Unrelated donor hematopoietic stem cell transplantation for patients with hematologic malignancies using a nonmyeloablative conditioning regimen of fludarabine, low-dose total body irradiation, and rabbit antithymocyte globulin

Fludarabine/busulfan versus fludarabine/total-body-irradiation (2 Gy) as conditioning prior to allogeneic stem cell transplantation in patients (≥60 years) with acute myelogenous leukemia: a study of the acute leukemia working party of the EBMT

Nonmyeloablative (NMA) conditioning regimens facilitate allogeneic stem cell transplantation (alloSCT) in elderly patients and/or in those with comorbidities. The acute leukemia working party (ALWP) of the European Society for Blood and Marrow Transplantation (EBMT) compared the outcomes of patients ≥60 years with AML in first complete remission (CR1), that had received an alloSCT following NMA conditioning, i.e. either fludarabine/busulfan (FB2) or fludarabine/total-body-irradiation-2Gy (FluTBI2Gy). A total of 1088 patients were included (median age 65 years). Donors were matched siblings (MSD) and matched unrelated donors (MUD) in 47% and 53%, respectively. In vivo T-cell depletion (TCD) was applied to 79% and none (0%) of patients in the FB2 and FluTBI2Gy groups, respectively. In the MSD group we found a trend for less extensive cGVHD in patients receiving FB2 with in vivo TCD, HR: 0.49, p = 0.08, and in those without worse NRM, HR: 2.14, p = 0.04, and a trend for more total cGVHD, HR: 1.61, p = 0.09. Patients transplanted from MUDs had a significantly higher incidence of total cGVHD, extensive cGVHD and a worse GRFS with FluTBI2Gy in comparison to FB2, HR: 2.44; p < 0.0001; HR 4.59; p < 0.00001 and HR: 1.35; p = 0.03, respectively. No differences were observed with respect to LFS, OS, RI, NRM, and aGVHD.

Older recipient age is paradoxically associated with a lower incidence of chronic GVHD in thymoglobulin recipients: a retrospective study exploring risk factors for GVHD in allogeneic transplantation with thymoglobulin GVHD prophylaxis

Thymoglobulin (TG) given with conditioning for allogeneic haematopoietic SCT (alloHSCT) is effective in reducing the risk of acute and chronic GVHD (cGVHD). Whether conventional risk factors for GVHD apply to TG-conditioned alloHSCT is unknown. We retrospectively studied 356 adults from three centres who received TG 4.5 mg/kg prior to alloHSCT for haematologic malignancy. Donors were unrelated in 64%. At 3 years, OS was 61% (95% confidence interval (CI) 55-67%), cumulative incidence of relapse was 28% (95% CI 23-33%) and non-relapse mortality was 19% (14-24%). The cumulative incidences of grade 2-4, and grade 3-4 acute GVHD were 23% (95% CI 19-28%) and 10% (95% CI 6-13%), respectively. The cumulative incidence of cGVHD requiring systemic immunosuppression (cGVHD-IS) at 3 years was 32% (95% CI 27-37%). On multivariate analysis, counterintuitively, recipient age over 40 was associated with a significantly decreased risk of cGVHD-IS (P=0.001). We report for the first time a paradoxical association of older age with reduced cGVHD in TG recipients, and conclude that traditional risk factors for GVHD may behave differently in the context of pre-transplant TG.

Response and toxicity of donor lymphocyte infusions following T-cell depleted non-myeloablative allogeneic hematopoietic SCT from 3-6/6 HLA matched donors

We report the outcome of early donor lymphocyte infusions (DLIs) after T-cell depleted non-myeloablative transplantation using stem cells from HLA-matched or mismatched donors. Sixty-nine patients with high-risk hematologic malignancies received DLI following fludarabine, CY and alemtuzumab with infusion of stem cells from a matched sibling (52) or partially matched family member donor (17). Patients received the first infusion at a median of 50 days after transplant, and doses ranged from 1 x 10(4) CD3+ cells/kg to 3.27 x 10(8) CD3+ cells/kg, depending on clinical status and the physician's discretion. A median cell dose of 1 x 10(5) CD3+ cells/kg in the mismatched setting and 1 x 10(6) CD3+ cells/kg in the matched sibling setting appears safe with only 1 of 7 (14%) and 4 of 31 patients (13%), respectively, experiencing severe acute GVHD at these doses. Importantly, 38% of patients with persistent disease before DLI attained a remission after infusion. Nine of the 69 patients remain alive and disease-free 32-71 months after the first DLI. In conclusion, low doses of DLI can be safely provided soon after T-cell depleted non-myeloablative therapy and provide a chance of remission. However, long-term survival still remains poor, primarily because of relapse in these patients.

Graft Versus Host Disease After Stem Cell Allotransplantation With Low-Dose Total Body Irradiation, Fludarabine, and Antithymocyte Globulin

BACKGROUND

We previously showed that antithymocyte globulin (ATG) given with total body irradiation (TBI) 200 cGy and fludarabine results in high rate of donor engraftment. Its influence on acute and chronic graft versus host disease (GVHD) and on graft versus tumor effect is less known.

METHODS

Sixty-five patients underwent nonmyeloablative stem cell transplant with ATG, TBI 200 cGy, and fludarabine. GVHD prophylaxis was mycophenolate mofetil and cyclosporine. Forty-two patients (pts) (65%) had match related donors, 18 (27%) match unrelated, 1 (1.5%) mismatch related, and 4 (6%) mismatch unrelated donors.

RESULTS

At a median follow-up of 862 days, 24 patients (37%) developed GVHD. The median age of the patients with and without GVHD was 56 years respectively. Acute GVHD grade II-IV developed in 19 pts (29%). Fatal GVHD of liver and/or gut occurred in nine pts (14%). Forty-one pts survived more than 100 days. Five pts (12%) had chronic GVHD, two had extensive, and three had limited involvement. Relapsed disease was observed in 22 pts (34%). Infections occurred in 15 pts (23%) and were fatal in 13 (20%).

CONCLUSIONS

The addition of ATG to TBI 200cGy and fludarabine resulted in a modest incidence of GVHD. The best transplant outcomes were observed in pts with lymphoid malignancies.

Umbilical cord blood transplantation after nonmyeloablative conditioning: impact on transplantation outcomes in 110 adults with hematologic disease

We evaluated the efficacy of umbilical cord blood (UCB) in the setting of a nonmyeloablative regimen consisting of fludarabine (200 mg/m2), cyclophosphamide (50 mg/kg), and a single fraction of total body irradiation (200 cGy) with cyclosporine and mycophenolate mofetil for posttransplantation immunoprophylaxis. The target cell dose for the UCB graft was 3.0 x 10(7) nucleated cells/kg, resulting in the selection of a second partially human leukocyte antigen-matched UCB unit in 85%. One hundred ten patients with hematologic disease were enrolled. Neutrophil recovery was achieved in 92% at a median of 12 days. Incidences of grades III and IV acute and chronic graft-versus-host disease (GVHD) were 22% and 23%, respectively. Transplantation-related mortality was 26% at 3 years. Survival and event-free survival (EFS) at 3 years were 45% and 38%, respectively. Favorable risk factors for survival were absence of high-risk clinical features (Karnofsky 50-60, serious organ dysfunction, recent fungal infection, P < .01) and absence of severe GVHD (P = .04), and favorable risk factors for EFS were absence of high-risk clinical features (P < .01) and use of 2 UCB units (P = .07). These findings support the use of UCB after a nonmyeloablative conditioning as a strategy for extending the availability of transplantation therapy, particularly for older patients.

Partially Matched, Nonmyeloablative Allogeneic Transplantation: Clinical Outcomes and Immune Reconstitution

Purpose

Allogeneic transplantation is typically limited to younger patients having a matched donor. To allow a donor to be found for nearly all patients, we have used a nonmyeloablative conditioning regimen in conjunction with stem cells from a related donor with one fully mismatched HLA haplotype.

Patients and Methods

Fludarabine, cyclophosphamide, and alemtuzumab were used as the preparatory regimen. Additional graft-versus-host disease (GVHD) prophylaxis included mycophenolate with or without cyclosporine. Patients with persistence of disease had a donor lymphocyte boost planned. Toxicities, engraftment, response, survival, and immune recovery are reported.

Results

Forty-nine patients with hematologic malignancies or marrow failure and no other available donors were enrolled. Ninety-four percent of patients had successful engraftment, and 8% had secondary graft failure. The treatment-related mortality rate was 10.2%, and 8% of patients had severe GVHD. Encouraging evidence of quantitative lymphocyte recovery through expansion of transplanted T cells was noted by 3 to 6 months. Seventy-five percent of patients attained a complete remission, and 1-year survival rate was 31% (95% CI, 18% to 44%). A standard-risk group of 19 patients with aplasia or in remission at transplantation demonstrated a 63% 1-year survival rate (95% CI, 38% to 80%) and 2.9-year median overall survival time (95% CI, 6.2 to 48 months).

Conclusion

Nonmyeloablative therapy using haploidentical family member donors is feasible because the main obstacles of GVHD and graft rejection are manageable, allowing readily available stem-cell donors to be found for nearly all patients. Further qualitative and quantitative improvement in immune recovery is needed to address the high rate of relapse and risk of severe infections.

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.

Intensive graft-versus-host disease prophylaxis is required after unrelated-donor nonmyeloablative stem cell transplantation

Nonmyeloablative stem cell transplantation (NST) harnesses the graft-versus-tumor effect while minimizing regimen-related toxicity, and can result in donor chimerism and remission. Acute graft-versus-host disease (GVHD) and infections are major complications after sibling NST. Toxicity of unrelated-donor (UD) NST and the most appropriate GVHD prophylaxis in this setting remain poorly defined. We describe 25 patients who received UD-NST conditioned with fludarabine and cyclophosphamide. The first six patients received cyclosporine (Cs) and mycophenolate mofetil (MMF) (n=5) or methotrexate (MTX) (n=1) as GVHD prophylaxis (group 1) and all developed grade III-IV acute GVHD. The next 19 patients received the same conditioning regimen with the addition of alemtuzumab, and all received Cs/MTX post-transplant. Engraftment and donor chimerism were achieved in all but one evaluable patient. In all, 15 patients died: five of six deaths in group 1 were attributable to acute GVHD, while deaths in group 2 were due to infection or progressive disease (P=0.05). The combination of Cs/MMF is inadequate GVHD prophylaxis for UD-NST. The use of Cs, MTX, and alemtuzumab eliminated severe acute GVHD; its impact on response merits further study.