Citations

Abstract Disease Overview POEMS syndrome is a paraneoplastic syndrome due to an underlying plasma cell neoplasm. The major criteria for the syndrome are polyradiculoneuropathy, clonal plasma cell disorder (PCD), sclerotic bone lesions, elevated vascular endothelial growth factor, and the presence of Castleman disease. Minor features include organomegaly, endocrinopathy, characteristic skin changes, papilledema, extravascular volume overload, and thrombocytosis. Diagnoses are often delayed because the syndrome is rare and can be mistaken for other neurologic disorders, most commonly chronic inflammatory demyelinating polyradiculoneuropathy. POEMS syndrome should be distinguished from the Castleman disease variant of POEMS syndrome, which has no clonal PCD and typically little to no peripheral neuropathy but has several of the minor diagnostic criteria for POEMS syndrome. Diagnosis The diagnosis of POEMS syndrome is made with 3 of the major criteria, two of which must include polyradiculoneuropathy and clonal plasma cell disorder, and at least one of the minor criteria. Risk Stratification Because the pathogenesis of the syndrome is not well understood, risk stratification is limited to clinical phenotype rather than specific molecular markers. The number of clinical criteria is not prognostic, but the extent of the plasma cell disorder is. Those patients with an iliac crest bone marrow biopsy that does not reveal a plasma cell clone are candidates for local radiation therapy; those with a more extensive or disseminated clone will be candidates for systemic therapy Risk‐Adapted Therapy For those patients with a dominant sclerotic plasmacytoma, first‐line therapy is irradiation. Patients with diffuse sclerotic lesions or disseminated bone marrow involvement and for those who have progression of their disease 3–6 months after completing radiation therapy should receive systemic therapy. Corticosteroids are temporizing, but alkylators are the mainstay of treatment, either in the form of low‐dose conventional therapy or high dose with stem cell transplantation. Lenalidomide shows promise with manageable toxicity. Thalidomide and bortezomib also have activity, but their benefit needs to be weighed against their risk of exacerbating the peripheral neuropathy. The benefit of anti‐VEGF antibodies is conflicting. Prompt recognition and institution of both supportive care measures and therapy directed against the plasma cell result in the best outcomes.

Key Points PVD is an active combination in relapsed lenalidomide-refractory MM patients. PVD with weekly bortezomib offers a simpler, more convenient, and well-tolerated regimen option.

ABSTRACTIntroduction: In polyradiculoneuropathy‐organomegaly‐endocrinopathy‐monoclonal protein‐skin changes (POEMS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), limb nerve conduction studies (NCSs) are limited in identifying demyelination and in detecting treatment effects in severely affected patients. Blink R1 latency may improve these assessments. Methods: POEMS and CIDP patients who had undergone NCS and blink reflex were identified. Correlations among R1 latency, limb NCS, and neuropathy impairment scores (NIS) were compared. Results: Among 182 patients (124 POEMS, 58 CIDP) who were identified, R1 prolongation (>13 ms) occurred in 64.3% (65.3% POEMS, 62.1% CIDP). R1 prolongation correlated with more severely affected NCS in both POEMS (ulnar CMAP 2.6 mV vs. 4.5 mV, P = 0.001) and CIDP (2.0 mV vs. 6.1 mV, P < 0.001). In severely affected patients (ulnar CMAP ≤0.5 mV [10%:18/182]), R1 (>13 ms) helped establish demyelination. In 31 patients (16 POEMS, 15 CIDP), the R1 latency changes were concordant with NIS changes in 94% of patients with POEMS and 60% of patients with CIDP. Discussion: Blink R1 latencies are valuable in defining demyelination and detecting improvement in severely affected POEMS and CIDP patients. Muscle Nerve 57: E8–E13, 2018

AbstractPrior studies have revealed that the presence of increasing number of polyclonal plasma cells (pPCs) in the bone marrow (BM) are associated with better outcomes in newly diagnosed multiple myeloma (MM) patients. This effect has not been studied in patients with MM at the time of disease relapse. We determined the prognostic value of depletion of pPCs in the BM by 7‐color multiparameter flow cytometry in a series of 174 relapsing MM patients. The time to next therapy (TTNT) in those with <5% pPCs was 9.4 months versus 13.9 months in those with ≥5% pPCs (P = .0091). The median overall survival (OS) in those with <5% pPCs was 21.4 months, while the median OS was not reached in those patients with ≥5% pPCs (P = .019). Of the 109 patients with standard risk cytogenetics, the median OS of those with <5% pPCs was 28.4 months, while the median OS was not reached in those with ≥5% pPCs (P = .033). As such, <5% pPCs in the BM appears to have prognostic utility in identifying a subset of relapsing MM patients, even with standard‐risk cytogenetics, who have a particularly adverse outcome.

Abstract This phase 1/2 study assessed the safety, tolerability, and preliminary efficacy of the oral proteasome inhibitor (PI) ixazomib in patients with relapsed/refractory immunoglobulin light chain (AL) amyloidosis. Ixazomib was administered to adult patients with relapsed/refractory AL amyloidosis after 1 or more prior lines of therapy (including bortezomib) on days 1, 8, and 15 of 28-day cycles, for up to 12 cycles. Patients with less than partial response after 3 cycles received oral dexamethasone (40 mg, days 1-4) from cycle 4. A 3+3 dose-escalation phase was followed by 2 expansion cohorts (PI-naive and PI-exposed patients) at the maximum tolerated dose (MTD). Twenty-seven patients were enrolled: 11 during dose escalation (6 at 4.0 mg and 5 at 5.5 mg) and 16 during dose expansion (4.0 mg). Three patients experienced dose-limiting toxicities: 1 at 4.0 mg and 2 at 5.5 mg; the MTD was determined as 4.0 mg. Most common adverse events (AEs) included nausea, skin and subcutaneous tissue disorders (SSTD), diarrhea, and fatigue; grade 3 or higher AEs included dyspnea, fatigue, and SSTD. Overall, the hematologic response rate was 52% in patients treated at the MTD (n = 21). Organ responses were seen in 56% of patients (5 cardiac, 5 renal). Median hematologic progression-free survival was 14.8 months; 1-year progression-free and overall survival rates were 60% and 85%, respectively (median follow-up, 16.9 months). Weekly oral ixazomib appears to be active in patients with relapsed/refractory AL amyloidosis, with a generally manageable safety profile. The study was registered at clinicaltrials.gov as #NCT01318902. A phase 3 study is ongoing (#NCT01659658).

The detection and quantification of monoclonal‐proteins (M‐proteins) are necessary for the diagnosis and evaluation of response in plasma cell dyscrasias. Immunoglobulin enrichment‐coupled with matrix‐assisted laser desorption ionization time‐of‐flight mass‐spectrometry (MASS‐FIX) is a simple and inexpensive method to identify M‐proteins, but its clinical generalizability has not yet been elucidated. We compared MASS‐FIX to protein electrophoresis (PEL), serum/urine immunofixation‐electrophoresis (IFE), and quantitative serum free‐light chain (FLC) for the identification of M‐proteins in different clinical diagnoses. Paired serum and urine samples from 257 patients were tested. There were six patients for whom s‐IFE and FLC ratio were positive and serum MASS‐FIX was negative, but when serum and urine MASS‐FIX results were combined, only one patient with light chain‐MGUS was missed. Serum/urine‐MASS‐FIX detected M‐proteins in 18 patients with negative serum/urine‐PEL/IFE and serum‐FLC, 10 of whom had multiple myeloma or AL amyloidosis, who were mistakenly thought to have complete hematologic response by serum/urine‐PEL/IFE and serum‐FLC. Nearly half of the AL amyloidosis patients had atypical spectra, which may prove to be a clue to the diagnosis and pathogenesis of the disease. In conclusion, MASS‐FIX has a comparable sensitivity with PEL/IFE/FLC methods and can help inform the clinical diagnosis.

AbstractBackgroundData on the effect of systemic immunoglobulin light chain amyloidosis (AL amyloidosis) on thyroid function are limited.ObjectiveTo assess the prevalence of hypothyroidism in AL amyloidosis patients and determine its predictors.Methods1142 newly diagnosed AL amyloidosis patients were grouped based on the thyroid‐stimulating hormone (TSH) measurement at diagnosis: hypothyroid group (TSH above upper normal reference; >5 mIU L−1; n = 217, 19% of study participants) and euthyroid group (n = 925, 81%). Predictors for hypothyroidism were assessed in a binary multivariate model. Survival between groups was compared using the log‐rank test and a multivariate analysis.ResultsPatients with hypothyroidism were older, more likely to present with renal and hepatic involvement and had a higher light chain burden compared to patients in the euthyroid group. Higher proteinuria in patients with renal involvement and lower albumin in patients with hepatic involvement were associated with hypothyroidism. In a binary logistic regression model, age ≥65 years, female sex, renal involvement, hepatic involvement, kappa light chain restriction and amiodarone use were independently associated with hypothyroidism. Ninety‐three per cent of patients in the hypothyroid group with free thyroxine measurement had normal values, consistent with subclinical hypothyroidism. Patients in the hypothyroid group had a shorter survival compared to patients in the euthyroid group (4‐year survival 36% vs 43%; P = 0.008), a difference that was maintained in a multivariate analysis.ConclusionA significant proportion of patients with AL amyloidosis present with hypothyroidism, predominantly subclinical, which carries a survival disadvantage. Routine assessment of TSH in these patients is warranted.