Search PubMed⌕ Search

Biomedical subjects

S Vincent Rajkumar

Publications and source records attributed to S Vincent Rajkumar.

At least 19 recordsLinked to original sources
PubMed2006

The activity of lenalidomide with or without dexamethasone in patients with primary systemic amyloidosis.

Primary systemic amyloidosis (AL) is an incurable plasma cell disorder. Lenalidomide, especially in conjunction with dexamethasone, is highly active in patients with multiple myeloma. We studied the toxicity and efficacy of lenalidomide in patients with AL. Patients with symptomatic AL, a measurable plasma cell disorder, and adequate hematologic and renal reserve were eligible. Patients received single-agent lenalidomide. If there was no evidence of progression after 3 months or of hematologic response after 3 cycles, dexamethasone was added. Twenty-three patients were enrolled. Thirteen were previously treated. Organ involvement was cardiac (64%), renal (73%), hepatic (23%), and nerve (14%). Within the first 3 cycles of therapy, 10 patients discontinued treatment: 4 early deaths, 3 adverse events, and 3 other causes. With a median follow-up of 17 months, 10 patients responded to treatment. In these patients, responses included 9 hematologic, 4 renal, 2 cardiac, and 2 hepatic. All but one of the responders had dexamethasone added to their treatment program. The most common grade 3 or 4 adverse events at least possibly attributable to lenalidomide were neutropenia (45%), thrombocytopenia (27%), rash (18%), and fatigue (18%). In AL patients, we saw limited activity of single-agent lenalidomide, but significant activity of the combination with dexamethasone, which warrants further investigation.

Administration, Oral↗
PubMed2006

Cytokine and chemokine profiles in multiple myeloma; significance of stromal interaction and correlation of IL-8 production with disease progression.

Multiple myeloma (MM) is a product of interactions between tumor plasma cells and multiple cell types native to the bone marrow (BM). We have used antibody array technology to examine the proteins produced by BM stromal cells in response to stimulation by BM taken from patients diagnosed with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and MM. We observed increased production of the chemokine IL-8 by stromal cells co-cultured with supernatants from bone marrow cells of patients with active myeloma. IL-8 production is correlated with active disease and is dependent upon IL-1beta and NF-kappaB signaling. Consistent with the pro-angiogenic activity of IL-8, increased BM microvessel density (MVD) correlated with stimulation of stromal cell IL-8 production. In addition, the majority of MM cell lines and MM patient plasma cells were found to express IL-8 receptors CXCR1 and CXCR2. We conclude that stromal cell IL-8 production parallels MM disease activity, is IL-1beta induced, and correlates with bone marrow angiogenesis.

Bone Marrow↗
PubMed2006

Differential expression of vascular endothelial growth factors and their receptors in multiple myeloma.

BACKGROUND AND OBJECTIVES: Bone marrow angiogenesis is increased in patients with multiple myeloma (MM) and correlates with disease stage. DESIGN AND METHODS: Previous studies of quantifying vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFR) in plasma cells from patients at different stages of MM found no significant difference in expression between overt MM and earlier pre-malignant stages of the disease namely, monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). RESULTS: In this report we used quantitative flow cytometry to study cytoplasmic VEGF (cyVEGF) expression (measured as antibody binding capacity) in plasma cells from patients with MM (n = 22), MGUS/SMM (n = 12), and AL-amyloidosis (AL) (n = 9). CyVEGF expression was higher in MM (169,591) than in MGUS/SMM (144,858), or AL (106,011) although these differences were not statistically significant. Using an indirect VEGFR assay that measures VEGF binding, we found VEGF receptors on plasma cells from all groups of patients, with the lowest expression on plasma cells from normal individuals. We detected VEGF R1, VEGF R2, and VEGF R3 on plasma cells from all groups of patients and found receptor expression predominantly in the subset of CD45-positive plasma cells. INTERPRETATION AND CONCLUSIONS: This study supports the concept that VEGF is involved in the pathogenesis of MM, and suggests that VEGF may differentially affect a subset of plasma cells.

Bone Marrow Cells↗
PubMed2006

A randomized phase 2 study of lenalidomide therapy for patients with relapsed or relapsed and refractory multiple myeloma.

This multicenter, open-label, randomized phase 2 study evaluated 2 dose regimens of lenalidomide for relapsed, refractory myeloma. Seventy patients were randomized to receive either 30 mg once-daily or 15 mg twice-daily oral lenalidomide for 21 days of every 28-day cycle. Patients with progressive or stable disease after 2 cycles received dexamethasone. Analysis of the first 70 patients showed increased grade 3/4 myelo-suppression in patients receiving 15 mg twice daily (41% versus 13%, P = .03). An additional 32 patients received 30 mg once daily. Responses were evaluated according to European Group for Blood and Marrow Transplantation (EBMT) criteria. Overall response rate (complete, partial, or minor) to lenalidomide alone was 25% (24% for once-daily and 29% for twice-daily lenalidomide). Median overall survival in 30-mg once-daily and twice-daily groups was 28 and 27 months, respectively. Median progression-free survival was 7.7 months on once-daily versus 3.9 months on twice-daily lenalidomide (P = .2). Dexamethasone was added in 68 patients and 29% responded. Time to first occurrence of clinically significant grade 3/4 myelosuppression was shorter in the twice-daily group (1.8 vs 5.5 months, P = .05). Significant peripheral neuropathy and deep vein thrombosis each occurred in only 3%. Lenalidomide is active and well tolerated in relapsed, refractory myeloma, with the 30-mg once-daily regimen providing the basis for future studies as monotherapy and with dexamethasone.

Adult↗
PubMed2006

Thalidomide and lenalidomide in the treatment of multiple myeloma.

Although multiple myeloma (MM) is incurable with currently available treatments, the introduction of thalidomide and the development of safer and more active thalidomide analogues represent a major advance in the therapy of this disease. Thalidomide, initially introduced for treatment of MM because of its anti-angiogenic properties, has shown remarkable activity alone and in combination with other drugs in patients across all stages of the disease. Given the potential for teratogenicity with thalidomide and the non-haematologic toxicities of the drug, several analogues referred to as "immunomodulatory drugs" (IMiDs) were developed with the intent of enhancing the immunomodulatory effect while minimizing the teratogenic risk. Lenalidomide (CC-5013) and Actimid (CC-4047) are the first such analogues to undergo clinical testing. Lenalidomide has shown impressive activity in relapsed refractory myeloma as well as newly diagnosed disease. The precise mechanism of anti-MM activity of thalidomide and the IMiDs is not clear, but studies suggest that several other mechanisms besides anti-angiogenic effects may play a role. In this paper we review the development, pharmacology, mechanism of action, pre-clinical and clinical efficacy, and the current status of thalidomide and the IMiDs in the treatment of MM.

Angiogenesis Inhibitors↗
PubMed2006

Frequency, characteristics, and reversibility of peripheral neuropathy during treatment of advanced multiple myeloma with bortezomib.

PURPOSE: To determine the frequency, characteristics, and reversibility of peripheral neuropathy from bortezomib treatment of advanced multiple myeloma. PATIENTS AND METHODS: Peripheral neuropathy was assessed in two phase II studies in 256 patients with relapsed and/or refractory myeloma treated with bortezomib 1.0 or 1.3 mg/m2 intravenous bolus on days 1, 4, 8, and 11, every 21 days, for up to eight cycles. Peripheral neuropathy was evaluated at baseline, during the study, and after the study by patient-reported symptoms using the Functional Assessment of Cancer Therapy Scale/Gynecologic Oncology Group-Neurotoxicity (FACT/GOG-Ntx) questionnaire and neurologic examination. During the study, peripheral neuropathy was also evaluated by investigator assessment. A subset of patients underwent nerve conduction studies (n = 13). RESULTS: Before treatment, 194 (81%) of 239 patients had peripheral neuropathy by FACT/GOG-Ntx questionnaire, and 203 (83%) of 244 patients had peripheral neuropathy by neurologic examination. Treatment-emergent neuropathy was reported in 35% of patients, including 37% (84 of 228 patients) receiving bortezomib 1.3 mg/m2 and 21% (six of 28 patients) receiving bortezomib 1.0 mg/m2. Grade 1 or 2, 3, and 4 neuropathy occurred in 22%, 13%, and 0.4% of patients, respectively. The incidence of grade > or = 3 neuropathy was higher among patients with baseline neuropathy by FACT/GOG-Ntx questionnaire compared with patients without baseline neuropathy (14% v 4%, respectively). In all 256 patients, neuropathy led to dose reduction in 12% and discontinuation in 5%. Of 35 patients with neuropathy > or = grade 3 and/or requiring discontinuation, resolution to baseline or improvement occurred in 71%. CONCLUSION: Bortezomib-associated peripheral neuropathy seemed reversible in the majority of patients after dose reduction or discontinuation. Although severe neuropathy was more frequent in the presence of baseline neuropathy, the overall occurrence was independent of baseline neuropathy or type of prior therapy.

Adult↗
PubMed2006

Immunoglobulin free light chains and solitary plasmacytoma of bone.

An abnormal serum immunoglobulin free light chain (FLC) ratio at diagnosis may identify risk of progression to myeloma in patients with solitary bone plasmacytoma (SBP). In the cohort of 116 patients, 43 have progressed to myeloma, with a median time to progression of 1.8 years. The FLC ratio was determined in all 116 patients on serum collected at time of diagnosis and was abnormal in 54 patients (47%). An abnormal FLC ratio was associated with a higher risk of progression to myeloma (P = .039). The risk of progression at 5 years was 44% in patients with an abnormal serum FLC ratio at diagnosis compared with 26% in those with a normal FLC ratio. One to 2 years following diagnosis, a persistent serum M protein level of 5 g/L (0.5 g/dL) or higher was an additional risk factor for progression. A risk stratification model was constructed using the 2 variables of FLC ratio and M protein level: patients with a normal FLC ratio at baseline and M protein level less than 5 g/L (0.5 g/dL) at 1 to 2 years following diagnosis (low risk, n = 31); with either risk factor abnormal (intermediate risk, n = 26); and with both an abnormal FLC ratio and M protein level of 5 g/L (0.5 g/dL) or higher (high risk, n = 18). The corresponding progression rates at 5 years were significantly different in the low, intermediate, and high groups: 13%, 26%, and 62%, respectively (P < .001).

Adult↗
PubMed2006

Prevalence of monoclonal gammopathy of undetermined significance.

BACKGROUND: The prevalence of monoclonal gammopathy of undetermined significance (MGUS), a premalignant plasma-cell disorder, among persons 50 years of age or older has not been accurately determined. We used sensitive laboratory techniques to ascertain the prevalence of MGUS in a large population in a well-defined geographic area. METHODS: We identified all living residents of Olmsted County, Minnesota, as of January 1, 1995. We obtained serum that remained after the performance of routine clinical tests at Mayo Clinic or asked subjects for whom such serum was unavailable to provide a sample. Agarose-gel electrophoresis was performed on all serum samples, and any serum sample with a discrete band of monoclonal protein or thought to have a localized band was subjected to immunofixation. RESULTS: Serum samples were obtained from 21,463 of the 28,038 enumerated residents 50 years of age or older (76.6 percent). MGUS was identified in 694 (3.2 percent) of these persons. Age-adjusted rates were higher in men than in women (4.0 percent vs. 2.7 percent, P<0.001). The prevalence of MGUS was 5.3 percent among persons 70 years of age or older and 7.5 percent among those 85 years of age or older. The concentration of monoclonal immunoglobulin was less than 1.0 g per deciliter in 63.5 percent and at least 2.0 g per deciliter in only 4.5 percent of 694 persons. The concentration of uninvolved immunoglobulins was reduced in 27.7 percent of 447 persons tested, and 21.5 percent of 79 tested had a monoclonal urinary light chain. CONCLUSIONS: Among residents of Olmsted County, Minnesota, MGUS was found in 3.2 percent of persons 50 years of age or older and 5.3 percent of persons 70 years of age or older.

Age Distribution↗
PubMed2006

Extended follow-up of a phase II trial in relapsed, refractory multiple myeloma:: final time-to-event results from the SUMMIT trial.

BACKGROUND: Bortezomib, a first-in-class proteasome inhibitor, has shown clinical activity in relapsed, refractory multiple myeloma in a pivotal Phase II trial, SUMMIT. METHODS: Patients received bortezomib 1.3 mg/m(2) on Days 1, 4, 8, and 11 followed by a 10-day rest period for up to 8 cycles. Dexamethasone 20 mg on the day of and the day after bortezomib was permitted for suboptimal response. Extended treatment beyond 8 cycles was offered to patients whose physicians felt they would benefit from additional therapy. Follow-up was conducted in all patients for a median of 23 months, an additional 13 months from the original report. RESULTS: Of 202 patients enrolled in SUMMIT, 193 were evaluable for response. Seven (4%) patients achieved a complete response, 12 (6%) achieved a nearly complete response, 34 (18%) achieved a partial response, and 14 (7%) had a minimal response while on bortezomib. The updated median duration of response to bortezomib alone was 12.7 months. The median overall time to progression for all SUMMIT patients was 7 months. For responding patients, the median time to progression was 13.9 months, whereas for those with progressive disease (PD) or who were not evaluable, the median time to progression was 1.3 months. The median overall survival (OS) for all SUMMIT patients was 17.0 months. Whereas the median OS for patients with PD or who were not evaluable was 8 months, the median OS for responding patients was not reached at 23 months of follow-up. CONCLUSIONS: These data demonstrate that treatment with bortezomib results in meaningful long-term benefit for patients with relapsed and refractory myeloma.

Adult↗
PubMed2006

Absolute values of immunoglobulin free light chains are prognostic in patients with primary systemic amyloidosis undergoing peripheral blood stem cell transplantation.

The immunoglobulin free light chain (FLC) is the precursor protein of amyloid in primary systemic amyloidosis (AL). Historically, the ability to monitor the amyloid protein precursor protein has been crude. We evaluated the utility of the FLC assay in a retrospective analysis of patients with AL undergoing peripheral blood stem cell transplantation (PBSCT). Ninety-three such patients had serial FLC measurements performed. The prognostic effects of the initial concentration and the extent of reduction of monoclonal FLC on survival were studied. There was a significantly higher risk of death in patients with higher baseline FLC (hazard ratio 2.6, P < .04). Baseline FLC correlated with serum cardiac troponin levels, and higher FLC levels were associated with more organs involved by amyloid, suggesting that high FLC levels may be associated with more advanced disease. The percent FLC reduction did not predict for survival, but the absolute level of FLC achieved after therapy did. Normalization of FLC level after PBSCT predicted for both organ response and complete hematologic response. Achievement of FLC response was a better predictor of survival than achievement of complete hematologic response or normalization of the FLC ratio. FLC measurements both before and after PBSCT are important predictors of patient outcome.

Adult↗
PubMed2006

Dermatologic adverse effects of lenalidomide therapy for amyloidosis and multiple myeloma.

OBJECTIVES: To examine dermatologic adverse effects of lenalidomide in patients with amyloidosis and multiple myeloma and to determine whether the adverse effects are different when lenalidomide is used alone compared with when it is used in combination with dexamethasone. DESIGN: Retrospective review of medical records. SETTING: Tertiary referral center. PATIENTS: Seventy-five patients with multiple myeloma and 23 patients with amyloidosis participating in clinical trials. INTERVENTION: In the 75 patients with multiple myeloma, lenalidomide was the treatment in 24 and lenalidomide and dexamethasone in 51. In the 23 patients with amyloidosis, lenalidomide was used alone. MAIN OUTCOME MEASURES: The frequency, type, severity, and time of onset of all skin eruptions that were temporally related to lenalidomide treatment were recorded. RESULTS: In the patients with amyloidosis treated with lenalidomide, 10 (43%) had rashes. In the patients with multiple myeloma, rashes occurred in 7 (29%) of those receiving lenalidomide alone and in 15 (29%) of those receiving lenalidomide and dexamethasone. The rashes were characterized as morbilliform, urticarial, dermatitic, acneiform, and undefined. Severe rashes required permanent discontinuation of lenalidomide therapy in 2 patients. In 23 patients (72%), rashes occurred in the first month after therapy was initiated; however, delayed-onset rashes occurred in 9 (28%). CONCLUSIONS: The prevalence of dermatologic adverse effects in patients receiving lenalidomide was higher in those with amyloidosis than in those with multiple myeloma. The prevalence of skin eruptions was not diminished by the concurrent use of systemic corticosteroids. Most skin eruptions were mild and did not necessitate withdrawal of lenalidomide therapy.

Amyloidosis↗
PubMed2006

6q deletion discriminates Waldenström macroglobulinemia from IgM monoclonal gammopathy of undetermined significance.

IgM monoclonal gammopathy of undetermined significance (IgM MGUS) and Waldenström macroglobulinemia (WM) are sometimes clinically difficult to distinguish. In our previous study, deletion of the long arm of chromosome 6 (6q) was found in about half of WM patients. To further clarify the area of minimal deletion at 6q (6q-) and to address the issue of whether 6q- occurs in IgM MGUS, 12 IgM MGUS and 38 WM patients were studied by fluorescence in situ hybridization using probes targeting different chromosomal segments of 6q. No 6q deletions were found in IgM MGUS samples. Of 38 successfully studied WM patients, 21 (55%) showed a deletion of 6q. The area of minimal deletion was between 6q23 and 6q24.3, but the deletion usually encompassed a large fragment of the 6q arm. These results indicate that 6q- can distinguish WM from IgM MGUS and is likely to be a secondary event.

Aged↗
PubMed2006

Treatment of multiple myeloma: an emphasis on new developments.

Not all patients who fulfill the minimal criteria for diagnosis of multiple myeloma should be treated. If doubt exists about beginning therapy, one should wait and re-evaluate the patient in 2 or 3 months. There is no evidence that early treatment of multiple myeloma is advantageous. All patients should be considered possible candidates for an autologous stem cell transplantation. If they are deemed to be eligible, they should be treated for 3 to 4 months with therapy that does not damage the hematopoietic stem cells. Currently, most physicians use thalidomide plus dexamethasone or dexamethasone alone for induction. Vincristine, doxorubicin (Adriamycin), and dexamethasone (VAD) have been used in the past. Autologous stem cell transplantation prolongs disease-free survival and overall survival. The treatment-related mortality rate is 1% to 2%. Melphalan, 200 mg/m2, is the most widely used preparative regimen. Although allogeneic transplantation is attractive, the mortality rate (about 20%) is too high to recommend conventional allogeneic transplantation. Non-myeloablative transplantation is currently under investigation. If the patient is not a candidate for autologous stem cell transplantation, therapy with melphalan and prednisone is a good choice. Patients with relapsed or refractory disease may be treated with dexamethasone, thalidomide and dexamethasone, bortezomib (Velcade, PS-341), or lenalidomide (Revlimid, not yet approved by the Food and Drug Administration).

Angiogenesis Inhibitors↗
PubMed2006

A phase II trial of imatinib in patients with refractory/relapsed myeloma.

Although imatinib was designed to specifically inhibit the bcr-abl gene product, it inhibits other receptor tyrosine kinases including c-kit. As pre-clinical data, 126 patients with plasma cell disorders and 19 controls were evaluated for c-kit expression. Patients were eligible for the treatment trial if they had relapsed/refractory myeloma. The primary end-point of the study was response. Of the 145 studied before the trial, c-kit expression was present on the bone marrow plasma cells of control (11%), AL amyloid (53%), MGUS (47%), SMM (67%) and MM (42%) patients. Twenty-three MM patients were enrolled on the therapeutic trial (imatinib 400 mg daily) and 52% had positive c-kit staining. There were no responses. The median duration of treatment was 48 days (range: 12-349). Patients ended treatment due to progressive disease (18 patients), death (3) and other (2). The data suggest that imatinib is not an active agent in patients with relapsed or refractory multiple myeloma.

Aged↗
PubMed2006

Natural history of thromboembolism in AL amyloidosis.

To determine the natural history of thromboembolism in patients with biopsy-proven AL amyloidosis, medical records of 2,132 patients evaluated at Mayo Clinic between 1975 and 2000 were reviewed. Forty patients (21 male) were found to have objectively documented thromboembolism. The median age was 65 years. Four patients had a monoclonal gammopathy of undetermined significance, 20 had an unspecified plasma cell proliferative disorder, 11 had multiple myeloma, and 1 had Waldenström macroglobulinemia. Twelve patients had cardiac amyloid, and 20 had renal amyloid. Neither the extent of the amyloid nor the type of monoclonal protein was predictive of the development of thromboembolic events. Thromboembolism preceded the diagnosis of AL amyloidosis in 11 patients, occurred at the time of diagnosis or within 1 month after diagnosis in 11 patients, and occurred 1 month or more after diagnosis in 18 patients. Twenty-nine patients (73%) had venous thrombosis and 11 (28%) had arterial thrombosis. Eight patients (20%) died within 1 month after the thrombotic event, and 18 (45%) died within 1 year. The development of thrombosis in patients with AL amyloidosis appears to predict significant mortality within the first month and year after the event.

Aged↗
PubMed2006

Prognostic model for disease-specific and overall mortality in newly diagnosed symptomatic patients with Waldenstrom macroglobulinaemia.

We sought to define prognostic factors for survival in Waldenstrom macroglobulinaemia (WM). Of 585 patients diagnosed with WM and seen at Mayo Clinic between 1960 and 2001, 337 symptomatic patients met the inclusion criteria and were analysed for overall and disease-specific survival. The median survival from the time of diagnosis was 6.4 years. The median disease-specific survival was 11.2 years. Univariate analysis for overall survival identified the following adverse prognostic factors: age >65 years (P < 0.001), organomegaly (P < 0.001), elevated beta2-microglobulin (<0.001), anaemia (Hb < 10.0 g/dl) (P = 0.01), leucopenia (<4.0 x 10(9)/l) (P = 0.03), thrombocytopenia (<150 x 10(9)/l) (P = 0.01), serum albumin <40 g/l (P = 0.001), and quantitative IgM < 0.4 g/l (P = 0.04). On multivariate analysis, age >65 years and organomegaly were associated with poor prognosis. A prognostic model was built based on these two variables. Patients at high risk (1-2 risk factors, median survival 4.2 years) experienced worse survival than patients at low risk (0 risk factors, median survival 10.6 years), P < 0.001. The prognostic model was validated in 204 patients who were not included in the analysis cohort. Beta2-microglobulin > or =4 mg/l was associated with a threefold increase in the risk of death when added to the prognostic model. We describe a simple prognostic model for overall survival for newly diagnosed patients with WM.

Adult↗
PubMed2006

Monoclonal gammopathy of undetermined significance.

Significant advances have been made in our understanding of the natural history, pathogenesis, mechanisms of progression and prognosis of monoclonal gammopathy of undetermined significance (MGUS). Although the overall incidence of MGUS progression is 1 per year, it is now possible to more accurately predict the risk of progression based on a new risk-stratification model. However, it is still hard to design chemopreventive trials given that the absolute risk of progression per year is low, even in the high-risk group. Therefore, further improvements in estimating the risk of progression are needed. Roughly 50% of MGUS may originate from primary translocation events at the heavy-chain immunoglobulin locus at chromosome 14q32. In most of the remaining MGUS patients, the initiating event is associated with genomic instability that results in hyperdiploidy of certain odd numbered chromosomes. Cytogenetically distinct subtypes of MGUS may carry significant differences in the risk of progression to malignancy. New markers, such as measures of bone marrow angiogenesis and circulating plasma cells may be additional prognostic factors. A better understanding of the mechanisms underlying the transition of normal plasma cells to the MGUS phenotype, and the transition of MGUS to myeloma or related malignancy, will help identify new risk factors for progression and new targets for chemopreventive interventions.

Aged↗