Faculty Bibliography

Over the past two decades, not only treatment options, but also the diagnosis, staging, and risk assessment of multiple myeloma (MM), have undergone significant development, partially due to a deeper understanding of MM pathogenesis. Conventional cytogenetics and fluorescence in situ hybridization are routinely assessed in MM, and when combined with ISS stage may attain an even better predictive potential. In order to achieve even more effective and individualized therapies, one crucial goal is the identification of genes and gene combinations that predict for response or resistance to chemotherapy. High-dose chemotherapy with autologous stem cell transplant (SCT) still remains the standard therapy for younger patients, with novel agents now being included in both pre-transplant regimens and post-transplant consolidation/maintenance approaches. Similarly, novel agents are also being incorporated into allogeneic SCT for selected patients. In the treatment of elderly patients with MM, novel agents have been successfully incorporated into less intensive regimens, including melphalan/prednisone, low-dose dexamethasone, and cyclophosphamide/dexamethasone. While second-generation proteasome inhibitors are currently being intensively investigated, the subcutaneous administration of bortezomib, being equivalent to the established i.v. route, is now entering clinical practice. Supportive care remains a crucial aspect in the management of MM. The European Myeloma Network Trialist Group aims to address these contemporary aspects in MM.

The introduction of thalidomide, lenalidomide, and bortezomib has changed the way that multiple myeloma (MM) is treated and has greatly improved survival outcomes. These novel agents are often used in combination with conventional drugs, such as dexamethasone, to optimize clinical responses; however, they are also being evaluated as part of novel treatment combinations to build upon the success of available treatment regimens. Lenalidomide-based combinations are a focus of clinical research due to the high efficacy, good tolerability, and lack of cumulative toxicity associated with lenalidomide. Lenalidomide is an IMiDs® immunomodulatory compound with a dual mechanism of action - tumoricidal effects rapidly reduce MM burden while long-term immunomodulatory actions maintain tumor suppression. Several new agents with antimyeloma effects have been identified including: epigenetic agents (e.g. histone deacetylase inhibitors); novel proteasome inhibitors; novel immunomodulatory compounds; cyclin-dependent kinase inhibitors; interleukin-6 inhibitors; and other experimental agents such as heat-shock protein 90 inhibitors and monoclonal antibodies targeting MM cell surface receptors (e.g. anti-CS1 and anti-CD40). Many of these new agents, in combination with lenalidomide, are in early phases of clinical evaluation. Early clinical results are promising, indicating that the novel lenalidomide-based drug combinations are effective and generally well tolerated in patients with MM; future research will continue to evaluate these novel combinations and help to identify the optimal setting (e.g. induction, salvage, or maintenance) in which they may provide the greatest impact on the disease course.

To obtain a comprehensive genomic profile of presenting multiple myeloma cases we performed high-resolution single nucleotide polymorphism mapping array analysis in 114 samples alongside 258 samples analyzed by U133 Plus 2.0 expression array (Affymetrix). We examined DNA copy number alterations and loss of heterozygosity (LOH) to define the spectrum of minimally deleted regions in which relevant genes of interest can be found. The most frequent deletions are located at 1p (30%), 6q (33%), 8p (25%), 12p (15%), 13q (59%), 14q (39%), 16q (35%), 17p (7%), 20 (12%), and 22 (18%). In addition, copy number-neutral LOH, or uniparental disomy, was also prevalent on 1q (8%), 16q (9%), and X (20%), and was associated with regions of gain and loss. Based on fluorescence in situ hybridization and expression quartile analysis, genes of prognostic importance were found to be located at 1p (FAF1, CDKN2C), 1q (ANP32E), and 17p (TP53). In addition, we identified common homozygously deleted genes that have functions relevant to myeloma biology. Taken together, these analyses indicate that the crucial pathways in myeloma pathogenesis include the nuclear factor-κB pathway, apoptosis, cell-cycle regulation, Wnt signaling, and histone modifications. This study was registered at http://isrctn.org as ISRCTN68454111.

PURPOSE/OBJECTIVE:To identify the maximum-tolerated dose (MTD) and to evaluate the antileukemic activity of tosedostat (formerly CHR-2797), an orally bioavailable aminopeptidase inhibitor. PATIENTS AND METHODS/METHODS:In phase I, the MTD of once daily oral doses of tosedostat in hematologic malignancies was defined. In phase II, the therapeutic activity of the maximum-acceptable dose (MAD) of tosedostat was evaluated in elderly and/or relapsing patients with acute myeloid leukemia (AML) or myelodysplastic syndrome. RESULTS:In phase I, 16 patients were treated in four cohorts with tosedostat (60 mg to 180 mg) for 28 days. Three patients reported dose-limiting toxicities: two with reversible thrombocytopenia (> 75% reduction in platelet count) at 180 mg (MTD) and one with a Common Toxicity Criteria (CTC) grade 3 ALT elevation at 130 mg (MAD). In phase II, 41 patients were treated with 130 mg tosedostat. In phases I and II, the most common severe (CTC grades 3 to 5) adverse event was a reduction in the platelet count. Of the 51 AML patients in this study, seven reached complete marrow response (< 5% marrow blasts), with three achieving complete remission, and a further seven patients reaching a partial marrow response (between 5% and 15% marrow blasts). The overall response rate was therefore 27%. All responders were age > 60 years, and 79% had either relapsed or refractory AML. CONCLUSION/CONCLUSIONS:This phase I/II study demonstrates that oral once daily dosing with 130 mg tosedostat is well tolerated and has significant antileukemic activity. The favorable risk-benefit profile suggests that further clinical trials are warranted.