HLA-mismatched Peripheral Blood Stem Cells Research Articles

A Phase II Trial of Melphalan Based Reduced Intensity Conditioning and Transplantation of Partially HLA-Mismatched Peripheral Blood Stem Cells for Patients with Hematologic Malignancies

HLA-haploidentical (haplo) stem cell transplantation is now widely used for patients lacking a suitably matched related or unrelated donor (MUD). Conventionally, T-replete Haplo transplantation has been performed using non-myeloablative conditioning and a bone marrow graft. Subsequently, our group has developed the use of myeloablative conditioning and PBSC grafts for Haplo (Solomon et al BBMT 2015, 2019). However, some patients with hematologic malignancies who are unable to tolerate a fully myeloablative regimen may benefit from intermediate intensity conditioning. We conducted a prospective phase II trial utilizing melphalan based preparative regimen ( fludarabine 30mg/m2 days -6 to -2, melphalan 140 mg/m2 day -1) followed by infusion of unmanipulated peripheral blood stem cells (PBSCs) ,capped at 5x10 6 CD34+/kg,from a haploidentical first degree family donor. Graft-versus-host disease (GVHD) prophylaxis consisted of Cy 50mg/kg on days 3 and 4, MMF through day 35, and tacrolimus through day 180. The primary endpoint was to estimate the incidence of graft rejection following Fludarabine/Melphalan conditioning. For the graft failure endpoint we tested the hypotheses H0: p=10% versus Ha: p<10% using a one-sided exact Binomial test. Assume that none of patients undergoing the proposed regimen will have graft failure, the power for confirming p less than 15% is always 100% if the null hypothesis is rejected. The population enrolled was needed to achieve rejection of the null hypothesis at the 5% significance level. Twenty-five patients had their first allogeneic transplant on this study, and their characteristics were as follows: median age 57 years (range 35-68), male sex 44%, transplant diagnosis included AML [11], ALL [3], MDS/MPN [7], NHL [3], and multiple myeloma [1]. Using disease risk index (DRI), patients were classified as low [1], intermediate [13], or high/very high [11]. Twenty patients (80%) had a comorbidity index (HCT-CI) of ≥ 3. Median follow up for survivors was 28.3 (range 8.7-43.9) months. Post infusion fevers that subsided after receiving Cytoxan were seen in 93% and two patients had grade 2 cytokine release syndrome. Median time to ANC and platelet engraftment was 18 days (13-32) and 36 days (21-224), respectively. Three patients failed to engraft with spontaneous count recovery in one of them. Two of the three graft failures ended up engrafting after a second transplant. All engrafting patients had sustained complete donor myeloid and T cell chimerism by day 30. Acute GVHD grade II-IV and III-IV was seen in 20% and 8% respectively. The cumulative incidence of chronic GVHD was 16% (moderate-severe 12%). The estimated 2-year overall survival (OS) was 56%, disease-free survival (DFS) 44%, non-relapse mortality (NRM) 20%, relapse rate 36% and GVHD-, relapse-free survival (GRFS) 41%. For patients with high/very high DRI, the 2 year OS was 53%. For patients with HCT-CI 0-2, 2 year OS and DFS were at 75%. When compared to a contemporaneous cohort of patients receiving haplo transplant using fludarabine, Cytoxan and low dose TBI (Baltimore regimen), outcomes were not significantly different for OS, DFS, NRM and relapse. Patients receiving Flu/Mel had lower incidence of acute II-IV GVHD at 100 days (16% vs 44%). A matched pairs comparison (n=18) using matching at age range, DRI and HCT-CI between Flu/Mel and patients receiving Flu/Cy/TBI at our center, showed significant difference in OS, DFS, NRM and relapse (graph 1) between Flu/Mel and flu/Cy/TBI. All patients with primary MPD (n=4) had successful engraftment on this protocol which historically had a high graft failure rate on the non-ablative flu/Cy/TBI. Haplo transplant using fludarabine/melphalan with PBSCs is a valid option for some patients lacking a timely access to a matched donor. It is well tolerated and provides full and rapid donor myeloid and T-cell chimerism. Figure 1:Overall Survival and Disease Free Survival In Matched Cohorts of Flu/Mel versus Flu/Cy/TBI Figure 1 Disclosures No relevant conflicts of interest to declare.

T Cell–Depleted Related HLA-Mismatched Peripheral Blood Stem Cell Transplantation as Salvage Therapy for Graft Failure after Single Unit Unrelated Donor Umbilical Cord Blood Transplantation

Graft failure is a severe treatment complication of unrelated donor umbilical cord blood transplantation (UCBT). Its incidence seems to be higher after UCBT than after transplantation with bone marrow or peripheral blood stem cells (PBSCs). The only curative option is to perform a second transplantation; however, both the ideal stem cell source and the conditioning regimen for this salvage transplantation remain unclear. We report a series of 11 patients who underwent haploidentical PBSC transplantation (PBSCT) as salvage therapy for graft failure after a previous UCBT. The reduced-intensity conditioning regimen consisted of fludarabine 150 mg/m2 for 3 days and horse antithymocyte globulin 8 mg/kg for 4 days. Ex vivo CD34+ positive selection was performed in all cases, and no post-transplantation graft-versus-host disease prophylaxis was used. Six of the 9 evaluable patients (67%) eventually engrafted, at a median time of 10 days. The cumulative incidence of engraftment at 28 days was 64% (95% confidence interval [CI], 35% to 92%). Two patients relapsed after PBSCT. The cumulative incidence of TRM was 55% at 2 years (95% CI, 25% to 84%), and the probability of overall survival at 2 years was 36%. Our findings suggest that haploidentical ex vivo T cell–depleted PBSCT is a feasible alternative for treating graft failure after UCBT.

A Bortezomib-Based Regimen Offers Excellent Outcomes In Myeloablative HLA-Mismatched and Unrelated Donor Transplantation: Phase II Results

In a phase I/II trial of a novel bortezomib-based regimen for reduced-intensity conditioning (RIC) hematopoietic stem cell transplantation (HSCT) recipients of HLA-mismatched peripheral blood stem cell (PBSC) grafts, we documented low rates of graft-versus-host disease (GVHD) and non-relapse mortality (NRM), with promising survival. In registry analyses, myeloablative conditioning (MAC) HSCT recipients of both HLA-matched (MUD) and 1-locus mismatched donor (MMUD) grafts also have impaired outcomes, with day +100 grade III-IV acute GVHD rates of 28% and 37% respectively, 1-year NRM of 36% and 45% respectively, 1-year progression-free (PFS) of 47% and 38% respectively, and 1-year overall survival (OS) of 52% and 43% respectively. We therefore evaluated a similar bortezomib-based regimen in MAC HSCT recipients lacking 8/8 HLA-matched (-A, -B, -C, -DRB1) related donors.In a prospective single-arm phase II trial, we enrolled patients with hematologic malignancies, aged 18-60 years, receiving MUD, MMUD, or mismatched related donor (MMRD) grafts. Myeloablative conditioning was IV busulfan (130 mg/m2, without PK dose adjustment) and fludarabine (40 mg/m2) once daily for 4 doses (days -7 to -4). T-replete PBSC grafts with ≥ 2x106 CD34+ cells/kg were infused on day 0. GVHD prophylaxis comprised bortezomib (1.3 mg/m2 IV on days +1, +4, +7), methotrexate (15 mg/m2 IV on day +1, 10 mg/m2 on days +3, +6, +11) and tacrolimus from day -3, with a planned taper starting day +100 and complete by day +180. The primary endpoint was day +100 acute GVHD incidence. Secondary endpoints included NRM, relapse, PFS, OS and chronic GVHD at 1 year.The 34 patients (19 male, 15 female), accrued between March 2011 and November 2012, had a median age of 49 years (range, 21-60) and variable diagnoses (17 AML, 6 MDS, 4 NHL, 3 MPD, 2 ALL, 1 CML, 1 MM) and disease risk indices (Low 1, Intermediate 24, High 9). They received 8/8 MUD (n=14), 7/8 MMUD (n=18) or 7/8 MMRD (n=2) PBSC grafts. Mismatches (16 antigen-, 4 allele-level) involved HLA-A (9), -B (1), -C (6) and -DRB1 (4). The median follow up in survivors is 20 months (range, 7.2-25.5).The regimen was feasible and well tolerated. Mucositis was noted in the MAC recipients, but no doses were missed due to toxicity. Excluding 1 patient who died of sepsis prior to engraftment, neutrophil and platelet engraftment was prompt, at a median of 14 (range, 3-33) and 17 (range, 7-54) days respectively. Median day +30 donor chimerism was 99% (range, 90-100). Grade II-IV acute GVHD incidence by day +100 and +180 was 32% and 36% respectively, but only 18% and 21% respectively if upper GI GVHD (which had excellent long term outcomes) was excluded. Grade III-IV acute GVHD incidence by day +100 and +180 was 12%. 2-year cumulative incidence of NRM and relapse was 8.8% and 5.9% respectively. 2-year PFS and OS was 85% and 84% respectively (Figure). 2-year cumulative incidence of extensive chronic GVHD was 57%. For 8/8 MUD vs. 7/8 MMRD/MMUD, grade II-IV acute GVHD by day +180 was 30% vs. 40% (p=0.47) (excluding upper GI GVHD, 16% vs. 25%, p=0.42), and grade III-IV acute GVHD was 7% vs. 15% (p=0.48) respectively. [Display omitted] In conclusion, bortezomib-based prophylaxis for MAC HSCT recipients of HLA-mismatched and unrelated donor grafts was safe and well-tolerated, with low rates of severe acute GVHD, NRM and relapse, and excellent long-term survival. On preliminary landmark analysis, upper GI GVHD did not appear to impair transplantation outcomes. Bortezomib-based prophylaxis is suitable for prospective randomized evaluation in myeloablative transplantation recipients lacking HLA-matched related donors. Disclosures:Koreth:Millennium pharmaceuticals: Research Funding; Takeda Pharmaceuticals: Consultancy. Off Label Use: Bortezomib for GVHD prophylaxis.

Severe acute radiation syndrome: treatment of a lethally 60Co-source irradiated accident victim in China with HLA-mismatched peripheral blood stem cell transplantation and mesenchymal stem cells

This is a case report of a 32-year-old man exposed to a total body dose of 14.5 Gy γ-radiation in a lethal 60Co-source irradiation accident in 2008 in China. Frequent nausea, vomiting and marked neutropenia and lymphopenia were observed from 30 min to 45 h after exposure. HLA-mismatched peripheral blood stem cell transplantation combined with infusion of mesenchymal stem cells was used at Day 7. Rapid hematopoietic recovery, stable donor engraftment and healing of radioactive skin ulceration were achieved during Days 18–36. The patient finally developed intestinal obstruction and died of multi-organ failure on Day 62, although intestinal obstruction was successfully released by emergency bowel resection.

Microtransplantation with Decitabine and Cytarabine Improves Patient Outcomes in Myelodysplastic Syndromes

Abstract 1709The outcome of myelodysplastic syndromes (MDS) still remains unsatisfactory, with a low complete remission (CR) rate and a poor overall survival rate. Decitabine improved the overall responses of MDS as a hypomethylating agent, but CR rates remain low and prolonged pancytopenia. Our recently study showed that infusion of G-CSF mobilized HLA-mismatched peripheral blood stem cells (G-PBSC) can improve the outcome of chemotherapy for acute myeloid leukemia in elderly patients. However, whether G-PBSC combining decitabine and cytarabine chemotherapy will improve outcomes in MDS patients is unknown. Material and methods:Total of 72 patients with MDS, from 16 to 82 years of age, were assigned to receive decitabine 25–30 mg/m2daily for 4 days with cytarabine 150 mg/m2 daily for 7 days by intravenous followed to infusion of G-PBSC on 24 hours after each completion of the cytarabine therapy (Microtransplantation-group, n=28) or decitabine 20 mg/m2 daily for 5days (Decitabine group, n=27) or 15 mg/m2 daily for 5days (low decitabine group, n=17). The infused cells of mononuclear cells and CD34+ cells with HLA-mismatched in 3 loci (n=22) and 2 loci (n=5) and 1 loci (n=1) were 3.33(3.04–10.8)108/kg, 2.26(0.68–5.25)106/kg and no any GVHD prophylactic treatment was used in the Microtransplantation-group. Results:Total CR rate of was 42.9%#x2610;#x0025; A14.8% and 29.4% in the three groups, respectively. That of MST-group is significantly higher than that of B group (P=0.02). The CR rate after first course in MST group is 21.5% which was higher the other two groups (10% and 0%, P=0.14#x2610;#x0025; GP=0.04). The complete cytogenetic response rate in the Microtransplantation-group was 90.9% which is highest than the other two groups (10% and 11%, P<0.001,P<0.001). The progress free survival(PFS) of Microtransplantation-group in 12 months is 50.1% which is higher than other two group (9.9%,9.6%, P=0.01#x2610;#x0025; GP=0.008). Median times of neutrophil recovering over 1×109/L in three groups after 1 course therapy was 17,19 and 13 days and median times of platelet recovering over 50×109/L was 17,26 and 28days, respectively. These of MST group recovered more fastly than those of the other groups. The severe infection rate and early phase mortality rate in three groups had no differences. No donor chimerism, no graft-versus-host disease were observed in all of the patients in the MST group. Conclusion:Our clinical results suggested that decitabine with cytarabine and microtransplantation may improve clinical response CR rate early, especially on complete cytogenetic response and PFS, no increase infection rate and early phase mortality rate. The MST may provide an new method for MDS treatment. Further studies with much more patients and long-term follow-up should be conducted. Disclosures:No relevant conflicts of interest to declare.

Infusion of HLA-mismatched peripheral blood stem cells improves the outcome of chemotherapy for acute myeloid leukemia in elderly patients

AbstractTreatment outcome of acute myeloid leukemia (AML) in elderly patients remains unsatisfactory. It has been shown that the infusion of granulocyte colony-stimulating factor–mobilized donor peripheral blood stem cells (G-PBSCs) can enhance graft-versus-leukemia effects and speed hematopoietic recovery. Fifty-eight AML patients aged 60-88 years were randomly assigned to receive induction chemotherapy with cytarabine and mitoxantrone (control group; n = 28) or it plus human leukocyte antigen–mismatched G-PBSCs (G-PBSC group; n = 30). Patients who achieved complete remission received another 2 cycles of postremission therapy with intermediate-dose cytarabine or it plus G-PBSCs. The complete remission rate was significantly higher in the G-PBSC group than in the control group (80.0% vs 42.8%; P = .006). The median recovery times of neutrophils and platelets were 11 days and 14.5 days, respectively, in the G-PBSC group and 16 days and 20 days, respectively, in the control group after chemotherapy. The 2-year probability of disease-free survival was significantly higher in the G-PBSC group than in the control group (38.9% vs 10.0%; P = .01). No graft-versus-host disease was observed in any patient. Persistent donor microchimerism was successfully detected in all of the 4 female patients. These results indicate that G-PBSCs in combination with conventional chemotherapy may provide a promising treatment method for AML in elderly patients.

Cotransplantation of Mesenchymal Stem Cells Might Prevent Death from Graft-versus-Host Disease (GVHD) without Abrogating Graft-versus-Tumor Effects after HLA-Mismatched Allogeneic Transplantation following Nonmyeloablative Conditioning

Recent studies have suggested that coinfusion of mesenchymal stem cells (MSCs) the day of hematopoietic cell transplantation (HCT) might promote engraftment and prevent graft-versus-host disease (GVHD) after myeloablative allogeneic HCT. This prompted us to investigate in a pilot study whether MSC infusion before HCT could allow nonmyeloablative (NMA) HCT (a transplant strategy based nearly exclusively on graft-versus-tumor effects for tumor eradication) from HLA-mismatched donors to be performed safely. Twenty patients with hematologic malignancies were given MSCs from third party unrelated donors 30-120 minutes before peripheral blood stem cells (PBSCs) from HLA-mismatched unrelated donors, after conditioning with 2 Gy total body irradiation (TBI) and fludarabine. The primary endpoint was safety, defined as a 100-day incidence of nonrelapse mortality (NRM) <35%. One patient had primary graft rejection, whereas the remaining 19 patients had sustained engraftment. The 100-day cumulative incidence of grade II-IV acute GVHD (aGVHD) was 35%, whereas 65% of the patients experienced moderate/severe chronic GVHD (cGVHD). One-year NRM (10%), relapse (30%), overall survival (OS) (80%) and progression-free survival (PFS) (60%), and 1-year incidence of death from GVHD or infection with GVHD (10%) were encouraging. These figures compare favorably with those observed in a historic group of 16 patients given HLA-mismatched PBSCs (but no MSCs) after NMA conditioning, which had a 1-year incidence of NRM of 37% (P = .02), a 1-year incidence of relapse of 25% (NS), a 1-year OS and PFS of 44% (P = .02), and 38% (P = .1), respectively, and a 1-year rate of death from GVHD or infection with GVHD of 31% (P = .04). In conclusion, our data suggest that HLA-mismatched NMA HCT with MSC coinfusion appeared to be safe.

Successful engraftment in crossmatch-positive HLA-mismatched peripheral blood stem cell transplantation after depletion of antidonor cytotoxic HLA antibodies with rituximab and donor platelet infusion

Successful engraftment in crossmatch-positive HLA-mismatched peripheral blood stem cell transplantation after depletion of antidonor cytotoxic HLA antibodies with rituximab and donor platelet infusion

Stem cell transplantation for the treatment of Fanconi anaemia using a fludarabine-based cytoreductive regimen and T-cell-depleted related HLA-mismatched peripheral blood stem cell grafts

We have employed a new cytoreductive regimen to transplant two patients with Fanconi anaemia (FA), using T cell-depleted two HLA-allele disparate related peripheral blood stem cell transplants (PBSCTs). Patient 1, a 5-year-old male with FA and aplastic anaemia, initially received an HLA two-antigen mismatched unrelated cord blood transplant and failed to engraft. He received fludarabine (Flu) and cyclophosphamide (Cy), followed by a CD34+ E-rosette− (CD34+E−), T cell-depleted, granulocyte colony-stimulating factor (G-CSF)-mobilized PBSCT from his HLA B-DRB1 mismatched father. He received anti-thymocyte globulin (ATG), steroids, FK506 and G-CSF after transplant for rejection and graft-versus-host disease (GVHD) prophylaxis. The patient is now 23 months after SCT with no evidence of GVHD and with full haematopoietic and immune reconstitution. Patient 2, a 10-year-old boy with FA and myelodysplastic syndrome, received single-dose total body irradiation (SDTBI), Flu and Cy followed by a CD34+E−, T-cell-depleted, G-CSF-mobilized PBSCT from his HLA B-DRB1 mismatched sister. He also received ATG, steroids, FK506 and G-CSF after transplant. The patient is now 12 months after SCT in complete remission with no evidence of GVHD. Absolute neutrophil counts (ANC) of > 1 × 109/l were achieved on day 11 and day 10 post transplant respectively. Both patients are fully engrafted. In summary, we report two successful T-cell-depleted stem cell transplants from mismatched related donors for the treatment of Fanconi anaemia, using a fludarabine-based cytoreduction. Both patients experienced minimal toxicity, rapid engraftment and no GVHD.