Faculty Bibliography

BACKGROUND:International collaborative research is a mechanism for improving the development of disease-specific therapies and for improving health at the population level. However, limited data are available to assess the trends in research output related to orphan diseases. METHODS AND FINDINGS/RESULTS:We used bibliometric mapping and clustering methods to illustrate the level of fragmentation in myeloma research and the development of collaborative efforts. Publication data from Thomson Reuters Web of Science were retrieved for 2005-2009 and followed until 2013. We created a database of multiple myeloma publications, and we analysed impact and co-authorship density to identify scientific collaborations, developments, and international key players over time. The global annual publication volume for studies on multiple myeloma increased from 1,144 in 2005 to 1,628 in 2009, which represents a 43% increase. This increase is high compared to the 24% and 14% increases observed for lymphoma and leukaemia. The major proportion (>90% of publications) was from the US and EU over the study period. The output and impact in terms of citations, identified several successful groups with a large number of intra-cluster collaborations in the US and EU. The US-based myeloma clusters clearly stand out as the most productive and highly cited, and the European Myeloma Network members exhibited a doubling of collaborative publications from 2005 to 2009, still increasing up to 2013. CONCLUSION AND PERSPECTIVE/CONCLUSIONS:Multiple myeloma research output has increased substantially in the past decade. The fragmented European myeloma research activities based on national or regional groups are progressing, but they require a broad range of targeted research investments to improve multiple myeloma health care.

Therapeutic advances and the availability of novel agents have significantly improved outcomes in myeloma; yet, it remains incurable and strategies to improve survival continue to be sought. One approach is to prolong the duration of response and increase progression-free survival (PFS) through consolidation or maintenance treatment with regimens that have low toxicity profiles, and do not negatively impact on quality of life. Data from several studies with thalidomide, lenalidomide and bortezomib consistently show improvements in response and PFS, although results have still to be confirmed with respect to overall survival (OS). Despite the promising data, the optimal use of consolidation and maintenance treatment in terms of regimen, dose and duration has yet to be defined. Given the evidence to date, the UK Myeloma Forum believes that both maintenance and consolidation therapy should be considered as treatment options for patients with myeloma. Patients should be encouraged to enrol in clinical studies. This document reviews the current position of maintenance and consolidation for patients with myeloma treated in the UK.

Does the dogma that multiple myeloma is incurable still hold?. The genomic chaos and resulting resistance to apoptosis of myeloma, long considered an obstacle to cure, formed the basis of Total Therapy (TT) program. The TT approach uses all myeloma-active drugs upfront to target drug-resistant subclones during initial treatment to prevent later relapse. Long-term follow-up of 1202 patients (TT1: n = 231, median follow-up: 21 years; TT2: 668, median follow-up: 12 years; TT3a: n = 303, median follow-up: 9 years) permitted investigation of whether progression-free survival (PFS) and complete response (CR) duration were consistent with curability, ie observation of plateaus in Kaplan-Meier plots for PFS and CR duration. In the subset of 627 patients with plasma cell gene expression profiling data, cure plateaus were apparent at 5 years in the 14% with high-risk myeloma compared with 10 years in the remainder with low-risk disease. A parametric model based on PFS and CR duration supported an increase in curability: 10-year PFS and CR estimates increased from 8.8%/17.9% in TT1 to 15.5%/28.2% in TT2's control arm to 25.1%/35.6% in TT2's thalidomide arm and to 32.9%/48.8% in TT3a. Toward developing novel therapies, we recommend a concerted focus on patients with high-risk myeloma whose outcome has not been advanced.

Constitutive NF-κB signaling promotes survival in multiple myeloma (MM) and other cancers; however, current NF-κB-targeting strategies lack cancer cell specificity. Here, we identify the interaction between the NF-κB-regulated antiapoptotic factor GADD45β and the JNK kinase MKK7 as a therapeutic target in MM. Using a drug-discovery strategy, we developed DTP3, a D-tripeptide, which disrupts the GADD45β/MKK7 complex, kills MM cells effectively, and, importantly, lacks toxicity to normal cells. DTP3 has similar anticancer potency to the clinical standard, bortezomib, but more than 100-fold higher cancer cell specificity in vitro. Notably, DTP3 ablates myeloma xenografts in mice with no apparent side effects at the effective doses. Hence, cancer-selective targeting of the NF-κB pathway is possible and, at least for myeloma patients, promises a profound benefit.

Glycosylation is a stepwise procedure of covalent attachment of oligosaccharide chains to proteins or lipids, and alterations in this process, especially increased sialylation, have been associated with malignant transformation and metastasis. The role of altered sialylation in multiple myeloma (MM) cell trafficking has not been previously investigated. In the present study we identified high expression of β-galactoside α-2,3-sialyltransferase, ST3GAL6, in MM cell lines and patients. This gene plays a key role in selectin ligand synthesis in humans through the generation of functional sialyl Lewis X. In MRC IX patients, high expression of this gene is associated with inferior overall survival. In this study we demonstrate that knockdown of ST3GAL6 results in a significant reduction in levels of α-2,3-linked sialic acid on the surface of MM cells with an associated significant reduction in adhesion to MM bone marrow stromal cells and fibronectin along with reduced transendothelial migration in vitro. In support of our in vitro findings, we demonstrate significantly reduced homing and engraftment of ST3GAL6 knockdown MM cells to the bone marrow niche in vivo, along with decreased tumor burden and prolonged survival. This study points to the importance of altered glycosylation, particularly sialylation, in MM cell adhesion and migration.

In recent years significant progress has been made in the understanding of multiple myeloma (MM) biology and its treatment. Current strategies for the treatment of MM involve the concept of sequential blocks of therapy given as an induction followed by consolidation and maintenance. In an age characterized by emerging and more powerful laboratory techniques, it is of primary importance to understand the biology of MM and how this biology can guide the development of new treatment strategies. This review focuses on the genetic basis of myeloma, including the most common genetic abnormalities and pathways affected and the effects that these have on MM treatment strategies. MM biology is discussed also in the light of more recent theory of intraclonal heterogeneity.