Thalidomide-prednisone maintenance following autologous stem cell transplant for multiple myeloma: effect on thrombin generation and procoagulant markers in NCIC CTG MY.10.

Venous thromboembolism (VTE) has an increased incidence in patients with multiple myeloma (MM), especially during chemotherapy. Mechanisms including upregulation of procoagulant factors, such as factor VIII, have been postulated. The National Cancer Institute of Canada Clinical Trials Group MY.10 phase III clinical trial compared thalidomide-prednisone to observation for 332 patients with MM post-autologous stem cell transplantation (ASCT), with a primary endpoint of overall survival and various secondary endpoints including the incidence of VTE. One hundred and fifty-three patients had biomarker data, including D-dimer, factor VIII and thrombin anti-thrombin (TAT) levels collected post-ASCT at baseline and 2 months after intervention investigating in-vivo thrombin generation. Differences between the time-points included a significant reduction over time in D-dimer, factor VIII and TAT levels in the observation group and sustained elevation of D-dimer, significant increase in factor VIII and reduction in TAT levels in the thalidomide-prednisone group. Eight VTE events were reported in this subset of study patients, all in the thalidomide-prednisone arm, with a trend to increase in D-dimer levels over time in those patients with VTE. This study provides physiological and clinical evidence for an increased risk of VTE associated with thalidomide-prednisone maintenance therapy post-ASCT for MM.

Randomized comparison of gemcitabine, dexamethasone, and cisplatin versus dexamethasone, cytarabine, and cisplatin chemotherapy before autologous stem-cell transplantation for relapsed and refractory aggressive lymphomas: NCIC-CTG LY.12.

PURPOSE: For patients with relapsed or refractory aggressive lymphoma, we hypothesized that gemcitabine-based therapy before autologous stem-cell transplantation (ASCT) is as effective as and less toxic than standard treatment. PATIENTS AND METHODS: We randomly assigned 619 patients with relapsed/refractory aggressive lymphoma to treatment with gemcitabine, dexamethasone, and cisplatin (GDP) or to dexamethasone, cytarabine, and cisplatin (DHAP). Patients with B-cell lymphoma also received rituximab. Responding patients proceeded to stem-cell collection and ASCT. Coprimary end points were response rate after two treatment cycles and transplantation rate. The noninferiority margin for the response rate to GDP relative to DHAP was set at 10%. Secondary end points included event-free and overall survival, treatment toxicity, and quality of life. RESULTS: For the intention-to-treat population, the response rate with GDP was 45.2%; with DHAP the response rate was 44.0% (95% CI for difference, -9.0% to 6.7%), meeting protocol-defined criteria for noninferiority of GDP (P = .005). Similar results were obtained in a per-protocol analysis. The transplantation rates were 52.1% with GDP and 49.3% with DHAP (P = .44). At a median follow-up of 53 months, no differences were detected in event-free survival (HR, 0.99; stratified log-rank P = .95) or overall survival (HR, 1.03; P = .78) between GDP and DHAP. Treatment with GDP was associated with less toxicity (P < .001) and need for hospitalization (P < .001), and preserved quality of life (P = .04). CONCLUSION: For patients with relapsed or refractory aggressive lymphoma, in comparison with DHAP, treatment with GDP is associated with a noninferior response rate, similar transplantation rate, event-free survival, and overall survival, less toxicity and hospitalization, and superior quality of life.

A prospective phase II study of RICE re-induction, then high-dose fludarabine and busulfan, followed by autologous or allogeneic blood stem cell transplantation for indolent b-cell lymphoma.

BACKGROUND: Optimal high dose conditioning and relative roles of autologous stem cell transplantation (autoSCT) or allogeneic (alloSCT) for indolent lymphoma are uncertain. METHODS: A prospective phase II study evaluated autoSCT and alloSCT depending on availability of sibling donor after uniform rituximab, ifosfamide, carboplatin, etoposide (RICE) re-induction and novel myeloablative fludarabine, busulfan (FluBu) conditioning for patients with mantle cell lymphoma in first remission or first relapse, or indolent lymphoma in first or second relapse. RESULTS: The 68 patients (autoSCT, 36; syngeneic [syn], 1; alloSCT, 31) who were accrued had a 10-month median progression-free survival (PFS) after their last chemotherapy treatment. After RICE, the overall response rate was 69%, and 24 of 39 patients (62%) cleared marrow of lymphoma. Treatment-related mortality at 100 days and 1 year after FluBu were both 0% post-auto/synSCT, but were 6% and 26% post-alloSCT, respectively. At a median follow-up of 60 months, the respective 5-year overall survival and PFS rates were 71% and 46% for auto/synSCT, and were 58% and 47% for alloSCT. Quality of life assessment 1-year post-SCT favoured auto/synSCT. CONCLUSIONS: The protocol was feasible, FluBu was well-tolerated, and both auto/synSCT and alloSCT conferred similar 5-year PFS following the RICE-FluBu protocol.

Lenalidomide oral monotherapy produces durable responses in relapsed or refractory indolent non-Hodgkin's Lymphoma.

PURPOSE: Lenalidomide is a novel immunomodulatory agent with antiproliferative activities. Given its efficacy in a wide range of hematologic malignancies, we conducted a phase II trial (NHL-001) of single-agent lenalidomide in indolent non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: Patients with relapsed/refractory indolent NHL were eligible, with no limit on the number of previous therapies. Oral lenalidomide 25 mg was self-administered once daily on days 1 to 21 of every 28-day cycle for up to 52 weeks as tolerated, or until disease progression. The primary end point was objective response rate (ORR), with secondary end points of duration of response (DR), progression-free survival (PFS), and safety. RESULTS: Forty-three enrolled patients were assessable for response and safety. Patients received a median of three prior systemic therapies (range, 1 to 17) and half were refractory to last therapy. ORR was 23% (10 of 43), including a 7% complete response (CR) or unconfirmed CR rate. Twenty-seven percent (six of 22) of patients with follicular lymphoma grade 1 or 2, and 22% (four of 18) with small lymphocytic lymphoma responded to therapy. Median DR was not reached, but was longer than 16.5 months with seven of 10 responses ongoing at 15 to 28 months. Median PFS for the whole group was 4.4 months (95% CI, 2.5 to 10.4 months). Adverse events were predictable and manageable; the most common grade 3 or 4 adverse events were neutropenia (30% and 16%, respectively) and thrombocytopenia (14% and 5%, respectively). CONCLUSION: Oral lenalidomide monotherapy produces durable responses with manageable adverse events in patients with relapsed/refractory indolent NHL, warranting further investigation of treatment for indolent NHL.

RIZ1 is potential CML tumor suppressor that is down-regulated during disease progression.

BACKGROUND: RIZ1 expression and activity are reduced in many cancers. In AML cell lines and patient material, RIZ1 expression is reduced relative to normal bone marrow. In chronic myelogenous leukemia (CML), blastic transformation is associated with loss of heterozygosity in the region where RIZ1 is located. RIZ1 is a PR domain methyltransferase that methylates histone H3 lysine 9, a modification important for transcriptional repression. In CML blast crisis cell lines RIZ1 represses insulin-like growth factor-1 expression and autocrine signaling. Together these observations suggest that RIZ1 may have a role in the chronic phase to blast crisis transition in CML. RESULTS: In CML patient material, we observed that RIZ1 expression was decreased during progression from chronic phase to blast crisis. RIZ1 was expressed in mature myeloid and CD34+ cells demonstrating that decreased RIZ1 expression in blast crisis is not due to an increased immature cell population. Expression of RIZ1 CML blast crisis cell lines decreased proliferation, increased apoptosis, and enhanced differentiation. CONCLUSION: RIZ1 is a candidate tumor suppressor gene whose expression is decreased in blast crisis. Loss of RIZ1 activity results in decreased apoptosis and differentiation and enhanced proliferation. Together these results suggest that loss of RIZ1 expression will lead to an increase in myeloid blast cell population resulting in CML progression.

Bortezomib in relapsed or refractory Waldenström's macroglobulinemia.

Bortezomib is a proteasome inhibitor that induces apoptosis in primary Waldenström's macroglobulinemia (WM) cells and WM cell lines. To date, 3 clinical trials of single-agent bortezomib in WM have been published. Of the 64 patients pooled from these studies (most with relapsed/refractory disease), a 25% or greater reduction of IgM was achieved in 78%-85%. Responses were rapid in onset, suggesting a role for bortezomib in the management of hyperviscosity or other settings where rapid IgM reduction is indicated. Neuropathy appears more severe and frequent in WM than in myeloma or other indolent lymphomas treated with bortezomib. Bortezomib-based combination therapies, with consideration for attenuated or intermittent dosing of bortezomib to minimize neuropathy, are under investigation.

Treatment of relapsed and refractory myeloma.

Multiple myeloma is a malignancy of plasma cells that remains incurable and almost all patients will eventually require some form of salvage therapy. Increasing insight into the biology of myeloma and the availability of new therapeutic options has resulted in rapid change in its management. Clinical trials have investigated numerous agents and regimens for the treatment of patients with relapsed/refractory myeloma, presenting a host of treatment options. Important questions in determining optimal therapy for patients with relapsed/refractory myeloma include the influence of prior therapy, optimal sequencing of regimens, sequential versus combination use of agents, and the role of cytogenetic and other prognostic factors. This article reviews the literature for the treatment of relapsed/refractory myeloma and considers the ability of the evidence to answer these questions, both for established regimens and newer regimens incorporating thalidomide, bortezomib and lenalidomide.

Bortezomib is active in patients with untreated or relapsed Waldenstrom's macroglobulinemia: a phase II study of the National Cancer Institute of Canada Clinical Trials Group.

PURPOSE: To evaluate the efficacy and toxicity of single-agent bortezomib in Waldenström's macroglobulinemia (WM). PATIENTS AND METHODS: Symptomatic WM patients, untreated or previously treated, received bortezomib 1.3 mg/m2 intravenously days 1, 4, 8, and 11 on a 21-day cycle until two cycles past complete response (CR), stable disease (SD) attained, progression (PD), or unacceptable toxicity. Responses were based on both paraprotein levels and bidimensional disease measurements. RESULTS: Twenty-seven patients were enrolled. A median of six cycles (range, two to 39) of bortezomib were administered. Twenty-one patients had a decrease in immunoglobulin M (IgM) of at least 25%, with 12 patients (44%) reaching at least 50% IgM reduction. Using both IgM and bidimensional criteria, responses included seven partial responses (PRs; 26%), 19 SDs (70%), and one PD (4%). Total response rate was 26%. IgM reductions were prompt, with nodal responses lagging. Hemoglobin levels increased by at least 10 g/L in 18 patients (66%). Most nonhematologic toxicities were grade 1 to 2, but 20 patients (74%) developed new or worsening peripheral neuropathy (five patients with grade 3, no grade 4), a common cause for dose reduction. Onset of neuropathy was within two to four cycles and reversible in the majority. Hematologic toxicities included grade 3 to 4 thrombocytopenia in eight patients (29.6%) and neutropenia in five (19%). Toxicity led to treatment discontinuation in 12 patients (44%), most commonly because of neuropathy. CONCLUSION: Bortezomib has efficacy in WM, but neurotoxicity can be dose limiting. The slower response in nodal disease may require prolonged therapy, perhaps with a less intensive dosing schedule to avoid early discontinuation because of toxicity. Future studies of bortezomib in combination with other agents are warranted.

Short nucleotide polymorphic insertions in the MCL-1 promoter affect gene expression.

We have recently reported novel short nucleotide (six and eighteen) polymorphic insertions, in the MCL-1 promoter and their association with higher mRNA and protein levels. The aim of the present study was to test the hypothesis that these insertions directly affect MCL-1 gene expression. Haematopoietic and epithelial human cell lines were transfected with +0, +6, or +18 MCL-1 promoter fragments positioned upstream of the Firefly luciferase reporter gene. The cells were stimulated with phorbol 12-myristate 13-acetate (PMA) and granulocyte macrophage colony-stimulating factor (GM-CSF). Compared to +0, both polymorphic insertions (+6 and +18) were associated with increased promoter activity. Although chromatin immunoprecipitation assay showed that there are Sp1/Sp3 binding sites in the MCL-1 promoter, electrophoretic mobility shift assay showed that it is unlikely that these sites are in the region harboring these insertions. These results provide further evidence for the biological effect of MCL-1 promoter polymorphisms on gene expression.

A molecular compendium of genes expressed in multiple myeloma.

We have created a molecular resource of genes expressed in primary malignant plasma cells using a combination of cDNA library construction, 5' end single-pass sequencing, bioinformatics, and microarray analysis. In total, we identified 9732 nonredundant expressed genes. This dataset is available as the Myeloma Gene Index (www.uhnres.utoronto.ca/akstewart_lab).Predictably, the sequenced profile of myeloma cDNAs mirrored the known function of immunoglobulin-producing, high-respiratory rate, low-cycling, terminally differentiated plasma cells. Nevertheless, approximately 10% of myeloma-expressed sequences matched only entries in the database of Expressed Sequence Tags (dbEST) or the high-throughput genomic sequence (htgs) database. Numerous novel genes of potential biologic significance were identified. We therefore spotted 4300 sequenced cDNAs on glass slides creating a myeloma-enriched microarray. Several of the most highly expressed genes identified by sequencing, such as a novel putative disulfide isomerase (MGC3178), tumor rejection antigen TRA1, heat shock 70-kDa protein 5, and annexin A2, were also differentially expressed between myeloma and B lymphoma cell lines using this myeloma-enriched microarray. Furthermore, a defined subset of 34 up-regulated and 18 down-regulated genes on the array were able to differentiate myeloma from nonmyeloma cell lines. These not only include genes involved in B-cell biology such as syndecan, BCMA, PIM2, MUM1/IRF4, and XBP1, but also novel uncharacterized genes matching sequences only in the public databases. In summary, our expressed gene catalog and myeloma-enriched microarray contains numerous genes of unknown function and may complement other commercially available arrays in defining the molecular portrait of this hematopoietic malignancy. GenBank Accession numbers include BF169967-BF176369, BF185966-BF185969, and BF177280-BF177455.

Antigenic open reading frames from HHV-8 are present in multiple myeloma patients and normal individuals at similar frequency.

It has been proposed that the absence of a humoral response to human herpes virus 8 (HHV-8) in patients with multiple myeloma (MM) reflects strain variation or the mutation, or absence, of the antigenic regions of HHV-8 recognized in ELISA screening tests. We therefore assessed DNA sequence of three antigenic regions (ORF65, ORF73 and ORFK8.1) and the transforming hypervariable K1 ORF of HHV-8 in fresh bone marrow cells, bone marrow derived dendritic cells (DCs) and bone marrow stromal cells (BMSCs) from 12 patients with MM and 8 normal individuals. HHV-8 ORFs were detectable by nested PCR in MM patients (ORF65: 67% ORF73: 22% and K8.1: 58%), but were also surprisingly frequent in normal individuals (ORF65: 37%, ORF73: 12.5% and K8.1: 62%). HHV-8 sequences were more frequently detected in cells from BMSC and DC culture than from fresh bone marrow in MM. In contrast no HHV-8 sequences were detected in BMSC from normal individuals. Sequence analysis of ORF65 failed to demonstrate productive mutations in any MM sample. K1 genomic sequences were detected in 42% of MM and 37% of normals and exhibited 98% homology with the K1-A1 HHV-8 strain. In conclusion, our data do not support the presence of a K1-C3 strain of HHV-8 with ORF65 expression deficiency in MM patients. HHV-8 infection appears to be common in the general population when sensitive PCR is employed and multiple samples are analyzed.