Novel therapy with 2-methoxyestradiol (2ME2) for the treatment of relapsed and plateau phase multiple myeloma

8108

Background: 2-methoxyestradiol (2ME2) is a natural endogenous product of estradiol metabolism with anti-angiogenic and anti-neoplastic properties that has demonstrated activity against multiple myeloma cell lines and xenografts in immunocompromised mice. We report results of the first phase II clinical trial of 2ME2 in pts with relapsed and plateau phase myeloma. Methods: This trial was designed with a one-stage design to accrue 60 pts in the setting of relapsed and plateau phase myeloma. 2ME2 was administered orally at a dose of 1000 mg daily. After the first 39 pts were accrued, based on the results of ongoing phase I trials, the dose of 2ME2 was increased to 800 mg twice daily for the remaining patients. Pts who were already on study at that point were also allowed to escalate their dose to 800 mg twice daily. The primary endpoint was overall response rate. Responses were assessed using Eastern Cooperative Oncology Group criteria. Results: Sixty patients were treated at Mayo Clinic and Dana Farber Cancer Institute. Median age was 60 years (range, 28–99). Thirty-one patients had relapsed/refractory myeloma and 29 patients had plateau phase myeloma. Median number of prior therapies was 4 including stem cell transplant (48%), thalidomide (62%), bortezomib (6%) and lenalidomide (3%). Therapy was well tolerated. Adverse events were anemia (35%), fatigue (35%), nausea (25%), diarrhea (20%), hot flashes (20%), headache (17%), muscle cramps (15%), and upper respiratory tract infection (15%). Most toxicities were mild (grade 1–2). Estimated progression-free survival rates for all pts at one, two, and three years are 24%, 16%, and 9% respectively. Three pts with plateau phase disease, have been on study for over 4 years without progression at 50, 60, and 63 months. Response assessment is ongoing; so far, whilst no partial responses have been seen, prolonged stable disease has been observed in 3 pts (5%). Conclusions: 2ME2 is a novel agent that appears to be safe and well tolerated. Although no responses have been seen, prolonged stable disease in some pts is promising. Preliminary pharmacokinetic data indicate that the dose of 2ME2 used in this study may be inadequate, and a new formulation with significantly better bioavailability will be tested soon in this patient population.

No significant financial relationships to disclose.

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.

Single-agent bortezomib in previously untreated multiple myeloma (MM): Results of a phase II multicenter study

7504

Background: Bortezomib is effective in relapsed and/or refractory MM. This trial evaluated its efficacy and safety as monotherapy in previously untreated MM. Methods: Pts with untreated, symptomatic MM were eligible, with pts receiving concomitant steroids, platelet count < 30 × 109/L, or grade > 2 peripheral neuropathy [PN] excluded. Endpoints included response rate (RR) [Bladé criteria], time to progression, safety, incidence/severity of PN, and effect of dose modifications on PN. Pts received bortezomib 1.3 mg/m2 (d1, 4, 8, 11 every 21d) for 8 cycles. Comprehensive neurologic evaluation including electrophysiologic testing [NCS] and skin biopsy was performed in a subset of pts (n = 34). Results: Sixty-six pts (47% with stage III MM) were treated and 60 pts are evaluable for response, with an overall RR of 38% (CR 10%, PR 28%). PN was reported in 55% (36/65) pts (23 grade 1, 12 grade 2). One pt with grade 3 PN was discontinued. Other common treatment-associated adverse events reported to date include grade 1–2 fatigue in 21% (6/29), and rash in 17% (5/29) pts. Preliminary analysis shows PN improved or resolved in 75% (6/8 pts, with available follow-up data) with dose reduction. At baseline, small-fiber neuropathy (SFN) was seen in 52% (17/33) and large fiber axonal neuropathy (LFN) occurred in 9% (3/34) pts by NCS. SFN worsened in 41% (7/17) pts with baseline SFN. After completion of treatment, new SFN was seen in 33% (8/24) pts and LFN in 17% (4/24) pts by NCS. Conclusion: Single agent bortezomib is active in newly diagnosed MM pts (CR 10%), has manageable toxicity and offers a steroid-sparing approach. Underlying SFN appears more common in MM than previously appreciated and can also develop during bortezomib therapy, with symptomatic PN improving with dose modification.

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Outcome after autologous and allogeneic stem cell transplantation for patients with multiple myeloma: impact of graft-versus-myeloma effect

A total of 228 patients with multiple myeloma (MM), 166 patients receiving autologous transplantation (124 PBSC and 38 BM) and 66 patients receiving T-cell-depleted allogeneic transplantation were analyzed to compare overall survival (OS), progression-free survival (PFS) and risk of relapse. Patients receiving autologous transplantation had a significantly improved OS (P=0.006) and PFS (P=0.002) at 2 years with OS and PFS for autologous transplant 74% and 48%, respectively, compared with 51% and 28% for allogeneic transplantation. By 4 years after transplantation, outcome was similar with OS and PFS for autologous transplantation 41% and 23%, respectively, compared with 39% and 18% for allogeneic transplantation. The 4-year cumulative incidence of nonrelapse mortality was significantly higher in patients receiving allogeneic transplantation (24% vs 13%) (P=0.004). Relapse was the principle cause of treatment failure for both groups; however, there was a significantly reduced risk of relapse associated with allogeneic transplantation at 4 years: 46% for allograft vs 56% for autograft (P=0.02). Despite a lower risk of relapse after allogeneic transplantation, autologous transplantation is associated with improved OS and PFS compared with allogeneic transplantation in patients with MM. Strategies focused on reducing nonrelapse mortality in allogeneic transplantation may translate into an improved outcome for patients receiving allogeneic transplantation.

Effect of total body irradiation dose escalation on outcome following T-cell-depleted allogeneic bone marrow transplantation

Prior studies of non-T-cell-depleted (TCD) transplantation have demonstrated a reduction in relapse in patients receiving escalated doses of TBI; however, overall survival in these studies was not significantly improved due to increased treatment-related toxicity seen at the higher doses of irradiation. Toxicity was in part related to an increased incidence of GVHD. Because T-cell depletion of donor bone marrow reduces the incidence of GVHD and other treatment-related complications after allogeneic bone marrow transplantation, it was postulated that TBI dose may be safely escalated in this setting and may decrease the risk of relapse following TCD BMT. Herein, we report the results of a trial assessing the safety and impact of escalated doses of TBI after TCD BMT. Two hundred adults with hematologic malignancies were treated in consecutive cohorts defined by increasing doses of TBI (1400, 1480, and 1560 cGy) in combination with cyclophosphamide. In vitro T-cell depletion using anti-CD6 monoclonal antibody was used for GVHD prophylaxis. The incidence of grade II or greater acute GVHD in patients receiving 1560 cGy (36%) was significantly higher than in patients receiving 1400 cGy (18%) (P = .04) or 1480 cGy (13%) (P = .01). Two-year treatment-related mortality was significantly higher in patients who received 1560 cGy of TBI (33%) than in those who received 1400 cGy (20%) (P = .04) or 1480 cGy (19%) (P = .05). The increased dose of TBI did not reduce the rates of relapse, with the estimated 2-year risk of relapse being 24% (1400 cGy), 24% (1480 cGy), and 31% (1560 cGy) for the 3 cohorts of patients. Overall survival at 2 years was inferior for patients receiving 1560 cGy of TBI (36%) compared with those who received 1400 cGy (55%) or 1480 cGy (58%) (P = .01). We conclude that dose escalation of TBI is associated with increased GVHD and inferior survival following TCD BMT. Future efforts to reduce the risk of relapse after TCD BMT should focus on immunologic methods to induce the graft-versus-leukemia effect after BMT rather than intensification of the ablative regimen by escalation of irradiation dose.

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.

T-cell--depleted allogeneic bone marrow transplantation followed by donor lymphocyte infusion in patients with multiple myeloma: induction of graft-versus-myeloma effect

Previous trials of allogeneic bone marrow transplantation (BMT) in patients with multiple myeloma (MM) have demonstrated high response rates but also high transplantation-related mortality (TRM) and high relapse rates. Exploitation of this strategy remains of interest because donor lymphocyte infusions (DLIs) can induce a potent graft-versus-myeloma (GVM) effect. CD6 T-cell--depleted allogeneic BMT was combined with prophylactic CD4(+) DLI administered 6 to 9 months after BMT in an effort to reduce TRM and to induce a GVM response after BMT. Twenty-four patients with matched sibling donors and chemotherapy-sensitive disease underwent BMT. CD6 T-cell depletion of donor bone marrow was the sole method of graft-versus-host disease (GVHD) prophylaxis. GVHD after BMT was minimal, 1 (4%) grade III and 4 (17%) grade II GVHD. Fourteen patients received DLI, 3 in complete response and 11 with persistent disease after BMT. Significant GVM responses were noted after DLI in 10 patients with persistent disease, resulting in 6 complete responses and 4 partial responses. After DLI, 50% of patients developed acute (> or = II) or extensive chronic GVHD. Two-year estimated overall survival and current progression-free survival (PFS) for all 24 patients is 55% and 42%, respectively. The 14 patients receiving DLI had an improved 2-year current PFS (65%) when compared with a historical cohort of MM patients who underwent CD6-depleted BMT survived 6 months with no GVHD and did not receive DLI (41%) (P =.13). Although this study suggests that prophylactic DLI induces significant GVM responses after allogeneic BMT, only 58% of patients were able to receive DLI despite T-cell--depleted BMT. Therefore, less toxic transplantation strategies are needed to allow a higher proportion of patients to receive DLI and the benefit from the GVM effect after transplantation. (Blood. 2001;98:934-939)

TRAIL/Apo2L ligand selectively induces apoptosis and overcomes drug resistance in multiple myeloma: therapeutic applications

Multiple myeloma (MM) remains incurable and novel treatments are urgently needed. Preclinical in vitro and in vivo evaluations were performed to assess the potential therapeutic applications of human recombinant tumor necrosis factor (TNF)-related apoptosis-inducing ligand/Apo2 ligand (TRAIL/Apo2L) in MM. TRAIL/Apo2L potently induced apoptosis of MM cells from patients and the majority of MM cell lines, including cells sensitive or resistant to dexamethasone (Dex), doxorubicin (Dox), melphalan, and mitoxantrone. TRAIL/Apo2L also overcame the survival effect of interleukin 6 on MM cells and did not affect the survival of peripheral blood and bone marrow mononuclear cells and purified B cells from healthy donors. The status of the TRAIL receptors (assessed by immunoblotting and flow cytometry) could not predict TRAIL sensitivity of MM cells. The anti-MM activity of TRAIL/Apo2L was confirmed in nu/xid/bg mice xenografted with human MM cells; TRAIL (500 microg intraperitoneally daily for 14 days) was well tolerated and significantly suppressed the growth of plasmacytomas. Dox up-regulated the expression of the TRAIL receptor death receptor 5 (DR5) and synergistically enhanced the effect of TRAIL not only against MM cells sensitive to, but also against those resistant to, Dex- or Dox-induced apoptosis. Nuclear factor (NF)-kappaB inhibitors, such as SN50 (a cell-permeable inhibitor of the nuclear translocation and transcriptional activity of NF-kappaB) or the proteasome inhibitor PS-341, enhanced the proapoptotic activity of TRAIL/Apo2L against TRAIL-sensitive MM cells, whereas SN50 reversed the TRAIL resistance of ARH-77 and IM-9 MM cells. Importantly, normal B lymphocytes were not sensitized to TRAIL by either Dox, SN50, or PS-341. These preclinical studies suggest that TRAIL/Apo2L can overcome conventional drug resistance and provide the basis for clinical trials of TRAIL-based treatment regimens to improve outcome in patients with MM. (Blood. 2001;98:795-804)

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.

Tumor cell expression of CD59 is associated with resistance to CD20 serotherapy in patients with B-cell malignancies

The anti-CD20 chimeric monoclonal antibody rituximab (Rituxan) is used to treat patients with various B-cell tumors, including patients with plasma cell dyscrasias who have CD20+ disease. Many patients with CD20+ disease have either primary unresponsive disease or progress after initially responding to rituximab; therefore, understanding how tumor cells are, or become, resistant to rituximab is of clinical relevance. In this report, we determined whether tumor cells express antigens that block complement-mediated lysis or antibody-dependent cell-mediated cytotoxicity (ADCC) and thereby contribute to rituximab resistance. We demonstrate that expression of the complement regulator CD59 is associated with resistance to rituximab-mediated complement lysis of multiple myeloma (MM) and non-Hodgkin's lymphoma (NHL) cell lines. Moreover, neutralization of CD59 using a blocking monoclonal antibody reversed resistance to rituximab-mediated complement lysis of CD20++ CD59++ ARH-77 MM cells. In addition, we demonstrate the presence of CD59 and rituximab binding on viable tumor cells from patients with MM and Waldenstrom's macroglobulinemia with progressive disease despite rituximab therapy. Last, we also examined MM and NHL B-cell lines, as well as patient tumor cells, for the expression of other antigens that may have a role in blocking ADCC activity, such as Fas ligand (FasL), MUCI, or TRAIL. FasL, MUC1, and/or TRAIL were coexpressed with complement regulators on many of these cells. These studies therefore show that complement regulators, particularly CD59 and antigens that may block ADCC, are present on various B-cell tumors and associated with rituximab resistance in patients. A prospective, clinical study is assessing the role of these antigens in mediating rituximab resistance.

CD20-directed antibody-mediated immunotherapy induces responses and facilitates hematologic recovery in patients with Waldenstrom's macroglobulinemia

Waldenstrom's macroglobulinemia (WM, lymphoplasmacytic lymphoma) is a B-cell lymphoproliferative disorder in which CD20 is expressed on tumor cells from most patients. Several small studies have suggested a benefit from the anti-CD20 monoclonal antibody rituximab (Rituxan, MabThera) in patients with WM. In this retrospective study, we examined the outcome of 30 previously unreported patients with WM who received treatment with single-agent rituximab (median age 60; range 32-83 years old). The median number of prior treatments for these patients was 1 (range 0-6), and 14 patients (47%) received a nucleoside analogue before rituximab therapy. Patients received a median of 4.0 (1-11.3) infusions of rituximab (375 mg/m2). Three patients received steroids with their infusions for prophylaxis of rituximab-related infusion syndrome. Overall, treatment was well tolerated. Median immunoglobulin M (IgM) levels for all patients declined from 2,403 mg/dL (range 720-7639 mg/dL) to 1,525 mg/dL (range 177-5,063 mg/dL) after rituximab therapy (p = 0.001), with 8 of 30 (27%) and 18 of 30 (60%) patients demonstrating >50% and >25% decline in IgM, respectively. Median bone marrow lymphoplasmacytic (BM LPC) cell involvement declined from 60% (range 5-90%) to 15% (range 0-80%) for 17 patients for whom pre- and post-BM biopsies were performed (p < 0.001). Moreover, 19 of 30 (63%) and 15 of 30 (50%) patients had an increase in their hematocrit (HCT) and platelet (PLT) counts, respectively. Before rituximab therapy, 7 of 30 (23.3%) patients were either transfusion or erythropoietin dependent, whereas only 1/30 (3.3%) patients required transfusions (no erythropoietin) after rituximab. Overall responses after treatment with rituximab were as follows: 8 (27%) and 10 (33%) of the patients achieved a partial (PR) and a minor (MR) response, respectively, and an additional 9 (30%) of patients demonstrated stable disease (SD). No patients attained a complete response. The median time to treatment failure for responding (PR and MR) patients was 8.0 months (mean 8.4: range 3-20+ months), and 5.0 months (mean 6.1; range 3-12+ months) for patients with SD. These studies therefore demonstrate that rituximab is an active agent in WM. Marked increases in HCT and PLT counts were noted for most patients, including patients with WM who had MR or SD. A prospective clinical trial to more completely define the benefit of single-agent rituximab in patients with WM has been initiated by many of our centers.

Conversion to full donor chimerism following donor lymphocyte infusion is associated with disease response in patients with multiple myeloma

Donor lymphocyte infusions (DLIs) have been demonstrated to induce clinical responses in patients with relapsed multiple myeloma after allogeneic bone marrow transplantation, but the immunologic mechanisms involved have not been well characterized. In patients with chronic myelocytic leukemia (CML), remissions following DLI are invariably associated with conversion to complete donor hematopoiesis, suggesting that the target antigens of this response are expressed on both normal and CML-derived hematopoietic stem cells. In the present study, we examined hematopoietic chimerism and the complexity of the T-cell receptor (TCR) repertoire in 4 patients with relapsed multiple myeloma who received infusions of donor CD4+ lymphocytes. Three of 4 patients had a clinical response that began 1 to 2 months after DLI. All 3 responding patients developed lymphocytosis at the initiation of response that was due to a 2- to 4.5-fold increase in the number of CD3+ T cells. In 1 patient, this was due primarily to increases in CD3+ and CD8+ cells; in 2 patients, to increased numbers of CD3+ and CD8+ and CD3+ and CD4+ T cells. In all responding patients, conversion to complete donor hematopoiesis occurred in the first 2 months after DLI. The single nonresponding patient remained it 100% recipient hematopoiesis. The TCR repertoire complexity was examined by polymerase chain reaction amplification of complementary-determining region 3 (CDR3) derived from 24 Vbeta gene subfamilies. In 2 patients, the initiation of myeloma response and conversion to complete donor hematopoiesis was associated with normalization of TCR complexity. Complete donor chimerism and normal TCR complexity remained stable in all patients and did not change with subsequent relapse or development of graft-versus-host disease (GVHD). Thus, conversion to full donor chimerism was temporally associated with the antimyeloma effect of DLI but not with the development of GVHD. Nevertheless, the maintenance of stable donor hematopoiesis did not prevent disease relapse and was not associated with prolonged remission. The selective relapse of myeloma cells without concomitant return of mixed hematopoietic chimerism suggests that myeloma tumor cells in some patients develop resistance to immune destruction.

Changes in T cell receptor repertoire associated with graft-versus-tumor effect and graft-versus-host disease in patients with relapsed multiple myeloma after donor lymphocyte infusion

Recent reports of clinical responses following donor lymphocyte infusions (DLI) in patients with relapsed multiple myeloma (MM) after allogeneic BMT have demonstrated the ability of allogeneic cells to mediate a graft-versus-myeloma (GVM) effect, but the mechanisms involved have not been determined. To identify changes in the T cell compartment associated with DLI, we performed a molecular analysis of the T cell receptor (TCR) repertoire in four patients with relapsed MM who received infusions of CD4+ lymphocytes from HLA-identical sibling donors. Three of the four patients demonstrated a clinical anti-myeloma response following DLI but also developed graft-versus-host disease (GVHD). The TCR repertoire was examined after PCR amplification of 24 Vbeta gene subfamilies. This method determines the relative utilization of each Vbeta gene subfamily and also allows the identification of clonal and oligoclonal T cell populations through analysis of CDR3 regions for each TCR Vbeta gene subfamily. Serial blood samples were obtained over at least a 1 year period before and after DLI and results compared to 10 normal donors. Serial analysis of CDR3 size profiles demonstrated the appearance of clonal T cell populations after DLI in each of the three responding patients. The appearance of some clones was noted within the first 3 months after DLI and coincided with decreasing levels of monoclonal paraprotein indicating an ongoing GVM response. Other T cell clones appeared at later time points and coincided with the development of GVHD. These findings demonstrate that T cell clones with different patterns of onset can be identified in the peripheral blood of MM patients following DLI. Further functional characterization of these distinct clonal expansions will be required to determine whether these T cell clones are mediators of either anti-myeloma or anti-host activity.

Long-term follow-up of autologous bone marrow transplantation in patients with relapsed follicular lymphoma

We report the results of high-dose chemoradiotherapy and anti-B-cell monoclonal antibody-purged autologous bone marrow transplantation (ABMT) in patients with relapsed indolent follicular lymphoma. Between March 1985 and May 1995, 153 patients underwent ABMT using a uniform ablative regimen with cyclophosphamide and total body irradiation and bone marrow (BM) purging. All patients received multiple chemotherapy regimens before ABMT. At BM harvest, only 30% of patients were in complete remission, and overt BM infiltration was present in 47%. The disease-free survival (DFS) and overall survival (OS) are estimated to be 42% and 66% at 8 years, respectively. Patients whose BM was negative by polymerase chain reaction (PCR) for bcl2/IgH rearrangement after purging experienced longer freedom from recurrence than those whose BM remained PCR positive (P <.0001). Continued PCR negativity in follow-up BM samples was also strongly predictive of continued complete remission (CR). The 12-year survival from diagnosis for these 153 patients is 69%. Considering that the median survival from diagnosis and first recurrence of patients with advanced follicular lymphoma are 8 and 5 years, respectively, our results provide evidence that myeloablative therapy and ABMT may prolong overall survival.

Autologous bone marrow transplantation after histologic transformation of indolent B cell malignancies

The role of high-dose therapy and autologous stem cell transplantation in diffuse large B cell lymphoma (DLBCL) after transformation is controversial. We have retrospectively analyzed patients with chemosensitive disease and a history of follicular lymphoma or chronic lymphocytic leukemia/small lymphocytic lymphoma who underwent high-dose chemoradiotherapy and bone marrow transplantation (BMT) with anti-B cell monoclonal antibody-purged autologous marrow for DLBCL. Between December 1982 and August 1997, 27 patients underwent autologous BMT using a uniform ablative regimen with cyclophosphamide, total-body irradiation, and bone marrow purging. All patients received multiple chemotherapy regimens before autologous BMT. At bone marrow (BM) harvest, only 44% of patients were in complete remission, and overt BM infiltration was present in 37%. After cyclophosphamide and total-body irradiation, no treatment-related deaths were seen. Eleven of the 27 patients relapsed, and four patients developed myelodysplasia/acute myelogenous leukemia. In seven patients in whom pathologic studies were available after relapse, the histology remained DLBCL. Twelve patients remained alive and in complete remission with a median follow-up of 36 months (range 10-132). The disease-free survival and overall survival are estimated to be 46% (90% confidence interval 28-64) and 58% (40-76) at 5 years, respectively. Patients whose disease underwent histologic transformation within 18 months of their initial diagnosis of indolent lymphoma had significantly better overall survival. Selected patients with histologic transformation, particularly those whose transformation occurs early in the course of their disease and who remain chemosensitive, may experience prolonged survival after autoBMT.

Multicenter phase III trial to evaluate CD34(+) selected versus unselected autologous peripheral blood progenitor cell transplantation in multiple myeloma

High-dose chemotherapy followed by autologous transplantation has been shown to improve response rates and survival in multiple myeloma and other malignancies. However, autografts frequently contain detectable tumor cells. Enrichment for stem cells using anti-CD34 antibodies has been shown to reduce autograft tumor contamination in phase I/II studies. To more definitively assess the safety and efficacy of CD34 selection, a phase III study was completed in 131 multiple myeloma patients randomized to receive an autologous transplant with either CD34-selected or unselected peripheral blood progenitor cells after myeloablative therapy. Tumor contamination in the autografts was assessed by a quantitative polymerase chain reaction detection assay using patient-specific, complementarity-determining region (CDR) Ig gene primers before and after CD34 selection. A median 3.1 log reduction in contaminating tumor cells was achieved in the CD34 selected product using the CEPRATE SC System (CellPro, Inc, Bothell, WA). Successful neutrophil engraftment was achieved in all patients by day 15 and no significant between-arm difference for time to platelet engraftment occurred in patients who received an infused dose of at least 2.0 x 10(6) CD34(+) cells/kg. In conclusion, this phase III trial demonstrates that CD34-selection of peripheral blood progenitor cells significantly reduces tumor cell contamination yet provides safe and rapid hematologic recovery for patients receiving myeloablative therapy.

Toxicity and efficacy of defined doses of CD4(+) donor lymphocytes for treatment of relapse after allogeneic bone marrow transplant

Donor lymphocyte infusions (DLI) can induce remissions in patients who have relapsed after allogeneic bone marrow transplantation (BMT). However, DLI frequently also result in significant acute and/or chronic graft-versus-host disease (GVHD). Several clinical and experimental lines of evidence have suggested that CD8(+) T cells play a critical role in the pathogenesis of GVHD. To develop methods to reduce the incidence of GVHD associated with DLI, we administered defined numbers of CD4(+) donor T cells after ex vivo depletion of CD8(+) lymphocytes to 40 patients with relapsed hematologic malignancies after allogeneic BMT. Cohorts of patients received 0.3, 1.0, or 1.5 x 10(8) CD4(+) cells/kg. Overall, 12 of 38 patients (32%) evaluable for toxicity developed acute or chronic GVHD. However, 6 of 27 patients (22%) receiving 0.3 x 10(8) CD4 cells/kg developed GVHD compared with 6 of 11 patients (55%) who received >/=1.0 x 10(8) CD4 cells/kg (P = .07). Treatment-related mortality was low (3%), with 1 death related to infection in the setting of immunosuppression for GVHD. Disease responses after CD4(+) DLI were documented in 15 of 19 patients (79%) with early-phase chronic myelogenous leukemia (CML) relapse, 5 of 6 patients (83%) with relapsed multiple myeloma, and 1 patient with myelodysplasia. For patients with early-phase CML relapse, the Kaplan-Meier probability of achieving complete cytogenetic remission was 87% and the probability of complete molecular response was 78% at 1 year after DLI. The median time to complete cytogenetic response and molecular response in patients with CML was 13 weeks (range, 9 to 30 weeks) and 34 weeks (range, 10 to 56 weeks), respectively. The median time to response in patients with multiple myeloma was 26 weeks (range, 15 to 62 weeks). All patients in this trial who developed GVHD demonstrated tumor regression, but the presence of GVHD was not required for patients to achieve a response, because 48% of responding patients never developed evidence of GVHD. Two patients with CML who did not respond at dose level 1 subsequently achieved complete cytogenetic remission after a second infusion of CD8-depleted cells at dose level 2. In patients with evidence of mixed hematopoietic chimerism who achieved a complete remission after DLI, cytogenetic analysis of marrow cells also demonstrated conversion to complete donor hematopoiesis in all evaluable patients. These studies suggest that relatively low numbers of CD8-depleted donor lymphocytes are effective in inducing complete remissions in patients with stable-phase CML and multiple myeloma who have relapsed after allogeneic BMT. Because of the relatively low risk of toxicity associated with the infusion of defined numbers of CD4(+) donor cells, further studies can be undertaken in the setting of persistent minimal residual disease to prevent relapse after allogeneic BMT.

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.

Cyclophosphamide, doxorubicin, vincristine, prednisone dose intensification with granulocyte colony-stimulating factor markedly depletes stem cell reserve for autologous bone marrow transplantation

Hematopoietic growth factors allow dose escalation of chemotherapy. This approach may potentially reduce the quality and quantity of hematopoietic stem cells. The capacity of stem cells recovered after dose intensification to support myeloablative therapy is unknown. In patients with previously untreated advanced follicular lymphoma, trilineage hematopoietic engraftment was compared in two sequential trials of induction therapy (standard dose cyclophosphamide, doxorubicin, vincristine, prednisone [CHOP] without growth factors or dose intensification CHOP supported by granulocyte colony-stimulating factor [G-CSF ]) followed by identical myeloablative therapy and autologous stem cell support. Neutrophil, platelet, and red blood cell (RBC) engraftment were compared on days 100, 180, and 360 after stem cell reinfusion. Despite similar patient characteristics including reinfusion of comparable numbers of marrow mononuclear cells, after stem cell transplantation, a highly significant prolongation of neutrophil and platelet engraftment was seen in patients who received high dose CHOP and G-CSF in comparison to standard dose CHOP. These findings suggest that dose intensified chemotherapy and G-CSF recruited stem cells into a proliferative phase and that G-CSF allowed retreatment at a time when stem cells were susceptible to damage by cytotoxic therapy. Such inadequate hematologic engraftment after myeloablative therapy might be avoided by either shortening the time that growth factor support is administered, lengthening the interval between cycles, or attempting to repetitively harvest additional stem cells either from the marrow or peripheral blood. Therefore, intensification of chemotherapy with growth factor support must be used with caution if stem cells are to be used to support myeloablative therapy.

CD6+ T cell depleted allogeneic bone marrow transplantation from genotypically HLA nonidentical related donors

The widespread use of allogeneic bone marrow transplantation (BMT) is limited by the availability of suitable donors. Recent attempts to expand the donor pool by employing HLA matched unrelated marrow have been partially successful. However, severe graft-versus-host disease (GVHD) and graft failure remain obstacles and contribute to the substantial morbidity and mortality associated with matched unrelated BMT. The use of genotypically nonidentical related or unrelated donor marrow could have wider application if problems associated with GVHD could be overcome. Based upon the low incidence of GVHD in recipients of HLA-matched related donor marrow depleted of T cells with T12, an anti-CD6 monoclonal antibody, we applied this approach to 27 adult recipients of HLA mismatched related bone marrow. Ten patients received marrow mismatched at 2 HLA loci, 13 received 1 antigen mismatched marrow, and 4 received phenotypically identical marrow from a non-sibling. Immediately prior to admission, patients were treated with total lymphoid irradiation (750-1050 cGy) to suppress host derived. T lymphocytes capable of mediating graft rejection. The ablative regimen consisted of cyclophosphamide (60 mg/kg x 2 days) followed by total body irradiation (1400 cGy in 7 fractions over 4 days). Patients then received marrow depleted of T cells with T12 (CD6) plus complement. No immune suppressive medications were administered to prevent GVHD. Twenty-four of 27 patients displayed stable hematologic engraftment, achieving an absolute neutrophil count of 0.5 x 10(9)/L at a median of 19 days post-BMT. Degree of HLA disparity did not influence engraftment. Among engrafting patients, grades 2-4 acute GVHD occurred in 40% and grade 3-4 GVHD in 8%. Chronic GVHD developed in 5 patients. Patients mismatched at 2 loci were more likely to develop GVHD than those mismatched at 0-1 loci (logrank, p = .04). Disease relapse has occurred in only 3 patients receiving mismatched marrow. Estimated overall survival for mismatched patients is 56% at 2 years and is independent of HLA disparity. Among the patients transplanted for chronic myelogenous in stable phase or acute leukemia in first remission, estimated event free survival is 69% at 2 years compared to 20% for patients with more advanced disease. Our results suggest that transplantation of mismatched related marrow using modalities designed to reduce GVHD without immune suppressive medication (CD6 depletion) is feasible and should prompt wider investigation into the extended families of patients in the search for potential marrow donors. This approach also merits investigation in recipients of matched unrelated marrow as a potential means of reducing transplant-related toxicity.

Monoclonal antibody-purged bone marrow transplantation therapy for multiple myeloma

This report describes the clinical characteristics, treatment associated toxicity, and follow-up of fifty-eight patients with plasma cell--dyscrasias treated with high dose chemotherapy and total body irradiation (TBI) at a single institution. Following TBI, 36 patients received anti-B cell monoclonal antibody (MoAb)-treated autologous bone marrow, 21 patients received anti-CD6 cell MoAb-treated allogeneic bone marrow to deplete T cells, and one patient received unpurged bone marrow from a syngeneic donor. Evaluation after high dose chemotherapy and bone marrow transplantation (BMT) demonstrated 26 complete responses (CR), 26 partial responses (PR), 2 non-responders, 1 not yet evaluated, and three toxic deaths. Fourteen of 36 patients who underwent autologous BMT are alive free from progression at 18 (range 5 to 68) months post transplant (post-BMT); of these, 11 remain in continuous complete response at 16 (range 5 to 68) months post-BMT. Seven of 21 patients who underwent allogeneic BMT are alive free from progression at 30 (range 4 to 44) months post-BMT; of these, three patients remain in continuous complete response at 43 (range 33 to 45) months post-BMT. These data suggest that high dose chemotherapy with TBI followed by MoAb purged BM can be performed with acceptable toxicity and high tumor response rates.

Localization of the simian virus 40 small t antigen in the nucleus and cytoplasm of monkey and mouse cells

Monkey and mouse cells producing simian virus 40 small t antigen in the absence of clearly detectable intact or truncated large T antigens were subjected to indirect immunofluorescence and biochemical cell compartment analyses. Results revealed specific immunofluorescence and small t polypeptide in both the nucleus and cytoplasm of these cells.