Nonmyeloablative Allogeneic Hematopoietic Cell Transplantation Research Articles

Tandem Autologous and Nonmyeloablative Allogeneic Hematopoietic Cell Transplantation (HCT) from HLA-matched Related Or Unrelated Donors for Advanced Lymphoma Or Chronic Lymphocytic Leukemia (CLL)

Tandem Autologous and Nonmyeloablative Allogeneic Hematopoietic Cell Transplantation (HCT) from HLA-matched Related Or Unrelated Donors for Advanced Lymphoma Or Chronic Lymphocytic Leukemia (CLL)

Allogeneic Hematopoietic Cell Transplantation (HCT) after Nonmyeloablative Conditioning for Patients (pts) Aged ≥60 Years.

Median ages of pts with most hematological malignancies are beyond 60 years. The advent of nonmyeloablative conditioning regimens has extended the use of allogeneic HCT to these older pts. Here, we retrospectively investigated outcomes among 280 pts aged ≥60 years, given HCT between 1998 and 2006. Results were broken down in 3 age groups 60–64 (n=166), 65–69 (n=90), and ≥70 (n=24) years old, respectively. Pts aged ≥70 years had less preceding chemotherapy, less often failed autologous HCT, more often had related grafts, and had higher comorbidity scores compared to pts in the other two age groups (table 1). Acute leukemias were more frequent and lymphoma/multiple myeloma were less frequent among pts aged ≥70 years old, resulting in higher risk for relapse (Table 1). After HCT, non-relapse mortality, relapse, and progression free survivals at 5-years for all pts were 26%, 41%, and 32% respectively. Five-year Kaplan Meier rate of overall survival was 35%, of those 12% vs. 23% were with vs. without chronic GVHD requiring immunosuppressive therapy, respectively. There were no statistically significant differences in outcomes among the three age groups except for more infections and days of hospitalization among pts aged 65–69 years compared to the other two age groups (Table 2). In multivariate analyses of risk factors, high HCT-comorbidity index (1–2 and ≥3) independently predicted higher NRM (HR: 2.84 and 3.0, respectively, p=0.01) and, not surprisingly, previously defined high relapse risk predicted relapse (HR: 2.17, p=0.06); both predicted worse OS (p=0.005 and p=0.0009, respectively) and PFS (p=0.01 and p=0.02, respectively). Pts given unrelated grafts did as well as recipients of related grafts. In conclusion, nonmyeloablative allogeneic HCT can be curative among pts older than 60 years with resolution of chronic GVHD among a majority of pts. Comorbidities and relapse risk rather than age should be used for benefit-risk assessment. Continued enrollment of elderly pts in prospective studies including unrelated donors is warranted.Table 1: Pt characteristicsAge groups, years(60–64) (n=166)(65–69) (n=90)(70–74) (n=24)Median Interval from Dx to HCT, months19158Median (range) # of prior regimens3 (0–14)3 (0–13)2 (0–10)Median CD34+ cell number x 106/kg6.76.76.5Median CD3+ cell number x 108/kg2.93.13.4%Prior radiotherapy181113Prior HCTFailed19124Planned864Positive patient CMV sero-status586579HLA-matched related545383DonorHLA-matched unrelated414417HLA-mismatched unrelated530Conditioning2 Gy TBI1213212 Gy TBI + FLU888779HCT-CI scores02727151–23039253–4301740≥5131720DiagnosesAcute leukemia354762Chronic leukemia151313Lymphoma/myeloma21238Myelodysplastic/myeloproliferative161617Others310Disease status at HCTCR464138PR153021Refractory282133Relapse1188Relapse riskLow19178Standard485138High333254Table 2: Outcomes per age groupsHCT OutcomesAge groups, yearsP*(60–64) (n=166)(65–69) (n=90)(70–74) (n=24)Bacterial1.42.31.7.0004Rates of Infection episodes per personViral0.71.10.7NSwithin 100 daysFUO0.30.40.1NSFungal0.30.20.3NSMedian (range) days of hospitalization1 (0–60)4.5 (0–179)0.5 (0–47)NS%Acute GVHDGrades II–IV524954NSμGrades III–IV161213NSμChronic extensive GVHD3945540.05μNCI-CTC criteria grades III–IV non-hematological toxicities425750NSμPts with Full donor chimerism at 1-yearCD3/CD33/BM68/ 84/ 8066/ 83/ 7767/ 79/ 71NSμCR at 2-years404763NSμ5-years Relapse/progression384646NSμ5-years NRM282229NSμ5-years OS373623NSμ5-years PFS343125NSμPatients alive and off all immunosuppression24255NSμFUO indicates fever of unknown origin*Test for trendμBased on hazard ratio analysis

Nonmyeloablative Allogeneic Hematopoietic Cell Transplantation in Patients with De Novo and Secondary Acute Myeloid Leukemia

We report the results of 256 patients (median age = 59; range, 5–74 years) with de novo AML in first complete remission (CR1; n=100), beyond CR1 (n=79) and with treatment-related or secondary AML (n=77) who underwent allogeneic hematopoietic cell transplantation (HCT) from HLA-matched related (n=109) or from unrelated donors (n=147). Indications of allogeneic HCT in CR1 were persistent cytogenetic or molecular evidence of disease, poor-risk cytogenetics at diagnosis, treatment-related or secondary AML and age more than 60 years. Younger patients were included if they had comorbid conditions that excluded them from conventional allogeneic HCT. Sixteen patients were mismatched with their donors for ≥ one HLA antigen, while the remainder were matched 10/10 at the antigen level. Conditioning consisted of low-dose total body irradiation (TBI; 2 Gy) on day 0 either alone (n=28) or combined with fludarabine, 30 mg/m2/day on days −4 to −2 (n=228). Calcineurin inhibitors (cyclosporine or tacrolimus) and mycophenolate mofetil were used for postgrafting immunosuppression. Durable engraftment was observed in 94% of patients. With a median follow-up of 35 (range, 3 – 111) months in surviving patients, the estimated progression-free and overall survivals at 5 years were 32% (95% CI: 25–38%) and 32% (95% CI: 25–38%), respectively. The cumulative incidences of relapse/progression and non-relapse mortality at 5 years were 40% (95% CI: 33–46%) and 29% (95% CI: 22–35%), respectively. Estimated 5-year survival rates, progression-free survival, relapse/progression rate, and non-relapse mortality according to disease status are shown in Table 1; Table 2 shows the same indices according to donor type. The cumulative incidences of grades II–IV and III–IV acute graft-versus-host disease (GVHD) in patients with related donors were 40% and 13%, and in those with unrelated donors were 58% and 14%, respectively. The cumulative incidence of chronic extensive GVHD at 5 years was 44% in patients with related donors, and 42% in patients with unrelated donors. Age > 60 years at the time of HCT did not have an impact on the outcome (univariate analysis). Additional analyses regarding the impact of HCT comorbidity scores and minimal residual disease at the time of HCT are in progress. Based on this multicenter analysis, we conclude that allogeneic HCT from related or unrelated donors, utilizing a conditioning regimen of low dose TBI (2 Gy) with fludarabine provides long term remission in elderly and/or medically infirm patients with AML, who were not considered candidates for conventional HCT.Table 1. Estimated 5-year overall survival (OS), progression-free survival (PFS), relapse/progression rate (RR), and non-relapse mortality (NRM) according to disease status. CR1: 1st remission; >CR1: subsequent remission, induction failure/persistent disease; sAML: treatment-related and secondary AML.Disease Statusn%OS (95% CI)%PFS (95% CI)RR (95% CI)NRM (95% CI)CR110033 (20–46)34 (23–46)36 (26–47)30 (19–40)>CR17938 (26–49)35 (23–46)40 (29–52)25 (15–35)sAML7720 (8–32)23 (11–35)45 (32–57)32 (20–45)Table 2. Estimated 5-year overall survival (OS), progression-free survival (PFS), relapse/progression rate (RR), and non-relapse mortality (NRM) according to donor type.Donor Typen%OS (95% CI)%PFS (95% CI)RR (95% CI)NRM (95% CI)HLA-identical related10934 (23–44)34 (24–45)47 (37–58)18 (10–26)HLA-matched unrelated13131 (22–40)30 (21–39)37 (29–46)33 (24–72)HLA mismatched unrelated1624 (0–50)24 (0–50)6 (0–18)70 (43–97)

Comparison of Two Mycophenolate Mofetil Dosing Regimens Following Hematopoietic Cell Transplantation (HCT).

Mycophenolate mofetil (MMF) is frequently used as part of the immunosuppressive regimen after allogeneic nonmyeloablative HCT. We and others have previously shown that low mycophenolic acid (MPA) exposure, the active component of MMF, is associated with poorer rates of engraftment and increased risk of graft-vs-host disease (GVHD). As therapeutic plasma targets are difficult to achieve in adult HCT recipients with doses of MMF 2 gm/day, higher doses are required. To determine if higher MMF doses of 3 gm/day would achieve the therapeutic plasma targets we conducted a prospective pharmacokinetic study in adult recipients of nonmyeloablative HCT treated with cyclophosphamide 50 mg/kg, fludarabine 200 mg/m2 and total body irradiation 200 cGy in combination with cyclosporine and MMF as either 1.5 gm every 12 hours (n=15) or 1 gm every 8 hours (n=15). MMF was initiated on day -3 intravenously and switched to the oral form within the first week at the same dose. Pharmacokinetic sampling at steady state was performed once in each patient between days -1 and +5 while on intravenous therapy and then repeated once between days 5 and 14 posttransplant after oral administration. There were no differences in total or unbound MPA 24 hour cumulative area under the curve (AUC), concentration at steady state (Css) or troughs between the two dosing regimens. Total MPA 24 hour AUC (median, [range]) exposures were not different between intravenous 1 gm every 8 hours (53.59 [22.86–101.99] mcg*hr/mL) and intravenous 1.5 gm every 12 hours (60.90 [35.89–127.24] mcg*hr/mL) regimen (p=0.34). Unbound MPA 24 hour AUC exposures were also not different between the intravenous 1 gm every 8 hours (0.942 [0.389–1.722] mcg*hr/mL) and intravenous 1.5 gm every 12 hours (1.081 [0.610–2.194] mcg*hr/mL)(p=0.25). Following oral therapy, total and unbound MPA 24 hour AUC exposures after 1 gm every 8 hours and 1.5 gm every 12 hours were also not different (p≥0.43). Total MPA Css after intravenous 1 gm every 8 hours, oral 1 gm every 8 hours, intravenous 1.5 gm every 12 hours, oral 1.5 gm every 12 hours were 2.23 [0.95–4.25], 2.05 [1.32–3.24], 2.53 [1.46–5.24] and 2.35 [1.47–4.05] mcg/ml, respectively (p≥0.15). We previously found that an unbound 24 hour cumulative MPA AUC <0.600 mcg*hr/mL was associated with higher risk of acute GVHD. The 3 gm/day regimens achieved an unbound 24 hour cumulative AUC target >0.600 mcg*hr/mL in 87–100% of subjects. All patients with the every 8 hour dosing had neutrophil recovery (ANC >500 cells/uL x 3 consecutive days) at a median [range] of day 10 [6–38] as compared to day 12 [0–31] in those with every 12 hour dosing. Acute GVHD grades II–IV developed in 3 (20%) and 6 (40%) patients in the MMF every 8 hour and every 12 hour dosing cohorts, respectively. When compared to our historical controls, MPA exposure is higher with MMF 3 gm/day compared to 2 gm/day regardless of dosing schedule and achieves adequate exposure in most adult patients. In conclusion, MMF 3 g/day should be considered the standard starting dose for adult patients undergoing nonmyeloablative HCT.

Comparison of Outcomes of HLA-Matched Related, Unrelated, or HLA-Haploidentical Related Hematopoietic Cell Transplantation following Nonmyeloablative Conditioning for Relapsed or Refractory Hodgkin Lymphoma

We compared the outcome of nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) for patients with relapsed or refractory Hodgkin lymphoma (HL) based on donor cell source. Ninety patients with HL were treated with nonmyeloablative conditioning followed by HCT from HLA-matched related, n=38, unrelated, n=24, or HLA-haploidentical related, n=28 donors. Patients were heavily pretreated with a median of 5 regimens and most patients had failed autologous HCT (92%) and local radiation therapy (83%). With a median follow-up of 25 months, 2-year overall survivals, progression-free survivals (OS)/(PFS), and incidences of relapsed/progressive disease were 53%, 23%, and 56% (HLA-matched related), 58%, 29%, and 63% (unrelated), and 58%, 51%, and 40% (HLA-haploidentical related), respectively. Nonrelapse mortality (NRM) was significantly lower for HLA-haploidentical related (P=.02) recipients compared to HLA-matched related recipients. There were also significantly decreased risks of relapse for HLA-haploidentical related recipients compared to HLA-matched related (P=.01) and unrelated (P=.03) recipients. The incidences of acute grades III-IV and extensive chronic graft-versus-host disease (aGVHD, cGVHD) were 16%/50% (HLA-matched related), 8%/63% (unrelated), and 11%/35% (HLA-haploidentical related). These data suggested that salvage allogeneic HCT using nonmyeloablative conditioning provided antitumor activity in patients with advanced HL; however, disease relapse/progression continued to be major problems. Importantly, alternative donor stem cell sources are a viable option.

Successful Outcome after Nonmyeloablative Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Renal Dysfunction

Nonmyeloablative allogeneic hematopoietic stem cell transplantation (HSCT) is a transplantation approach that enables patients with comorbid conditions to undergo allogeneic HSCT. We investigated the outcome of patients with reduced renal function as a single comorbidity before HSCT. Thirteen patients with a glomerular filtration rate (GFR) of <60 mL/min/1.73 m2 were matched on sex, age, and type of transplant to 26 controls with normal renal function. All patients received a nonmyeloablative HSCT with fludarabine and/or total body irradiation conditioning (TBI). Graft-versus-host disease (GVHD) prophylaxis consisted of mycophenolate mofetil and cyclosporine. Data on renal function, cyclosporine dose, cyclosporine trough levels, hypertension, and GVHD were collected. Of the 13 patients with impaired renal function, 7 patients (54%) improved or stabilized to a GFR>or=60 mL/min/1.73 m2 at last follow-up. Four patients (31%) developed chronic kidney disease stage 3 (GFR <60 mL/min/1.73 m2) compared to 3 patients (12%) in the control group (P=.039). There was no difference in survival between cases and controls. Furthermore, there were no differences in complications after HSCT, and cyclosporine dose and trough levels were similar between cases and controls. Nonmyeloablative HSCT can be safely offered to patients with mildly reduced renal function. Cyclosporine can be administered at the same dose as patients without renal dysfunction, as long as cyclosporine trough levels and creatinine are monitored and dose adjustments are made if necessary.

Non‐myeloablative allogeneic haematopoietic cell transplantation for relapsed diffuse large B‐cell lymphoma: a multicentre experience

Patients with relapsed diffuse large B-cell lymphoma (DLBCL) who have failed or are ineligible for autologous haematopoietic cell transplantation (HCT) have a poor prognosis. We examined the outcomes of non-myeloablative allogeneic HCT in this setting. Thirty-one patients with DLBCL and one patient with Burkitt lymphoma received allogeneic HCT following 2 Gy total body irradiation with or without fludarabine. Median age was 52 years. Twenty-four patients (75%) had undergone prior autologous HCT. Disease status at HCT was complete response (14/32, 44%), partial response (9/32, 28%), or refractory (9/32, 28%). Cumulative incidences of acute graft-versus-host disease (GVHD) grades II-IV, grades III-IV, and chronic GVHD were 53%, 19%, and 47% respectively. With a median follow-up of 45 months, 3-year estimated overall (OS) and progression-free survival (PFS) was 45% and 35% respectively. Three-year cumulative incidences of relapse and non-relapse mortality were 41% and 25% respectively. In multivariate models, chemosensitive disease and receipt of >or=4 lines of treatment before HCT were associated with better OS. Patients with chemosensitive disease had 3-year OS and PFS of 56% and 43% respectively. Non-myeloablative allogeneic HCT can produce long-term disease-free survival in patients with chemosensitive relapsed DLBCL who have failed or are ineligible for autologous HCT.

C19orf48Encodes a Minor Histocompatibility Antigen Recognized by CD8+ Cytotoxic T Cells from Renal Cell Carcinoma Patients

Tumor regression has been observed in some patients with metastatic renal cell carcinoma (RCC) after nonmyeloablative allogeneic hematopoietic cell transplantation (HCT). Cellular and molecular characterization of antigens recognized by tumor-reactive T cells isolated from responding patients could potentially provide insight into the mechanisms of tumor regression. CD8+ CTL clones that recognized a novel RCC-associated minor histocompatibility (H) antigen presented by HLA-A*0201 were isolated from two patients with metastatic RCC who experienced tumor regression or stable disease following nonmyeloablative allogeneic HCT. These clones were used to screen a cDNA library and isolate the unique cDNA encoding the antigen. An alternative open reading frame in the C19orf48 gene located on chromosome 19q13 encodes the HLA-A*0201-restricted minor H antigen recognized by the RCC-reactive T cells. The differential T-cell recognition of donor- and recipient-derived target cells is attributable to a nonsynonymous single-nucleotide polymorphism within the nucleotide interval that encodes the antigenic peptide. Assays for gene expression and CTL recognition showed that the C19orf48-encoded peptide is widely expressed in renal tumors and solid tumors of other histologies. The antigenic peptide can be processed for CTL recognition via both TAP-dependent and TAP-independent pathways. Donor T-cell responses against the HLA-A*0201-restricted minor H antigen encoded by C19orf48 may contribute to RCC regression after MHC-matched allogeneic HCT.

Long-term follow-up after nonmyeloablative allogeneic hematopoietic stem cell transplantation for systemic sclerosis

Systemic sclerosis (SSc) characteristically consists of fibrotic changes in various organs, and immunological abnormality is the main cause of the disease. Although high-dose immunosuppressive therapies with autologous or allogeneic hematopoietic stem cell support can reverse the disease course, they have a high treatment-related mortality. We report the successful use of nonmyeloablative allogeneic hematopoietic stem cell transplantation (HSCT) for SSc. A 40-year-old woman with diffuse scleroderma and interstitial pneumonia underwent allogeneic peripheral blood stem cell transplantation from an HLA-identical sibling after conditioning with low-dose total-body irradiation and fludarabine. Prophylaxis for graft-versus-host disease (GVHD) consisted of cyclosporine and mycophenolate mofetil. No infection or acute GVHD developed. One year after transplantation, the patient developed membranous glomerulopathy caused by chronic GVHD that was successfully treated with prednisolone. The patient's skin score decreased dramatically, and her pulmonary function is stable 4 years after transplantation. Nonmyeloablative allogeneic HSCT may be more effective than conventional therapies for SSc.

Hematopoietic cell transplantation‐comorbidity index and Karnofsky performance status are independent predictors of morbidity and mortality after allogeneic nonmyeloablative hematopoietic cell transplantation

Elderly and medically infirm cancer patients are increasingly offered allogeneic nonmyeloablative hematopoietic cell transplantation (HCT). A better understanding of the impact of health status on HCT outcomes is warranted. Herein, a recently developed HCT-specific comorbidity index (HCT-CI) was compared with a widely acceptable measure of health status, the Karnofsky performance status (KPS). The outcomes of 341 patients were evaluated, conditioned for either related or unrelated HCT by 2-gray (Gy) total body irradiation given alone or combined with fludarabine at a dose of 90 mg/m(2). Comorbidities were assessed retrospectively by the HCT-CI. Performance status before and toxicities after HCT were graded prospectively using the KPS and National Cancer Institute Common Toxicity criteria, respectively. Weak Spearman rank correlations were noted between HCT-CI and KPS and between the 2 measures and age, number of prior chemotherapy regimens, and intervals between diagnosis and HCT (all r < 0.20). High-risk diseases correlated significantly with higher mean HCT-CI scores (P = .009) but not low KPS (P = .37). In multivariate models, the HCT-CI had significantly greater independent predictive power for toxicities (P = .004), nonrelapse mortality (P = .0002), and overall mortality (P = .0002) compared with the KPS (P = .05, .13, and .05, respectively). Using consolidated HCT-CI and KPS scores, patients were stratified into 4 risk groups with 2-year survivals of 68%, 58%, 41%, and 32%, respectively. HCT-CI and KPS should be assessed simultaneously before HCT. The use of both tools combined likely refines risk-stratification for HCT outcomes. Novel guidelines for assessment of performance status among HCT patients are warranted.

Enhancement of Graft-versus-leukemia Effects by Mesenchymal Stem Cells in Mixed Chimerisim after a Murine Non-myeloablative Hematopoietic Stem Cell Transplantation

Background: Mesenchymal stem cells (MSCs) may be useful for reducing graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The GVHD and a graft-versus-leukemia (GVL) effect are inversely related. We therefore wanted to determine whether MSCs can preserve the GVL effect following experimental allo-HSCT. Methods: After non-myeloablative allogeneic hematopoietic stem cell transplantation (NM-HSCT) using C57BL/6 (H-2b)→B6D2F1 (H-2b/d), some mice received donor lymphocyte infusion (DLI) for induction of GVL effects by virtue of complete chimerism (CC), while the other groups did not receive DLI with persistence of mixed chimerism (MC). All mice were inoculated subcutaneously with P815 tumor cells and were intravenously treated with either donor MSCs or diluents. Results: Between the DLI-treated groups with CC, tumor-related deaths and tumor growths were comparable irrespective to the infusion of MSCs. On the contrary, among mice without DLI which showed MC, the administration of MSCs significantly delayed tumor-related deaths compared to those without the administration of MSCs (50-day percent survival, 54.5% vs. 18.1%, P=0.0225). In the MC animals, tumor growth seemed to be more delayed in the mice injected with MSCs than in the controls (P=0.09). Donor MSCs injection was associated with increased donor effector/memory CD62L- T cells in MC but not in CC. Conclusion: In spite of the observed immunosuppressive effects of donor MSCs, our results indicate that the GVL effects were not influenced by the injection of MSCs but that under a given condition such as MC, the injection of donor MSCs could result in enhanced GVL effects.

Pharmacokinetics of oral mycophenolate mofetil in combination with CsA in dogs after nonmyeloablative allogeneic hematopoietic stem cell transplantation

Mycophenolate mofetil (MMF) has been used successfully in solid organ transplantation (SOT) and more recently in nonmyeloablative hematopoietic stem cell transplantation (HSCT) for prophylaxis of graft rejection and acute graft-versus-host disease. However, the pharmacokinetics of MMF seem to differ when applied in HSCT compared to SOT. Here, we analyzed pharmacokinetics of mycophenolic acid (MPA), the active metabolite of MMF, in a nonmyeloablative canine HSCT model. Dogs received nonmyeloablative TBI for conditioning followed by leukocyte antigen-identical littermate HSCT and immunosuppression containing cyclosporin A (CsA) and different doses of MMF. Pharmacokinetics were performed on days 2, 14 and 27. Dose escalation of MMF from 10 to 30 mg/kg tended to increase area under the curve (AUC) and the apparent oral clearance by 45 and 110%, respectively. Doses applied had no linear association with MPA concentration or blood trough level. No significant drug accumulation occurred over time. Using a twice daily MMF regimen, we conclude that an AUC of 30-60 mug/ml h as recommended for SOT cannot be reached in HSCT. Toxicities did not permit single doses higher than 30 mg/kg. Thus, if larger AUCs are desired in order to assure sufficient immunosuppression in HSCT, MMF might have to be administered at least three times daily.

Nonmyeloablative Allogeneic Hematopoietic Cell Transplantation in Relapsed, Refractory, and Transformed Indolent Non-Hodgkin's Lymphoma

Few effective treatment options exist for chemotherapy-refractory indolent or transformed non-Hodgkin's lymphoma (NHL). We examined the outcome of nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) in this setting. Sixty-two patients with indolent or transformed NHL were treated with allogeneic HCT from related (n = 34) or unrelated (n = 28) donors after conditioning with 2 Gy of total-body irradiation with or without fludarabine. Nine unrelated donors were mismatched for >/= one HLA antigen. Sixteen patients had histologic transformation before HCT. Twenty patients (32%) had progressive disease after previous high-dose therapy with autologous HCT. Median age was 54 years, and patients had received a median of six lines of treatment before HCT. Median follow-up time after HCT was 36.6 months. At 3 years, the estimated overall survival (OS) and progression-free survival (PFS) rates were 52% and 43%, respectively, for patients with indolent disease, and 18% and 21%, respectively, for patients with transformed disease. Patients with indolent disease and related donors (n = 26) had 3-year estimated OS and PFS rates of 67% and 54%, respectively. The incidences of grade 2 to 4 acute graft-versus-host disease (GVHD), grade 3 and 4 acute GVHD, and extensive chronic GVHD were 63%, 18%, and 47%, respectively. Among survivors, the median Karnofsky performance status at last follow-up was 85%. Nonmyeloablative allogeneic HCT can produce durable disease-free survival in patients with relapsed or refractory indolent NHL, even in this relatively elderly and heavily pretreated cohort. Outcomes were particularly good in patients with untransformed disease and related donors, whereas patients with transformed disease did poorly. Long-term survivors reported good overall functional status.

No recovery of T-cell receptor excision circles (TRECs) after non-myeloablative allogeneic hematopoietic stem cell transplantation is correlated with the onset of GvHD

Improper T-cell reconstitution with its consequences, graft-vs-host disease (GvHD) and outbreak of viral infections, is the major cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). To determine the factors affecting reconstitution of naive T-cells after non-myeloablative HSCT (NM-HSCT), the T-cell receptor excision circle (TREC) content was measured on a weekly basis in 24 transplanted patients with various malignant diseases. We analysed correlations of the results with the development of GvHD. In addition, in 11 chronic myeloid leukaemia (CML) patients, we correlated TREC and BCR-ABL transcript numbers. After HSCT, in most patients (22/24) TRECs became undetectable. In 12 patients, TRECs reappeared 3-4 months after HSCT, in 1 patient TRECs reappeared 5 months after HSCT, and in 11 patients TRECs remained negative for more than a year. All 11 patients who remained TREC-negative, developed acute GvHD grade 2-3, while only 6 out of 13 patients who recovered TRECs developed GvHD. We show that after non-myeloablative HSCT, thymopoiesis takes place and is affected by GvHD. Our results indicate that no recovery of TRECs after NM-HSCT (which most likely reflect the expansion of host-reactive co-transplanted mature T-cells) correlates with the onset of GvHD.

Outcomes of Allogeneic Hematopoietic Cell Transplantation (HCT) after Non-Myeloablative Conditioning in Relapsed Diffuse Large B-Cell Lymphoma (DLBCL).

BACKGROUND: We report on outcomes after non-myeloablative allogeneic HCT in patients (pts) with relapsed DLBCL.PATIENTS: Thirty-two pts with relapsed DLBCL were treated at 11 centers with allogeneic HCT from related (n=21) and unrelated (n=11) donors following non-myeloablative conditioning with 2 Gy total body irradiation, with or without fludarabine. Median age was 51.8 years. Twenty-four pts (75%) had undergone prior high-dose therapy (HDT) with autologous HCT: 18 (56%) had failed HDT, and 6 (19%) underwent planned tandem autologous/allogeneic HCT. The remaining 8 pts (25%) were medically ineligible for HDT. Twenty-three pts (72%) had chemosensitive disease at HCT, while 9 (28%) were chemorefractory. Disease status at HCT was complete response (CR, 14/32, 44%), partial response (PR, 9/32, 28%), or relapsed/refractory (9/32, 28%).RESULTS: All patients engrafted. Cumulative incidences of acute GVHD grades II-IV, acute GVHD grades III-IV, and chronic GVHD were 53%, 19%, and 47%, respectively. Median follow-up of surviving patients was 45 months. Of pts with measurable disease at HCT (n=18), responses were seen in 7/18 (39%), with 6 CR's and 1 PR. Nine of these eighteen pts progressed, and 2/18 were not evaluable due to early death from non-relapse causes. Of pts in CR at HCT, 10/14 (71%) remained in CR while 4/14 (29%) progressed. Three-year estimated overall (OS) and progression-free survival (PFS) were 45% and 35%, respectively. Three-year cumulative incidences of relapse and non-relapse mortality were 41% and 25%, respectively (see Fig. 1). In multivariate models, chemosensitive disease and receipt of >4 lines of chemotherapy prior to HCT were associated with better overall survival. Pts with chemosensitive disease at HCT had 3-year OS and PFS of 56% and 43%, respectively, while those with chemorefractory disease had 3-year OS/PFS of 11% (see Fig. 2). Prior failed or tandem autologous HCT did not have a significant effect on outcome.CONCLUSION: Non-myeloablative allogeneic HCT can produce sustained disease responses in pts with chemosensitive relapsed DLBCL. Patients with relapsed DLBCL who have failed or are ineligible for autologous HCT lack effective therapeutic options. Non-myeloablative allogeneic HCT is a promising treatment for such patients. [Display omitted] [Display omitted]

Duration of Immunosuppressive Therapy for Chronic Graft-vs.-Host Disease (cGVHD) Following Non-Myeloablative Allogeneic Hematopoietic Cell Transplantation (HCT).

BACKGROUND: Chronic GVHD is a major determinant of quality of life after allogeneic HCT. Systemic immunosuppressants (IS) are the mainstay of treatment for cGVHD. Patients (pts) with cGVHD after myeloablative HCT are able to discontinue IS at a median of 23 months after HCT (Stewart et al., Blood 2004 Dec 1;104[12]:3501–6). We examined the duration of treatment with IS in patients with cGVHD after non-myeloablative HCT.METHODS: All pts who underwent non-myeloablative HCT at our institutions through 31 Dec 2003 were assessed for inclusion. Two hundred sixty-nine pts were alive and free of their underlying disease at day +84 after HCT; 138 of these (51%) began systemic IS for cGVHD, at a median of 112 days after HCT. We analyzed these 138 pts with cGVHD to determine duration of treatment with IS. Diagnoses are listed in Table 1. Sixty-eight pts received related allografts and 70 received unrelated allografts; median age at HCT was 53.3 years. The allograft source was granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cells (G-PBMC) in 137 pts and bone marrow in 1 pt. Relapsed malignancy and death were considered competing risk events in the estimation of cumulative incidence of discontinuation of IS; follow-up was censored at the time of death, relapsed malignancy, or discontinuation of all systemic IS.RESULTS: Thirty-seven pts (27%) had recurrent malignancy and 23/138 (16%) died without recurrent malignancy while on IS; 41/138 (30%) discontinued all systemic IS after resolution of cGVHD; and 37/138 (27%) were alive without malignancy at last follow-up (median 3.7 years after cGVHD diagnosis), but remained on IS for cGVHD. Five-year cumulative incidence estimates by outcome are listed in Table 2. Of pts alive and free of malignancy at 5 years after cGVHD diagnosis, 58% had discontinued IS. In pts who discontinued IS, the median time to discontinuation was 2.0 (range, 0.3 – 5.7) years (see Figure).CONCLUSION: The median time to resolution of cGVHD and discontinuation of IS in this group is comparable to that reported after myeloablative HCT (24 months vs. 23 months), despite the older age of these pts (median age 53.3 years, vs. 39.5 years in myeloablative cohort) and the prevalence of G-PBMC allografts (>99%, vs. 20% in myeloablative cohort). In this older population with cGVHD after non-myeloablative allogeneic HCT, the majority of pts who remain alive and free of relapsed malignancy have resolution of cGVHD over time.Table 1Underlying diagnoses among pts with cGVHDDiagnosisNo. of pts (%)AML19 (14%)ALL6 (4%)CML6 (4%)CLL11 (8%)MDS14 (10%)HD9 (6%)NHL31 (22%)MM32 (23%)MPD1 (<1%)Waldenstrom's1 (<1%)Renal cell carcinoma1 (<1%)Wilms' tumor1 (<1%)Immunodeficiency syndrome6 (4%)Total138Table 2Five-year cumulative incidencesOutcome5-year cumulative incidence % (95% CI)Relapsed malignancy/death45 (36–54)Alive, malignancy-free, on IS23 (15–33)Alive, malignancy-free, discontinued IS32 (23–41) [Display omitted]

Long-Term Outcome of Autologous Followed by Nonmyeloablative Allografting from HLA-Identical Sibling for Multiple Myeloma (MM).

BACKGROUND: Nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) as consolidation following high dose therapy with autologous HCT is a promising treatment for MM. Low early transplant mortality and high response rates were described in small patient (pts) cohorts with limited follow-up (FU). Here we report on the outcome of pts with HLA-identical siblings treated with this tandem auto/allo approach after a median FU of 5 year.PATIENTS: Pts with stage II-III MM (n=102) were treated with tandem auto/nonmyeloablative allografting at 8 centers between August 1998 and August 2005. Median age was 55(range 32–71) years. Median number of prior treatments was 1(1–2), and median number of prior cycles of treatment was 6 (2–18). Median time between initiation of treatment and autografting was 13(2–118) months and 73/102 (72%) pts initiated their tandem HCT within 10 months of initial therapy. Median time between auto and allo HCT was 80(40–281) days. Autologous HCT conditioning was with melphalan 200 mg/m2 and allogeneic conditioning with 2Gy total body irradiation (TBI) alone (n=75, 73%) or with 2Gy TBI plus fludarabine 90 mg/m2 (n=27, 23%). Post allografting immunosuppression was with mycophenolate mofetil (MMF) and cyclosporine (n=91, 89%) or MMF and tacrolimus (n=11, 11%). Sixty-seven pts (66%) had chemoresponsive disease and 35 (34%) were refractory. The disease status at allo HCT included complete remission (CR, 29 pts, 28%), partial remission (PR, 38 pts, 37%), refractory (RD, 27pts, 26%) or progressive disease (PD, 8pts, 8%).RESULTS: 101/102 pts had sustained donor engrafment. Forty one (41%) and 8 pts (8%) experienced grade 2 to 4 and 3 to 4 acute graft-versus-host-disease (GVHD); 70 pts (69%) had extensive chronic GVHD. Median FU post-allografting was 5(0.75–8.66) years. The overall response rate was 94%, with 64 (63%) and 32 pts (31%) achieving CR and PR respectively. Median time to progression was 4 years. Median progression-free survival (PFS) was 3 years while 5-year estimated PFS was 35%. Median overall survival (OS) has not been reached. Three and 5-year estimated OS were 75% and 63% respectively. Cumulative incidence of nonrelapse mortality (NRM) at 100 days, 1 and 5 year were 1%, 13% and 19% respectively. Most of the NRM (89%) was related to GVHD and/or infection. In the subset of 73 pts who initiated their tandem HCT within 10 months from initial therapy, the estimated OS and PFS at 3 and 5-years were 80% and 55%, 69% and 40% respectively. In univariate analysis refractory or progressive disease at allo HCT was associated with higher risk of relapse (p=0.004) and relapse plus NRM (p<0.0001).CONCLUSION: Long-term disease control and GVHD and its complications remain key issues to address following tandem auto/nonmyeloablative allogeneic HCT. Comparison with tandem autologous HCT awaits results of the BMT-CTN 0102 and similar trials.

Pharmacogenetics of Mycophenolate Mofetil in Patients Undergoing Hematopoietic Cell Transplantation (HCT).

Mycophenolate mofetil (MMF) is commonly used to provide host immunosuppression for hematopoietic cell engraftment and prevention of acute graft vs host disease (GVHD) in recipients of nonmyeloablative allogeneic HCT. There is wide variability in plasma concentrations of mycophenolic acid (MPA), the active metabolite of mycophenolate. Low MPA exposure is associated with poorer rates of engraftment and development of acute GVHD. This variability is not satisfactorily explained by hepatic or renal function suggesting variability may be due to genetic factors involved in drug metabolism or transport. MPA is glucuronidated by UDP glucuronosyltransferase enzymes UGT1A8, 1A9, and 1A10 to the primary metabolite, mycophenolic acid glucuronide (MPAG). MPAG is excreted into the urine and bile through multidrug resistant protein (MRP2) transporters. Several genetic variants of UGT enzymes and MRP2 are known to modify MPA pharmacokinetic parameters in kidney transplant recipients but have not been evaluated in HCT. We hypothesized that these variants are associated with systemic MPA and MPAG concentrations in HCT recipients. Recipient pretransplant DNA was obtained in 133 patients and evaluated for UGT1A8*2, UGT1A8*3, UGT1A9*2, UGT1A9*3, UGT1A9 T-275A, UGT1A9 C-2152T, UGT1A10*2, UGT2B7*2, MRP2 C-24T, MRP2 C-3972T, and MRP2 G-1249A. Patients received MMF at 1–1.5 gm IV or PO every 8–12 hours along with cyclosporine. Each subject had steady-state pharmacokinetics studied once or twice within the first 15 days of transplant for a total of 118 pharmacokinetic profiles. Frequencies of all variants were consistent with published data. Thirty three (24.8%) subjects were heterozygous (CT) and 3 (2.26%) were homozygous (TT) for the MRP2 C-24T variant. MRP2 C-3972T was heterozygous (CT) and homozygous (TT) in 56(42.2%) and 7(5.3%) individuals, respectively. In univariate analysis, there was no association between UGT variants and MPA IV or PO pharmacokinetics. Patients receiving oral MMF and carrying at least one MRP2 C-24T variant had significantly higher median (range) total dose adjusted MPAG Cmax 90.8ug/ml(40.0–164.8) vs 63.3(30.8–202.7), p= 0.02, trough 54.5ug/ml(16.1–99.6) vs 39.7(11.9–173.5), p=0.01 and MPAG Css 71.5ug/ml(28.9–123.0) vs 51.0(19.9–175.6), p=0.01. Similar results were observed for the C-3972T. These data suggest that single UGT variants do not significantly alter MPA exposure but MRP2 variants influence MPAG exposure. Reasons for observed UGT effects on MPA exposure in kidney transplant and not HCT remain unclear but may be due to bioavailability, lack of enterohepatic recycling due to gut decontamination, chemotherapy-induced mucosal and subclinical hepatic damage, and unidentified drug interactions. MRP2 variants may have an impact on other MRP2 substrates such as cyclophosphamide or inhibitors such as cyclosporine. A single UGT genotype to assist in dose selection is unlikely to be of clinical benefit; therefore the effect of combined variants should be explored.

Comparison of Myeloablative and Nonmyeloablative Hematopoietic Stem Cell Transplantation for Treatment of Chronic Myeloid Leukemia

This retrospective study compared outcomes for 81 chronic myeloid leukemia patients who underwent myeloablative or nonmyeloablative allogeneic hematopoietic stem cell transplantation (HSCT). Sixty-five patients received myeloablative HSCT, and 16 patients received fludarabine (Fd), low-dose busulfan (Bu), and antithymocyte globulin (ATG) in nonmyeloablative HSCT. We determined overall survival (OS) and disease-free survival (DFS), as well as the occurrence of acute and chronic graft-versus-host disease (GVHD). The incidences of acute GVHD of grades II to IV were 14.0% and 18.7% for the myeloablative and nonmyeloablative groups, respectively. The incidence of chronic GVHD was significantly higher in the nonmyeloablative group (80% versus 66%). Five-year OS and DFS rates were significantly higher in nonmyeloablative group (70% for both), compared with 56% and 54%, respectively, for the myeloablative group. A univariate analysis, however, revealed a strong but statistically insignificant trend for enhanced overall OS and DFS in the nonmyeloablative group (P = .1 and .07, respectively). A multivariate analysis with the factors of treatment, age, sex, acute and chronic GVHD, and disease status at the time of transplantation revealed that both OS and DFS were significantly higher in the nonmyeloablative group than in the myeloablative group. These findings suggest that nonmyeloablative Fd/Bu/ATG treatment is at least not inferior (and quite probably superior) in terms of patient outcome compared with standard myeloablative therapy. Further larger-scale randomized clinical trials are warranted to clarify the efficacy of this treatment regimen.

A Novel Method to Quantify and Characterize Leukemia-Reactive Natural Killer Cells in Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation following Conventional or Reduced-Dose Conditioning

The antitumor activity of natural killer (NK) cells has recently been shown to be assessable at a single-cell level via flow cytometric detection of CD107a. We used this novel method to prospectively quantify and characterize tumor-reactive NK cells in patients undergoing myeloablative or nonmyeloablative conditioning and allogeneic hematopoietic stem cell transplantation (HSCT). Degranulation of NK cells in the peripheral blood of 34 patients after HSCT (day +30, day +90) was determined by evaluating CD107a expression after coincubation of the cells with tumor targets. The percentage of degranulating NK cells was higher after nonmyeloablative conditioning than after myeloablative conditioning (P<.001), indicating a higher activation state and increased antitumor activity of NK cells after nonmyeloablative conditioning. We were able to analyze NK cell subsets separately and found that CD56bright NK cells following HSCT are functionally different from CD56bright NK cells in healthy donors, as indicated by a high percentage of degranulating NK cells in response to tumor targets in patients after HSCT. The CD107a assay is a new and feasible method to quantify and characterize tumor-reactive NK cells after HSCT. Using this method, we found that NK cells had high antitumor cytotoxic activity after nonmyeloablative conditioning, which may contribute to the effectiveness of nonmyeloablative conditioning.