Faculty Bibliography

Bone disease in myeloma occurs as a result of complex interactions between myeloma cells and the bone marrow microenvironment. A custom-built DNA single nucleotide polymorphism (SNP) chip containing 3404 SNPs was used to test genomic DNA from myeloma patients classified by the extent of bone disease. Correlations identified with a Total Therapy 2 (TT2) (Arkansas) data set were validated with Eastern Cooperative Oncology Group (ECOG) and Southwest Oncology Group (SWOG) data sets. Univariate correlates with bone disease included: EPHX1, IGF1R, IL-4 and Gsk3beta. SNP signatures were linked to the number of bone lesions, log(2) DKK-1 myeloma cell expression levels and patient survival. Using stepwise multivariate regression analysis, the following SNPs: EPHX1 (P=0.0026); log(2) DKK-1 expression (P=0.0046); serum lactic dehydrogenase (LDH) (P=0.0074); Gsk3beta (P=0.02) and TNFSF8 (P=0.04) were linked to bone disease. This assessment of genetic polymorphisms identifies SNPs with both potential biological relevance and utility in prognostic models of myeloma bone disease.

Empirical antifungal therapy is frequently used in allogeneic transplant patients who have persistent febrile neutropenia and can be associated with high cost, toxicity and breakthrough infections. There are limited reports of strategies for early diagnosis of invasive fungal infection (IFI) and, to our knowledge, no reports of treatment strategies based only on high-resolution computerized tomography (HRCT) scans. We used an early treatment strategy for IFI in 99 consecutive patients undergoing allogeneic transplantation. Patients received caspofungin if they had antibiotic-resistant neutropenic fever for more than 72 h and a positive HRCT scan. Fifty-three of 99 patients (54%) had antibiotic-resistant neutropenic fever at 72 h and would have received parenteral antifungal treatment if an empirical approach had been used. The HRCT-based strategy reduced the use of parenteral antifungal agents to 17/99 patients (17%), a 68% reduction. No subsequent diagnoses of IFI occurred within 100 days in patients with a negative HRCT. Only one patient died from IFI within 100 days. These data suggest that this non-empirical strategy may be feasible and that caspofungin may be effective in this setting. A randomized controlled trial is warranted to further assess these results.

Myeloma cells are highly dependent on the unfolded protein response to assemble folded immunoglobulins correctly. Therefore, targeting protein handling within a myeloma cell by inhibiting the aminopeptidase enzyme system, which catalyses the hydrolysis of amino acids from the proteins NH2 terminus, represents a therapeutic approach. CHR-2797, a novel aminopeptidase inhibitor, is able to inhibit proliferation and induce growth arrest and apoptosis in myeloma cells, including cells resistant to conventional chemotherapeutics. It causes minimal inhibition of bone marrow stromal cell (BMSC) proliferation but is able to overcome the microenvironmental protective effects, inhibiting the proliferation of myeloma cells bound to BMSCs and the increase in vascular endothelial growth factor levels seen when myeloma cells and BMSCs are bound together. Additive and synergistic effects are seen with bortezomib, melphalan, and dexamethasone. Apoptosis occurs via both caspase-dependent and non-caspase-dependent pathways with an increase in Noxa, cleavage of Mcl-1, and activation of the unfolded protein response. Autophagy is also seen. CHR-2797 causes an up-regulation of genes involved in the proteasome/ubiquitin pathway, as well as aminopeptidases, and amino acid deprivation response genes. In conclusion, inhibiting protein turnover using the aminopeptidase inhibitor CHR-2797 results in myeloma cell apoptosis and represents a novel therapeutic approach that warrants further investigation in the clinical setting.

Lenalidomide is an immunomodulatory drug, which has anti-myeloma activity in vitro. Phase II clinical trials have demonstrated lenalidomide in combination with dexamethasone is effective for the treatment of both relapsed refractory myeloma and newly diagnosed patients. Two large phase III studies comparing lenalidomide and dexamethasone to dexamethasone alone in relapsed patients showed superiority in response, progression free and overall survival. It is administered orally for 21 days in a 28 day cycle. Side effects are manageable and include neutropenia and venous thrombotic events. It is currently approved, in combination with dexamethasone, for the treatment of multiple myeloma patients who have received at least one prior therapy. Studies in front line patients and with other drug combinations are ongoing. Given the strength of this data the UK Myeloma Forum believe that lenalidomide in combination with dexamethasone should be available for prescription by UK haematologists according to its licensed indication in patients with relapsed myeloma.

This study was conducted to compare the presenting features and outcome of newly-diagnosed myeloma with and without extramedullary (EM) manifestations and to determine the optimum treatment. Seventy-five (16.3%) patients with EM involvement at diagnosis were compared with 384 cases without EM disease. EM patients had a more favourable International Staging System and a different distribution of myeloma isotypes. When adjusted according to the independent risk factors, patients in the EM group treated with chemotherapy alone had significantly shorter overall survival (OS) compared to those without EM disease receiving similar treatment. High-dose treatment (HDT) was associated with significantly improved OS in both groups; however, it had more impact on OS among EM group, overcoming the negative prognostic impact of presenting EM disease. Patients in the EM group treated with HDT have a similar outcome to those without EM manifestations treated with HDT. HDT should form an integral component of first-line treatment for patients with EM disease whenever possible.

The serum immunoglobulin-free light chain (FLC) assay measures levels of free kappa and lambda immunoglobulin light chains. There are three major indications for the FLC assay in the evaluation and management of multiple myeloma and related plasma cell disorders (PCD). In the context of screening, the serum FLC assay in combination with serum protein electrophoresis (PEL) and immunofixation yields high sensitivity, and negates the need for 24-h urine studies for diagnoses other than light chain amyloidosis (AL). Second, the baseline FLC measurement is of major prognostic value in virtually every PCD. Third, the FLC assay allows for quantitative monitoring of patients with oligosecretory PCD, including AL, oligosecretory myeloma and nearly two-thirds of patients who had previously been deemed to have non-secretory myeloma. In AL patients, serial FLC measurements outperform PEL and immunofixation. In oligosecretory myeloma patients, although not formally validated, serial FLC measurements reduce the need for frequent bone marrow biopsies. In contrast, there are no data to support using FLC assay in place of 24-h urine PEL for monitoring or for serial measurements in PCD with measurable disease by serum or urine PEL. This paper provides consensus guidelines for the use of this important assay, in the diagnosis and management of clonal PCD.

BACKGROUND:The recurrent immunoglobulin translocation, t(4;14)(p16;q32) occurs in 15% of multiple myeloma patients and is associated with poor prognosis, through an unknown mechanism. The t(4;14) up-regulates fibroblast growth factor receptor 3 (FGFR3) and multiple myeloma SET domain (MMSET) genes. The involvement of MMSET in the pathogenesis of t(4;14) multiple myeloma and the mechanism or genes deregulated by MMSET upregulation are still unclear. DESIGN AND METHODS/METHODS:The expression of MMSET was analyzed using a novel antibody. The involvement of MMSET in t(4;14) myelomagenesis was assessed by small interfering RNA mediated knockdown combined with several biological assays. In addition, the differential gene expression of MMSET-induced knockdown was analyzed with expression microarrays. MMSET gene targets in primary patient material was analyzed by expression microarrays. RESULTS:We found that MMSET isoforms are expressed in multiple myeloma cell lines, being exclusively up-regulated in t(4;14)-positive cells. Suppression of MMSET expression affected cell proliferation by both decreasing cell viability and cell cycle progression of cells with the t(4;14) translocation. These findings were associated with reduced expression of genes involved in the regulation of cell cycle progression (e.g. CCND2, CCNG1, BRCA1, AURKA and CHEK1), apoptosis (CASP1, CASP4 and FOXO3A) and cell adhesion (ADAM9 and DSG2). Furthermore, we identified genes involved in the latter processes that were differentially expressed in t(4;14) multiple myeloma patient samples. CONCLUSIONS:In conclusion, dysregulation of MMSET affects the expression of several genes involved in the regulation of cell cycle progression, cell adhesion and survival.

A venous thromboembolism (VTE) with the subsequent risk of pulmonary embolism is a major concern in the treatment of patients with multiple myeloma with thalidomide. The susceptibility to developing a VTE in response to thalidomide therapy is likely to be influenced by both genetic and environmental factors. To test genetic variation associated with treatment related VTE in patient peripheral blood DNA, we used a custom-built molecular inversion probe (MIP)-based single nucleotide polymorphism (SNP) chip containing 3404 SNPs. SNPs on the chip were selected in "functional regions" within 964 genes spanning 67 molecular pathways thought to be involved in the pathogenesis, treatment response, and side effects associated with myeloma therapy. Patients and controls were taken from 3 large clinical trials: Medical Research Council (MRC) Myeloma IX, Hovon-50, and Eastern Cooperative Oncology Group (ECOG) EA100, which compared conventional treatments with thalidomide in patients with myeloma. Our analysis showed that the set of SNPs associated with thalidomide-related VTE were enriched in genes and pathways important in drug transport/metabolism, DNA repair, and cytokine balance. The effects of the SNPs associated with thalidomide-related VTE may be functional at the level of the tumor cell, the tumor-related microenvironment, and the endothelium. The clinical trials described in this paper have been registered as follows: MRC Myeloma IX: ISRCTN68454111; Hovon-50: NCT00028886; and ECOG EA100: NCT00033332.

One-hundred-twenty consecutive adult patients aged 15-69 years (median 40) with acute myeloid leukemia (AML) excluding t(15;17) received induction therapy comprising idarubicin, high-dose cytarabine and etoposide. Planned post-induction treatment included two courses of moderate-intensity consolidation therapy followed by stem cell transplantation. 11 patients (9%) died during induction therapy. The complete remission (CR) rate with a single cycle of induction therapy was 71%. The overall CR rate, after salvage chemotherapy but excluding allogeneic transplantation for primary refractory disease, was 82%. CR rates with one cycle of therapy for patients with good, intermediate and poor karyotype were 96, 72 and 41%, respectively (P<0.0001). The impact of karyotype on the overall CR rate was also significant (96 vs. 88 vs. 59%; P=0.001). Overall, 84 of 98 patients (86%) attaining CR underwent autologous (n=59), allogeneic (n=23) or syngeneic (n=2) hematopoietic stem cell transplantation in first CR. The 5-year overall survival (OS) of 43% (95% CI: 34-52%) was significantly influenced by the karyotype: good 73%, intermediate 41%, and poor 18% (P=0.0001). These data suggest that the sequence of therapy employed is active in AML, but additional steps are needed to improve the outcome of patients with intermediate- and high-risk cytogenetic abnormalities.

Blastoid morphology is a rare presenting feature of myeloma which is frequently seen in patients with extramedullary myeloma and is associated with poor clinical outcome. Cell cycle active agents can be effective as treatment for aggressive myeloma and their activity enhanced by using them in combination with the anti-angiogenic agent thalidomide. DT-PACE is an example of such a regimen which we have used to treat 26 relapsed and or refractory patients with extramedullary/blastoid myeloma. The overall response rate (complete response/PR) was 59%, but despite these initial good responses, patients had a short progression free survival (PFS) and overall survival (OS). A subgroup of patients who proceeded to autologous stem cell transplant (ASCT) have a trend towards a better PFS and OS when compared with the group receiving chemotherapy alone (PFS = 10 vs. 3 months P = 0.273 and OS 10 vs. 7 months P = 0.235). Interestingly of the group who received ASCT consolidation three patients remain alive beyond 18 months. In conclusion, the clinical outcome of this group of cases is poor even when treated with the intensive regimen DT-PACE; however, a subgroup can do well if DT-PACE is consolidated by ASCT.