Reduced-intensity conditioning allogeneic stem cell transplantation with donor T-cell depletion using alemtuzumab added to the graft ('Campath in the bag').

Reduced-intensity conditioning (RIC) has allowed the use of allogeneic stem cell transplantation (alloSCT) for haematological malignancies in elderly patients. A major problem of this type of transplantation is the high incidence of persisting chronic graft-versus-host disease (GvHD), leading to increased morbidity and mortality. The inclusion of alemtuzumab added to the graft ('Campath in the bag') for donor T-cell depletion offers an easy procedure to diminish the incidence of GvHD. Good engraftment is observed in most patients, whereas almost no GvHD is observed after transplantation. Most patients become mixed chimeric after transplantation, requiring donor lymphocyte infusion for conversion to full donor chimerism. Although subsequent acute and chronic GvHD is observed in 50-60% of patients, it is responsive to therapy in many patients, resulting in a low incidence of persisting chronic GvHD. AlloSCT with RIC and alemtuzumab-induced T-cell depletion offers a suitable platform for the investigation of novel cellular immunotherapy.

Outcomes after myeloablative unrelated donor stem cell transplantation using both in vitro and in vivo T-cell depletion with alemtuzumab.

HLA-matched unrelated donor (MUD) stem cell transplantation (MUD) is complicated by a high incidence of graft-versus-host-disease (GVHD) resulting in significant morbidity and mortality. To circumvent this problem we included alemtuzumab for in vivo and in vitro T-cell depletion in a myeloablative MUD-SCT regimen. After SCT, no severe acute GVHD was observed in the 30 transplanted patients. Donor lymphocyte infusion administered at a later time point resulted in sustained anti-tumor responses in most patients with chronic myeloid leukemia. After donor lymphocyte infusion three patients developed severe acute GVHD. Due to good responsiveness to immunosuppressive therapy only two patients developed persistent chronic GVHD. The main advantage of the transplantation regimen including alemtuzumab is that not only mortality due to GVHD is limited but also extensive chronic GVHD, which potentially leads to chronic morbidity and diminished quality of life, is hardly observed.

Long-term follow-up of myeloablative allogeneic stem cell transplantation using Campath "in the bag" as T-cell depletion: the Leiden experience.

Graft-versus-host disease (GVHD) is a major cause of mortality and morbidity after allogeneic stem cell transplantation (alloSCT) but can be prevented by removing T-lymphocytes from the graft. Campath (anti-CD52) antibodies have been widely used in vivo for T-cell depletion following conventional and reduced intensity conditioning regimens. The use of Campath in vivo was associated with a significant reduction in GVHD but at the cost of impaired immune reconstitution. We evaluated the long-term outcome of 73 myeloablative allogeneic stem cell transplants with HLA-identical sibling donors using Campath "in the bag" as method of in vitro T-cell depletion. All patients engrafted and hematopoietic recovery was uneventful, resulting in a median of 99% donor chimerism at 3 months after alloSCT. Cytomegalovirus (CMV) reactivation occurred in 53% of the patients. No CMV disease was observed probably as a result of pre-emptive (val)ganciclovir treatment. The incidence of aGVHD was low (22% grade II). No grades III-IV aGVHD was observed and extensive chronic GVHD (cGVHD) occurred in 19% of the patients. The low incidence of GVHD and successful pre-emptive antiviral therapy resulted in low TRM of 8%. Sixteen patients died due to disease relapse after alloSCT, resulting in an overall survival of 48% at 5-years after alloSCT.

Alpha-interferon with very-low-dose donor lymphocyte infusion for hematologic or cytogenetic relapse of chronic myeloid leukemia induces rapid and durable complete remissions and is associated with acceptable graft-versus-host disease.

Donor lymphocyte infusion (DLI) results in complete cytogenetic remission (CCR) of relapsed chronic-phase chronic myeloid leukemia (CML-CP) after allogeneic stem cell transplantation (SCT) in up to 80% of patients. The main complication of DLI is graft-versus-host disease (GVHD). Decreasing the dose of DLI is associated with less GVHD but also with a longer interval between treatment and CCR. We postulated that combining alpha-interferon (alpha-IFN) with DLI would enable us to decrease the dose of DLI, thereby limiting GVHD, and at the same time to decrease the interval between DLI and CCR for patients with either a hematologic or cytogenetic relapse. For molecular relapses, we hypothesized that because of a lower tumor load, very low doses of DLI without alpha-IFN could be an effective treatment. Two groups of CML-CP patients treated with DLI at a very low dose of 0.5 to 1.0 x 10(7) mononuclear cells per kilogram, containing 2 to 6 x 10(6) CD3+ T cells per kilogram, were analyzed: 13 patients with a cytogenetic or a hematologic relapse after allogeneic SCT (group A) were treated with additional alpha-IFN therapy at a dose of 3 x 10(6) U 5 d/wk, and 8 patients with a molecular relapse were treated without alpha-IFN (group B). Twelve patients from group A reached a CCR. The median interval between DLI and CCR was 7 weeks (range, 5-18 weeks) for group A. All patients with a CCR reached complete donor chimerism at a median of 10 weeks after DLI (range, 6-121 weeks). Eleven patients reached molecular remission at a median of 15 weeks after DLI (range, 8-34 weeks). In group B, all patients reached a molecular remission at a median of 14 weeks (range, 12-29 weeks). Five patients from group A developed acute GVHD grade II to IV and extensive chronic GVHD. In group B, 1 patient developed acute GVHD grade II to IV and subsequently developed extensive chronic GVHD. With a median follow-up of 62 months, 10 patients in group A are alive and in continuous CCR. One patient had a molecular relapse, for which she successfully received additional DLI; another patient reached molecular remission only after 5 doses of DLI. Two patients from group A died of a gram-negative sepsis, and 1 died of an acute myocardial infection. In group B, all patients are alive and in molecular remission with a median follow-up of 20 months. One patient's disease progressed but was successfully treated with DLI plus alpha-IFN. In conclusion, very-low-dose DLI in combination with alpha-IFN as treatment for cytogenetic or hematologic relapses of CML-CP after allogeneic SCT reduced the interval to obtain a CCR with acceptable GVHD when compared with the literature. Patients with a CCR also reached complete donor chimerism and complete molecular remissions. For patients with a molecular relapse, very-low-dose DLI alone is sufficient to induce molecular remissions in most patients and is associated with limited GVHD.

Minimal GVHD following in-vitro T cell-depleted allogeneic stem cell transplantation with reduced-intensity conditioning allowing subsequent infusions of donor lymphocytes in patients with hematological malignancies and solid tumors.

OBJECTIVE: Allogeneic stem cell transplantation (alloSCT) following reduced-intensity conditioning offers a relatively nontoxic regimen while preserving rapid and sustained engraftment. Acute and chronic graft-vs-host disease (GVHD) is, however, a significant cause of severe morbidity. To reduce the incidence of GVHD, we treated a group of high-risk patients with a reduced-intensity conditioning regimen followed by in vitro T-cell-depleted alloSCT using Campath 1-H incubation. PATIENTS AND METHODS: Eighteen patients were treated with fludarabine (6 x 30 mg/m(2)), busulphan (2 x 3.2 mg/kg), and ATG (4 x 10 mg/kg) followed by the infusion of high-dose T-cell-depleted peripheral stem cells from sibling donors. No posttransplant GVHD prophylaxis was administered. At 6 months after alloSCT, low-dose donor lymphocyte infusion (DLI) was administered. RESULTS: All patients had sustained engraftment of donor cells with a median of 95% donor cells at 3 months after alloSCT. Minimal acute and no chronic GVHD was observed after alloSCT. A high incidence of cytomegalovirus (CMV) reactivation but no CMV disease was observed. Eleven patients received DLI at a median of 6.5 months after alloSCT. Acute GVHD grade II-III developed in 6 patients. All patients showed improvement of donor chimerism after DLI. With a median follow-up of 211 days, 11 patients are alive. Particular in patients with chronic lymphocytic leukemia and acute myeloid leukemia, a significant graft-vs-tumor effect was observed. CONCLUSIONS: In vitro T-cell-depleted alloSCT following reduced-intensity conditioning leads to durable donor engraftment without GVHD. The high levels of donor chimerism allow the subsequent use of cellular immunotherapy to treat residual disease.

Comparison of allogeneic T cell-depleted peripheral blood stem cell and bone marrow transplantation: effect of stem cell source on short- and long-term outcome.

We report the results of a retrospective single-center study comparing engraftment, acute and chronic GVHD, relapse and survival in patients with malignant hematological disorders transplanted with allogeneic peripheral blood stem cells (alloPBSCT, n = 40) or bone marrow cells (alloBMT, n = 42). All transplants were T cell depleted by in vitro incubation with the Campath-1 monoclonal antibody. Primary graft failure occurred in none of the patients receiving an alloPBSCT compared with 3/42 of the recipients of an alloBMT. In addition, two patients in the alloBMT group showed no platelet engraftment. Recipients of PBSC had a more rapid recovery of neutrophils (median 14 days) compared to BM transplant recipients (median 32 days). Platelet recovery was also accelerated in PBSC recipients compared to BM recipients (11 vs 38 days). There was an increase in the incidence of grade II acute GVHD and chronic GVHD in patients after alloPBSCT (18% and 23%, respectively) compared to patients receiving alloBMT (5% and 8%, respectively). The 2-year cumulative incidence of relapse was similar in both groups (47%). At 6 months after transplantation, transplant-related mortality (TRM) was lower in PBSCT recipients than in BMT recipients. However, at a follow-up of 3 years TRM was similar in both groups. The disease-free survival rate at 3 years after transplantation did not differ between the groups (42% for PBSCT and 41% for BMT recipients). Our results indicate that T cell-depleted alloPBSCT compared to alloBMT is associated with a more rapid hematopoietic reconstitution and a decreased TRM at 6 months follow-up after transplantation. However, at a follow-up of 3 years, no sustained survival benefits were observed.

High-dose Ara-C for remission induction and consolidation of previously untreated adults with ALL or lymphoblastic lymphoma.

Thirty-two patients with untreated ALL (n = 26) or lymphoblastic lymphoma (n = 6) between 17 and 65 years of age were treated with a short remission induction course with VP16-213, amsacrine, intermediate dose Ara-C for 6 days, prednisone and intrathecal methotrexate, followed by a consolidation course with vincristine, amsacrine, high dose Ara-C for 4 days, prednisone and intrathecal methotrexate. After subsequent cranial irradiation, no further maintenance was planned. However, some patients underwent an allogenic (n = 5) or autologous (n = 5) bone marrow transplantation after the consolidation treatment. Twenty-three of 32 patients (72%) achieved a complete remission. Ten of 13 patients with T-ALL or lymphoma, six of eight patients with pre-B or common ALL, and seven of 11 patients with B-ALL or Burkitt's lymphoma achieved a complete remission. The median duration of remission was 24 months. Overall survival for the whole group was 35% at 5 years. The disease-free survival was 45% at 5 years. Long-term survival for patients with B or T-ALL was approximately 60%, compared with 15% for those with common or pre B-ALL. Short term intensive courses including intermediate or high dose Ara-C during remission and consolidation treatment lead to results comparable to those obtained with long-term maintenance regimens. Our regimen may be sufficient for patients with T or B-ALL. Larger randomized studies are needed to investigate the relative importance of our observations.

Deoxycytidine kinase, thymidine kinase and cytidine deaminase and the formation of Ara-CTP in leukemic cells in different phases of the cell cycle.

In this study we investigated the Ara-CTP-forming capacity of leukemic cells in different phases of the cell cycle. Cells from two leukemic cell lines and leukemic bone marrow cells from patients and rats (BNML model) with acute myelocytic leukemia were separated according to cell cycle phase by means of an albumin density gradient in a specially designed sedimentation chamber. We found that the activity of CdR kinase and Cyt deaminase is much less influenced by cell-cycle phase progression than TdR kinase activity. For the leukemic cell lines HL-60 and BNML-CL/O CdR kinase activity is even independent of cell-cycle phase. In addition, Ara-CTP formation is not restricted to cells in S-phase. Cell cycle phase-independent Ara-CTP formation creates a situation in which cells which are not in S-phase during exposure to Ara-C might undergo the cytotoxic effects of Ara-C as soon as they enter S-phase.

Deoxycytidine kinase and deoxycytidine deaminase values correspond closely to clinical response to cytosine arabinoside remission induction therapy in patients with acute myelogenous leukemia.

In this study, it has been shown that in 21 patients with AML the dCyd kinase and dCyd deaminase activities correspond closely to the clinical response to ara-C remission induction therapy. Patients with primary disease were treated with a conventional-dose ara-C regimen whereas nonresponders and relapsed patients followed an ID ara-C regimen (1 g/m2 X 12). Of these 21 patients (11 with primary disease and ten relapsed), seven had ara-C resistant disease (three primary and four relapsed patients). Five of the seven patients had a very low dCyd kinase and normal dCyd deaminase activity, whereas the other two had a normal dCyd kinase and an increased dCyd deaminase activity.