Waiting Time for Second Kidney Transplantation and Mortality

Background and objectivesThe median kidney transplant half-life is 10–15 years. Because of the scarcity of donor organs and immunologic sensitization of candidates for retransplantation, there is a need for quantitative information on if and when a second transplantation is no longer associated with a lower risk of mortality compared with waitlisted patients treated by dialysis. Therefore, we investigated the association of time on waiting list with patient survival in patients who received a second transplantation versus remaining on the waiting list.Design, setting, participants, & measurementsIn this retrospective study using target trial emulation, we analyzed data of 2346 patients from the Austrian Dialysis and Transplant Registry and Eurotransplant with a failed first graft, aged over 18 years, and waitlisted for a second kidney transplantation in Austria during the years 1980–2019. The differences in restricted mean survival time and hazard ratios for all-cause mortality comparing the treatment strategies “retransplant” versus “remain waitlisted with maintenance dialysis” are reported for different waiting times after first graft loss.ResultsSecond kidney transplantation showed a longer restricted mean survival time at 10 years of follow-up compared with remaining on the waiting list (5.8 life months gained; 95% confidence interval, 0.9 to 11.1). This survival difference was diminished in patients with longer waiting time after loss of the first allograft; restricted mean survival time differences at 10 years were 8.0 (95% confidence interval, 1.9 to 14.0) and 0.1 life months gained (95% confidence interval, −14.3 to 15.2) for patients with waiting time for retransplantation of <1 and 8 years, respectively.ConclusionsSecond kidney transplant is associated with patient survival compared with remaining waitlisted and treatment by dialysis, but the survival difference diminishes with longer waiting time.

Haploidentical Versus Cord Blood Stem Cell Transplantation As the Second Transplant for Relapsed Acute Myeloid Leukemia Patients after the First Stem Cell Transplantation

Despite recent emergence of novel target agents, allogeneic stem cell transplantation is still the favored option for disease control in relapsed patients with acute myeloid leukemia (AML). Allotransplant from alternative donors such as haploidentical donor or cord blood can be done when fully HLA matched donor is not available. As for patients relapsed after the first stem cell transplantation (SCT1), these alternative stem cell sources often become only available options for the second transplantation. However, there has been no report comparing haploidentical stem cell (HIT) and cord blood transplantation (CBT), especially for the second transplantation. We performed a retrospective cohort study on AML patients who relapsed after SCT1 and underwent second allogeneic SCT from either alternative donor at our institution. We identified a total of 50 corresponding patients between January 2008 and February 2021 where 31 HIT and 19 CBT were included, and analyzed SCT outcomes including overall survival (OS), disease free survival (DFS), cumulative incidence of relapse (CIR), non-relapse mortality (NRM) and the incidence of SCT complications with comparing between the 2 groups. Conditioning regimens for HIT and for CBT were as follows: Fludarabine (30mg/m2/day intravenous (IV) for 5 days), busulfan (3.2mg/kg/day IV for 2 days), fractionated total body irradiation (fTBI, 4-8Gy total) and rabbit antithymoglobulin at a dose of 1.25mg/kg/day for four days for in vivo T cell depletion from D-5 to D-2 was given for HIT. G-CSF-mobilized peripheral blood stem cell was used as allograft. Graft-versus-host disease (GVHD) prophylaxis was done with tacrolimus and methotrexate. For CBT, fludarabine (30mg/m2/day IV for 5 days), cytarabine (1.5g/m2 twice daily for 3 days) with fTBI (12Gy). All CBT patients received double cord blood units. GVHD prophylaxis was done with tacrolimus and mycophenolate mofetil. The median follow-up period for survivors was 64.6 months (range 5.3-154.1). The type of SCT1 differed between the two groups; more patients of HIT were the recipient of prior autologous transplantation (41.9%), and 63.2% of CBT had underwent prior HIT (p&lt;0.001). However, age, sex, disease status pre-transplant, HCT-CI, time from SCT1 to relapse, time from post-transplant relapse to SCT2, FLT3-ITD mutation status and cytogenetic risk distribution did not differ between each group. Overall respective outcomes of HIT and CBT were as follows; 41% and 29% for 2-year OS (p=0.017), 41% and 16% for 2-year DFS (p=0.016), 36% and 36% for 2-year CIR (p=0.91) and 23% and 48% for 2-year NRM (p=0.021). Early NRM within 100 days of SCT2 was more frequent in CBT than HIT although not statistically significant (26.3% vs 9.7%, p=0.23). Median days to neutrophil and platelet engraftment were 12 (range 11-23) and 13 (range 9-38) in HIT, and 29 (range 16-48), 51 (range 27-167) for CBT, respectively (p&lt;0.001 for both). Cumulative incidence of acute and chronic GVHD were analyzed as follows; 39% and 42% for 1-year acute GVHD (p=0.82) and 43% and 11% for 2-year chronic GVHD (p=0.037) in HIT and CBT. In multivariate analysis, acute GVHD ≥ grade 2 after SCT1 (HR for OS 2.68, p=0.023; HR for DFS 2.49, p=0.036) and cytogenetic risk at diagnosis (HR for OS 2.07, p=0.018; HR for DFS 2.02, p=0.019) were significantly associated with worse outcomes. Hemorrhagic cystitis occurred more frequently in HIT patients than CBT group (32.3% vs 5.3%, p=0.035), while there were no significant differences between incidences of CMV DNAemia, CMV disease, thrombotic microangiopathy and sinusoidal obstructive syndrome. In subgroup analysis for patients relapsed after first allogeneic SCT1 only (18 patients in HIT and CBT group each), trend towards better outcomes in HIT than CBT were present, similar to those of all patients; 38% and 25% for 2-year OS (p=0.095), 39% and 10% for 2-year DFS (p=0.10), 22% and 51% for 2-year NRM (p=0.11) and 40% and 39% for 2-year CIR (p=0.90). This is the first report, to the best of our knowledge, to compare outcomes of the second transplantation from alternative donors for relapsed AML patients after SCT1. Our unique T-cell replete HIT using a reduced-toxicity conditioning regimen seems to provide better survival than CBT. Figure 1 Figure 1. Disclosures Lee: Alexion, AstraZeneca Rare Disease: Honoraria, Membership on an entity's Board of Directors or advisory committees. Kim: AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AIMS Biosciense: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; AML-Hub: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BL & H: Research Funding; BMS & Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Boryung Pharm Co.: Consultancy; Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Handok: Consultancy, Honoraria; LG Chem: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria; Pintherapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi Genzyme: Honoraria, Speakers Bureau; SL VaxiGen: Consultancy, Honoraria; VigenCell: Consultancy, Honoraria.

Graft Failure in Patients With Hematological Malignancies: A Successful Salvage With a Second Transplantation From a Different Haploidentical Donor

Graft failure (GF) is a fatal complication of allogeneic stem cell transplantation, especially after haploidentical transplantation. The mortality of GF is nearly 100% without an effective salvage method. A second transplantation is usually necessary to save the patient's life. However, there is no standardized regimen, and the outcome is usually disappointing. We report on a prospective single-center study using a reduced-intensity conditioning regimen with different haploidentical donors (HIDs). Patients with GF after the first transplantation were enrolled in a prospective single-arm clinical trial (ClinicalTrials.Gov ID: NCT03717545) at the Peking University Institute of Hematology. The conditioning regimen consisted of fludarabine (30 mg/m2) (days−6 to−2) and cyclophosphamide (1,000 mg/m2/day) (days−5 to−4). Patients underwent a second transplant from a different HID using a granulocyte colony-stimulating factor primed bone marrow and peripheral blood stem cells. The primary outcome was neutrophil engraftment at day 28. The secondary outcomes included platelet engraftment at day 100, transplant-related mortality (TRM) at day 30, TRM at day 100, and overall survival (OS) at 1 year. From March 2018 to June 2020, 13 patients were enrolled in this clinical trial. Of the 13 patients, five had acute myeloid leukemia, five had acute lymphoblastic leukemia, two had myelodysplastic syndromes, and one had a non-Hodgkin lymphoma. The median age at first transplantation was 38 years (range, 8–55 years). As for the first transplantation, 11 patients underwent haploidentical transplantations and two underwent unrelated donor transplantations. At the time of GF, three patients had complete donor chimerism, five had mixed chimerism, and five had complete recipient chimerism. The median time from the first transplantation to the second transplantation was 49 (range 35–120) days. The medians of infused cell doses were as follows: mononuclear cells 7.93 (5.95–12.51) × 108/kg and CD34 + cells 2.28 (0.75–5.57) × 106/kg. All 13 patients achieved neutrophil engraftment after the second transplantation, with a median engraftment time of 11 (range 10–20) days after transplantation. The platelet engraftment rate on day 100 after transplantation was 76.9%. The TRMs at day 30, day 100, and 1-year were 0, 0, and 23.1%, respectively. The OS and disease-free survival at 1-year were 56.6 and 48.4%, respectively. For patients with GF after first transplantation, a second transplantation using a fludarabine/cyclophosphamide regimen from a different HID was a promising salvage option. Further investigation is needed to confirm the suitability of this method.

Second Allogeneic Stem Cell Transplantation: A Mortality Analysis

Second allogeneic stem cell transplantation (SCT) was realized in 48 patients with myeloid and lymphoid neoplasms at Gustave Roussy institute since 1987. Overall survival rate was about 30 % with better outcome in acute myeloid leukemia cases. Non-relapse related mortality is overwhelming, especially in myelodysplasia patients and despite the fact that complete remission was obtained in their majority. Graft versus Host disease (GvHD) is very common after second transplantation with many grade III - IV cases and one death from severe pulmonary GvHD lesions. Reduced intensity conditioning is certainly less toxic and together with optimal GvHD and infectious disease management, Second SCT may be a reasonable therapeutic option and the only curative treatment for many hematological malignancies.

SECOND ALLOGENEIC STEM CELL TRANSPLANTATION: A MORTALITY ANALYSIS

Second allogeneic stem cell transplantation was realized in 48 patients with myeloid and lymphoid neoplasms at Gustave Roussy institute since 1987. Overall survival rate was about 30 % with better outcome in acute myeloid leukemia cases. Non-relapse related mortality is overwhelming, especially in myelodysplasia patients and despite the fact that complete remission was obtained in their majority. Graft versus Host disease is very common after second transplantation with many grade III IV cases and one death from severe pulmonary GvHD lesions. Reduced intensity conditioning is certainly less toxic and together with optimal GvHD and infectious disease management, Second SCT may be a reasonable therapeutic option and the only curative treatment for many hematological malignancies.