Faculty Bibliography

Monitoring multiple myeloma (MM) is essential during the evaluation of response to each therapy line, after transplantation and at the time of relapse or progression in all patients. An initial complete workup, including appropriate protein studies in serum and urine is mandatory. The use of uniform criteria is particularly important in the context of clinical trials. Complete remission (CR) definition, the goal for the majority of patients, is now in constant evolution, with immunophenotypic and molecular minimal residual disease measurement in bone marrow as well as imaging techniques. Identification of relapse/progression with traditional and novel techniques for eventual prompt intervention with rescue treatment is a current issue of debate.

Bendamustine is a unique bifunctional alkylating agent with promising activity in myeloma. Despite the increasing number of studies demonstrating its efficacy in both the upfront and relapse settings, including patients with renal insufficiency, the optimal use of bendamustine, in terms of dosage, schedule and combination with other agents, has yet to be defined. It is currently licensed for use as frontline treatment with prednisolone for patients with myeloma who are unsuitable for transplantation and who are contraindicated for thalidomide and bortezomib. Studies in relapsed/refractory patients are currently ongoing with other combinations. Given the increasing data to date, the UK Myeloma Forum believes that bendamustine with steroids alone or in combination with a novel agent could be considered for patients with multiply relapsed myeloma. This document provides guidance for the use of bendamustine for patients with myeloma until the results of definitive studies are available.

The mechanisms involved in the progression from monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma (SMM) to malignant multiple myeloma (MM) and plasma cell leukemia (PCL) are poorly understood but believed to involve the sequential acquisition of genetic hits. We performed exome and whole-genome sequencing on a series of MGUS (n=4), high-risk (HR)SMM (n=4), MM (n=26) and PCL (n=2) samples, including four cases who transformed from HR-SMM to MM, to determine the genetic factors that drive progression of disease. The pattern and number of non-synonymous mutations show that the MGUS disease stage is less genetically complex than MM, and HR-SMM is similar to presenting MM. Intraclonal heterogeneity is present at all stages and using cases of HR-SMM, which transformed to MM, we show that intraclonal heterogeneity is a typical feature of the disease. At the HR-SMM stage of disease, the majority of the genetic changes necessary to give rise to MM are already present. These data suggest that clonal progression is the key feature of transformation of HR-SMM to MM and as such the invasive clinically predominant clone typical of MM is already present at the SMM stage and would be amenable to therapeutic intervention at that stage.

PURPOSE/OBJECTIVE:Novel multiple myeloma (MM) therapies have increased patient longevity but are often associated with notable symptom burden. This study quantified the effect of general symptom level, specific symptoms, and treatment-related adverse events (AEs) on MM patients' health-related quality of life (HRQoL). METHODS:The European Organization for Research and Treatment of Cancer (EORTC) generic cancer questionnaire (Quality of Life Questionnaire Core 30) and MM-specific questionnaire (QLQ-MY20) were used in this study to assess patients' HRQoL. Data were collected on sociodemographics, disease and treatment history, and the presence/severity of MM-related symptoms or treatment-related AEs from patients with MM in UK and German centers. Multiple regression analyses were conducted. RESULTS:Of 154 patients (63 % male; mean age, 66.4 years; mean time since diagnosis, 3.7 years; 52 % currently on treatment; and 43 % with ≥ 1 prior MM therapy), 25, 32, 31, and 11 % were severely symptomatic, moderately symptomatic, mildly symptomatic, and asymptomatic, respectively. Fatigue (59 %), bone pain (51 %), sleepiness (36 %), hypoesthesia or paresthesia (33 %), and muscle cramps (31 %) were most commonly reported. Moderate and severe general symptom levels, bone symptoms, depression, and mental status changes were identified as strong determinants of HRQoL. CONCLUSIONS:Severity, type of disease symptoms, and treatment related AEs are important HRQoL determinants in patients with MM, allowing for targeted treatment.

The chromosomal translocation t(4;14) deregulates MMSET (WHSC1/NSD2) expression and is a poor prognostic factor in multiple myeloma (MM). MMSET encodes two major protein isoforms. We have characterized the role of the shorter isoform (REIIBP) in myeloma cells and identified a clear and novel interaction of REIIBP with members of the SMN (survival of motor neuron) complex that directly affects the assembly of the spliceosomal ribonucleic particles. Using RNA-seq we show that REIIBP influences the RNA splicing pattern of the cell. This new discovery provides novel insights into the understanding of MM pathology, and potential new leads for therapeutic targeting.

PURPOSE/OBJECTIVE:Medical Research Council (MRC) Myeloma IX was a phase III trial evaluating bisphosphonate and thalidomide-based therapy for newly diagnosed multiple myeloma. Results were reported previously after a median follow-up of 3.7 years (current controlled trials number: ISRCTN68454111). Survival outcomes were reanalyzed after an extended follow-up (median, 5.9 years). EXPERIMENTAL DESIGN/METHODS:At first randomization, patients (N = 1,970) were assigned to bisphosphonate (clodronic acid or zoledronic acid) and induction therapies [cyclophosphamide-vincristine-doxorubicin-dexamethasone (CVAD) or cyclophosphamide-thalidomide-dexamethasone (CTD) followed by high-dose therapy plus autologous stem cell transplantation for younger/fitter patients (intensive pathway), and melphalan-prednisone (MP) or attenuated CTD (CTDa) for older/less fit patients (nonintensive pathway)]. At second randomization, patients were assigned to thalidomide maintenance therapy or no maintenance. Interphase FISH (iFISH) was used to analyze cytogenics. RESULTS:Zoledronic acid significantly improved progression-free survival (PFS; HR, 0.89; P = 0.02) and overall survival (OS; HR, 0.86; P = 0.01) compared with clodronic acid. In the intensive pathway, CTD showed noninferior PFS and OS compared with CVAD, with a trend toward improved OS in patients with favorable cytogenics (P = 0.068). In the nonintensive pathway, CTDa significantly improved PFS (HR, 0.81; P = 0.007) compared with MP and there was an emergent survival benefit after 18 to 24 months. Thalidomide maintenance improved PFS (HR, 1.44; P < 0.0001) but not OS (HR, 0.96; P = 0.70), and was associated with shorter OS in patients with adverse cytogenics (P = 0.01). CONCLUSIONS:Long-term follow-up is essential to identify clinically meaningful treatment effects in myeloma subgroups based on cytogenetics.

Significant benefits for zoledronic acid (ZOL) over clodronate acid (CLO) were seen in the Medical Research Council Myeloma IX randomized trial. ZOL significantly reduced skeletal-related events (SREs), and improved progression-free survival and overall survival (OS), making it the bisphosphonate of choice for newly diagnosed myeloma patients. In this analysis of Myeloma IX data, we have investigated the impact of response on bone disease in 1111 transplant-eligible patients. At posttransplant day 100, complete response (CR) was seen in 48% of patients, very good partial response (VGPR) in 20%, and partial response (PR) in 23%. For patients in VGPR or less, ZOL was superior to CLO in reducing SREs (P = .048), whereas for patients in CR, both agents were equivalent (P = .83). For OS, ZOL was associated with a significant benefit in patients in PR (P = .0091). No difference in OS was seen with patients in CR (P = .91) or VGPR (P = .74). These findings indicate that response category posttransplant may influence the impact of bisphosphonate therapy.

Multiple myeloma (MM) cells rely on protein homeostatic mechanisms for survival. These mechanisms could be therapeutically targeted via modulation of the heat shock response. We studied the roles of Hsp72 and Hsc70, and show that the two major cytoplasmic Hsp70s play a key role in regulating protein homeostasis and controlling multiple oncogenic pathways in MM, and their inhibition can lead to myeloma cell death. Our study provides further evidence that targeting Hsp70 represents a novel therapeutic approach which may be effective in the treatment of MM.

The first of the so-called "novel agents" (thalidomide, lenalidomide, and bortezomib), thalidomide has demonstrated activity as a single agent and in combination with other agents in patients with relapsed and/or refractory MM. The combination of melphalan, prednisone, and thalidomide (MPT) has become a standard treatment option for newly diagnosed patients who are ineligible for high-dose chemotherapy with autologous stem cell transplantation (ASCT). For patients intending to undergo ASCT, the combination of thalidomide, dexamethasone and cyclophosphamide can be used as a non-myelosuppressive induction regimen. Treatment with thalidomide is associated with an increased risk of developing peripheral neuropathy, which can be managed with dose reductions and discontinuation, and venous thromboembolism, which warrants thromboprophylaxis. While its adverse event profile may preclude prolonged use as maintenance therapy, thalidomide is an effective and well-tolerated salvage therapy option. Ongoing trials continue to evaluate novel thalidomide-based regimens to further optimize the use of thalidomide in the management of MM.