Citations

Abstract POEMS syndrome is a paraneoplastic syndrome whose acronym stands for less than half of the defining features of the disease, that is, polyradiculoneuropathy, organomegaly, potentially including coexisting Castleman disease, endocrinopathy, monoclonal plasma cell neoplasm, and skin changes. The other important features include papilledema, extravascular volume overload, sclerotic bone lesions, thrombocytosis, elevated VEGF, and abnormal pulmonary function. The diagnosis is based on having both the polyradiculoneuropathy and the monoclonal plasma cell disorder, and at least 1 of the other 3 major criteria (Castleman disease, sclerotic bone lesions, or elevated VEGF) and at least one minor criterion. The diagnosis is often delayed with intervening incorrect diagnoses of chronic inflammatory demyelinating polyradiculoneuropathy, myeloproliferative disorder, and monoclonal gammopathy of undetermined significance. Prompt treatment directed at the underlying plasma cell clone produces dramatic responses in the majority of patients. Although there are no randomized clinical trial data to direct best therapy, for patients with disseminated disease, high-dose chemotherapy with peripheral blood transplantation has yielded durable benefit, whereas radiation therapy is typically effective for patients with a more localized presentation. More universal recognition of and more scientific inquiry into the underpinnings of the disease will provide direction toward the best treatment strategies in the future.

Abstract Light-chain (AL) amyloidosis remains incurable despite recent therapeutic advances. Given the activity of the lenalidomide-alkylating agent combination in myeloma, we designed this phase 2 trial of lenalidomide, cyclophosphamide, and dexamethasone in AL amyloidosis. Thirty-five patients, including 24 previously untreated, were enrolled. Nearly one-half of the patients had cardiac stage III disease and 28% had ≥ 3 organs involved. The overall hematologic response (≥ partial response [PR]) rate was 60%, including 40% with very-good partial response or better. Using serum-free light chain for assessing response, 77% of patients had a hematologic response. Organ responses were seen in 29% of patients and were limited to those with a hematologic response. The median hematologic progression-free survival was 28.3 months, and the median overall survival was 37.8 months. Hematologic toxicity was the predominant adverse event, followed by fatigue, edema, and gastrointestinal symptoms. A grade 3 or higher toxicity occurred in 26 patients (74%) including ≥ grade 3 hematologic toxicity in 16 patients (46%) and ≥ grade 3 nonhematologic toxicity in 25 patients (71%). Seven patients (20%) died on study, primarily because of advanced disease. Lenalidomide, cyclophosphamide, and dexamethasone (CRd) is an effective combination for treatment of AL amyloidosis and leads to durable hematologic responses as well as organ responses with manageable toxicity. The trial was registered at www.clinicaltrials.gov (NCT00564889).

Abstract Emerging evidence indicates that tumors can follow several evolutionary paths over a patient's disease course. With the use of serial genomic analysis of samples collected at different points during the disease course of 28 patients with multiple myeloma, we found that the genomes of standard-risk patients show few changes over time, whereas those of cytogenetically high-risk patients show significantly more changes over time. The results indicate the existence of 3 temporal tumor types, which can either be genetically stable, linearly evolving, or heterogeneous clonal mixtures with shifting predominant clones. A detailed analysis of one high-risk patient sampled at 7 time points over the entire disease course identified 2 competing subclones that alternate in a back and forth manner for dominance with therapy until one clone underwent a dramatic linear evolution. With the use of the Vk*MYC genetically engineered mouse model of myeloma we modeled this competition between subclones for predominance occurring spontaneously and with therapeutic selection.

Abstract Immunoglobulin light-chain (AL) amyloidosis is a rare, incurable plasma cell disorder. Its therapy has benefited immensely from the expanding drug armamentarium available for multiple myeloma. Pomalidomide in combination with weekly dexamethasone (Pom/dex) is active among patients with relapsed myeloma. In the present study, we explored the Pom/dex combination in patients with previously treated AL. Patients were eligible for this prospective phase 2 trial if they had had at least one prior regimen and if they had reasonably preserved organ function. Patients were treated with oral Pom/dex. Thirty-three patients were enrolled. The median age was 66 years. Median time from diagnosis to on-study was 37 months. Eighty-two percent had cardiac involvement. The confirmed hematologic response rate was 48%, with a median time to response of 1.9 months. Organ improvement was documented in 5 patients. The median overall and progression-free survival rates were 28 and 14 months, respectively; the 1-year overall and progression-free survival rates were 76% and 59%, respectively. There was a discordance between the hematologic response and the N-terminal pro-brain natriuretic peptide response. The most common grade 3-5 adverse events, regardless of attribution, were neutropenia and fatigue. We conclude that pomalidomide appears to be a valuable drug covering an unmet clinical need in patients with previously treated AL. The trial is registered at www.clinicaltrials.gov as NCT00558896.

AbstractThe purpose of this study was to define the risk of progression and survival of patients with smoldering Waldenström macroglobulinemia (SWM). SWM is defined clinically as having a serum monoclonal IgM protein ≥ 3 g/dL and/or ≥ 10% bone marrow lymphoplasmacytic infiltration but no evidence of end-organ damage (anemia, constitutional symptoms, hyperviscosity, lymphadenopathy, or hepatosplenomegaly). We searched a computerized database and reviewed the medical records of all patients at Mayo Clinic who fulfilled the criteria of SWM between 1974 and 1995. During 285 cumulative person-years of follow-up of the 48 patients with SWM (median, 15.4 years), 34 (71%) progressed to symptomatic Waldenström macroglobulinemia (WM) requiring treatment, one to primary amyloidosis, and one to lymphoma (total, 75%). The cumulative probability of progression to symptomatic WM, amyloidosis, or lymphoma was 6% at 1 year, 39% at 3 years, 59% at 5 years, and 68% at 10 years. The major risk factors for progression were percentage of lymphoplasmacytic cells in the bone marrow, size of the serum M-spike, and the hemoglobin value. Patients with SWM should be followed and not treated until symptomatic WM develops. Treatment on a clinical trial for those at greatest risk of progression should be considered.

SummaryPreviously, we reported increased risk of heavy‐chain (HC) monoclonal gammopathy of undetermined significance (MGUS) among first‐degree (1°) relatives of multiple myeloma (MM) or HC‐MGUS probands. This study investigated whether there was comparable risk for light‐chain (LC) MGUS among 911 relatives of the same HC‐MGUS/MM probands versus a reference population of 21 463. Seventeen 1° relatives had LC‐MGUS (adjusted prevalence = 1·7%, 95% CI = 0·9–2·6%). There was increased risk of LC‐MGUS in relatives of MM probands (RR = 3·4, 95% CI = 2·0–5·5). We saw no increased risk in relatives of HC‐MGUS probands. We conclude that the prevalence of LC‐MGUS is significantly higher among 1° relatives of MM probands compared to the reference population.

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.