Faculty Bibliography

BACKGROUND:Bisphosphonates are the standard of care for reducing the risk of skeletal-related events in patients with bone lesions from multiple myeloma. The MRC Myeloma IX study was designed to compare the effects of zoledronic acid versus clodronic acid in newly diagnosed patients with multiple myeloma. Here, we report the secondary outcomes relating to skeletal events. METHODS:Patients (≥18 years) with newly diagnosed multiple myeloma were enrolled from 120 centres in the UK and received intensive or non-intensive antimyeloma treatment. A computer-generated randomisation sequence was used to allocate patients in a 1:1 ratio, through an automated telephone service to intravenous zoledronic acid (4 mg every 21-28 days) or oral clodronic acid (1600 mg/day), and the drugs were continued at least until disease progression. No investigators, staff, or patients were masked to treatment allocation. The primary endpoints--overall survival, progression-free survival, and overall response rate--and adverse events have been reported previously. We assessed between-group differences with Cox proportional hazards models for time to first skeletal-related event and incidence of skeletal-related events. These were defined as fractures, spinal cord compression, radiation or surgery to bone, and new osteolytic lesions. Data were analysed until disease progression. Analyses were by intention to treat. This trial is registered, number ISRCTN68454111. FINDINGS/RESULTS:1960 patients were randomly assigned and analysed--981 in the zoledronic acid group and 979 in the clodronic acid group. This trial is fully enrolled, and follow-up continues. At a median follow-up of 3·7 years (IQR 2·9-4·7), patients in the zoledronic acid group had a lower incidence of skeletal-related events than did those in the clodronic acid group (265 [27%] vs 346 [35%], respectively; hazard ratio 0·74, 95% CI 0·62-0·87; p=0·0004). Zoledronic acid was also associated with a lower risk of any skeletal-related event in the subsets of patients with (233 [35%] of 668 vs 292 [43%] of 682 with clodronic acid; 0·77, 0·65-0·92; p=0·0038) and without bone lesions at baseline (29 [10%] of 302 vs 48 [17%] of 276 with clodronic acid; 0·53, 0·33-0·84; p=0·0068). Fewer patients in the zoledronic acid group had vertebral fractures than did those in the clodronic acid group (50 [5%] in the zoledronic acid group vs 88 [9%] in the clodronic acid group; p=0·0008), other fractures (45 [5%] vs 66 [7%]; p=0·04), and new osteolytic lesions (46 [5%] vs 95 [10%]; p<0·0001). INTERPRETATION/CONCLUSIONS:The results of this study support the early use of zoledronic acid rather than clodronic acid in patients with newly diagnosed multiple myeloma for the prevention of skeletal-related events, irrespective of bone disease status at baseline. FUNDING/BACKGROUND:Medical Research Council (London, UK), Novartis, Schering Health Care, Chugai, Pharmion, Celgene, and Ortho Biotech.

Viral haemorrhagic cystitis (HC) is a significant complication after haematopoietic stem cell transplantation (HSCT), with a potential for major morbidity. The aim of this 7-year analysis of 1160 HSCT patients was to evaluate risk factors for the incidence, severity, toxicity of therapy, clinical course, and outcome of this condition. The overall incidence of HC was 5·8%, with most cases occurring after allogeneic HSCT. Unrelated donors (P = 0·001), non-peripheral blood stem cell source (P = 0·005), myeloablative conditioning (P<0·001), use of alemtuzumab in conditioning (P = 0·001), and severe acute graft versus host disease (P<0·001) were independent risk factors for an increased incidence of HC post-allogeneic transplant on multivariate analysis. Severe forms of HC were associated with grades II-IV acute graft versus host disease and a longer duration of haematuria. Contrary to previous studies which were carried out on smaller patient populations, busulphan, cyclophosphamide, anti-thymocyte globulin, and total body irradiation were not found to independently increase the risk of viral HC, unless used in a myeloablative combination. Neither duration of viriuria nor peak viral load in urine influenced the severity of HC on multivariate analysis. Severe HC contributed to the deaths of two patients. Overall survival was not statistically different between patient subgroups with non-severe and severe HC.

Despite tangible progress in recent years, substantial therapeutic challenges remain in multiple myeloma (MM), particularly for patients at high risk for early relapse or death and for those with advanced multi-drug resistant disease and refractoriness to currently available combination regimens. Addressing these challenges requires identification of novel classes of anti-MM agents, their incorporation into safe and more effective combination regimens, and development of efficient algorithms to select the most appropriate therapeutic options for the clinical and molecular features of individual patients at a given time during their disease. Ideally, these goals can be facilitated by preclinical identification of the "driver" molecular lesions on which different myeloma subtypes exquisitely depend, and by informative preclinical models simulating the clinical setting(s) in which trials will be conducted. Large prospective studies of patients treated uniformly with contemporary clinical regimens are essential, but there is also a major need for flexibility in studying new regimens in the future. Long-term patient follow-up and integrated annotation of clinical (safety and efficacy) and correlative (molecular, biochemical, etc) data are also critical. Novel molecular profiling techniques will likely identify more clinically and biologically discrete subsets of patients with recurrent, even if infrequent, lesions. This molecular heterogeneity, combined with the increasing numbers of candidate therapeutic targets and respective investigational agents, may pose formidable challenges for the development and implementation of personalized medicine in MM. This review discusses these challenges, as well as potential strategies to address them, with the aim of making significant improvement in the clinical outcome of patients with MM.

An expert panel convened to reach a consensus regarding the optimal use of lenalidomide in combination with dexamethasone (Len/Dex) in patients with relapsed or refractory multiple myeloma (RRMM). On the basis of the available evidence, the panel agreed that Len/Dex is a valid and effective treatment option for most patients with RRMM. As with other therapies, using Len/Dex at first relapse is more effective regarding response rate and durability than using it after multiple salvage therapies. Len/Dex may be beneficial regardless of patient age, disease stage and renal function, although the starting dose of lenalidomide should be adjusted for renal impairment and cytopenias. Long-term treatment until there is evidence of disease progression may be recommended at the best-tolerated doses of both lenalidomide and dexamethasone. Recommendations regarding the prevention and management of adverse events, particularly venous thromboembolism and myelosuppression, were provided on the basis of the available evidence and practical experience of panel members. Ongoing trials will provide more insight into the effects of continuous lenalidomide-based therapy in myeloma.

Ire1 (Ern1) is an unusual transmembrane protein kinase essential for the endoplasmic reticulum (ER) unfolded protein response (UPR). Activation of Ire1 by association of its N-terminal ER luminal domains promotes autophosphorylation by its cytoplasmic kinase domain, leading to activation of the C-terminal ribonuclease domain, which splices Xbp1 mRNA generating an active Xbp1s transcriptional activator. We have determined the crystal structure of the cytoplasmic portion of dephosphorylated human Ire1α bound to ADP, revealing the 'phosphoryl-transfer' competent dimeric face-to-face complex, which precedes and is distinct from the back-to-back RNase 'active' conformation described for yeast Ire1. We show that the Xbp1-specific ribonuclease activity depends on autophosphorylation, and that ATP-competitive inhibitors staurosporin and sunitinib, which inhibit autophosphorylation in vitro, also inhibit Xbp1 splicing in vivo. Furthermore, we demonstrate that activated Ire1α is a competent protein kinase, able to phosphorylate a heterologous peptide substrate. These studies identify human Ire1α as a target for development of ATP-competitive inhibitors that will modulate the UPR in human cells, which has particular relevance for myeloma and other secretory malignancies.

PURPOSE/OBJECTIVE:To indentify genetic variation that can modulate and predict the risk of developing thalidomide-related peripheral neuropathy (TrPN). PATIENTS AND METHODS/METHODS:We analyzed DNA from 1,495 patients with multiple myeloma. Using a custom-built single nucleotide polymorphism (SNP) array, we tested the association of TrPN with 3,404 SNPs. The SNPs were selected in predicted functional regions within 964 genes spanning 67 molecular pathways thought to be involved in the pathogenesis, treatment response, and adverse effects associated with myeloma and its therapy. Patient cases and controls were derived from two large clinical trials that compared thalidomide with conventional-based treatment in myeloma patients (Medical Research Council Myeloma-IX and HOVON-50/GMMG-HD3). RESULTS:We report TrPN associations with SNPs-ABCA1 (rs363717), ICAM1 (rs1799969), PPARD (rs2076169), SERPINB2 (rs6103), and SLC12A6 (rs7164902)-where we show cross validation of the associations in both trials. To investigate whether TrPN SNP associations were related to exposure to thalidomide only or general drug-related peripheral neuropathy, we performed a second analysis on patients treated with vincristine. We report SNPs associated with vincristine neuropathy, with a seemingly distinct underlying genetic mechanism. CONCLUSION/CONCLUSIONS:Our results are consistent with the hypothesis that an individual's risk of developing a peripheral neuropathy after thalidomide treatment can be mediated by polymorphisms in genes governing repair mechanisms and inflammation in the peripheral nervous system. These findings will contribute to the development of future neuroprotective strategies with thalidomide therapy and the better use of this important compound.

Mycophenolate mofetil (MMF) is used to treat acute and chronic graft versus host disease (GvHD). There is scant evidence in the literature about mycophenolic acid (MPA) trough level monitoring in GvHD. We therefore reviewed 32 patients treated with MMF for acute (n = 19) or chronic GvHD (n = 13). Twelve (63%) of 19 patients with acute GvHD and nine (69%) of 13 with chronic GvHD showed a good response. In all 21 patients who responded to MMF, their mean total MPA levels were therapeutic (1-3.5 mg/L), whereas five of 11 patients who did not respond had sub-therapeutic mean MPA levels (p = 0.002). Sixteen (66%) of 24 steroid refractory or dependent patients responded to MMF. Associations between the mean total MPA level for each patient and the corresponding mean serum albumin concentration showed therapeutic mean total MPA levels for all 23 patients with mean albumin ≥ 31 g/L but sub-therapeutic mean total MPA levels in five of nine patients with mean albumin <31 g/L (p = 0.0006). In conclusion, MMF is efficacious in steroid refractory and dependent acute or chronic GvHD with statistically significant correlation between therapeutic plasma total MPA trough levels and clinical response. Serum albumin levels should be taken into account when considering MMF dose adjustments.