advisory committees, Other: Consultant/Advisor; Janssen, Celgene: Other: Research Grant, Research Funding. Morgan: Amgen, Roche, Abbvie, Takeda, Celgene, Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Other: research grant, Research Funding.XXCopyright

Background: Carfilzomib is a second-generation irreversible proteasome inhibitor that has shown significant efficacy in phase III studies of relapsed myeloma patients. The UK NCRI Myeloma XI study is the first phase III randomised study that has reported outcomes for the use of carfilzomib as induction therapy in newly diagnosed myeloma patients prior to autologous stem cell transplant (ASCT). The KCRD combination deepened responses and prolonged progression-free survival compared to response adapted immunomodulatory agent-based triplet +/-proteasome inhibitor-based triplet therapy (Jackson GH et al, ASH 2018).
Aim(s): In this exploratory analysis we examine the efficacy of KCRD compared to triplet therapy across different molecular subgroups within the Myeloma XI trial.
Method(s): 1056 patients were randomised between KCRD (28 day cycles of carfilzomib (K) 36 mg/m² IV d1-2, 8-9, 15-16 (20 mg/m² #1d1-2), cyclophosphamide (C) 500 mg PO d1,8, lenalidomide (R) 25 mg PO d1-21, dexamethasone (D) 40 mg PO d1-4,8-9,15-16) and triplet CTD/CRD prior to ASCT. Patients who received CTD/CRD underwent response-adapted intensification for suboptimal responders with a randomization to proteasome inhibitor (bortezomib, CVD) containing triplet or no further therapy. A maintenance randomisation at 3 months post ASCT compared lenalidomide to observation. Molecular analysis was available for a representative subset of patients (n = 339). High-risk (HiR) was classified in the study as the presence of t(4;14), t(14;16), t(14;20), del(17p) or gain(1q) and ultra-high risk (UHiR) the presence of two or more lesions. Exploratory analyses of outcome by individual molecular risk lesion and by HiR defined without the inclusion of gain(1q) and t(14;20) were also performed. Efficacy analyses included PFS and response.
Result(s): KCRD was associated with a significantly longer PFS than triplet therapy for the whole population, with no significant heterogeneity between risk groups (standard risk (SR) hazard ratio (HR) 0.55, 95%CI 0.33, 0.92, median PFS KCRD NR vs CTD/CRD 36 months), HiR (HR 0.68, 95%CI 0.40, 1.19, median PFS KCRD NR vs CTD/CRD 37 months) and UHiR (HR 0.72, 95%CI 0.26, 2.02, median PFS KCRD 25 vs CTD/CRD 20 months, phet = 0.7841). For patients receiving KCRD there was no difference in response rate at the end of induction 1 by risk group (> = VGPR: SR 86.0%, HiR 87.0% and UHiR 88.2%). However, UHiR disease was associated with significantly shorter PFS than both SR (p = 0.0073) and HiR (p = 0.0180) whilst there was no significant difference in outcome between patients with HiR (only one adverse lesion) and SR (p = 0.7213). Within groups of patients with each HiR lesion there was a benefit for KCRD over CTD/CRD. The lowest hazard ratio was observed in patients with a del(17p), (HR 0.12, 95%CI 0.03, 0.51, median PFS KCRD 38 vs CTD/CRD 17 months). When HiR was defined only by the presence of t(4;14), t(14;16) and/or del(17p) there remained a significant benefit for KCRD over CTD/CRD (HiR: HR 0.38, 95%CI 0.19, 0.77, median PFS KCRD 38 vs CTD/CRD 22 months, SR: HR 0.58, 95%CI 0.39, 0.88, median PFS KCRD NR vs CTD/CRD 38 months) with no heterogeneity of effect identified between risk groups. Summary/Conclusion: KCRD is associated with prolonged PFS compared with response-adapted triplet therapy across all molecular risk subgroups, however these are defined. Even with the highly effective quadruplet combination KCRD, UHiR patients continue to have significantly worse outcomes than patients with standard risk disease and there remains an unmet need for novel therapeutic approaches for these patients