Abstract

Allogeneic blood or marrow transplantation (alloBMT) is standard of care for adults with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) in first complete remission (CR1). The routine pretransplant and posttransplant use of tyrosine kinase inhibitors (TKIs) has dramatically improved outcomes, but the optimal conditioning regimen, donor type, and TKI remain undefined. The bone marrow transplant database at Johns Hopkins was queried for adult patients with de novo Ph+ ALL who received alloBMT using posttransplantation cyclophosphamide (PTCy) as a component of graft-versus-host disease (GVHD) prophylaxis from 2008 to 2018. Among transplants for Ph+ ALL, 69 (85%) were performed in CR1, and 12 (15%) were performed in second or greater remission (CR2+). The majority of transplants (58%) were HLA haploidentical. Nearly all patients (91.4%) initiated TKI posttransplant. For patients in CR1, the 5-year relapse-free survival (RFS) was 66%. The use of nonmyeloablative conditioning, absence of measurable residual disease (MRD) according to flow cytometry at transplant, and the use of dasatinib vs imatinib at diagnosis were associated with improved overall survival (OS) and RFS. Neither donor type nor recipient age ≥60 years affected RFS. When analyzing all transplants, alloBMT in CR1 (vs CR2+) and the absence of pretransplant MRD were associated with improved RFS. Most relapses were associated with the emergence of kinase domain mutations. The cumulative incidence of grade 3 to 4 acute GVHD at 1 year was 9%, and moderate to severe chronic GVHD at 2 years was 8%. Nonmyeloablative alloBMT with PTCy for Ph+ ALL in an MRD-negative CR1 after initial treatment with dasatinib yields favorable outcomes.

Abstract

With post-transplantation cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis, nonmyeloablative (NMA) HLA-haploidentical (haplo) and HLA-matched blood or marrow (BMT) have comparable outcomes. Previous reports showed that discontinuation of immunosuppression (IS) as early as day 60 after infusion of bone marrow (BM) haplo allograft with PTCy is feasible. There are certain diseases in which peripheral blood (PB) may be favored over BM, but, given the higher rates of GVHD with PB, excessive GVHD becomes an increased concern. We present a completed, prospective single-center trial of stopping IS at days 90 and 60 after NMA PB transplantation. Between 12/2015-7/2018, 117 consecutive patients with hematologic malignancies associated with higher rates of graft failure after NMA conditioned BM transplantation and PTCy, received NMA PB allografts on trial. The primary objective was to evaluate the safety and feasibility of reduced-duration IS (from Day 5 through Day 90 in cohort 1 and through Day 60 in cohort 2). Of the 117 patients (median age 64 years, range 22-78), the most common diagnoses were myelodysplastic syndrome (33%), acute myeloid leukemia (with minimal residual disease or arising from antecedent disorder) (32%), myeloproliferative neoplasms (19%) myeloma (9%), and chronic lymphocytic leukemia (7%). Shortened IS was feasible in 75 pts (64%) overall. Ineligibility for shortened IS resulted most commonly from GVHD (17 pts), followed by early relapse (11 pts), non-relapse mortality (NRM) (7 pts), patient/ physician preference (4 pts) or graft failure (3 pts). Of the 57 patients in the D90 cohort, 33 (58%) stopped IS early as planned. Of the 60 patients in the D60 cohort, 42 (70%) stopped IS early as planned. The graft failure rate was 2.6%. After IS cessation, the median time to diagnosis of grade II-IV GVHD was 21 days and 32 days in the day 90 and day 60 cohorts respectively, with almost all cases developing within 40 days. Approximately one-third of these patients did restart IS. All outcome measures were similar in the 2 cohorts and to our historical outcomes with 180 days of IS. The cumulative incidence of grade 3-4 acute GVHD were low at 2 and 7% in D90 and D60, respectively. Severe chronic GVHD was 9% (D90) and 5% (D60) at 2 years. The two year overall survival was 67% for both the D90 and D60 cohorts, The two year progression free survival was 47% for the Day 90 cohort and 52% for the Day 60 cohort with the GVHD-free relapse-free survival less than 35% for both cohorts. These data suggest that reduced-duration IS in pts receiving NMA PB grafts with PTCy is feasible and carries an acceptable safety profile.

Abstract

Severe aplastic anemia (SAA) is a stem cell disorder often treated with bone marrow transplantation (BMT) to reconstitute hematopoiesis. Outcomes of related HLA-haploidentical (haplo) donors after reduced-intensity conditioning with intensive graft-versus-host disease (GVHD) prophylaxis including posttransplantation cyclophosphamide are presented here from 37 SAA, 20 relapsed/refractory (R/R), and 17 treatment-naive (TN) SAA patients. Median follow-up is 32 months (90% confidence interval [CI], 29-44). The median age was 25 (range, 4-69) years. The median time to neutrophil recovery was 17 days (range, 15-88). Four of 37 patients (11%) experienced graft failure (GF). There was 1 primary GF of 20 patients in the R/R group and 3 of 17 in the TN group at 200 cGy (1 primary, 2 secondary), but none in the 10 patients who received 400 cGy total body irradiation. Two patients with GF succumbed to infection and 2 were rescued with second haplo BMT. The overall survival for all patients is 94% (90% CI, 88-100) at 1 and 2 years. The cumulative incidence of grade II-IV acute GVHD at day 100 is 11%. The cumulative index of chronic GVHD at 2 years is 8%. Similar results were seen in 10 SAA patients who received the identical nonmyeloablative regimen with posttransplant cyclophosphamide but matched donor transplants. Haplo BMT with posttransplant cyclophosphamide represents a potential cure in SAA, with all 20 R/R currently alive, disease-free, and with no evidence of active GVHD. Extending this approach to TN patients was associated with higher GF rates, but an increase in total body irradiation dose to 400 cGy was associated with durable engraftment without greater early toxicity. Nonmyeloablative haplo BMT in TN SAA could lead to a paradigm shift, such that essentially all patients can proceed quickly to safe, curative BMT. These trials were registered at www.cincialtrials.gov as #NCT02224872) and #NCT02833805.

Abstract

Transplant-associated thrombotic microangiopathy (taTMA) is a systemic vascular illness associated with significant morbidity and mortality, resulting from a convergence of risk factors after allogeneic blood or marrow transplantation (alloBMT). The diagnosis of taTMA has been a challenge, but most criteria include an elevated lactate dehydrogenase (LDH), low haptoglobin, and schistocytes on peripheral blood smear. We performed a retrospective review of the 678 consecutive adults who received high-dose post-transplantation cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) between January 1, 2015, and August 31, 2018. In April 2016, we initiated a monitoring program of weekly LDH and haptoglobin measurements and blood smears when those 2 parameters were both abnormal on all of our adult patients undergoing alloBMT for hematologic malignancies. During the entire period, the 1-year cumulative incidence of taTMA was 1.4% (95% confidence interval, 0.5% to 2.3%). Eight patients were taking tacrolimus at the time of diagnosis, and 1 was not on any immunosuppression. Eight of 9 patients (89%) were hypertensive. Four patients had invasive infections at the time of diagnosis, 4 patients required renal replacement therapy, and 5 of 9 patients were neurologically impaired. Eculizumab was given to 6 patients (0.9%), of whom 2 died and 4 recovered with resolution of end-organ dysfunction. The paucity of events made the determination of risk factors difficult; however, the low incidence of taTMA in this cohort may be related to the limited use of myeloablative conditioning regimens, low incidence of severe GVHD, and use of PTCy. PTCy-based GVHD prophylaxis appears to be associated with a low incidence of severe taTMA.

Abstract

Outcomes of nonmyeloablative (NMA) haploidentical (haplo) blood or marrow transplant (BMT) with post-transplantation cyclophosphamide (PTCy) using non-first-degree relatives are unknown. We evaluated 33 consecutive adult patients (median age 56 years) with hematologic malignancies who underwent NMA haplo T-cell replete BMT with PTCy at Johns Hopkins using second- or third-degree related donors. Donors consisted of 10 nieces (30%), 9 nephews (27%), 7 first cousins (21%), 5 grandchildren (15%), and 2 uncles (6%). Thirty-one patients (94%) reached full donor chimerism by day 60. The estimated cumulative incidence (CuI) of grade II-IV acute GVHD (aGVHD) at day 180 was 24% (90% CI: 9-38%). Only 1 patient experienced grade III-IV aGVHD. At 1 year, the CuI of chronic GVHD was 10% (90% CI: 0-21%). The CuI of nonrelapse mortality at 1 year was 5% (90% CI: 0-14%). At 1 year, the probability of relapse was 31% (90% CI: 12-49%), progression-free survival was 64% (90% CI: 48-86%) and overall survival was 95% (90% CI: 87-100%). The 1-year probability of GVHD-free, relapse free survival was 57% (90% CI: 41-79%). NMA haplo BMT with PTCy from non-first-degree relatives is an acceptably safe and effective alternative donor platform, with results similar to those seen with first degree relatives.