ALBERT

Description: Background The use of haploidentical hematopoietic cell transplantation (haplo-HCT) with post-transplant cyclophosphamide (PTCy) is rapidly increasing. The safety and efficacy of myeloablative conditioning (MAC) in haplo-HCT has been reported in patients with acute leukemia. However, optimal MAC in haplo-HCT setting is unknown. We studied the outcomes of total body irradiation (TBI) vs. chemotherapy (CT) based MAC regimens in acute myelogenous leukemia (AML) patients undergoing haplo-HCT and reported to the Acute Leukemia Working Party of the EBMT. Methods The study included 1008 AML patients (secondary AML=149, 15%) who underwent haplo-HCT with PTCy during the years 2010-2018, following TBI (n=89, 9%) or CT (n=919, 91%) based MAC. Regimen intensity was defined by EBMT criteria and cases with busulfan dose

Description: Using a polyclonal antiserum against canine CD34, we previously found that CD34 is expressed on canine bone marrow progenitor cells in a manner analogous to that found in humans. To further characterize CD34+ cells and to facilitate preclinical canine stem cell transplant studies, monoclonal antibodies (MoAbs) were raised to CD34. A panel of 10 MoAbs was generated that reacted with recombinant CD34 and with CD34+ cell lines and failed to react with CD34− cell lines. Binding properties of five purified MoAbs were determined by BIAcore analysis and flow cytometric staining, and several MoAbs showed high affinity for CD34. Two antibodies, 1H6 and 2E9, were further characterized, and in flow cytometry studies typically 1% to 3% of stained bone marrow cells were CD34+. Purified CD34+ bone marrow cells were 1.8- to 55-fold enriched for colony-forming unit–granulocyte-macrophage and for long-term culture initiating cells as compared with bone marrow mononuclear cells, whereas CD34− cells were depleted of progenitors. Three autologous transplants were performed with CD34+ cell fractions enriched by immunomagnetic separation. After marrow ablative total body irradiation (920 cGy), prompt hematopoietic recovery was seen with transplanted cell doses of ≤1.1 × 107 /kg that were 29% to 70% CD34+. Engraftment kinetics were similar to those of dogs previously transplanted with approximately 10- to 100-fold more unmodified autologous marrow cells. This suggests that CD34+ is a marker not only of canine bone marrow progenitors but also for cells with radioprotective or marrow repopulating function in vivo. MoAbs to CD34 will be valuable for future studies of canine hematopoiesis and preclinical studies concerning stem cell transplantation, gene therapy, and ex vivo progenitor cell expansion.

Description: Autologous hematopoietic cell transplantation (HCT) followed by nonmyeloablative allogeneic HCT (auto/alloHCT) provides cytoreduction and graft-versus-myeloma effects. We report on long-term outcomes of 102 patients with multiple myeloma who received auto/alloHCT with a median follow-up of 6.3 years. Treatment consisted of high-dose melphalan and autograft followed by 2-Gy total body irradiation, with or without fludarabine, and alloHCT from human leukocyte antigen-identical siblings. Postgrafting immunosuppressive agent was cyclosporine or tacrolimus and mycophenolate mofetil. Forty-two percent of patients developed grade 2 to 4 acute graft-versus-host disease (GVHD) and 74% extensive chronic GVHD. Five-year nonrelapse mortality after allografting was 18%, 95% related to GVHD or infections. Among 95 patients with detectable disease, 59 achieved complete remissions. Median time to progression was 5 years. Median overall survival (OS) was not reached. Median progression-free survival (PFS) was 3 years. Five-year OS and PFS were 64% and 36%, respectively. Seventy-three patients receiving autoHCT within 10 months from treatment initiation had 5-year OS of 69% and PFS of 37%. In multivariate analysis, β-2-microglobulin of more than 3.5 μg/mL at diagnosis and auto/alloHCT more than 10 months after treatment initiation correlated with shorter OS (P = .03 and P = .02) and PFS (P = .04 and P = .03), whereas Karnofsky scores less than 90% at allotransplantation correlated with shorter PFS only (P = .005). Long-term disease control and GVHD remain key issues.

Description: We previously reported 2-year overall survival (OS) of 60% among 64 pts given nonmyeloablative HCT (Sorror et al, JCO2005, 23: 3819). Here, we update our results on the initial 64 pts with median follow up of 5 (range:3–7) years and report on 18 additional pts with emphasis on: 1) long-term disease control, 2) resolution of chronic GVHD, and 3) outcomes of pts with poor-risk genomic features. Conditioning consisted of 2 Gy total body irradiation with or without fludarabine (90 mg/m2). Median age was 56 (range 42–72) years and median number of prior regimens was 4. Eighty-seven percent, 56%, and 41% of pts had fludarabine-refractory CLL, chemo-resistant disease at HCT, and unfavorable cytogenetics, respectively. Donors were related (n=52) or unrelated (n=30). The incidences of grades II, III, and IV acute GVHD were 39%, 14%, and 2% respectively, and chronic extensive GVHD was 51%. Overall disease response was seen in 70% of pts, and 55% achieved complete remission (CR). Estimated 5-years rates of non-relapse mortality (NRM), progression/relapse, OS, and progression-free survival (PFS) were 23%, 38%, 50%, and 39%, respectively (Table 1 shows outcomes by donor type). Overall, 42 patients are alive; 31 in CR, 4 in PR, 1 with stable disease, and 6 with relapse/progression. Among 14 responding pts tested and found to have molecular eradication of their disease, 2 died of NRM, 2 eventually relapsed, and 10 remained negative at a median of 6 years. Lymph node diameter 〉5 cm was an independent risk factor for relapse (p=0.008) and PFS (p=0.01), while unfavorable cytogenetics (Table 2) were not (p=0.65 and 0.88, respectively). Among the pts who were alive at 5-years, 76% were without chronic GVHD while 24% received immunosuppression for chronic GVHD. Median performance status (PS) was 100% and 90% among pts without or with chronic GVHD, respectively. Nonmyeloablative HCT resulted in a median survival of 5 years for fludarabine-refractory CLL. Sustained molecular remissions and continuing resolution of chronic GVHD with good PS were observed in most pts with extended follow up. Nonmyeloablative HCT might change the natural history of CLL with unfavorable cytogenetics if considered earlier. Table 1: Outcomes by donor type Donor At 5-years Related (n=52) Unrelated (n=30) p-value % % CR 48 67 0.04 NRM 22 24 0.97 Pgrossion/relapse 43 26 0.18 PFS 35 51 0.28 OS 49 51 0.57 Pts alive with chronic GVHD requiring immunosuppression 14 7 Table 2: Outcomes of pts with poor genomic features Abnormality (n) Pts alive Pts who died Median interval, years Median interval, years CR/PR/PD From Dx From HCT CR/PR/NE/PD From Dx From HCT PR indicates partial remission; PD, progression; Dx, diagnosis; and NE, not evaluated del 17p (7) 4/0/0 6.5 3.3 1/0/0/2 6.5 0.3 del 11q (7) 1/2/2 8.1 2.1 1/0/0/1 7.5 0.7 Tri 12 (7) 4/0/0 6.7 4.4 0/0/2/1 3.8 0.2 Complex (9) 4/0/0 11.4 5.7 0/1/0/4 10.5 3.5

Description: Sixty-four patients (pts) with chemotherapy-refractory CLL who were ineligible for ablative allogeneic HCT due to age and/or comorbidities were given nonablative-HCT from related (n=44) or unrelated donors (n=20) between 1997-2003 (Table). Median pt age was 56 (range 44–69) years, interval from diagnosis to HCT was 4.4 (3–25) years, and number of prior regimens was 4 (range 1–12). Sixty-one pts were refractory to at least 1 regimen, 56 to fludarabine (FLU), 19 to alkylating agents, 14 to rituxumab and 4 to CAMPATH, and 2 had failed autologous HCT. Twenty-three pts (36%) had disease responsive to last chemotherapy [28% partial (PR) and 8% complete remission (CR)] while 34 were nonresponsive and 7 had untested relapse. Conditioning for HCT consisted of 2 Gy TBI alone (n=11) or combined with FLU (n=53), 90 mg/m2. Postgrafting immunosuppression consisted of mycophenolate mofetil and cyclosporine. Pts received G-CSF mobilized peripheral blood mononuclear cells. After HCT, pts became neutropenic for a median of 11 days. Forty-four percent of pts had thrombocytopenia (

Description: Using a polyclonal antiserum against canine CD34, we previously found that CD34 is expressed on canine bone marrow progenitor cells in a manner analogous to that found in humans. To further characterize CD34+ cells and to facilitate preclinical canine stem cell transplant studies, monoclonal antibodies (MoAbs) were raised to CD34. A panel of 10 MoAbs was generated that reacted with recombinant CD34 and with CD34+ cell lines and failed to react with CD34− cell lines. Binding properties of five purified MoAbs were determined by BIAcore analysis and flow cytometric staining, and several MoAbs showed high affinity for CD34. Two antibodies, 1H6 and 2E9, were further characterized, and in flow cytometry studies typically 1% to 3% of stained bone marrow cells were CD34+. Purified CD34+ bone marrow cells were 1.8- to 55-fold enriched for colony-forming unit–granulocyte-macrophage and for long-term culture initiating cells as compared with bone marrow mononuclear cells, whereas CD34− cells were depleted of progenitors. Three autologous transplants were performed with CD34+ cell fractions enriched by immunomagnetic separation. After marrow ablative total body irradiation (920 cGy), prompt hematopoietic recovery was seen with transplanted cell doses of ≤1.1 × 107 /kg that were 29% to 70% CD34+. Engraftment kinetics were similar to those of dogs previously transplanted with approximately 10- to 100-fold more unmodified autologous marrow cells. This suggests that CD34+ is a marker not only of canine bone marrow progenitors but also for cells with radioprotective or marrow repopulating function in vivo. MoAbs to CD34 will be valuable for future studies of canine hematopoiesis and preclinical studies concerning stem cell transplantation, gene therapy, and ex vivo progenitor cell expansion.

Description: We evaluated the utility of allogeneic HCT using nonmyeloablative conditioning as a potential treatment option for 79 patients (pts) with HL who were ineligible for high dose conventional allogeneic HCT and compared outcome based on donor cell source (MRD n=34, URD n=24, Haplo n=21). Conditioning consisted of 2 Gy TBI alone (n=15, MRD) or combined with either 90 mg/m2 (MRD n=19, all URD) or 150 mg/m2 (all Haplo) fludarabine. All haplo recipients also received cyclophosphamide pre (29 mg/kg) and post (50 or 100 mg/kg) HCT. GVHD prophylaxis consisted of mycophenolate mofetil and a calcineurin inhibitor. Pts were heavily pretreated with a median number of 5 (range, 2–10) prior regimens. Most pts failed prior autologous HCT (91%) and radiation therapy (86%). There were no graft rejections. The incidences of acute grades III–IV and extensive chronic GVHD were 15%/47% (MRD), 8%/60% (URD), and 10%/31% (Haplo). There were no statistically significant differences in the ability to discontinue immunosuppression based on donor cell sources. With a median follow up of 20 (range, 4–91) months for living pts; the 18 month overall survivals (OS), progression free survivals (PFS), and incidences of relapse/progressive disease (PD) were 47%, 20%, and 55% (MRD), 74%, 27%, and 65% (URD), and 71%, 60%, and 35% (Haplo), respectively. Nonrelapse mortalities (NRM) were significantly lower for URD (HR 0.16; p=0.03) and Haplo (HR 0.13; p=0.02) recipients compared to MRD recipients. There were also significantly decreased risks of relapse for Haplo recipients compared to MRD (HR 0.35; p=0.03) and URD (HR 0.36; p=0.02) recipients. These data suggest that salvage allogeneic HCT using nonmyeloablative conditioning provides anti-tumor activity in pts with very advanced disease; however, Rel/PD continue to be major problems regardless of stem cell source. Importantly, alternative donor sources are a viable option particularly for those pts who may have a limited window of opportunity to proceed to HCT. Pt Characteristics MRD (n=34) URD (n=24) Haplo (n=21) Median Age (yrs) 33 28 31 Disease Status at HCT CR 11 (32%) 5 (21%) 5 (24%) PR 16 (47%) 8 (33%) 5 (24%) Rel/Ref 7 (21%) 11 (46%) 11 (52%) Disease Bulk 〉 5cm 3 (9%) 3 (13%) 3 (14%) HCT-Comorbidity Index 〉2 21 (62%) 17 (74%) 13 (62%) Regimens 〉 5 16 (47%) 16 (67%) 12 (57%) Failed Prior Auto HCT 30 (88%) 23 (96%) 19 (90%) Median Time Diagnosis - Allo HCT (months) 33 31 32 Median Time Auto-Allo HCT (months) 16 19 17 Outcomes by donor type MRD (n=34) URD (n=24) Haplo (n=21) Median f/u living pts months (range) 15 (4–91) 26 (8–58) 15 (4–49) Acute GVHD grade II–IV, III–IV 53%, 15% 50%, 8% 43%, 10% 18 month extensive chronic GVHD 47% 60% 31% Day 200 NRM 18% 0% 0% 18 month OS 47% 74% 71% NRM 25% 8% 5% Rel/PD 55% 65% 35% PFS 20% 27% 60%

Description: 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 characteristics Age groups, years (60–64) (n=166) (65–69) (n=90) (70–74) (n=24) Median Interval from Dx to HCT, months 19 15 8 Median (range) # of prior regimens 3 (0–14) 3 (0–13) 2 (0–10) Median CD34+ cell number x 106/kg 6.7 6.7 6.5 Median CD3+ cell number x 108/kg 2.9 3.1 3.4 % Prior radiotherapy 18 11 13 Prior HCT Failed 19 12 4 Planned 8 6 4 Positive patient CMV sero-status 58 65 79 HLA-matched related 54 53 83 Donor HLA-matched unrelated 41 44 17 HLA-mismatched unrelated 5 3 0 Conditioning 2 Gy TBI 12 13 21 2 Gy TBI + FLU 88 87 79 HCT-CI scores 0 27 27 15 1–2 30 39 25 3–4 30 17 40 ≥5 13 17 20 Diagnoses Acute leukemia 35 47 62 Chronic leukemia 15 13 13 Lymphoma/myeloma 21 23 8 Myelodysplastic/myeloproliferative 16 16 17 Others 3 1 0 Disease status at HCT CR 46 41 38 PR 15 30 21 Refractory 28 21 33 Relapse 11 8 8 Relapse risk Low 19 17 8 Standard 48 51 38 High 33 32 54 Table 2: Outcomes per age groups HCT Outcomes Age groups, years P* (60–64) (n=166) (65–69) (n=90) (70–74) (n=24) FUO indicates fever of unknown origin *Test for trend μBased on hazard ratio analysis Bacterial 1.4 2.3 1.7 .0004 Rates of Infection episodes per person Viral 0.7 1.1 0.7 NS within 100 days FUO 0.3 0.4 0.1 NS Fungal 0.3 0.2 0.3 NS Median (range) days of hospitalization 1 (0–60) 4.5 (0–179) 0.5 (0–47) NS % Acute GVHD Grades II–IV 52 49 54 NSμ Grades III–IV 16 12 13 NSμ Chronic extensive GVHD 39 45 54 0.05μ NCI-CTC criteria grades III–IV non-hematological toxicities 42 57 50 NSμ Pts with Full donor chimerism at 1-year CD3/CD33/BM 68/ 84/ 80 66/ 83/ 77 67/ 79/ 71 NSμ CR at 2-years 40 47 63 NSμ 5-years Relapse/progression 38 46 46 NSμ 5-years NRM 28 22 29 NSμ 5-years OS 37 36 23 NSμ 5-years PFS 34 31 25 NSμ Patients alive and off all immunosuppression 24 25 5 NSμ

Description: The curative potential of allogeneic hematopoietic cell transplantation (HCT) with low dose total body irradiation (TBI) based conditionings relies exclusively upon a graft-versus-myeloma effect through donor lymphocytes. Thus, low tumor burden and well-controlled disease at transplant could play a pivotal role. Forty-four consecutive patients with myeloma were treated at 4 different Institutions. Thirty newly diagnosed patients (group A) received a planned autologous transplant with melphalan 200 mg/m2 followed by 200 cGy TBI and allogeneic G-CSF mobilized PBSC infusions from HLA identical siblings. Median time from diagnosis to HCT was 9 months (range, 5–46). At allografting, 7 (23%) patients were in complete remission (CR), 17 (57%) in partial response (PR) and 6 (20%) had refractory disease. The remaining 14 patients received fludarabine 90 mg/m2 and 200 cGy TBI followed by allogeneic PBSC from HLA identical siblings as salvage therapy (group B) after a median of at least 2 lines of previous chemotherapy (range, 2–5); all patients, except one, had received 2 autologous transplants. Patients in group B underwent allografting at a median of 37 months (range, 15–105) from diagnosis; 7 (50%) were in PR, 3 (21%) had refractory disease and 4 (28%) were in overt progression. Post-grafting immunosuppression consisted of cyclosporine and micophenolate mofetil in both groups. All patients readely engrafted with median donor T cell chimerism of 97% (range, 55–100%) at day 100. Overall, 64% (28/44) and 43% (19/44) patients developed acute graft-versus-host disease (GVHD) and chronic clinical extensive GVHD, respectively. There were no significant differences in engraftment kinetics and incidence of GVHD between the 2 groups. After a median follow-up of 16 months (range, 2–50) in group A and 19 months (range, 2–48) in group B, treatment related mortality was 23% among patients who received HCT earlier (group A) and 21% among those who were treated later (group B) in the disease course. Overall survival was 74% and 43% in group A and B, respectively. Disease responses are described in the table. n complete remission partial response stable disease progression Disease response Group A 30 17 6 7 0 Group B 14 0 0 3 11 p value – 0.0001 0.08 0.3

Description: Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective treatment for patients with hematological malignancies but its use is limited to young patients without comorbidities. The aim of present study was to evaluate the efficacy of a reduced-intensity conditioning (RIC) consisting of fludarabine and TBI in older patients aged 60 to 70 years. Methods: between March 2000 and May 2003, 22 patients (median age 62 years; range 59–70) with hematological malignancies (n=18 AML/MDS; n=1 ALL; n=1 CLL; n=1 myelofibrosis) and solid tumor (n=1 renal cell carcinoma) were treated with a RIC regimen based on fludarabine (30 mg/m2 x 3–5 days) and 200 cCy TBI followed by alloHSCT from a matched-sibling donor. GVHD prophylaxis consisted of cyclosporine and mycophenolate. The source of stem cell was blood in all patients. The median CD34+ content of the grafts was 5.7 x 106/kg (range 3.1–8.7). Three patients had received a prior allograft. Eleven patients had active disease at transplantation, 5 patients were untreated and 6 were allografted in complete remission (CR). Results: neutrophil recovery occurred in 15 patients (68%) at a median time of 16 days (range 8–33). One patient who died early after transplantation (day +5) and 4 patients who experienced an autologous reconstitution, failed to reach this threshold; 2 patients did not become granulocytopenic. Fifty-eight percent of the patients had 〉 90% donor chimerism on day +30. Twelve of 17 evaluable patients (70%) developed acute GVHD (n=5 grade I; n=6 grade II; n=1 grade III), whereas chronic GVHD was observed in 11 of 13 patients (85%) surviving more than 100 days (limited in 7 cases and extensive in 4 cases). The probability of acute GVHD grades II–IV and extensive chronic GVHD was 43% and 31% respectively. Two patients died of treatment-related complications: 1 patient died of toxic encephalopathy on day 5 after transplantation and 1 patient of thrombotic thrombocytopenic purpura on day 915. The 100-day nonrelapse mortality for the whole population was 5%.Ten patients (45%) died as a result of relapse. With a median follow-up of 586 days (range 50–1128) 10 patients are alive (9 with CR and 1 with relapsed disease).The probability of overall survival at 2 years was 86% for patients treated in CR or at diagnosis and 9% for patients transplanted in advanced phase of disease (p= 0.0008). Conclusion: Our analysis would suggest that for patients older than 60, this RIC regimen is well tolerated and associated with a low incidence of transplant-related mortality and serious acute and chronic GVHD. The leukemic burden at time of transplant has proven to be the most important risk factor for the outcome.