Allogeneic cell therapy for patients who relapse after autologous stem cell transplantation

How I prevent GVHD in high-risk patients: posttransplant cyclophosphamide and beyond

Advances in conditioning, graft-versus-host disease (GVHD) prophylaxis and antimicrobial prophylaxis have improved the safety of allogeneic hematopoietic cell transplantation (HCT), leading to a substantial increase in the number of patients transplanted each year. This influx of patients along with progress in remission-inducing and posttransplant maintenance strategies for hematologic malignancies has led to new GVHD risk factors and high-risk groups: HLA-mismatched related (haplo) and unrelated (MMUD) donors; older recipient age; posttransplant maintenance; prior checkpoint inhibitor and autologous HCT exposure; and patients with benign hematologic disorders. Along with the changing transplant population, the field of HCT has dramatically shifted in the past decade because of the widespread adoption of posttransplantation cyclophosphamide (PTCy), which has increased the use of HLA-mismatched related donors to levels comparable to HLA-matched related donors. Its success has led investigators to explore PTCy's utility for HLA-matched HCT, where we predict it will be embraced as well. Additionally, combinations of promising new agents for GVHD prophylaxis such as abatacept and JAK inhibitors with PTCy inspire hope for an even safer transplant platform. Using 3 illustrative cases, we review our current approach to transplantation of patients at high risk of GVHD using our modern armamentarium.

Clinical Studies in Hematologic Microtransplantation

The anti-tumor effects of allogeneic hematopoietic stem cell transplantation depend upon engraftment of donor cells followed by a graft-versus-tumor (GVT) effect. However, pre-clinical and clinical studies have established that under certain circumstances, anti-tumor responses can occur despite the absence of high levels of durable donor cell engraftment. Tumor response with little or no donor engraftment has been termed "microtransplantation." It has been hard to define conditions leading to tumor responses without donor cell persistence in humans because the degree of engraftment depends very heavily upon many patient-specific factors, including immune status and degree of prior therapy. Likewise, it is unknown to what degree donor chimerism in the blood or tissue is required for an anti-tumor effect under conditions of microtransplantation. In this review, we summarize some key studies supporting the concept of microtransplantation and emphasize the importance of recent large studies of microtransplantation in patients with acute myelogenous leukemia (AML). These AML studies provide the first evidence of the efficacy of microtransplantation as a therapeutic strategy and lay the foundation for additional pre-clinical studies and clinical trials that will refine the understanding of the mechanisms involved and guide its further development as a treatment modality.

Cell-based strategies to manage leukemia relapse: efficacy and feasibility of immunotherapy approaches

When treatment fails, the clinical outcome of acute leukemia patients is usually very poor, particularly when failure occurs after transplantation. A second allogeneic stem cell transplant could be envisaged as an effective and feasible salvage option in younger patients having a late relapse and an available donor. Unmanipulated or minimally manipulated donor T cells may also be effective in a minority of patients but the main limit remains the induction of severe graft-versus-host disease. This clinical complication has brought about a huge research effort that led to the development of leukemia-specific T-cell therapy aiming at the direct recognition of leukemia-specific rather than minor histocompatibility antigens. Despite a great scientific interest, the clinical feasibility of such an approach has proven to be quite problematic. To overcome this limitation, more research has moved toward the choice of targeting commonly expressed hematopoietic specific antigens by the genetic modification of unselected T cells. The best example of this is represented by the anti-CD19 chimeric antigen receptor (CD19.CAR) T cells. As a possible alternative to the genetic manipulation of unselected T cells, specific T-cell subpopulations with in vivo favorable homing and long-term survival properties have been genetically modified by CAR molecules. Finally, the use of naturally cytotoxic effector cells such as natural killer and cytokine-induced killer cells has been proposed in several clinical trials. The clinical development of these latter cells could also be further expanded by additional genetic modifications using the CAR technology.

Efficacy of adoptive immunotherapy with donor lymphocyte infusion in relapsed lymphoid malignancies

Aims: There is a perceived benefit associated with the administration of donor lymphocyte infusion (DLI) in patients with lymphoid malignancies relapsing after allogeneic hematopoietic cell transplantation. However, it is unclear if and how this benefit varies according to specific diseases. Because administration of DLI is not universally effective and could be associated with significant toxicities resulting in morbidity and mortality, it is imperative to identify cases where benefits outweigh harms of the procedure. Materials & methods: We conducted a systematic review of the published literature and extracted and pooled data independently for each disease cohort: acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), multiple myeloma (MM), non-Hodgkin’s lymphoma (NHL) and Hodgkin’s lymphoma (HL). Results: In summary, 39 studies met inclusion criteria. The pooled proportion (95% CI) for complete response was 27% (16–40) in ALL, 55% (15–92) in CLL, 26% (19–33) in MM, 52% (33–71) in NHL and 37% (20–56) in HL. Conclusion: Complete response rates appear higher when DLI is used for relapsed CLL and lymphomas (NHL and HL), and less pronounced in ALL or MM. Absence of data pertaining to disease-specific prognostic determinants, such as adverse genetic or molecular abnormalities, or quantitative disease burden when applicable, limit our ability to identify cases in whom benefits from DLI outweigh risks associated with the procedure within a particular disease.

Outcome of lower-intensity allogeneic transplantation in non-Hodgkin lymphoma after autologous transplantation failure

We studied the outcome of allogeneic hematopoietic stem cell transplantation after lower-intensity conditioning regimens (reduced-intensity conditioning and nonmyeloablative) in patients with non-Hodgkin lymphoma who relapsed after autologous hematopoietic stem cell transplantation. Nonrelapse mortality, lymphoma progression/relapse, progression-free survival (PFS), and overall survival were analyzed in 263 patients with non-Hodgkin lymphoma. All 263 patients had relapsed after a previous autologous hematopoietic stem cell transplantation and then had undergone allogeneic hematopoietic stem cell transplantation from a related (n = 26) or unrelated (n = 237) donor after reduced-intensity conditioning (n = 128) or nonmyeloablative (n = 135) and were reported to the Center for International Blood and Marrow Transplant Research between 1996 and 2006. The median follow-up of survivors was 68 months (range, 3-111 months). Three-year nonrelapse mortality was 44% (95% confidence interval [CI], 37%-50%). Lymphoma progression/relapse at 3 years was 35% (95% CI, 29%-41%). Three-year probabilities of PFS and overall survival were 21% (95% CI, 16%-27%) and 32% (95% CI, 27%-38%), respectively. Superior Karnofsky Performance Score, longer interval between transplantations, total body irradiation-based conditioning regimen, and lymphoma remission at transplantation were correlated with improved PFS. Allogeneic hematopoietic stem cell transplantation after lower-intensity conditioning is associated with significant nonrelapse mortality but can result in long-term PFS. We describe a quantitative risk model based on pretransplantation risk factors to identify those patients likely to benefit from this approach.

Second hematopoietic SCT for lymphoma patients who relapse after autotransplantation: another autograft or switch to allograft?

Although autologous hematopoietic SCT (auto-HSCT) is the only potentially curative treatment for lymphoma that has relapsed after conventional chemotherapy, the prognosis of patients with disease recurrence after auto-HSCT is poor. Some highly selected patients can benefit from second transplants. One-third with late recurrence after initial auto-HSCT may attain a prolonged remission after second auto-HSCT. Non-myeloablative or reduced-intensity conditioning (RIC) allogeneic hematopoietic SCT (allo-HSCT) has been used successfully after auto-HSCT failures, especially in subjects who have an HLA-compatible donor, chemosensitive disease and good performance status. Patients with chemosenstive disease recurrence who have completed at least 1 year after their first auto-HSCT should be considered for a second auto-HSCT. Patients who have chemoresistant disease are best served by participation in a well-designed clinical trial examining novel antitumor agents.

Fludarabine-melphalan as a preparative regimen for reduced-intensity conditioning allogeneic stem cell transplantation in relapsed and refractory Hodgkin's lymphoma: the updated M.D. Anderson Cancer Center experience

BACKGROUND

The role of reduced-intensity conditioning allogeneic stem cell transplantation in relapsed/refractory Hodgkin's lymphoma remains poorly defined. We here present an update of our single-center experience with fludarabine-melphalan as a preparative regimen.

DESIGN AND METHODS

Fifty-eight patients with relapsed/refractory Hodgkin's lymphoma underwent RIC and allogeneic stem cell transplantation from a matched related donor (MRD; n=25) or a matched unrelated donor (MUD; n=33). Forty-eight (83%) had undergone prior autologous stem cell transplantation. Disease status at transplant was refractory relapse (n=28) or sensitive relapse (n=30).

RESULTS

Cumulative day 100 and 2-year transplant-related mortality rates were 7% and 15%, respectively (day 100 transplant-related mortality MRD vs. MUD 8% vs. 6%, p=ns; 2-year MRD vs. MUD 13% vs. 16%, p=ns). The cumulative incidence of acute (grade II-IV) graft-versus-host disease in the first 100 days was 28% (MRD vs. MUD 12% vs. 39%, p=0.04). The cumulative incidence of chronic graft-versus-host disease at any time was 73% (MRD vs. MUD 57% vs. 85%, p=0.006). Projected 2-year overall and progression-free survival rates are 64% (49-76%) and 32% (20-45%), with 2-year disease progression/relapse at 55% (43-70%). There was no statistically significant differences in overall survival progression-free survival, and disease progression/relapse between MRD and MUD transplants. There was a trend for the response status pretransplant to have a favorable impact on progression-free survival (p=0.07) and disease progression/relapse (p=0.049), but not on overall survival (p=0.4)

CONCLUSIONS

Fludarabine-melphalan as a preparative regimen for reduced-intensity conditioning allogeneic stem cell transplantation in progression-free survival Hodgkin's lymphoma is associated with a significant reduction in transplant-related mortality, with comparable results in MRD and MUD allografts. Optimizing pretransplant response status may improve patients' outcome.

Hyperacute GVHD: risk factors, outcomes, and clinical implications

Acute graft-versus-host disease (GVHD) is a major limiting factor in allogeneic hematopoietic stem cell transplantation (HSCT), and the timing of acute GVHD may affect patient outcomes. We evaluated the incidence, risk factors, clinical manifestations, and outcomes of hyperacute GVHD, defined as that occurring within 14 days after transplantation, among 809 consecutive HSCTs at the University of Texas M.D. Anderson Cancer Center. Of 265 patients with grade II-IV acute GVHD, 27% had biopsy-proven hyperacute GVHD. Skin involvement was significantly more common (88% versus 44%) and more severe (stage III-IV, 88% versus 66%) in the hyperacute group compared with acute GVHD diagnosed after day 14. On multivariate analysis, significant risk factors for hyperacute GVHD included a mismatched related or matched unrelated donor, a myeloablative conditioning regimen, more than 5 prior chemotherapy regimens, and donor-recipient sex mismatch. Hyperacute GVHD was associated with a significantly lower response rate to first-line therapy and a higher rate of nonrelapse mortality in patients with a mismatched related or matched unrelated donor graft. In conclusion, hyperacute GVHD accounts for a substantial proportion of grade II-IV acute GVHD after HSCT. Patients at high risk or with a diagnosis of hyperacute GVHD should be included in clinical studies.

Reduced-intensity allogeneic transplantation in patients with refractory or progressive Hodgkin's disease after high-dose chemotherapy and autologous stem cell infusion

BACKGROUND

We analysed the feasibility and efficacy of allogeneic stem cell transplantation (allo-SCT) with reduced-intensity conditioning (RIC) in patients with refractory or progressive Hodgkin's disease (HD) after high-dose chemotherapy (HDCT).

PATIENTS AND METHODS

Fourteen patients with HD received allo-SCT with RIC: eleven patients had a human leucocytes antigen-identical related donor and three a matched unrelated donor. Six had chemoresistant disease and eight had chemosensitive one at the time of transplantation. All patients received a fludarabine-based RIC.

RESULTS

All patients engrafted and full donor chimerism was achieved in all patients. Grade II acute graft-vs.-host disease (GvHD) developed in six of the 14 patients (43%). Chronic GvHD developed in eight of the 13 patients (61%). There was neither early nor late treatment-related mortality (TRM). With a median follow-up of 21 months (range 3-74), 10 of the 14 patients were alive (71%). Estimated overall survival at 1 and 2 yr was 93% and 73%, respectively, for the whole population, 83% and 44% respectively for patients with chemoresistant disease and 100% for those with chemosensitive disease. Estimated progression-free survival at 1 yr was 36%; 62.5% for chemosensitive patients and 0% for those with chemoresistant disease.

CONCLUSIONS

In conclusion, allo-SCT with fludarabine-based RIC is a feasible procedure, without TRM in HD patients relapsed and refractory after HDCT. Even if several questions are still open, this approach should proposed for these poor prognosis patients.

Reduced-Intensity Stem Cell Transplantation

The recognition that the immune system can play a major role in the control and cure of transplantable disorders led to the development of reduced-intensity allogeneic transplantation. The notion is that a compromise can be made between the intensity of conditioning and the fostering of graft-versus-host disease/ graft-versus-leukemia (GVHD/GVL), allowing the use of less intense conditioning with concomitantly less intense immediate toxicity. Reduced-intensity conditioning regimens have allowed the application of transplantation to older patients and to patients with underlying medical problems that preclude full-dose transplantation. Clearly, in some settings in which dose intensity is important, reduced-intensity regimens are less useful. However, for diseases that are either indolent, highly susceptible to GVL, or under good control before entering transplantation, this approach appears to have substantial benefits. Although the therapy appears to be valuable, concerns about delayed immune reconstitution and GVHD remain.

Comparison of Reduced-Intensity and Conventional Myeloablative Regimens for Allogeneic Transplantation in Non-Hodgkin’s Lymphoma

Reduced-intensity regimens (RIRs) are being used with increasing frequency in patients with non-Hodgkin's lymphoma (NHL) undergoing allogeneic transplantation. The impact of dose reduction on relapse and survival has not been extensively studied. We performed a retrospective analysis of 88 patients conditioned with conventional myeloablative regimens (CMRs) (n = 48) and an RIR (n = 40) of fludarabine 125 mg/m(2) and melphalan 140 mg/m(2). Compared with the patients receiving CMR, those receiving RIR were older, had more often failed autologous transplantation, and had more frequently received peripheral blood and unrelated donor transplants. Graft-versus-host disease prophylaxis was provided with cyclosporine + methotrexate +/- prednisone for the CMR and with cyclosporine + mycophenolate +/- methotrexate for the RIR. The relapse rate was significantly lower in the patients receiving CMR than in those receiving RIR (13% vs 28%; P = .05). The 1-year transplantation-related mortality rate was 33% for CMR and 28% for RIR (P = .40). Kaplan-Meier 2-year overall survival and progression-free survival were 52% and 46% for CMR versus 53% and 40% for RIR (P = not significant). Using cumulative incidence functions based on competing risks, univariate analysis, and treatment-related prognostic factors, we found that higher treatment intensity (P = .03; relative risk [RR] = 35%) and absence of previous autologous transplantation (P = .0007; RR = 20%) were associated with a lower relapse rate. Using a Cox univariate proportional hazards model, we found that chemosensitive disease at transplantation (P = .05; RR = 57%) and absence of previous autologous transplantation (P = .002; RR = 37%) were associated with improved survival. Our observation of similar survival in the patients receiving CMR and those receiving RIR confirms that RIRs are feasible alternatives for high-risk patients with NHL; however, the data suggest that reduced treatment intensity and previous autologous transplantation are associated with increased relapse.

Donor leukocyte infusions after unrelated donor hematopoietic stem cell transplantation

PURPOSE OF REVIEW

Donor leukocyte infusions provide direct and potent graft-versus-tumor activity to treat relapse after allogeneic stem cell transplantation. Extensive data are available on the use of donor leukocyte infusion after matched-sibling stem cell transplantation, but reports are remarkably few on the use of donor leukocyte infusion after unrelated-donor stem cell transplantation. But the role for unrelated-donor leukocyte infusion is not well established.

RECENT FINDINGS

The dramatic success of donor leukocyte infusion to treat relapse after matched-sibling stem cell transplantation has led to the use of unrelated-donor leukocyte infusion in many patients. Several case studies suggest that unrelated-donor leukocyte infusion effectively induces direct graft-versus-tumor reactions with toxicity comparable to that of matched-sibling donor leukocyte infusion. Important issues include the relationship between dose and response/toxicity appropriate timing, dose, and schedule; and identification of the best tumor targets. In particular nonmyeloablative transplant strategies using unrelated donors are expanding rapidly, but relapse rates are high. There is a paucity of data on unrelated-donor leukocyte infusion in this setting.

SUMMARY

This review summarizes recent data on the use of unrelated-donor leukocyte infusion. We discuss anticipated outcomes and identify areas under active investigation in both ablative and nonmyeloablative unrelated-donor stem cell transplantation.

Reduced Intensity Conditioning for Allogeneic Stem Cell Transplantation in Relapsed and Refractory Hodgkin Lymphoma: Where Do We Stand?

Allogeneic stem cell transplantation following myeloablative conditioning in relapsed and refractory Hodgkin lymphoma (HL) has been associated with substantial transplant-related morbidity and mortality, as well as high relapse rates. Despite these problems, a minority of patients have experienced long-term remissions and presumably cure. As in other hematologic malignancies, reduced intensity conditioning (RIC) has now been introduced as an alternative approach. The published experience with RIC in HL patients is reviewed. While early transplant-related morbidity and mortality seem markedly reduced and preliminary data on patient outcome look promising, this remains a challenging area and additional work will be needed to clearly define the role of RIC in relapsed and refractory HL.

Cellular immune therapy for refractory cancers: novel therapeutic strategies

OBJECTIVE

Allogeneic stem cell transplantation is curative for certain cancers, but the high doses of chemotherapy and radiotherapy may lead to toxicity. This review summarizes the field of cellular immune therapy using very-low-dose conditioning for refractory cancers.

METHODS

In our initial study, we treated 25 patients with refractory cancers with 100 cGy total body irradiation followed by allogeneic, nonmobilized peripheral blood cells. Eighteen patients received sibling and seven patients received unrelated cord blood stem cells.

RESULTS

None of the 13 patients with solid tumors achieved donor chimerism or had a sustained response. Twelve patients with hematologic malignancies were treated, 1 received a cord blood transplant and 11 received sibling donor cells. Nine of these 11 patients achieved donor chimerism, ranging from 5% to 100%. Four patients had sustained complete remission of their cancers. The patients who received cord blood transplants did not respond. Development of chimerism correlated with total previous myelotoxic chemotherapy (p < 0.001). We review additional studies in this area, including data in the haploidentical and unrelated donor setting. The data presented comprises studies performed at the four institutions represented by the authors, and a review of other pertinent studies in this area.

CONCLUSIONS

Cellular immune therapy is an emerging application of transplantation therapy, which may be appropriate for refractory cancers. New studies in solid tumors, and with alternative donors, will expand the application of this new and promising treatment.

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 allogeneic stem cell transplantation in relapsed and refractory Hodgkin's disease: low transplant-related mortality and impact of intensity of conditioning regimen

A total of 40 patients with relapsed/refractory Hodgkin's disease (HD) underwent reduced-intensity conditioning (RIC) allogeneic stem cell transplantation (allo-SCT) from an HLA-identical sibling (n=20) or a matched unrelated donor (n=20). The median age was 31 years (range 18-58). Disease status at allo-SCT was refractory relapse (n=14) or sensitive relapse (n=26). The conditioning regimens were fludarabine-cyclophosphamide+/-antithymocyte globulin (n=14), a less intensive regimen, and fludarabine-melphalan (FM) (n=26), a more intensive one. The two groups had similar prognostic factors. The median time to neutrophil recovery (ie absolute neutrophil count >/=500/microl) was 12 days (range 10-24). The median time to platelet recovery (ie platelet count >/=20 000/microl) was 17 days (range 7-132). Day 100 and cumulative (18-month) transplant-related mortalities (TRMs) were 5 and 22%. Twenty-four patients (60%) are alive (14 in complete remission or complete remission, unconfirmed/uncertain) with a median follow-up of 13 months (4-78). In all, 16 patients expired (TRM n=8, disease progression n=8). FM patients had better overall survival (73 vs 39% at 18 months; P=0.03), and a trend towards better progression-free survival (37 vs 21% at 18 months; P=0.2). RIC allo-SCT is feasible in relapsed/refractory HD patients with a low TRM. The intensity of the preparative regimen affects survival.

Graft-versus-lymphoma effects: clinical review, policy proposals, and immunobiology

The indubitable existence of a graft-versus-lymphoma (GVL) effect is difficult to prove directly. This article reviews the difficulties in interpreting the current literature in this field and, with a number of caveats, argues for the existence of a clinically meaningful GVL effect in follicular, mantle cell, small lymphocytic, and Hodgkin lymphomas. The evidence, however, for a potent GVL effect in diffuse large-cell lymphoma and Burkitt lymphoma is not convincing. Policies for allografting in lymphoma are proposed on the basis of this evidence. The immunobiology of GVL effects is discussed--in particular, the expression of HLA class I and II and co-stimulatory molecules on lymphomas that influence the generation of alloreactive T cells--together with future directions in immunotherapy that may help to eradicate chemoresistant disease.

Low dose total body irradiation followed by allogeneic lymphocyte infusion for refractory hematologic malignancy--an updated review

Allogeneic stem cell transplantation is curative for certain cancers, but the high doses of chemotherapy and radiotherapy used in conventional myeloablative conditioning regimens may lead to severe toxicity. In our initial study, we treated 25 patients with refractory cancers with 100 cGy total body irradiation (TBI) followed by allogeneic, non mobilized peripheral blood cells. Eighteen patients received sibling and 7 patients received unrelated cord blood stem cells. None of the 13 patients with solid tumors achieved donor chimerism or had a sustained response. Twelve patients with hematologic malignancies were treated, 1 received a cord blood transplant and 11 received sibling donor cells. Nine of these 11 patients achieved donor chimerism, ranging from 5% to 100%. Four patients had sustained complete remission of their cancers, and 2 are long-term survivors. The development of chimerism correlated with total previous myelotoxic chemotherapy (p < 0.001). This technique is now being extended into the haploidentical setting.

A novel reduced intensity regimen for allogeneic hematopoietic stem cell transplantation associated with a reduced incidence of graft-versus-host disease

SUMMARY

In all, 55 patients at high risk or ineligible for a conventional allogeneic hematopoietic stem cell transplant (HSCT) received a regimen consisting of extracorporeal photopheresis, pentostatin, and reduced dose total body irradiation. The median age was 49 years (18-70 years); 44 received a sibling and 11 an unrelated HSCT; 44% were over the age of 50 years and 31% had undergone a prior HSCT. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and methotrexate. Full donor chimerism was documented in 98% by day +100. The 1000-day nonrelapse mortality was 11%. The median follow-up is 502 days (154-1104 days). The 1- and 2-year overall survival (OS) and event-free survival (EFS) are 67, 58 and 55%, and 47%, respectively. Patients who had not received a prior HSCT or had less than three prior chemotherapy regimens had a 71% OS and 67% EFS at 1 year. Greater than grade II aGVHD developed in 9% and chronic GVHD (cGVHD) in 43%, and extensive in 12% and limited in 31%. Of the patients, 86% who engrafted had a disease response, 72% had complete and 14% partial responses. This novel reduced intensity preparative regimen was well tolerated and associated with a low incidence of transplant-related mortality and serious acute and cGVHD.

Donor leukocyte infusions in relapsed Hodgkin's lymphoma following allogeneic stem cell transplantation: CD3+ cell dose, GVHD and disease response

Nine patients with advanced Hodgkin's lymphoma (HL) who had undergone allogeneic stem cell transplantation (allo-SCT) received donor leukocyte infusions (DLIs) for treatment of persistent or progressive disease (PD). A total of 15 DLIs were performed, with four patients receiving more than one DLI. In four patients, prior salvage chemotherapy was administered. The median CD3+ cell dose administered was 77.5 x 10(6)/kg (range 5-285). GVHD developed in all but one patient. The response rate was 4/9 (44%). Three of these four responders developed GVHD and 3/4 had received chemotherapy. No correlation was observed between CD3+ cell dose infused and disease response. At the latest follow-up, three patients are alive and six have expired (PD n=3, nonrelapse mortality n=3). The median response duration was 7 months (range 4-9), with one response currently ongoing. These data suggest that DLIs for immunotherapy of recurrent HL have significant activity, although they frequently leads to GVHD. The small sample size does not allow any conclusion as to whether chemotherapy administration increases the chance of response. The CD3 cell dose infused does not seem to correlate with disease response.

Adoptive immunotherapy with donor lymphocyte infusions and interleukin-2 after high-dose therapy and autologous stem cell rescue for multiple myeloma

In an attempt to induce a graft-versus-myeloma effect, we administered donor lymphocyte infusions (DLI) after high-dose therapy with autologous stem cell transplant rescue to seven patients with refractory or relapsed multiple myeloma. High-dose therapy consisted of melphalan, idarubicin and etoposide (days -9 to -6) followed by autologous stem cell infusion on day 0. DLI (five of seven donors with two or three HLA antigens mismatched) were administered on days +1, +5 and +10 along with IL-2 (from day +1 through +12). Six of the seven patients developed acute graft-versus-host disease (GVHD), which resolved spontaneously, coincidentally with autologous hematopoietic reconstitution. One patient failed to engraft and received a second autologous graft. One patient died from complications of a pulmonary hemorrhage after experiencing GVHD. With a minimum follow-up of 38 months, five patients remain without disease progression in complete remission or with minimal residual disease. In this setting, DLI/IL-2 is biologically active resulting in GVHD. A graft-versus-myeloma effect is suggested by the improved outcome of our small cohort of high-risk patients. The use of partially mismatched related donors makes this approach potentially available to nearly all patients.

Stem cell transplantation-harnessing of graft-versus-malignancy

PURPOSE OF REVIEW

Allogeneic transplantation can cure a number of hematologic malignancies; however, the cost in morbidity and mortality is high. Much of the toxicity is a direct consequence of the intensity of the conditioning regimen. It has gradually been recognized that the conditioning regimen is important but not critical for the success of transplantation, particularly in the less aggressive hematologic malignancies. The graft-versus-malignancy effect, that is, the recognition of residual cancer cells by the T cells of the donor, is a critical component of the transplantation process.

RECENT FINDINGS

This effect has been emphasized over high-dose therapy by using less intensive, and therefore less toxic conditioning regimens, thus allowing the graft-versus-malignancy effect to predominate. Reduced-intensity conditioning regimens have allowed the application of transplantation to older patients and to patients with underlying medical problems that preclude full-dose transplantation.

SUMMARY

Although the long-term results of this type of approach have not yet been defined, it appears to be effective in diseases such as chronic myelogenous leukemia, chronic lymphocytic leukemia, and low-grade lymphomas that are not intrinsically very aggressive. Although the therapy appears to be valuable, concerns about delayed immune reconstitution and graft-versus-host disease remain.

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.

Outcome and toxicity of salvage treatment on patients relapsing after autologous hematopoietic stem cell transplantation--experience from a single center

Patients with hematological malignancies who relapse after autologous stem cell transplantation (auto-SCT) generally have poor prognosis. Salvage treatment is often associated with severe toxicities. The aim of our study was to evaluate retrospectively the toxicity and outcome of rescue therapy in patients with acute leukemias, non-Hodgkin's lymphoma (NHL), Hodgkin's disease (HD) and multiple myeloma (MM) relapsing after auto-SCT. Fifty-four of the 62 patients who relapsed received some form of salvage chemotherapy. Six (10%) patients were treated by second stem cell transplantation, which was allogeneic in 5 cases. Toxicity of the salvage therapy was significant. As a result of adverse effects, salvage therapy had to be discontinued or reduced in 14 patients (26%). The outcome of salvage was evaluated after 90 days. Of the treated patients, 14 (26%) entered into complete remission with another 5 (9%) reaching partial response. The disease was stabilized in 5 patients (9%) but 30 (56%) patients were in progression or dead. Overall survival of the patients was poor with the median survival of 8.7 months after relapse and the leading cause of death being progressive disease. In conclusion, the development of new, more efficient regimens is critical if disease-free survival is to be increased in patients who relapse after auto SCT.

'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.

Hematopoietic stem-cell transplantation for Hodgkin's disease (HD): current status

Not all patients with Hodgkin's disease (HD) respond to standard chemotherapy and/or radiation, and hematopoietic stem-cell transplantation has been gaining increasing acceptance in the management of HD. Phase II and, to a lesser extent, phase III studies of high-dose chemotherapy and autologous stem cell transplantation carried out at multiple institutions worldwide have proven the feasibility of the procedure and provided extended progression-free survival (and possibly cure) in a sizable number of patients with relapsed or refractory HD. Prognostic factors have been identified by multiple investigators (with response to chemotherapy being the most impressive one) and may ultimately allow a risk-adapted strategy. While early and late treatment-related morbidity and mortality remains an issue, with current supportive care modalities most patients tolerate this procedure with only minor or manageable complications. Disease recurrence remains a problem in many patients, and this can unfortunately occur as late as six or seven years after a seemingly successful transplant. New chemotherapeutic agents and strategies (such as post-transplant maintenance and possibly immunomodulation) will be required to successfully tackle this issue. Allogeneic stem-cell transplantation from HLA-compatible donors has yielded largely unsatisfactory results in the published studies in the literature, despite favorable results in a small minority of patients. Recently, however, newer approaches and strategies (such as the introduction of reduced-intensity, purine analog-based conditioning regimens and possibly cellular immunotherapy in the form of donor lymphocyte infusions) have provided very encouraging early results and seem to brighten the outlook for this procedure.

High rate of invasive fungal infections following nonmyeloablative allogeneic transplantation

Nonmyeloablative allogeneic transplantation is an emerging therapy for hematologic and solid malignancies and potentially offers patients reduced transplant-related toxicity. Data regarding infectious complications of these protocols are limited, but early studies have demonstrated little infectious morbidity, particularly low rates of invasive fungal infections (IFIs). In the present study, 31 consecutive cases of nonmyeloablative transplantation were reviewed over a 2.5-year period, with a specific focus on infectious complications. Twenty-six patients (84%) had at least 1 significant infection during the year after transplantation, and infection-related mortality was 37%. Cytomegalovirus end-organ disease was diagnosed in 3 patients (10%). Ten patients (32%) were given the diagnosis of IFI; 7 (23%) met criteria for proven IFI. Fungal-related mortality was 80% within the group of patients with IFI and accounted for a significant portion of the overall mortality in the study. Severe graft-versus-host disease, high-dose corticosteroid use, recurrent neutropenia, and relapsed or refractory disease were factors associated with development of IFI.

Role of nonmyeloablative allogeneic stem-cell transplantation after failure of autologous transplantation in patients with lymphoproliferative malignancies

PURPOSE

Conventional allogeneic stem-cell transplantation (SCT) after a prior failed autograft is associated with a transplant-related mortality rate of 50% to 80%. The aim of the current study was to evaluate the safety and efficacy of sibling, HLA-matched, nonmyeloablative allogeneic SCT with donor lymphocyte infusion (DLI) in patients with lymphoid malignancy after failure of autologous SCT.

PATIENTS AND METHODS

A total of 38 patients with refractory, progressive, or relapsed disease after autologous SCT were entered onto this study. The conditioning regimen consisted of the humanized monoclonal antibody CAMPATH-1H, fludarabine, and melphalan. Fifteen of 35 assessable patients received DLI after SCT.

RESULTS

Sustained neutrophil engraftment was achieved in 37 recipients, and platelet engraftment was achieved in 35 patients. The estimated transplant-related mortality was 7.9% at day 100 and 20% at 14 months, the median duration of follow-up. Eight patients experienced grade I/II acute graft-versus-host disease (GVHD) after transplantation, but no grade III/IV GVHD was observed in this setting. However, grade III/IV GVHD occurred in seven patients who received DLI. The actuarial overall survival at 14 months was 53%, with a progression-free survival of 50%. DLI produced a further response in three of 15 recipients.

CONCLUSION

Nonmyeloablative allogeneic SCT after CAMPATH-1H-containing conditioning is a relatively safe option compared with conventional allogeneic transplantation for patients who have failed previous autologous SCT. The low incidence of early GVHD enabled the subsequent administration of DLI to improve further clinical responses in this poor-risk group of lymphoma and myeloma patients.

Reduced-intensity allogeneic transplantation for lymphoma

Reduced-intensity allogeneic transplants are promising, increasingly used treatments for hematologic malignancies, exploiting graft-versus-tumor effects for eradicating malignancies. This article reviews approximately 40 published reports of reduced-intensity allogeneic transplants in lymphomas. Overall, reduced-intensity allogeneic transplants have been well tolerated and have produced encouraging results despite a diversity of transplant approaches used largely in heavily pretreated and older patients. Of 368 lymphoma patients who underwent reduced-intensity allogeneic transplants, 66.3% had responses, most of which were complete. Many had chemotherapy-refractory lymphomas, including some that relapsed after autologous transplants. Although the short follow-up periods of many studies do not permit assessments of response duration, protracted remissions were reported in some studies. Additionally, some patients entered molecular remissions, suggesting that graft-versus-tumor effects could, by themselves, cure some lymphomas. Graft-versus-host disease is the major risk of reduced-intensity allogeneic transplants, and treatment methods need refinement to reduce transplant risks while preserving graft-versus-tumor effects. Controlled trials involving patients with earlier-stage disease appear warranted to define better the role of reduced-intensity allogeneic transplants in treating lymphomas.

Hematopoietic stem cell transplantation in Hodgkin disease

Intensive therapy and autologous stem cell transplantation represent the standard of care in most patients whose Hodgkin disease has not been cured with conventional chemotherapy. With more prolonged follow-up of autografted patients, the problems with autologous stem cell transplantation are clear. In particular, recurrent disease and late transplant-related complications limit the effectiveness of this approach. A number of autologous stem cell transplantation studies have reported prognostic factors that will help identify patients at high risk for relapse. Several new approaches for decreasing recurrence rates are discussed, including novel immune strategies and re-evaluation of allogeneic stem cell transplantation. Although the risk of secondary malignancy and other causes of late morbidity and mortality after autologous stem cell transplantation is relatively low, current studies contribute to understanding of the pathogenesis of these complications and may diminish their impact in the future.