Allogeneic bone marrow transplantation with T-cell-depleted marrow grafts for patients with poor-risk relapsed low-grade non-Hodgkin's lymphoma

The role of autologous and allogeneic stem cell transplantation in the management of indolent B-cell lymphoma

Despite improvements over the past decade in the overall survival of patients with indolent non-Hodgkin lymphomas, these lymphomas remain largely incurable with standard therapies. Immunochemotherapy with rituximab-based regimens has become a well-established standard of care in the primary and relapsed disease settings. The role of hematopoietic stem cell transplantation in indolent lymphoma has been defined by the adoption of this therapy largely in the relapse setting because randomized trials in the first-line setting have not shown survival advantages. Allogeneic stem cell transplantation has the possibility for cure because of the potential for immunologic graft-versus-lymphoma effect, but there are significant concerns regarding nonrelapse mortality. Autologous stem cell transplantation offers a safe treatment platform, but relapse remains a significant issue. The role of transplantation in the current treatment landscape of immunochemotherapy has not been conclusively proven, and randomized trials are lacking. This review summarizes the current relevant data regarding transplantation in indolent non-Hodgkin lymphoma and highlights the issues relevant to clinicians in the field.

Association of disparities in known minor histocompatibility antigens with relapse-free survival and graft-versus-host disease after allogeneic stem cell transplantation

Allogeneic stem cell transplantation (allo-SCT) can induce remission in patients with hematologic malignancies due to graft-versus-tumor (GVT) responses. This immune-mediated antitumor effect is often accompanied by detrimental graft-versus-host disease (GVHD), however. Both GVT and GVHD are mediated by minor histocompatibility antigen (MiHA)-specific T cells recognizing peptide products from polymorphic genes that differ between recipient and donor. In this study, we evaluated whether mismatches in a panel of 17 MiHAs are associated with clinical outcome after partially T cell-depleted allo-SCT. Comprehensive statistical analysis revealed that DNA mismatches for one or more autosomal-encoded MiHAs was associated with increased relapse-free survival in recipients of sibling transplants (P = .04), particularly in those with multiple myeloma (P = .02). Moreover, mismatches for the ubiquitous Y chromosome-derived MiHAs resulted in a higher incidence of acute GVHD grade III-IV (P = .004), whereas autosomal MiHA mismatches, ubiquitous or restricted to hematopoietic cells, were not associated with severe GVHD. Finally, we found considerable differences among MiHAs in their capability of inducing in vivo T cell responses using dual-color tetramer analysis of peripheral blood samples collected after allo-SCT. Importantly, detection of MiHA-specific T cell responses was associated with improved relapse-free survival in recipients of sibling transplants (P = .01). Our findings provide a rationale for further boosting GVT immunity toward autosomal MiHAs with a hematopoietic restriction to improve outcomes after HLA-matched allo-SCT.

Reduced intensity conditioning HLA identical sibling donor allogeneic stem cell transplantation for patients with follicular lymphoma: long-term follow-up from two prospective multicenter trials

BACKGROUND

Allogeneic hematopoietic stem cell transplantation is an effective treatment for patients with poor risk lymphoma, at least in part because of the graft-versus-lymphoma effect. Over the past decade, reduced intensity conditioning regimens have been shown to offer results similar to those of conventional high-dose conditioning regimens but with lower toxicity early after transplantation, especially in patients with chemosensitive disease at transplant.

DESIGN AND METHODS

The aim of this study was to analyze the long-term outcome of patients with follicular lymphoma who received an HLA identical sibling allogeneic stem cell transplant with a reduced intensity conditioning regimen within prospective trials. The prospective multicenter studies considered included 37 patients with follicular lymphoma who underwent allogeneic stem cell transplantation between 1998 and 2007 with a fludarabine plus melphalan-based reduced intensity conditioning regimen.

RESULTS

The median age of the patients was 50 years (range, 34-62 years) and the median follow-up was 52 months (range, 0.6 to 113 months). Most patients (77%) had stage III-IV at diagnosis, and patients had received a median of three lines of therapy before the reduced intensity conditioning allogeneic stem cell transplantation. At the time of transplantation, 14 patients were in complete remission, 16 in partial remission and 7 had refractory or progressive disease after salvage chemotherapy. The 4-year overall survival rates for patients in complete remission, partial remission, or with refractory or progressive disease were 71%, 48% and 29%, respectively (P=0.09), whereas the 4-year cumulative incidences of non-relapse mortality were 26% (95% CI, 11-61), 33% (95% CI, 16-68) and 71% (95% CI, 44-100), respectively. The incidence of relapse for the whole group was only 8% (95% CI, 2-23).

CONCLUSIONS

We conclude that this strategy of reduced intensity conditioning allogeneic stem cell transplantation may be associated with significant non-relapse mortality in heavily pre-treated patients with follicular lymphoma, but a remarkably low relapse rate. Long-term survival is likely in patients without progressive or refractory disease at the time of transplantation.

Allogeneic stem cell transplantation in follicular lymphoma: recent progress and controversy

Allogeneic stem cell transplantation (allo HCT) is a curative treatment for follicular lymphoma, but is hampered by a relatively high treatment-related mortality and by difficulties in identifying high-risk groups for whom transplant is warranted. Results with myeloablative conditioning have improved, but the field has shifted largely to reduced-intensity conditioning and non-myeloablative transplantation, though morbidity and mortality are also substantial. Some groups have investigated T cell–depleted transplantation, which results in a low rate of chronic graft-versus-host disease (GVHD) and, in most studies, excellent rates of disease control. Overall, outcome after alloHCT for follicular lymphoma correlates more with disease status, with performance status and with comorbidities than with any particular conditioning regimen used. For patients with chemotherapy-sensitive disease, the treatment-related mortality has stabilized in the 15% to 20% range and, depending on the method of GVHD prophylaxis and the donor type, there is an additional 20% to 60% incidence of chronic GVHD. For patients with chemotherapy-refractory disease, both treatment-related mortality and recurrence rates are much higher, but their prognosis is dismal with other treatments and some may be cured, particularly with myeloablative transplants. Ongoing studies focus on improving conditioning regimens, on prevention of disease recurrence and on decreasing chronic GVHD.

Follicular lymphomas

Follicular lymphomas constitute approximately 30% of all non-Hodgkin lymphomas. These lymphomas are characterized by at least partially follicular growth pattern, but diffuse areas may be present. The proportions of follicular or diffuse areas vary also from case to case, which seems to be associated with prognosis. Follicular lymphomas should not be divided into distinct subtypes, but rather shows a continuous gradation in the number of large cells. On the bases of this grading, three groups have been defined: grades 1-3. There is a consensus that grade 3 follicular lymphomas, namely grade 3b, should be discriminated from lower-grade cases. The cells of follicular lymphomas express surface immunoglobulin, more frequently IgM+/-IgD>IgG>IgA, B-cell-associated antigens, CD10+/-; they are CD5-, CD23-/+, CD43-, and CD11c-. Follicular lymphomas express bcl-2 proteins, which is useful in distinguishing reactive from neoplastic follicles. t(14;18) is present in 70-95% of follicular lymphomas, involving rearrangement of bcl-2 gene. Clinical behavior of follicular lymphomas is heterogeneous and differs according to the histologic grade and extension of disease. Moreover, the evaluation of these malignancies is conditioned by therapeutic decision, which is also determined by main prognostic factors. The International Prognostic Index for aggressive lymphomas is not optimal for follicular lymphomas. Conversely, the Italian Lymphoma Intergroup Index and, more recently, the Follicular Lymphoma International Prognostic Index (FLIPI), designed in pre-rituximab era, seem to correlate well with outcome. Several active therapeutic approaches from the "wait and watch" strategy to the allogeneic transplantation are available for management of patients with follicular lymphoma. Therapeutic decision is mostly conditioned by patient's characteristics, stage, histologic grade, tumor burden, and risk-predicting factors.

Histopathological bone marrow changes after reduced-intensity hematopoietic stem cell transplantation for follicular lymphoma involving bone marrow

Allogeneic stem cell transplantation (allo-SCT) is used as curative therapy for malignant lymphoma, and reduced-intensity hematopoietic stem cell transplantation (RIST) is sometimes performed to avoid the toxicity and mortality associated with myeloablative allo-SCT. RIST is generally preferred for elderly patients with malignant lymphoma. A 62-year-old woman with follicular lymphoma (FL) involving bone marrow (BM) suffered relapse after autologous SCT. RIST was performed; cells were from an unrelated, fully human leukocyte antigen-matched donor. To study the hematopoietic reconstitution, BM biopsy specimens that were obtained at different times after RIST, were evaluated. Engraftment of donor cells was observed on days 19 and 48 after RIST, and residual FL in BM had completely disappeared by day 73 after RIST. This is the first report to document histological BM regeneration after RIST and disappearance of FL involving the BM.

Allogeneic stem cell transplantation with T cell-depleted grafts for lymphoproliferative malignancies

In non-Hodgkin lymphoma allogeneic stem cell transplantation (SCT) can be curative, but with standard dose conditioning patients may have substantial morbidity and mortality from graft-versus-host disease (GVHD); for aggressive malignancies, reduced intensity conditioning may result in higher recurrence. Patients with advanced follicular lymphoma (n = 12), transformed B cell malignancy (n = 11), and non-CD30+T cell lymphomas (n = 17) responsive to chemotherapy who had an HLA-identical sibling were offered T cell depleted (CAMPATH-1 G or H antibodies) SCT. Conditioning was with ablative doses of chemotherapy or radiotherapy. Before SCT, patients with follicular lymphoma had a median of 3 treatment courses, and those with transformed B cell and those diagnosed with T cell non-Hodgkin lymphoma had 2 (range, 1-3). At SCT the median age was 46 years (range, 21-59 years) and the number of CD34+ cells infused was 2.85 x 10(6)/kg. All patients showed engraftment but 7 patients (17.5%) developed GVHD. In total 12 subjects expired of transplant-related causes (n = 6) or from disease recurrence. One-year transplant-related mortality was 15%. There was no difference in survival across diagnostic groups. At a median of 1051 days, 70% survived and 68% are without disease. By reducing the incidence and severity of GVHD, patients can tolerate myeloablative doses of chemotherapy satisfactorily. This has resulted in low treatment-related mortality and adequate protection from disease recurrence.

The evolving role of autologous and allogeneic stem cell transplantation in follicular lymphoma

Treatment options for follicular lymphoma have expanded dramatically. The most important relate to the introduction of monoclonal antibodies and the completion of important studies regarding autologous and allogeneic transplantation. The EBMTR-sponsored "CUP Trial" (conventional Chemotherapy, Unpurged autograft, Purged autograft), demonstrated that for patients under age 60 years with recurrent chemotherapy-sensitive disease, autologous stem cell transplantation (ASCT) provides a survival benefit over conventional therapy. Three randomized studies demonstrated that consolidation with autologous transplantation in first remission leads to improvement in progression free survival and perhaps in overall survival, but possibly with an increased risk for secondary MDS. Novel approaches involve the incorporation of rituximab as an in-vivo purging agent or as post-transplant therapy, and the use of radiolabelled monoclonals in the conditioning regimens. Allogeneic stem cell transplantation (alloSCT) has become a more effective option but continues to have a high TRM. Reduced-intensity alloSCT procedures now are being performed at an increasing rate and may have advantages in particular situations. A CIBMTR analysis unfortunately did not show a major advantage in terms of TRM or EFS to non-myeloablative transplantation. Performance status and disease sensitivity remain the major predictors of outcome for allogeneic transplantation.

The graft-versus-lymphoma effect: clinical review and future opportunities

Numerous lines of preclinical and clinical evidence support the existence of a graft-versus-leukemia effect, but less evidence supporting a comparable graft-versus-lymphoma effect exists. We review here current clinical data addressing the graft-versus-lymphoma effect, including comparisons of autologous, syngeneic, and allogeneic transplantation; responses to immunomodulation; and responses to nonmyeloablative stem cell transplantation. Despite several limitations of the data, we believe that there is sufficient evidence suggesting a significant graft-versus-lymphoma effect. In addition, we discuss approaches for clinical management of lymphoma patients, opportunities for mechanistic studies afforded by donor leukocyte infusions and nonmyeloablative transplantation, and suggestions for clinical studies to further define the magnitude and applicability of the graft-versus-lymphoma effect.

Reduced-intensity hematopoietic stem-cell transplantation for malignant lymphoma: a retrospective survey of 112 adult patients in Japan

We conducted a nation-wide survey of 112 adult Japanese patients who underwent reduced-intensity stem cell transplantation (RIST) from 1999 to 2002. Underlying diseases included indolent (n=45), aggressive (n=58) and highly aggressive lymphomas (n=9). Median age of the patients was 49 years. A total of 40 patients (36%) had relapsed diseases after autologous stem cell transplantation and 36 patients (32%) had received radiotherapy. RIST regimens were fludarabine-based (n=95), low-dose total body irradiation-based (n=6) and others (n=11). Cumulative incidences of grade II-IV acute graft-versus-host disease (GVHD) and chronic GVHD were, respectively, 49 and 59%. Cumulative incidences of progression and progression-free mortality were 18 and 25%, respectively. With a median follow-up of 23.9 months, 3-year overall survival rates were 59%. A multivariate analysis identified three significant factors for progression, which are history of radiation (relative risk (RR) 3.45, confidential interval (CI) 1.12-10.0, P=0.03), central nervous system involvement (RR 6.25, CI 2.08-20.0, P=0.001) and development of GVHD (RR 0.28, CI 0.090-0.86, P=0.026). RIST may have decreased the rate of transplant-related mortality, and GVHD may have induced a graft-versus-lymphoma effect. However, whether or not these potential benefits can be directly translated into improved patient survival should be evaluated in further studies.

The role of allogeneic transplantation in non-Hodgkin's lymphoma

The evolution of combination chemotherapy regimens, combined with improvements in supportive care, has incrementally improved survival outcomes for patients with non-Hodgkin's lymphomas (NHL). Although 40-60% of younger patients with diffuse large cell lymphoma can now expect to be cured, significant numbers will either fail to achieve a remission or relapse after attaining a remission. In addition, certain histological subtypes are associated with particularly poor prognoses with combination chemotherapy alone (e.g. mantle cell lymphoma, B-cell prolymphocytic leukaemia). Relatively few of these patients can achieve long-term responses. Other NHL subtypes, whilst associated with more favourable prognoses in terms of overall survival, are rarely, if ever, cured (e.g. most low grade NHL including follicular lymphoma, chronic lymphocytic leukaemia and small lymphocytic lymphoma). For these reasons dose escalation and allogeneic transplantation have been investigated as potential ways of improving outcome, although this has mainly been in the setting of advanced disease. Any possible benefits have frequently been out-weighed by procedural morbidity and mortality. The parallel development of transplantation approaches that limit procedural toxicity along with advances in supportive care require that the role of allogeneic haematopoietic stem cell transplantation in the management of lymphoma be re-evaluated.

Stem cell transplantation in follicular lymphoma: progress at last?

Follicular non-Hodgkin's lymphomas usually present in advanced stage and although frequently are chemotherapy-sensitive remain incurable using conventional approaches. Treatment options are evolving rapidly and now include targeted therapies such as monoclonal antibodies. Recent studies, including the EBMTR-sponsored 'CUP Trial' (conventional Chemotherapy, Unpurged autograft, Purged autograft), demonstrate that for patients under age 60 years with recurrent chemotherapy-sensitive disease, autologous stem cell transplantation (ASCT) provides a survival benefit over conventional therapy. Allogeneic stem cell transplantation (alloSCT) has become a more effective option. Although incorporation of TBI into the preparative regimen may increase treatment-related mortality (TRM), relapses appear to be reduced compared to a chemotherapy-alone regimen. Reduced-intensity alloSCT procedures are now being performed at an increasing rate, in part due to a lower risk for TRM. Until more data are available, however, reduced-intensity alloSCT should be considered only in cases where myeloablative conditioning is contra-indicated. There are no clear means for choosing ASCT vs alloSCT, a decision influenced by the amount of residual tumor, disease-responsiveness, degree of marrow involvement and extent of prior chemotherapy. ASCT or alloSCT in first remission remains an investigational procedure. Future considerations include incorporation of novel preparative regimens, in vitro purging techniques, antilymphoma vaccines, post transplant immunotherapy and ex vivo-manipulated donor lymphocyte infusions.

Long-term disease-free survival of patients with advanced follicular lymphoma after allogeneic bone marrow transplantation

Myeloablative allogeneic bone marrow transplantation (BMT) may be curative in patients with follicular non-Hodgkin's lymphoma, however, the impact of this therapy on long-term survival, disease progression and functional status is less clear. Twenty-nine patients (median age 42 years, range: 20-53) with advanced stage follicular lymphoma proceeded to allogeneic BMT a median of 25 (range: 8-154) months postdiagnosis, between 1985 and 2001, and have been followed for a minimum of 2 years. Eleven of 29 (38%) had refractory disease (n = 5 induction failure, n = 6 resistant relapse). Most (27 of 29, 93%) received total body irradiation-based conditioning; stem cell source was marrow from a related donor (n = 20) or unrelated donor (n = 9). Seventeen of 29 patients (59%) were alive a median of 5 years (range: 2-11) post-BMT with a median Karnofsky Performance Score of 100%. Death occurred because of transplant complications in seven patients (cumulative incidence of non-relapse mortality 24%), and progressive lymphoma in five patients (cumulative incidence of refractory/recurrent lymphoma 23%). The 5-year probability of overall and event-free survival was 58% and 53% respectively. Allogeneic BMT has resulted in long-term disease-free survival for approximately 50% of this cohort of patients with advanced follicular lymphoma and most of them now enjoy robust health.

Graft-versus-lymphoma effect of donor lymphocyte infusion in indolent lymphomas relapsed after allogeneic stem cell transplantation

Donor lymphocyte infusions (DLI) are used to treat relapsed haematological diseases after allogeneic stem cell transplantation (SCT). We treated seven patients with DLI for indolent non-Hodgkin's lymphoma relapsed after SCT. In available blood and bone marrow samples, lymphoma cells were analysed by real-time quantitative polymerase chain reaction of t(14;18)-positive cells in follicular lymphoma, and by immunophenotyping in small lymphocytic lymphoma. Before DLI, three patients were treated with chemo- and/or radiotherapy, and one with rituximab. Evaluable responses to pre-DLI therapy were stable disease in one and partial remission (PR) in two patients. Six patients responded to DLI (complete remission (CR) in four and PR in two). After DLI, acute graft-versus-host disease (GVHD) occurred in 3/6 patients, classified as grade 2, whereas only limited chronic GVHD was seen (n=5). The four continuous CR are lasting for median 65+ (43-89) months. In the remaining patient, not responding to DLI, progressive disease was seen later on; chemotherapy followed by another DLI resulted in CR. In three cases, clinical responses to DLI could be substantiated by molecular or immunophenotypic analysis of lymphoma cells. We conclude that DLI is effective for treatment of indolent lymphoma relapsing after SCT.

Allogeneic Hematopoietic Stem Cell Transplantation for Lymphoma

For patients with relapsed or refractory Hodgkin's or non-Hodgkin's lymphomas, allogeneic hematopoietic stem cell transplantation (HSCT) is a treatment option when autologous HSCT fails to achieve durable remission or is deemed inappropriate. Allogeneic HSCT can result in long-term survival even in patients with refractory lymphomas. The efficacy of allogeneic HSCT is attributed, at least in part, to an immune-mediated graft-versus-lymphoma (GVL) effect that can also be associated with significant toxicity resulting from graft-versus-host disease. However, clinical evidence of a potent GVL effect is inconsistent. Reduced-intensity conditioning before allogeneic HSCT can facilitate the use of this treatment in older patients and those at high risk. The decrease in toxicity with reduced-intensity regimens may be associated with a loss of antitumor effects. Patients with lymphoma should be selected for allogeneic HSCT on the basis of characteristics that strongly influence transplant outcomes, including histology, chemosensitivity, and donor source.

Syngeneic hematopoietic stem-cell transplantation for non-Hodgkin's lymphoma: a comparison with allogeneic and autologous transplantation--The Lymphoma Working Committee of the International Bone Marrow Transplant Registry and the European Group for Blood and Marrow Transplantation

PURPOSE

To compare results of syngeneic, allogeneic, and autologous hematopoietic stem-cell transplantation for non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

The databases of the International Bone Marrow Transplant Registry (IBMTR) and the European Group for Blood and Marrow Transplantation were used to identify 89 NHL patients who received syngeneic transplants. These patients were compared with NHL patients identified from the IBMTR and the Autologous Blood and Marrow Transplant Registry who received allogeneic (T-cell depleted and T-cell replete) and autologous (purged and unpurged) transplants.

RESULTS

No significant differences in relapse rates were observed when results of allogeneic transplantation were compared with syngeneic transplantation for any histology. T-cell depletion of allografts was not associated with a higher relapse risk, but was associated with improved overall survival for patients with low-grade and intermediate-grade histology. Patients who received unpurged autografts for low-grade NHL had a five-fold (P =.008) greater risk of relapse than recipients of syngeneic transplants, and recipients of unpurged autografts had a two-fold (P =.0009) greater relapse risk than patients who received purged autografts. Among low-grade NHL patients, the use of purging was associated with significantly better disease-free survival (P =.003) and overall survival (P =.04) when compared with patients who received unpurged autografts.

CONCLUSION

These analyses failed to find evidence of a graft-versus-lymphoma effect, but do provide indirect evidence to support the hypothesis that tumor contamination may contribute to lymphoma relapse, and that purging may be beneficial for patients undergoing autologous hematopoietic stem-cell transplantation for low-grade NHL.

'GVHD': graft-versus-host disease or graft-versus-Hodgkin's disease? An old acronym with new meaning

The majority of patients with relapsed or refractory Hodgkin's lymphoma (HL) will not be cured with standard therapy. Relapse rates remain high even after autologous stem cell transplantation (SCT), particularly for patients with high-risk disease. Allogeneic SCT offers several potential advantages for patients with HL. It is feasible when autologous stem cells are not available and stem cell grafts will be tumor free. Perhaps a more important advantage is the potential to generate a graft-versus-Hodgkin's lymphoma (GVHL) effect. Unfortunately, although allogeneic SCT may cure some HL patients, treatment-related mortality has been unusually high, and superior survival, when compared to autologous SCT, has not been demonstrated. Nonmyeloablative conditioning and allogeneic SCT may induce a direct GVHL reaction with less conditioning regimen-related toxicity and ultimately may have the potential to improve cure rates and survival for advanced HL patients.

An EBMT registry matched study of allogeneic stem cell transplants for lymphoma: allogeneic transplantation is associated with a lower relapse rate but a higher procedure-related mortality rate than autologous transplantation

The role of allogeneic bone marrow transplantation in lymphoma remains uncertain. We have analyzed 1185 allogeneic transplants for lymphoma reported to the EBMT registry between 1982 and 1998 and compared the results with those of 14687 autologous procedures performed over the same period. Patients receiving allogeneic transplants were subdivided according to histology: low-grade non-Hodgkin's lymphoma (NHL) 231 patients; intermediate-grade NHL 147 patients; high-grade NHL 255 patients; lymphoblastic NHL 314 patients; Burkitt's lymphoma 71 patients; and Hodgkin's disease 167 patients. These patients received allogeneic transplants as their first transplant procedure. Actuarial overall survival (OS) at 4 years from transplantation was: low-grade NHL 51.1%; intermediate-grade NHL 38.3%; high-grade NHL 41.2%; lymphoblastic lymphoma 42.0% years; Burkitt's lymphoma 37.1%; and Hodgkin's disease 24.7% years. These outcomes are relatively poor because of the high procedure-related mortality associated with these procedures, particularly in patients with Hodgkin's disease (51.7% actuarial procedure-related mortality at 4 years). Multivariate analysis showed that for all lymphomas apart from Hodgkin's disease, status at transplantation significantly affected outcome. A matched analysis was performed: for all categories of lymphoma, OS was better for autologous than for allogeneic transplantation. Relapse rate was better in the allogeneic group for low-, intermediate- and high-grade, and lymphoblastic NHL. It was equivalent for Burkitt's lymphoma and worse in the allogeneic group for Hodgkin's disease. Allogeneic transplantation appears to be superior to autologous procedures in terms of producing a lower relapse rate. The toxicity of allogeneic procedures must however be reduced before this translates into an improvement in OS.

Is there a role for reduced-intensity haematopoietic stem cell transplantation for indolent non-Hodgkin's lymphoma?

The therapeutic options for the indolent non-Hodgkin's lymphomas have evolved significantly over the years. However, at present, allogeneic haematopoietic stem cell transplantation (HSCT), despite its significant transplant associated complications, is still the only option which may be delivered with curative potential. The debut of reduced-intensity conditioning regimens has extended the applicability of allogeneic transplants to groups of patients ineligible for conventional myeloablative allografts. However, there are still substantial hurdles to overcome, namely that of relapse, graft-versus-host disease and infection. Whilst follow-up is still relatively limited for a disease group with a median survival of up to 10 years, early results are extremely encouraging and further studies are warranted.

Allogeneic haemopoietic stem cell transplantation for non-Hodgkin's lymphoma

This chapter outlines the rationale for allogeneic haemopoietic stem cell transplantation in non-Hodgkin's lymphoma and pertinent results from published studies. Trials comparing allogeneic with autologous transplantation are discussed, as are disease-specific results for low-grade (including transformed), mantle cell and high-grade (Burkitt's and lymphoblastic) subtypes of the disease. Allogeneic transplantation for non-Hodgkin's lymphoma in the paediatric population, the use of unrelated donors, allografting after failed autologous or allogeneic transplantation, the graft-versus-lymphoma effect, the use of donor leukocyte infusions and non-myeloablative allografts are considered.

Prophylactic T cell infusion after T cell-depleted bone marrow transplantation in patients with refractory lymphoma

Fifty-two patients with refractory lymphoma were prospectively treated with prophylactic T lymphocyte infusion after T cell-depleted allogeneic bone marrow transplantation, to induce graft-versus-lymphoma effect. Thirty-three patients had related donors; 19 had unrelated donors. After transplantation with marrow that had 0.8 +/- 0.4 x 10(5)CD3(+) cells/kg, T cells up to 1.75 x 10(6) CD3(+) cells/kg were given over 3 months provided > or = grade II acute graft-versus-host disease (GVHD) was not seen. The cumulative incidence of grades II-IV acute GVHD was 69%. Twenty of 32 evaluable patients (63%) developed chronic GVHD. Ten patients (19%) died of GVHD. The Kaplan-Meier 5-year overall survival of all patients was 34%. On multivariate analyses, chronic GVHD was significant for relapse (hazard ratio of 1.7, P < 0.05), and for overall survival (hazard ratio 1.4, P < 0.001). Chemosensitivity was significant for relapse only on univariate analysis. Patients who developed chronic GVHD had 4 years median survival, compared with 9 months in patients without chronic GVHD, P < 0.001. The study shows that patients with chronic GVHD have superior survivals, most probably related to a graft-versus-lymphoma effect, which could be modulated by prophylactic T cell infusion.

Donor lymphocyte infusions to treat hematologic malignancies in relapse after allogeneic blood or marrow transplantation

BACKGROUND

Patients with hematologic malignancies in relapse after allogeneic bone marrow transplantation can be treated by infusing leukocytes from the original stem cell donor.

METHODS

The published literature on donor lymphocyte infusion (DLI) was reviewed.

RESULTS

DLI induces complete remissions in the majority of patients with chronic myeloid leukemia (CML) in early-stage relapse and in less than 30% of patients with relapsed acute leukemia, myelodysplasia, and multiple myeloma. DLI-induced remissions of chronic phase CML are durable, but as many as half of patients with other diseases ultimately relapse. Complications of DLI include acute and chronic graft-vs-host disease (GVHD) and aplasia, which induce profound immunosuppression and susceptibility to opportunistic infections. There is a strong correlation of GVHD and disease response.

CONCLUSIONS

Novel methods of augmenting the antitumor efficacy of DLI and of dissociating the graft-vs-leukemia effect from GVHD are needed. These studies will require an improved understanding of the cellular and molecular mechanisms of alloreactivity and the development of novel agents to control the nature and intensity of the alloimmune response.

High-dose therapy for indolent lymphoma

Stem-cell transplantation (SCT) has become the treatment of choice for patients with relapsed aggressive non-Hodgkin's lymphoma (NHL). However, the role of SCT in the management of patients with indolent NHL remains controversial. Indolent follicular lymphomas are diseases which are generally incurable with conventional therapy. Although patients can survive for prolonged periods, the median duration of first remission is approximately 3 years, and subsequent remissions are progressively shorter with time. Emerging evidence suggests that high-dose chemotherapy with SCT leads to prolonged disease-free and overall survival in a subset of patients with indolent NHL. However, there is increasing concern regarding the toxicity of SCT, especially the long-term risk of developing myelodysplastic syndrome. It is still unclear as to when this approach should be used. Poorer outcomes have been obtained in heavily pretreated patients but encouraging results are being reported for patients undergoing SCT early during the course of their disease. Investigators are now focusing on how to improve SCT efficacy in order to eradicate minimal residual disease. Many ongoing studies are especially exploring the impact of stem-cell purging and novel ablative regimens combined with allogeneic transplantation.

New approaches to blood and marrow transplantation for patients with low-grade lymphomas

Low-grade lymphomas are generally considered incurable diseases with current standard therapies. Blood or marrow transplantation may be the exception. Nevertheless, the role of bone marrow transplantation in low-grade lymphomas has been limited by the usual indolent course of this heterogeneous group of diseases and the historically high rates of transplant-related mortality associated with most transplant procedures. This review discusses the current issues pertaining to bone marrow transplantation and comments on investigational approaches such as the use of monoclonal antibodies as in vivo purging mechanisms and nonmyeloablative and radioimmunoconjugated antibodies as alternate preparative regimens.

Long-term clinical and molecular remission after allogeneic stem cell transplantation (SCT) in patients with poor prognosis non-Hodgkin's lymphoma

From 1987 to 1999 35 patients with poor prognosis non-Hodgkin's lymphoma (NHL) underwent allogeneic stem cell transplantation (SCT) at the University Hospitals of Vienna and Graz. Initial biopsy specimens were reclassified according to the Revised European-American Classification of Lymphoid Neoplasms (REAL). All patients surviving 28 days engrafted. Twenty-eight of them (93%) attained clinical remission. At the last follow-up 14 patients were alive and disease-free at a median of 5.0 (range, 2.3-12.9) years after allogeneic SCT. The actuarial overall survival is 35%. Five patients relapsed 1.8 to 27.6 months after transplant, the probability of relapse is 23%. Of the 21 deaths following SCT, seven were due to relapse/refractory disease and 14 due to transplant-related causes. The probability of treatment-related mortality is 48%. After SCT, minimal residual disease (MRD) was monitored by polymerase chain reaction (PCR) in seven patients with a BCL-2/IgH translocation and in 13 with a clonal immunoglobulin heavy chain (IgH) rearrangement. All 20 patients attained clinical remission rapidly and converted to PCR negativity. In the follow-up nine of these patients are in long-term clinical and molecular remission, six PCR-negative patients died of transplant-related causes and five patients relapsed. In summary, allogeneic stem cell transplantation has a curative potential for patients with refractory and recurrent non-Hodgkin's lymphoma. In our series long-term disease-free survival was associated with molecular disease eradication after SCT. Treatment-related mortality rate was high, thus earlier referral of selected patients to allogeneic SCT should be considered.

Allogeneic stem cell transplantation for the non-Hodgkin's lymphomas and Hodgkin's disease

Certain poor-prognosis patients with non-Hodgkin's lymphoma and Hodgkin's disease, usually with recurrent and/or refractory disease, are rarely curable with standard chemoradiotherapy. Autologous hematopoietic stem cell transplantation has been shown to result in improved long-term disease-free survival in some of these patients. Unfortunately, a number of patients are not suitable for autologous transplantation due to a damaged stem cell pool involvement or other disease processes of the marrow. These patients may benefit from allogeneic stem cell transplantation. In addition to the therapeutic effect of high-dose chemotherapy with or without total body irradiation, an immunologic [i.e. graft-versus-lymphoma (GVLym)] effect may be present in some patients undergoing allogeneic transplantation, resulting in a lower relapse rate than autotransplants. However, allografts are almost always associated with a higher non-relapse mortality due primarily to graft-versus-host disease (GVHD); unfortunately, GVHD and GVLym are difficult to separate. Thus, full exploitation of this GVLym effect may require the modification of commonly used conditioning regimens; if successful, these modifications may allow an additional decrement in the incidence of relapse without additional morbidity. Also, when combined with lesser intensity conditioning, such may permit patients who otherwise would not be candidates for standard transplant regimens to be allografted.

Follicular lymphomas--a review of treatment modalities

Follicular lymphoma is the most common low-grade non Hodgkin's lymphoma and represent an homogeneous entity as defined by pathological, molecular and clinical data. This indolent disease is characterised by a slow growth pattern with possible spontaneous regression, is often disseminated but remains incurable with available treatments when disseminated. For localised stages, involved field radiotherapy remains the standard choice but other approaches remain to be investigated. In advanced disease, chemotherapy has been demonstrated to produce high response rates but recent trials with new treatment strategies including interferon and monoclonal antibodies may improve the current situation. In this article, we will review treatment of follicular lymphomas, specially emphasising published phase III trials.

Allogeneic peripheral blood stem cell transplantation using a fludarabine-based low intensity conditioning regimen for malignant lymphoma

Relapse is a serious complication following high-dose therapy and autologous bone marrow transplantation (ABMT) for malignant lymphoma (ML). Allogeneic transplantation (alloSCT) is a therapeutic option. However, it is associated with a high incidence of transplant-related organ toxicity and mortality. We recently reported fast engraftment and minimal transplant-related toxicity, using fludarabine-based conditioning with reduced amounts of chemotoxic drugs prior to alloSCT. We now present our experience with 23 heavily treated high risk ML patients who underwent matched alloSCT following the same low intensity conditioning. The patients (20 male, three female) were aged 13-63 years. Nineteen had NHL and four HD (resistant disease 12, partial remission 11). Five were post ABMT. Twenty-two patients had fully matched sibling donors, and one a fully matched unrelated donor. Engraftment was fast. There was no rejection or non-engraftment. Organ toxicity was moderate with no liver or renal toxicity >grade II. Four patients developed >grade II graft-versus-host disease (GVHD). Seven patients died - four of grade III-IV GVHD and severe infections, two of bacterial sepsis, one of pulmonary failure. Ten patients are alive after 22.5 (15-37) months. Survival and disease-free survival at 37 months are both 40%. Probability of relapse is 26%. These encouraging results suggest that alloSCT following fludarabine-based low intensity conditioning in high-risk patients merits further evaluation. Bone Marrow Transplantation (2000).

Allogeneic bone marrow transplantation for lymphoma

Registry data show that use of allogeneic transplantation for non-Hodgkin's lymphoma, and to a lesser extent, Hodgkin's disease is increasing. Although no prospective randomized trials have been performed, most comparisons show a significantly lower relapse rate when allogeneic transplant results are compared to results of autologous hematopoietic stem cell transplantation. The lower relapse rate following allogeneic transplantation, as well as several other lines of evidence, support the existence of a graft-versus-lymphoma effect. Nevertheless, in most comparisons, the lower relapse rate following allogeneic transplantation is offset by higher transplant-related mortality. These results make it difficult to find situations where definite overall survival advantages associated with the use of allogeneic transplantation can be demonstrated. The use of low-intensity non-myeloablative regimens for allogeneic transplantation is attracting attention. It is hoped that this approach may harness a graft-versus-lymphoma effect with less morbidity and mortality than conventional allogeneic transplantation, but more data are required to assess the value of this treatment.

Allogeneic hematopoietic transplantation for mantle-cell lymphoma: molecular remissions and evidence of graft-versus-malignancy

BACKGROUND

The presence of a graft-versus-tumor effect has been well established for various hematological malignancies but not for mantle-cell lymphoma (MCL). We report preliminary results suggestive of a graft-versus-lymphoma effect in such patients post allogeneic hematopoietic transplantation.

PATIENTS AND METHODS

Sixteen patients with the diffuse type of MCL received allogeneic transplantation. Three had blastic features. Fifteen had an HLA-identical and one, a one HLA antigen mismatched sibling donor. Fifteen had stage IV disease. Eleven patients were previously treated, including one who failed prior autologous transplantation. Five patients were newly diagnosed and received transplantation after cytoreduction with three to eight courses of HYPER-CVAD (fractionated cyclophosphamide, doxorubicin, vincristine, dexamethasone) alternating with high-dose methotrexate and cytarabine.

RESULTS

Eleven patients received high-dose cyclophosphamide 120 mg/kg and total body irradiation (TBI) (12 Gy given in four daily fractions). Three patients were not eligible for TBI and received the BEAM regimen. Twelve (85.7%) achieved complete and two (14.3%) partial response. Two additional patients received a nonablative preparative regimen consisting of cisplatin, cytarabine and fludarabine. One failed to engraft and later relapsed. The other patient had progressive disease one month post transplant but later achieved complete remission now durable for 14+ months after developing graft-versus-host disease (GVHD). Residual lymphoma was assessed in seven patients by polymerase chain reaction assay (PCR) for bcl-1 or immunoglobulin gene rearrangement. All had detectable disease at the time of transplant. When tested within four months post transplant, four of these patients attained molecular remission. One of the three molecular non-responders converted to a negative PCR status seven months later and one fluctuates between positive and negative PCR fourteen months post transplant. Overall survival (OS) and failure-from-progression (FFP) at three years were both 55% (95% confidence interval (95% CI): 28%-83%). For patients with chemosensitive disease, FFP and OS at one year were both 90% (95% CI: 71%-100%) compared with 44% (95% CI: 1%-88%) (P = 0.04) for those who were refractory to conventional chemotherapy at the time of transplantation. There were six deaths. These were related to GVHD (three cases), infection (one case), multiorgan failure (one case), and graft failure (one case).

CONCLUSIONS

This report demonstrates the potential efficacy of allogeneic hematopoietic transplantation for MCL and provides the first evidence suggestive of graft-versus-malignancy in MCL. Data supportive of this concept include 1) achievement of remission concomitant with GVHD, 2) the conversion from a positive PCR status early after transplant to negative PCR status over time and 3) that the only relapse was in a patient who failed to engraft.

Allogeneic bone marrow transplantation in aggressive non-Hodgkin's lymphoma (excluding Burkitt and lymphoblastic lymphoma): a series of 73 patients from the SFGM database. Sociét Française de Greffe de Moelle

The place of allogeneic bone marrow transplantation (BMT) in the treatment of aggressive non-Hodgkin's lymphoma (NHL) remains controversial. We conducted a retrospective study of French experience in allografting NHL between 1984 and 1994. To improve the homogeneity of the study population, cases of low-grade, Burkitt and lymphoblastic NHL were excluded. 73 patients were included in the analysis. Median age at transplantation was 35 years (range 9-61 years); 64 patients were in stage IV and 45 had bone marrow involvement at diagnosis. At the time of transplantation, 46 patients had sensitive disease (25 in complete remission; CR). The overall survival (OS) and progression-free survival (PFS) rates were 41% and 40% respectively at 5 years (median follow-up of survivors 90 months). The probability of disease progression was 30% at 5 years, and only one relapse occurred after 15 months. 32 patients died of transplantation-related complications. In multivariate analysis, pretransplant complete remission was the main factor associated with longer survival (OS at 60 months of 76% among the 25 patients in CR at transplant and of 23% among the 48 patients not in CR at transplant). Neither acute nor chronic graft-versus-host disease (GvHD) influenced the relapse rate. In conclusion, in this high-risk population the overall results of allogeneic BMT were encouraging, despite a high transplant-related mortality rate. We believe this procedure should be studied further in prospective controlled trials.

Hodgkin's disease and non-Hodgkin's lymphoma

The development of new classification schemes and prognostic analyses for lymphomas has helped to identify patients at high risk for relapse who may benefit from intensification of primary therapy. Conventional salvage therapy for relapsed follicular or low-grade lymphomas now includes monoclonal antibody therapy. The combination of chemotherapy and monoclonal antibody therapy may improve outcomes for patients with advanced-stage aggressive non-Hodgkin's lymphomas. Confirmatory randomized trials are now in progress. Therapy for Hodgkin's disease continues to evolve toward the most efficacious programs, which also minimize the long-term probability of toxicity. The combination of high-dose chemotherapy and stem cell transplantation is probably the most effective therapy for patients with relapsed or refractory Hodgkin's disease.

Allogeneic versus autologous bone marrow transplantation for refractory and recurrent low-grade non-Hodgkin's lymphoma: updated results of the Utrecht experience

This study was conducted to compare the results of myeloablative therapy followed either by autologous stem cell transplantation (SCT) or allogeneic SCT for poor-risk low-grade non-Hodgkin's lymphoma. Eighteen patients received autologous SCT and 15 patients received allogeneic SCT. All autologous patients had chemosensitive disease while this was the case in only 8 allogeneic patients. Besides, 14 of 15 allogeneic patients still had overt lymphoma infiltration of the marrow, when SCT took place. Despite these unfavorable characteristics, all allogeneic patients achieved complete remission (CR) with this procedure and, until now, none has relapsed. In contrast, 14 of 18 autologous patients achieved CR with SCT but 11 (79%) relapsed. Four allogeneic patients (27%) had a treatment-related death, whereas this did not occur with autologous SCT. The 3-year probabilities of relapse, overall survival, and event-free survival were 0%, 70% (95% CI, 38-87%), and 70% (95% CI, 38-87%) respectively for allogeneic SCT and 78% (95% CI, 57-93%), 33% (95% CI, 13-54%), and 22% (95% CI, 7-43%) respectively for autologous SCT. The differences in relapse and event-free survival were highly significant, p = 0.0002 and p= 0.015, respectively. These data show that allogeneic SCT leads to prolonged disease-free survival in patients with advanced poor-risk low-grade lymphoma which rarely occurs after autologous SCT. There is substantial evidence for a graft-versus-low-grade lymphoma effect.