Citations

Purpose Cardiac involvement predicts poor prognosis in light chain (AL) amyloidosis, and the current prognostic classification is based on cardiac biomarkers troponin-T (cTnT) and N-terminal pro–B-type natriuretic peptide (NT-ProBNP). However, long-term outcome is dependent on the underlying plasma cell clone, and incorporation of clonal characteristics may allow for better risk stratification. Patients and Methods We developed a prognostic model based on 810 patients with newly diagnosed AL amyloidosis, which was further examined in two other datasets: 303 patients undergoing stem-cell transplantation, and 103 patients enrolled onto different clinical trials. Results We examined the prognostic value of plasma cell–related characteristics (ie, difference between involved and uninvolved light chain [FLC-diff], marrow plasma cell percentage, circulating plasma cells, plasma cell labeling index, and β 2 microglobulin). In a multivariate model that included these characteristics as well as cTnT and NT-ProBNP, only FLC-diff, cTnT, and NT-ProBNP were independently prognostic for overall survival (OS). Patients were assigned a score of 1 for each of FLC-diff ≥ 18 mg/dL, cTnT ≥ 0.025 ng/mL, and NT-ProBNP ≥ 1,800 pg/mL, creating stages I to IV with scores of 0 to 3 points, respectively. The proportions of patients with stages I, II, III and IV disease were 189 (25%), 206 (27%), 186 (25%) and 177 (23%), and their median OS from diagnosis was 94.1, 40.3, 14, and 5.8 months, respectively (P < .001). This classification system was validated in the other datasets. Conclusion Incorporation of serum FLC-diff into the current staging system improves risk stratification for patients with AL amyloidosis and will help develop risk-adapted therapies for AL amyloidosis.

Abstract Routine incorporation of FISH into multiple myeloma (MM) diagnostic testing has led to a better appreciation of the heterogeneity of genetic abnormalities associated with this disease. We studied a group of 484 patients with newly diagnosed symptomatic MM to better understand the prevalence of the various abnormalities and the prognostic significance of the overlapping abnormalities. A translocation involving the IgH locus and 1 of the 5 recurrent partner chromosomes was seen in 161 (33%) patients, and 275 (57%) had trisomy of at least 1 odd-numbered chromosome. High-risk FISH, defined as the presence of t(4;14), t(14;16), t(14;20), or loss of P53, was seen in 115 (24%) patients; the median overall survival for this group was 3.9 years, compared with “not reached” for standard-risk patients (P < .001). Among the patients with high-risk FISH, 49 patients who also had at least 1 trisomy had a median overall survival that was not reached, compared with 3 years for high-risk patients without a concurrent trisomy (P = .01). Based on the current findings, we conclude that the presence of trisomies in patients with t(4;14), t(14;16), t(14;20), or p53 deletion abnormalities in MM ameliorates the usual adverse impact associated with these prognostic markers.

Abstract High-dose melphalan (HDM) plus stem cell transplantation is an effective treatment for light-chain amyloidosis (AL), but is associated with high treatment-related mortality in patients with cardiac involvement. We studied 187 patients with cardiac involvement with AL who underwent HDM between 1996 and 2008. The median age was 57 years and the median time from diagnosis to HDM was 3.6 months. Half of the patients received reduced-dose melphalan (100-160 mg/m2). The median overall survival (OS) was 66 months, 54 months from diagnosis and HDM, respectively, and 91 patients (49%) were alive at the last follow-up 52 months (median) from HDM. Thirty patients (16%) died within 100 days of transplantation; only low serum albumin predicted early deaths. Overall, hematologic response (HR) and cardiac responses were seen in 66% and 41% of patients, respectively. The median OS for patients with and without HR was not reached and 22 months, respectively (P < .01); and for those with any decrease and no decrease in N-terminal-pro-brain natriuretic peptide was not reached and 26 months, respectively (P < .01). In multivariate analysis of baseline factors, only reduced-dose melphalan predicted shorter OS. HDM is feasible in patients with cardiac amyloidosis, and achievement of HR and organ response is associated with improved survival.

Abstract IgD monoclonal gammopathies are uncommon. They are seen rarely as a monoclonal gammopathy of undetermined significance and are present in 1%-2% of patients with multiple myeloma. In light-chain amyloidosis, IgD monoclonal proteins are found in ap-proximately 1% of patients. When an IgD monoclonal protein is found, amyloidosis is often omitted from the differential diagnosis. In the present study, we reviewed the natural history of IgD-associated amyloidosis among 53 patients seen over 41 years. The distribution of clinical syndromes suggests that these patients have a lower frequency of renal and cardiac involvement. The overall survival of these patients does not appear to be different from that of patients who have light-chain amyloidosis associated with another monoclonal protein.

Abstract Recent population-based studies demonstrate an increased fracture risk with monoclonal gammopathy of undetermined significance (MGUS). The etiology of this increased risk remains unclear, however, because areal bone mineral density (aBMD) measurements by dual-energy x-ray absorptiometry cannot assess bone microstructural properties critical to determining bone quality and strength. To better define the skeletal effects of MGUS, we performed aBMD and high-resolution peripheral quantitative computed tomography volumetric bone mineral density (vBMD) measurements in 50 MGUS patients (20 females, 30 males; mean ± SEM age, 70.5 ± 1.4 years) and 100 matched control subjects. Relative to controls, MGUS patients had decreased aBMD at the femoral neck (P = .05) and total femur (P < .05) but no differences at other sites. In contrast, high-resolution peripheral quantitative computed tomography showed markedly diminished cortical thickness (P < .05) and increased endocortical area (P < .01). Average vBMD (P < .01), cortical vBMD (P < .001), and trabecular thickness (P < .01) were all significantly decreased in MGUS patients, suggestive of impaired bone formation. Serum levels of the Wnt pathway inhibitor Dickkopf-related protein 1 (P < .001) and osteoclast-activating factor MIP-1α (P < .05) also were significantly elevated in MGUS patients. Our data provide the first evidence of altered bone microstructure in MGUS and suggest that cytokines elevated in osteolytic myeloma also may be associated with bone loss in MGUS.

Abstract The POEMS syndrome is associated with elevated vascular endothelial growth factor (VEGF) levels. Several studies have compared serum VEGF levels between POEMS patients and other disease entities showing higher serum VEGF in POEMS syndrome; however, it is unknown whether serum levels are reliable and reproducible given variable platelet release of VEGF. We therefore compared plasma levels of VEGF in 29 patients with POEMS syndrome with those of other disorders (n = 76). We demonstrated that plasma VEGF levels are useful in differentiating POEMS from other plasma cell dyscrasias, neuropathic processes, and multisystem illnesses. Plasma VEGF is also useful in monitoring disease activity after treatment and correlates with clinical improvements better than hematologic response.

Abstract Detection of specific chromosomal abnormalities by FISH and metaphase cytogenetics allows risk stratification in multiple myeloma; however, gene expression profiling (GEP) based signatures may enable more specific risk categorization. We examined the utility of 2 GEP-based risk stratification systems among patients undergoing initial therapy with lenalidomide in the context of a phase 3 trial. Among 45 patients studied at baseline, 7 (16%) and 10 (22%), respectively, were high-risk using the GEP70 and GEP15 signatures. The median overall survival for the GEP70 high-risk group was 19 months versus not reached for the rest (hazard ratio = 14.1). Although the medians were not reached, the GEP15 also predicted a poor outcome among the high-risk patients. The C-statistic for the GEP70, GEP15, and FISH based risk stratification systems was 0.74, 0.7, and 0.7, respectively. Here we demonstrate the prognostic value for GEP risk stratification in a group of patients primarily treated with novel agents. This trial was registered at www.clinicaltrials.gov as #NCT00098475.

Abstract During the course of multiple myeloma (MM), new monoclonal proteins of an isotype distinct from the original clone, referred to as secondary monoclonal gammopathy of undetermined significance (MGUS), have been described. We report on the frequency, characteristics, and outcome of secondary MGUS. Of the 1942 patients with MM, 128 (6.6%) developed a secondary MGUS, at a median of 12 months from the diagnosis of MM. The median duration of secondary MGUS was 5.9 months. Secondary MGUS was more common in patients after stem cell transplantation than in those who had not undergone such treatment (22.7% vs 1.6%, P &lt; .001). Overall survival was significantly superior in MM patients who developed secondary MGUS compared with the rest of the cohort (73 vs 38 months, respectively; P &lt; .001). The time of onset and the duration of secondary MGUS, as well as failure to resolve spontaneously, had an effect on overall survival and require further study.

Abstract Allogeneic hematopoietic cell transplantation in multiple myeloma is limited by prior reports of high treatment-related mortality. We analyzed outcomes after allogeneic hematopoietic cell transplantation for multiple myeloma in 1207 recipients in 3 cohorts based on the year of transplantation: 1989-1994 (n = 343), 1995-2000 (n = 376), and 2001-2005 (n = 488). The most recent cohort was significantly older (53% > 50 years) and had more recipients after prior autotransplantation. Use of unrelated donors, reduced-intensity conditioning and the blood cell grafts increased over time. Rates of acute graft-versus-host (GVHD) were similar, but chronic GVHD rates were highest in the most recent cohort. Overall survival (OS) at 1-year increased over time, reflecting a decrease in treatment-related mortality, but 5-year relapse rates increased from 39% (95% confidence interval [CI], 33%-44%) in 1989-1994 to 58% (95% CI, 51%-64%; P < .001) in the 2001-2005 cohort. Projected 5-year progression-free survival and OS are 14% (95% CI, 9%-20%) and 29% (95% CI, 23%-35%), respectively, in the latest cohort. Increasing age, longer interval from diagnosis to transplantation, and unrelated donor grafts adversely affected OS in multivariate analysis. Survival at 5 years for subjects with none, 1, 2, or 3 of these risk factors were 41% (range, 36%-47%), 32% (range, 27%-37%), 25% (range, 19%-31%), and 3% (range, 0%-11%), respectively (P < .0001).

Abstract Pomalidomide at doses of 2 or 4 mg/d has demonstrated excellent activity in patients with multiple myeloma (MM). We opened 2 sequential phase 2 trials using the pomalidomide with weekly dexamethasone (Pom/dex) regimen at differing doses to study the efficacy of this regimen in patients who have failed both lenalidomide and bortezomib. Pomalidomide was given orally 2 or 4 mg daily with dexamethasone 40 mg weekly. Thirty-five patients were enrolled in each cohort. Confirmed responses in the 2-mg cohort consisted of very good partial response (VGPR) in 5 (14%), partial response (PR) in 4 (11%), minor response (MR) in 8 (23%) for an overall response rate of 49%. In the 4-mg cohort, confirmed responses consisted of complete response (CR) in 1 (3%), VGPR in 3 (9%), PR in 6 (17%), MR in 5 (14%) for an overall response rate of 43%. Overall survival at 6 months is 78% and 67% in the 2- and 4-mg cohort, respectively. Myelosuppression was the most common toxicity. This nonrandomized data suggests no advantage for 4 mg over the 2 mg daily. Pomalidomide overcomes resistance in myeloma refractory to both lenalidomide and bortezomib. This trial is registered at http://ClinicalTrials.gov, number NCT00558896.