A novel Bcl-2/Bcl-X(L)/Bcl-w inhibitor ABT-737 as therapy in multiple myeloma.

Bcl-2 or Bcl-X(L) confers resistance to chemotherapy in multiple myeloma (MM). Here we characterized the effects of ABT-737, a potent small-molecule inhibitor of antiapoptotic proteins Bcl-2, Bcl-X(L) and Bcl-w with markedly higher affinity than previously reported compounds, on human MM cells. ABT-737 induces apoptosis in MM cells, including those resistant to conventional therapy. Examination of purified patient MM cells demonstrated similar results, without significant toxicity against normal peripheral blood mononuclear cells and MM bone marrow stromal cells. Importantly, ABT-737 decreases the viability of bortezomib-, dexamethasone-(Dex) and thalidomide-refractory patient MM cells. Additionally, ABT-737 abrogates MM cell growth triggered by interleukin-6 or insulin-like growth factor-1. Mechanistic studies show that ABT-737-induced apoptosis is associated with activation of caspase-8, caspase-9 and caspase-3, followed by poly(ADP-ribose) polymerase cleavage. Combining ABT-737 with proteasome inhibitor bortezomib, melphalan or dexamethasone induces additive anti-MM activity. Taken together, our study provides the rationale for clinical protocols evaluating ABT-737, alone and together with botezomib, mephalan or dexamethasone, to enhance MM cell killing, overcome drug resistance conferred by Bcl-2 and improve patient outcome in MM.

The role of tumor necrosis factor alpha in the pathophysiology of human multiple myeloma: therapeutic applications.

In this study we demonstrate that tumor necrosis factor alpha (TNFalpha) triggers only modest proliferation, as well as p44/p42 mitogen-activated protein kinase (MAPK) and NF-kappaB activation, in MM.1S multiple myeloma (MM) cells. TNFalpha also activates NF-kappaB and markedly upregulates (fivefold) secretion of interleukin-6 (IL-6), a myeloma growth and survival factor, in bone marrow stromal cells (BMSCs). TNFalpha in both a dose and time dependent fashion induced expression of CD11a (LFA-1), CD54 (intercellular adhesion molecule-1, ICAM-1), CD106 (vascular cell adhesion molecule-1, VCAM-1), CD49d (very late activating antigen-4, VLA-4), and/or MUC-1 on MM cell lines; as well as CD106 (VCAM-1) and CD54 (ICAM-1) expression on BMSCs. This resulted in increased (2-4-fold) per cent specific binding of MM cells to BMSCs, with related IL-6 secretion. Importantly, the proteasome inhibitor PS-341 abrogated TNFalpha-induced NF-kappaB activation, induction of ICAM-1 or VCAM-1, and increased adhesion of MM cells to BMSCs. Agents which act to inhibit TNFalpha may therefore abrogate the paracrine growth and survival advantage conferred by MM cell adhesion in the BM microenvironment.

Recovery after stem-cell transplantation for hematologic diseases.

PURPOSE: Although the number of autologous and allogeneic stem-cell transplantations (SCT) is increasing, relatively little information about recovery after transplantation is available. Quantitative information appropriate for patient counseling is difficult to discern from the literature. We sought to suggest reasonable expectations for recovery and symptoms after SCT for hematologic malignancies and other disorders using the following measures: (1) objective measures of health status, such as frequency of clinic visits, need for rehospitalization, medication usage, work status, and overall and event-free survival; (2) qualitative assessment of quality of life, such as returning to a normal life, resumption of normal activities, satisfaction with appearance, and whether recovery has occurred; and (3) quantification of specific bothersome symptoms. PATIENTS AND METHODS: Autologous and allogeneic SCT recipients at a tertiary-care transplant center participated in the prospective, longitudinal questionnaire study. RESULTS: Three hundred twenty patients were studied. Questionnaire response rates at 6, 12, and 24 months range from 85% to 88% among survivors. Although autologous patients had better event-free and overall survival, fewer symptoms, and more complete recovery at 6 months, these advantages had largely equalized by 12 months. Specific bothersome symptoms were reported by less than 24% of patients after transplantation, except for fatigue and financial and sexual difficulties, which were more prevalent. CONCLUSION: These findings may help counsel patients considering transplantation and educate them about reasonable expectations for recovery. Overall, the low level of bothersome symptoms and continued recovery through the first year after transplantation are encouraging.

High-dose chemoradiotherapy and anti-B-cell monoclonal antibody-purged autologous bone marrow transplantation in mantle-cell lymphoma: no evidence for long-term remission.

PURPOSE: The role for high-dose therapy and autologous stem-cell transplantation in mantle-cell lymphoma (MCL) is unknown. We retrospectively analyzed patients with chemosensitive disease who underwent high-dose chemoradiotherapy and anti-B-cell monoclonal antibody-purged autologous bone marrow transplantation (ABMT) for MCL in first remission, as well as following relapse from conventional therapy. PATIENTS AND METHODS: Between August 1985 and April 1996, 28 patients underwent ABMT using a uniform ablative regimen with cyclophosphamide and total-body irradiation (TBI) and a bone marrow-purging regimen. Re-review of original tissue demonstrated that all patients had morphologic, phenotypic, and genotypic characteristics of MCL. MCL was the original diagnosis in 21 patients, whereas seven patients had a prior diagnosis of diffuse small cleaved-cell lymphoma. RESULTS: Twenty patients received multiple regimens before ABMT, while eight underwent ABMT in first complete remission (CR)/partial remission (PR) following CHOP induction. At bone marrow harvest, only 18% of patients were in CR and overt BM infiltration was present in 57%. Following cyclophosphamide/TBI, no treatment-related deaths were seen. Nineteen of 28 patients have relapsed at a median time of 21 months (range, 3 to 70). Of eight patients transplanted in first CR/PR, five have relapsed. Nine patients are in continuous CR with a median follow-up time of 24 months (range, 10 to 135). Disease-free survival (DFS) and overall survival (OS) are estimated to be 31% and 62% at 4 years, respectively. CONCLUSION: ABMT using cyclophosphamide/TBI conditioning may at best be effective in only a small fraction of patients with relapsed MCL. The lack of plateau with a median follow-up time of 24 months suggests cure may not be achievable. The role of this therapy in patients in first remission requires more study using better induction therapy to enhance the CR rate before ABMT.

CD6+ donor marrow T-cell depletion as the sole form of graft-versus-host disease prophylaxis in patients undergoing allogeneic bone marrow transplant from unrelated donors.

PURPOSE: The role of donor marrow T-cell depletion (TCD) in preventing graft-versus-host disease (GVHD) after transplantation of unrelated allogeneic marrow remains undefined. Because different TCD methodologies differ in the degree and specificity with which T cells are removed, it is likely that transplant outcomes would depend on which technique is used. Herein, we report results in the first 48 recipients of unrelated marrow using CD6+ TCD as the sole form of GVHD prophylaxis. PATIENTS AND METHODS: Median age of patients was 46 years (20 to 58 years). Donors were matched at A/B HLA loci. Ablation consisted of cyclophosphamide and fractionated total-body irradiation (TBI; 14 Gy). To facilitate engraftment, patients also received 7.5 Gy (22 patients) [corrected] or 4.5 Gy (26 patients) [corrected] of total lymphoid irradiation (TLI) before admission. No additional immune suppressive prophylaxis was administered. Granulocyte colony-stimulating factor was administered daily from day +1 to engraftment. RESULTS: All 48 patients demonstrated neutrophil engraftment. An absolute neutrophil count of 500 x 10(6)/L was achieved at a median of 12 days (range, 9 to 23 days). There were no cases of late graft failure. The number of CD34+ cells infused/kg was associated with speed of platelet and neutrophil recovery. The dose of TLI did not influence engraftment. Grades 2-4 acute GVHD occurred in 42% of patients (95% confidence interval [CI], 0.28 to 0.57). Mortality at day 100 was 19%. There have been only five relapses. Estimated 2-year survival was 44% (95% CI, 0.28 to 0.59) for the entire group, 58% for patients less than 50 years of age. In multivariable analysis, age less than 50 years (P =.002), cytomegalovirus seronegative status (P =.04), and early disease status at bone marrow transplant (P =.05) were associated with superior survival. CONCLUSION: CD6+ TCD does not impede engraftment of unrelated bone marrow after low-dose TLI, cyclophosphamide, and TBI. CD6+ TCD as the sole form of GVHD prophylaxis results in an incidence of GVHD that compares favorably with many adult studies of unrelated transplantation using unmanipulated marrow and immune-suppressive medications, especially in light of the median age of our patients (46 years). Although event-free survival in patients less than 50 years of age is very encouraging, older patients experience frequent transplantation-related complications despite TCD.

Purging of autologous peripheral-blood stem cells using CD34 selection does not improve overall or progression-free survival after high-dose chemotherapy for multiple myeloma: results of a multicenter randomized controlled trial.

PURPOSE: Although high-dose chemotherapy supported by autologous peripheral-blood progenitor-cell (PBPC) transplantation improves response rates and survival for patients with multiple myeloma, all patients eventually develop progressive disease after transplantation. It has been hypothesized that depletion of malignant plasma cells from autografts may improve outcome by reducing infused cells contributing to relapse. PATIENTS AND METHODS: A randomized phase III study using the CEPRATE SC System (Cellpro, Bothell, WA) to enrich CD34(+) autograft cells and passively purge malignant plasma cells was completed in 190 myeloma patients randomized to receive an autograft of CD34-selected or unselected PBPCs. RESULTS: After CD34 selection, tumor burden was reduced by 1.6 to 6.0 logs (median, 3.1), with 54% of CD34-enriched products having no detectable tumor. Median time to count recovery, number of transfusions, transplantation-related mortality, and days in hospital were equivalent between the two transplantation arms. With a median follow-up of 37 months, 33 patients (36%) in the selected and 34 patients (35%) in the unselected arm had died (P =.784). Median overall survival in the selected arm was reached at 50 months and is not reached at this time in the unselected arm (P =.78). Median disease-free survival was 100 versus 104 weeks (P =.82), with 67% of patients in the selected arm and 66% of patients in the unselected arm relapsing. CONCLUSION: This phase III trial demonstrates that although CD34 selection significantly reduces myeloma cell contamination in PBPC collections, no improvement in disease-free or overall survival was achieved.

Intracardiac leiomyomatosis: diagnosis and treatment.

Intracardiac leiomyomatosis is the presence of a benign smooth muscle tumor within a cardiac chamber reaching the heart by direct intravenous extension from an extracardiac source. After a case report and a review of the 13 previously reported cases, the clinical features, diagnostic considerations, differential diagnosis and treatment modalities of intracardiac leiomyomatosis are discussed.

Routine screening for psychosocial distress following hematopoietic stem cell transplantation.

The diagnosis and treatment of cancer is often associated with high levels of psychosocial distress, yet exploration of these issues is rarely included in routine oncologic care. We conducted a pilot study to evaluate the feasibility of screening for psychosocial distress after autologous and allogeneic stem cell transplantation. A total of 80 adults were enrolled in Boston, MA, USA. Subjects completed self-administered assessments prior to hospital admission, at their first clinic visit after hospital discharge, and at 100 days post transplant. Assessments included validated instruments assessing psychosocial distress and quality of life (QOL). Elevated levels of anxiety and/or depression were detected in 55% of those providing pre-transplant assessments and were associated with compromised QOL. Post transplant screening was successfully performed in 69% of subjects and identified that 44% had symptoms of depression, anxiety or post traumatic stress disorder. Pre-transplant distress was associated with detection of distress after transplantation (81 vs 13%, P< 0.0001). In summary, we detected high levels of distress in transplant patients using self-administered tools. Pre-transplant distress appears to be highly predictive of distress post transplant and is a feasible marker to target screening and intervention programs.

Adherence of multiple myeloma cells to bone marrow stromal cells upregulates vascular endothelial growth factor secretion: therapeutic applications.

Increased angiogenesis has recently been recognized in active multiple myeloma (MM). Since vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are two key mediators of angiogenesis, we characterized the production of VEGF, b-FGF and interleukin-6 (IL-6) (a MM growth and survival factor) in MM cell lines and Epstein-Barr virus (EBV) transformed B cell lines from MM patients, patient MM cells, as well as bone marrow stromal cells (BMSCs) from normal healthy donors and MM patients. We detected secretion of VEGF, but no bFGF and IL-6, in MM cell lines (MM.1S, RPMI 8226 and U266); EBV transformed B cell lines from MM patients (IM-9, HS-Sultan and ARH77); MM cell lines resistant to doxorubicin (RPMI-DOX40), mitoxantrone (RPMI-MR20), melphalan (RPMI-LR5) and dexamethasone (MM.1R); and patient MM cells (MM1 and MM2). BMSCs from MM patients and normal donors secreted VEGF, b-FGF and IL-6. Importantly, when MM cells were adhered to BMSCs, there was a significant increase in VEGF (1.5- to 3.1-fold) and IL-6 (1.9- to 56-fold) secretion. In contrast, the bFGF decreased in co-cultures of BMSCs and MM cells. Paraformaldehyde fixation of BMSCs or MM cells prior to adhesion revealed that VEGF was produced both from BMSCs and MM cells, though it may come primarily from BMSCs in some cultures. IL-6 was produced exclusively in BMSCs, rather than MM cells. Moreover, when MM cells were placed in Transwell insert chambers to allow their juxtaposition to BMSCs without cell to cell contact, induction of VEGF and IL-6 secretion persisted, suggesting the importance of humoral factors. Addition of exogenous IL-6 (10 ng/ml) increased VEGF secretion by BMSCs. Conversely, VEGF (100 ng/ml) significantly increased IL-6 secretion by BMSCs. Moreover, anti-human VEGF (1 microg/ml) and anti-human IL-6 (10 microg/ml) neutralizing antibodies reduced IL-6 and VEGF secretion, respectively, in cultures of BMSCs alone and co-cultures of BMSCs and MM cells. Finally, thalidomide (100 microM) and its immunomodulatory analog IMiD1-CC4047 (1 microM) decreased the upregulation of IL-6 and VEGF secretion in cultures of BMSCs, MM cells and co-cultures of BMSCs with MM cells. These data demonstrate the importance of stromal-MM cell interactions in regulating VEGF and IL-6 secretion, and suggest additional mechanisms whereby thalidomide and IMiD1-CC4047 act against MM cells in the BM millieu.

Novel therapies targeting the myeloma cell and its bone marrow microenvironment.

Novel therapies in multiple myeloma (MM) target not only the tumor cell but also the bone marrow (BM) microenvironment. Thalidomide (Thal), as well as derivative immunomodulatory drugs (IMiDs), directly induce apoptosis or G1 growth arrest in MM cell lines and patient's MM cells which are resistant to melphalan (Mel), doxorubicin (Dox), and dexamethasone (Dex). Although Thal and IMiDs do not alter adhesion of MM cells to bone marrow stromal cells (BMSCs), they inhibit the upregulation of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) secretion triggered by the binding of MM cells to BMSCs. Proteasome inhibitors represent another potential anticancer therapy targeting the MM cell and the BM microenvironment. The proteasome inhibitor PS-341 directly inhibits proliferation and induces apoptosis in both human MM cell lines and freshly isolated patient's MM cells which are resistant to Mel, Dox, and Dex. PS-341 inhibits p44/42 mitogen-activated protein kinase (MAPK) growth signaling triggered by IL-6 and induces apoptosis, despite induction of p21 and p27, in p53 wild-type and p53 mutant MM cells. PS-341 adds to the anti-MM activity of dexamethasone and overcomes IL-6-mediated protection against dexamethasone-induced apoptosis. PS-341 blocks the paracrine growth of human MM cells by decreasing their adherence to BMSCs and related NF-kappaB-dependent induction of IL-6 secretion in BMSCs. Moreover, proliferation and MAPK growth signaling of those residual adherent MM cells is also inhibited. Tumor necrosis factor-alpha (TNF-alpha), which is produced by some MM cells, induces only low-level MM proliferation and MAPK activation in MM cells, but markedly upregulates IL-6 secretion from BMSCs and upregulates expression of adhesion molecules (VLA-4 and LFA-1) on MM cells and their receptors (VCAM-1 and ICAM-1) on BMSCs, with resultant increased binding of MM cells to BMSCs. Inhibition of TNF-alpha-induced NF-kappaB activation with PS-341 inhibits both the upregulation of these molecules on MM cells and BMSCs and the resultant increased adhesion. Therefore, inhibiting TNF-alpha and its sequelae may be useful treatment strategies in MM. Our data show that VEGF causes proliferation and enhances migration of MM as well as plasma cell leukemia (PCL) cells. VEGF induced twofold activation of cell migration in MM cells and more than 100-fold activation of cell migration in PCL cells, suggesting an important role of VEGF in the progression of MM to PCL. These data indicate that VEGF plays a pivotal role not only in neoangiogenesis in MM BM but also in proliferation and migration of tumor cells.