Lust, John A.

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.

AbstractStandard myeloma treatment response criteria are determined principally by changes in the monoclonal protein. Reduction in the size of the proliferative component of malignant plasma cells may be an additional metric of assessing response to therapy. We retrospectively analyzed 176 patients with newly diagnosed myeloma with a measurable plasma cell labeling index (PCLI) at diagnosis and repeat measurement 4 months after initiation of therapy. PCLI response was defined as a ≥ 60% reduction. Baseline PCLI is an independent prognostic factor; therefore, we categorized patients into 3 groups: PCLI ≥ 3% (high), ≥ 1% (intermediate), and < 1% (low). Patients achieving a greater PCLI response had improved median overall survival of 54 months compared with 29 months in nonresponders (P = .02). Improved median overall survival with PCLI response occurred in the high initial PCLI group (28 vs 7 months; P = .003) and intermediate group (64 vs 24 months; P = .002). The application of PCLI response and serum M-spike response together provided further prognostic information. On multivariate analysis, the prognostic value of PCLI response was independent of β2-microglobulin, elevated creatinine, serum M-spike response, and baseline PCLI. We conclude that a significant reduction in plasma cell proliferation in patients with newly diagnosed myeloma is an important predictor of survival.

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.

AbstractThe efficacy of retreatment with immunomodulatory drugs (IMiDs) among patients with multiple myeloma who received this class of drugs for initial therapy is unknown. We studied 140 patients who received either thalidomide-dexamethasone (81; 58%) or lenalidomide-dexamethasone (59; 42%) as first-line therapy of multiple myeloma followed by repeat IMiD (thalidomide [34; 24%] or lenalidomide [106; 76%]) as one of the salvage regimens. A median of 2 treatments (range, 1-6), including a stem cell transplant in 105 patients (75%), were administered before IMiD-based salvage therapy. The median time from diagnosis to repeat exposure to IMiD was 28 months. Among the 113 evaluable patients, 50 (44%) achieved at least a partial response, and 63 (56%) achieved less than a partial response to repeat IMiD. Response rates with lenalidomide retreatment were higher than with repeat administration of thalidomide.

Abstract Background: IL-6 is a central myeloma growth factor and in vitro abnormal production of IL-1beta in the myeloma microenvironment stimulates the generation of paracrine IL-6. Mimicking in vitro observations, we have shown that responsive early stage myeloma patients at risk for progression to active myeloma who were treated with IL-1 inhibitors demonstrated decreases in the myeloma proliferative rate and C-reactive protein (IL-6 surrogate marker) leading to a chronic disease state with an improved progression free survival. In this study we investigated the effect of XOMA 052, a humanized anti-IL-1 antibody to inhibit stromal cell IL-6 production induced by either recombinant IL-1beta or supernatants generated from unsorted bone marrow cells from patients with smoldering multiple myeloma. Methods: Bone marrow stromal cells were incubated with varying concentrations of recombinant IL-1β (100, 10, 1, 0.1 pg/ml) in the absence or presence of anti-IL-1 antibody, anti-TNF antibody, or dexamethasone. In a similar fashion, supernatants from unsorted bone marrow cells from six patients with smoldering myeloma were co-cultured with bone marrow stromal cells and the effect of the humanized anti-IL-1β antibody was tested. Results: The anti-IL-1β antibody inhibited the IL-1 induced IL-6 production in vitro by &gt; 85% at 100 pg/ml of IL-1 and &gt; 90% at 10, 1, and 0.1 pg/ml of IL-1; specifically, using 10 pg/ml of IL-1, IL-6 production was inhibited from 149 down to 5.2 ng/ml in the presence of anti-IL-1 antibody. Anti-TNF antibody had minimal effect. At 10 pg/ml of IL-1 beta, a physiologically relevant amount of IL-1 in vitro in bone marrow samples from myeloma patients, the anti-IL-1 antibody was superior to dexamethasone at inhibition of IL-6 production. In in vitro testing of patient supernatants from unsorted bone marrow cells, three patients were high inducers and three patients low inducers of paracrine IL-6 production. The results demonstrate &gt; 85% reduction of IL-6 production in all patients' samples tested. Importantly, the anti-IL-1β antibody was highly effective in samples from the three patients who were high inducers of paracrine IL-6 production (IL-6 production was inhibited from 191 down to 12 ng/ml; 157 to 13 ng/ml and 320 to 11 ng/ml). In comparison, the anti-TNF antibody had marginal effects. Conclusion: The humanized anti-IL-1beta antibody is highly effective in vitro at the inhibition of IL-6 generated by supernatant cultures from patients with early stage myeloma or by recombinant IL-1. Combination therapy with IL-1 inhibitors and apoptosis inducing agents may be useful in patients with active myeloma that have elevated IL-6 levels and a high growth rate at diagnosis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2449.

AbstractThe objective of this case-control study was to compare the efficacy and toxicity of lenalidomide plus dexamethasone (len/dex) versus thalidomide plus dexamethasone (thal/dex) as initial therapy for newly diagnosed myeloma. We retrospectively studied 411 newly diagnosed patients treated with len/dex (228) or thal/dex (183) at the Mayo Clinic. The differences were similar in a matched-pair analysis that adjusted for age, sex, transplantation status, and dexamethasone dose. The proportions of patients achieving at least a partial response to len/dex and thal/dex were 80.3% versus 61.2%, respectively (P < .001); very good partial response rates were 34.2% and 12.0%, respectively (P < .001). Patients receiving len/dex had longer time to progression (median, 27.4 vs 17.2 months; P = .019), progression-free survival (median, 26.7 vs 17.1 months; P = .036), and overall survival (median not reached vs 57.2 months; P = .018). A similar proportion of patients in the 2 groups experienced at least one grade 3 or 4 adverse event (57.5% vs 54.6%, P = .568). Main grade 3 or 4 toxicities of len/dex were hematologic, mainly neutropenia (14.6% vs 0.6%, P < .001); the most common toxicities in thal/dex were venous thromboembolism (15.3% vs 9.2%, P = .058) and peripheral neuropathy (10.4% vs 0.9%, P < .001). Len/dex appears well-tolerated and more effective than thal/dex. Randomized trials are needed to confirm these results.

Purpose Thalidomide and lenalidomide are immunomodulatory drugs (IMiDs) that produce high remission rates in the treatment of multiple myeloma. Pomalidomide is a new IMiD with high in vitro potency. We report, to our knowledge, the first phase II trial of pomalidomide administered in combination with low-dose dexamethasone for the treatment of relapsed or refractory multiple myeloma. Patients and Methods Pomalidomide was administered orally at a dose of 2 mg daily on days 1 through 28 of a 28-day cycle. Dexamethasone 40 mg daily was administered orally on days 1, 8, 15, and 22 of each cycle. Responses were recorded using the criteria of the International Myeloma Working Group. Results Sixty patients were enrolled. Thirty-eight patients (63%) achieved confirmed response including complete response in three patients (5%), very good partial response in 17 patients (28%), and partial response in 18 patients (30%). Responses were seen in 40% of lenalidomide-refractory patients, 37% of thalidomide-refractory patients, and 60% of bortezomib-refractory patients. Responses were seen in 74% of patients with high-risk cytogenetic or molecular markers. Toxicity consisted primarily of myelosuppression. Grade 3 or 4 hematologic toxicity consisted of anemia (5%), thrombocytopenia (3%), and neutropenia (32%). One patient (1.6%) had a thromboembolic event. The median progression-free survival time was 11.6 months and was not significantly different in patients with high-risk disease compared with patients with standard-risk disease. Conclusion The combination of pomalidomide and low-dose dexamethasone is extremely active in the treatment of relapsed multiple myeloma, including high response rates in patients refractory to other novel agents.

Abstract Background: The repertoire of serologic tests for identifying a monoclonal gammopathy includes serum and urine protein electrophoresis (PEL), serum and urine immunofixation electrophoresis (IFE), and quantitative serum free light chain (FLC). Although there are several reports on the relative diagnostic contribution of these assays, none has looked at the tests singly and in combination for the various plasma cell proliferative disorders (PCPDs). Methods: Patients with a PCPD and all 5 assays performed within 30 days of diagnosis were included (n = 1877). The diagnoses were multiple myeloma (MM) (n = 467), smoldering multiple myeloma (SMM) (n = 191), monoclonal gammopathy of undetermined significance (MGUS) (n = 524), plasmacytoma (n = 29), extramedullary plasmacytoma (n = 10), Waldenström macroglobulinemia (WM) (n = 26), primary amyloidosis (AL) (n = 581), light chain deposition disease (LCDD) (n = 18), and POEMS syndrome (n = 31). Results: Of the 1877 patients, 26 were negative in all assays. Omitting urine from the panel lost an additional 23 patients (15 MGUS, 6 AL, 1 plasmacytoma, 1 LCDD), whereas the omission of FLC lost 30 patients (6 MM, 23 AL, and 1 LCDD). The omission of serum IFE as well as urine lost an additional 58 patients (44 MGUS, 7 POEMS, 5 AL, 1 SMM, and 1 plasmacytoma). Conclusions: The major impact of using a simplified screening panel of serum PEL plus FLC rather than PEL, IFE, and FLC is an 8% reduction in sensitivity for MGUS, 23% for POEMS (7 patients), 4% for plasmacytoma (1 patient), 1% for AL, and 0.5% for SMM. There is no diminution in sensitivity for detecting MM, macroglobulinemia, and LCDD.