Posttransplant cyclophosphamide versus anti-thymocyte globulin versus combination for graft-versus-host disease prevention in haploidentical transplantation for adult acute myeloid leukemia: A report from the European Society for Blood and Marrow Transplantation Acute Leukemia Working Party

BACKGROUND

The optimal choice for graft-versus-host disease (GVHD) prophylaxis in haploidentical stem cell transplantation (haplo-SCT) remains debatable. Posttransplant cyclophosphamide (PTCy) and anti-thymocyte globulin (ATG) are two common strategies, but little is known about their combination.

METHODS

Using the European Society for Blood and Marrow Transplantation (EBMT) registry, the authors identified 3649 adult patients with acute myeloid leukemia (AML) who underwent haplo-SCT in complete remission between 2007 and 2021 at 260 EBMT-participating centers who received either PTCy (n = 2999), ATG (n = 358), or combination prophylaxis (n = 292). Cord blood transplants, combined bone marrow and peripheral grafts, and transplants with ex vivo graft manipulation were excluded. Median follow-up was 31.8 months.

RESULTS

On multivariate analysis, adjusting for patient age and performance status, disease status at transplant, cytogenetic risk, conditioning intensity, stem cell source, female-to-male graft, and donor and patient CMV status, we present the following. Compared to PTCy, ATG had a higher risk of nonrelapse mortality (hazard ratio [HR], 1.6; p = .003), worse leukemia-free survival (HR, 1.4; p = .002), overall survival (HR, 1.49; p = .0009), and GVHD-free and relapse-free survival (HR, 1.29; p = .012). The combination of PTCy and ATG, however, led to significantly reduced rates of grade 2-4 (HR, 0.51; p = .0003) and grade 3-4 (HR, 0.5; p = .018) acute GVHD and did not affect any transplant outcomes compared to PTCy without ATG.

CONCLUSION

The authors conclude that ATG alone is a less effective prophylaxis strategy compared to PTCy, however, the combination of PTCy and ATG is superior to either monotherapy. They propose that this combination could be considered a potential new standard of care for GVHD prophylaxis in haplo-SCT for AML.

ATG or post-transplant cyclophosphamide to prevent GVHD in matched unrelated stem cell transplantation?

There is a high risk of GVHD and non-relapse mortality (NRM) after allogeneic stem cell transplantations (alloSCT) from unrelated donors. Prophylaxis with rabbit anti-thymocyte globulin (rATG) is standard in Europe but post-transplantation Cyclophosphamide (PTCy) is an emerging alternative. We analyzed outcomes of rATG (n = 7725) vs. PTCy (n = 1039) prophylaxis in adult patients with hematologic malignancies undergoing peripheral blood alloSCT from 10/10 antigen-matched unrelated donors (MUD) between January 2018 and June 2021 in the EBMT database. The provided P-values and hazard ratios (HR) are derived from multivariate analysis. Two years after alloSCT, NRM in the PTCy group was 12.1% vs. 16.4% in the rATG group; p = 0.016; HR 0.72. Relapse was less frequent after PTCy vs. rATG (22.8% vs. 26.6%; p = 0.046; HR 0.87). Overall survival after PTCy was higher (73.1% vs. 65.9%; p = 0.001, HR 0.82). Progression free survival was better after PTCy vs. rATG (64.9% vs. 57.2%; p < 0.001, HR 0.83). The incidence of chronic GVHD was lower after PTCy (28.4% vs. rATG 31.4%; p = 0.012; HR 0.77), whereas the incidence and severity of acute GVHD were not significantly different. GVHD-free relapse-free survival was significantly higher in the PTCy arm compared to the rATG arm (2 y incidence: 51% vs. 45%; HR: 0.86 [95% CI 0.75-0.99], p = 0.035). In the absence of evidence from randomized controlled trials, our findings support a preference for the use of PTCy in adult recipients of peripheral blood alloSCTs from MUD.

Phase 3 randomized trial of mavorixafor, CXCR4 antagonist, in WHIM syndrome

We investigated efficacy and safety of mavorixafor, an oral CXCR4 antagonist for participants with Warts, Hypogammaglobulinemia, Infections, and Myelokathexis (WHIM) syndrome, a rare immunodeficiency caused by CXCR4 gain-of-function variants. This randomized (1:1), double-blind, placebo-controlled, phase 3 trial enrolled participants aged ≥12 years with WHIM syndrome and absolute neutrophil count (ANC) ≤400/μL. Participants received once-daily mavorixafor or placebo for 52 weeks. Primary endpoint was time (hours) above ANC threshold ≥500/μL (TATANC; over 24 hours). Secondary endpoints included TAT absolute lymphocyte count ≥1000/μL (TATALC; defined similar to TATANC); absolute changes in white blood cell (WBC), ANC, and ALC from baseline; annualized infection rate; infection duration and total infection score (combined infection number/severity). In 31 participants (mavorixafor, n=14; placebo, n=17), mavorixafor least squares (LS) mean TATANC was 15.0 hours, placebo 2.8 hours (P<0.001). Mavorixafor LS mean TATALC was 15.8 hours, placebo 4.6 hours (P<0.001). Higher absolute WBC, ANC, and ALC levels were seen with mavorixafor than placebo at each timepoint assessed. Annualized infection rates were 60% lower with mavorixafor versus placebo (LS mean 1.7 versus 4.2; nominal P=0.007) and total infection scores were 40% lower (7.4 [95% CI, 1.6-13.2] versus 12.3 [95% CI, 7.2-17.3]). Treatment with mavorixafor reduced infection frequency, severity, duration, and antibiotic use. No discontinuations occurred due to treatment-emergent adverse events (TEAEs); no related serious TEAEs were observed. Overall, mavorixafor-treated participants showed significant increases in LS mean TATANC and TATALC, reduced infection frequency, severity/duration. Mavorixafor was well tolerated in participants with WHIM syndrome. Trial was registered at ClinicalTrials.gov NCT03995108.

Alternative donor transplantation for severe aplastic anemia: a comparative study of the SAAWP EBMT

Selecting the most suitable alternative donor becomes challenging in severe aplastic anemia (SAA) when a matched sibling donor (MSD) is unavailable. We compared outcomes in SAA patients undergoing SCT from matched unrelated donors (MUD, n=1106), mismatched unrelated donors (MMUD, n=340), and haploidentical donors (Haplo, n=206) registered in the EBMT database (2012-2021). For Haplo-SCT, only those receiving post-transplant cyclophosphamide (PT-Cy) for graft-versus-host disease (GVHD) prophylaxis were included. Median age was 20 years, and the median time from diagnosis to transplantation 8.7 months. Compared to MUD, MMUD (HR, 2.93; 95% CI, 1.52-5.6) and Haplo (HR, 5.15; 95% CI, 2.5-10.58) showed significantly higher risks of primary graft failure. MUD had lower rates of acute GVHD compared to MMUD and Haplo, grade II-IV (13%, 22%, and 19%, respectively, p<0.001) and III-IV (5%, 9%, and 7%, respectively, p=0.028). The 3-year non-relapse mortality was 14% for MUD, 19% for MMUD, and 27% for Haplo (p<0.001), while overall survival (OS) and GVHD and relapse-free survival (GRFS) were 81% and 73% for MUD, 74% and 65% for MMUD, and 63% and 54% for Haplo, respectively (p<0.001). In addition to donor type, multivariable analysis identified other factors like patient age, performance status, and interval between diagnosis and transplant associated with GRFS. For SAA patients lacking an MSD, our findings support MUD transplantation as the preferable alternative donor. However, selecting between a MMUD or Haplo donor remains uncertain and requires further exploration.

Post-transplant cyclophosphamide, calcineurin inhibitor, and mycophenolate mofetil compared to anti-thymocyte globulin, calcineurin inhibitor, and methotrexate combinations as graft-versus-host disease prophylaxis post allogeneic stem cell transplantation from sibling and unrelated donors in patients with acute myeloid leukemia: a study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Post-transplant cyclophosphamide plus calcineurin inhibitor (CNI)(tacrolimus or cyclosporine A) plus mycophenolate mofetil (PTCy/TAC or CSA/MMF) and anti-thymocyte globulin plus CNI (tacrolimus or cyclosporine A) plus methotrexate (ATG/TAC or CSA/MTX) are common graft-versus-host disease (GVHD) prophylaxis regimens. We compared the two regimens in patients with acute myeloid leukemia (AML) undergoing allogeneic transplantation from matched siblings or unrelated donors. 402 received PTCy/TAC or CSA/MMF and 5648 received ATG/TAC or CSA/MTX. Patients in the PTCy-based group were younger (48.7 vs. 51.5 years, p = 0.024) and there was a higher frequency of patient cytomegalovirus seropositivity and female donor to male patient combination in this group (77.8% vs. 71.8%, p = 0.009 and 18.4% vs. 14.4%, p = 0.029, respectively). More patients in the PTCy-based group received reduced-intensity conditioning (51.5% vs. 41%, p < 0.0001). No differences were observed in the incidence of acute GVHD grade II-IV and III-IV (21.2% vs. 20.4%, p = 0.92 and 8.1% vs. 6%, p = 0.1) or 2-year total and extensive chronic GVHD (33.7% vs. 30%, p = 0.09 and 10.7% vs. 11.2%, p = 0.81) between the groups. In the multivariate analysis, all transplant outcomes did not differ between the groups. PTCy/CNI/MMF and ATG/CNI/MTX are alternative regimens for GVHD prophylaxis in AML patients.

Donor KIR genotype based outcome prediction after allogeneic stem cell transplantation: no land in sight

Optimizing natural killer (NK) cell alloreactivity could further improve outcome after allogeneic hematopoietic cell transplantation (alloHCT). The donor's Killer-cell Immunoglobulin-like Receptor (KIR) genotype may provide important information in this regard. In the past decade, different models have been proposed aiming at maximizing NK cell activation by activating KIR-ligand interactions or minimizing inhibitory KIR-ligand interactions. Alternative classifications intended predicting outcome after alloHCT by donor KIR-haplotypes. In the present study, we aimed at validating proposed models and exploring more classification approaches. To this end, we analyzed samples stored at the Collaborative Biobank from HLA-compatible unrelated stem cell donors who had donated for patients with acute myeloid leukemia (AML) or myelodysplastic neoplasm (MDS) and whose outcome data had been reported to EBMT or CIBMTR. The donor KIR genotype was determined by high resolution amplicon-based next generation sequencing. We analyzed data from 5,017 transplants. The median patient age at alloHCT was 56 years. Patients were transplanted for AML between 2013 and 2018. Donor-recipient pairs were matched for HLA-A, -B, -C, -DRB1, and -DQB1 (79%) or had single HLA mismatches. Myeloablative conditioning was given to 56% of patients. Fifty-two percent of patients received anti-thymocyte-globulin-based graft-versus-host disease prophylaxis, 32% calcineurin-inhibitor-based prophylaxis, and 7% post-transplant cyclophosphamide-based prophylaxis. We tested several previously reported classifications in multivariable regression analyses but could not confirm outcome associations. Exploratory analyses in 1,939 patients (39%) who were transplanted from donors with homozygous centromeric (cen) or telomeric (tel) A or B motifs, showed that the donor cen B/B-tel A/A diplotype was associated with a trend to better event-free survival (HR 0.84, p=.08) and reduced risk of non-relapse mortality (NRM) (HR 0.65, p=.01). When we further dissected the contribution of B subtypes, we found that only the cen B01/B01-telA/A diplotype was associated with a reduced risk of relapse (HR 0.40, p=.04) while all subtype combinations contributed to a reduced risk of NRM. This exploratory finding has to be validated in an independent data set. In summary, the existing body of evidence is not (yet) consistent enough to recommend use of donor KIR genotype information for donor selection in routine clinical practice.

Younger unrelated donors may be preferable over HLA match in the PTCy era: A study from the ALWP of the EBMT

There is a paucity of information on how to select the most appropriate unrelated donor (UD) in hematopoietic stem cell transplant (HSCT) using post-transplant cyclophosphamide (PTCy). We retrospectively analyzed the characteristics of 10/10 matched unrelated donors (MUD) and 9/10 mismatched unrelated donors (MMUD) that may affect transplant outcomes in patients with acute myeloid leukemia (AML) in first or second complete remission (CR1 or CR2). The primary endpoint was leukemia-free survival (LFS). Overall, 1011 patients were included with a median age of 54 years (range, 18-77). Donors had a median age of 29 years (range, 18-64); 304 (30%) were females of which 150 (15% of whole group) were donors to male recipients, and 621 (61%) were MUDs; 522 (52%) had negative cytomegalovirus (CMV-neg) serostatus of which 189 (19%) were used for CMV-neg recipients. Donor age older than 30 years had a negative impact on relapse (HR 1.38; 95% CI 1.06-1.8), LFS (HR 1.4; 95% CI 1.12-1.74), overall survival (HR 1.45; 95% CI 1.14-1.85) and GVHD-free, relapse-free survival (HR 1.29; 95% CI 1.07-1.56). Additionally, CMV-neg donor for CMV-neg recipient was associated with improved LFS (HR 0.74; 95% CI 0.55-0.99). The use of MMUD and female donors for male recipients did not significantly impact any transplant outcomes. For patients undergoing HSCT from an UD with PTCy for AML, donor age < 30 years significantly improves survival. In this context, donor age might be prioritized over HLA match considerations. In addition, CMV neg donors are preferable for CMV neg recipients. However, further research is needed to validate and refine these recommendations.

Artificial intelligence methods to estimate overall mortality and non-relapse mortality following allogeneic HCT in the modern era: an EBMT-TCWP study

Allogeneic haematopoietic cell transplantation (alloHCT) has curative potential counterbalanced by its toxicity. Prognostic scores fail to include current era patients and alternative donors. We examined adult patients from the EBMT registry who underwent alloHCT between 2010 and 2019 for oncohaematological disease. Our primary objective was to develop a new prognostic score for overall mortality (OM), with a secondary objective of predicting non-relapse mortality (NRM) using the OM score. AI techniques were employed. The model for OM was trained, optimized, and validated using 70%, 15%, and 15% of the data set, respectively. The top models, "gradient boosting" for OM (AUC = 0.64) and "elasticnet" for NRM (AUC = 0.62), were selected. The analysis included 33,927 patients. In the final prognostic model, patients with the lowest score had a 2-year OM and NRM of 18 and 13%, respectively, while those with the highest score had a 2-year OM and NRM of 82 and 93%, respectively. The results were consistent in the subset of the haploidentical cohort (n = 4386). Our score effectively stratifies the risk of OM and NRM in the current era but do not significantly improve mortality prediction. Future prognostic scores can benefit from identifying biological or dynamic markers post alloHCT.

Graft-versus-host disease and relapse/rejection-free survival after allogeneic transplantation for idiopathic severe aplastic anemia: a comprehensive analysis from the SAAWP of the EBMT

Survival after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for severe idiopathic aplastic anemia (SAA) has improved in recent years, approaching 75% at 5 years. However, an SAA-adapted composite endpoint, graft-versus-host disease (GvHD) and relapse/rejection-free survival (GRFS), may more accurately assess patient outcomes beyond survival. We analyzed GRFS to identify risk factors and specific causes of GRFS failure. Our retrospective analysis from the Severe Aplastic Anemia Working Party of the European Society for Blood and Marrow Transplantation included 479 patients with idiopathic SAA who underwent allo-HSCT in two conventional situations: i) upfront allo-HSCT from a matched related donor (MRD) (upfront cohort), and ii) allo-HSCT for relapsed or refractory SAA (rel/ref cohort). Relevant events for GRFS calculation included graft failure, grade 3-4 acute GvHD, extensive chronic GvHD, and death. In the upfront cohort (n=209), 5-year GRFS was 77%. Late allo-HSCT (i.e., >6 months after SAA diagnosis) was the main poor prognostic factor, specifically increasing the risk of death as the cause of GRFS failure (hazard ratio [HR]=4.08; 95% confidence interval [CI]: 1.41-11.83; P=0.010). In the rel/ref cohort (n=270), 5-year GRFS was 61%. Age was the main factor significantly increasing the risk of death (HR=1.04; 95% CI: 1.02-1.06; P<0.001), acute GvHD (HR=1.03; 95% CI: 1.00-1.07; P=0.041), and chronic GvHD (HR=1.04; 95% CI: 1.01-1.08; P=0.032) as the cause of GRFS failure. GRFS after upfront MRD allo-HSCT was very good, notably with early allo-HSCT, confirming that younger patients with an MRD should be transplanted immediately. GRFS was worse in cases of salvage allo-HSCT, most notably in older patients, questioning the utility of allo-HSCT earlier in the disease course.

Long-term outcome of second allogeneic hematopoietic stem cell transplantation (HSCT2) for primary graft failure in patients with acute leukemia in remission: A study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Second transplantation (HSCT2) is a potential treatment for primary graft failure (pGF). We assessed the outcome of HSCT2, performed between 2000 and 2021, for pGF in 243 patients with acute leukemia. Median age was 44.8 years. Conditioning at first HSCT (HSCT1) was myeloablative (MAC) in 58.4%. Median time from HSCT1 to HSCT2 was 48 days. Donors for HSCT2 were the same as for HSCT1 in 49%. Engraftment post HSCT2 was achieved by 73.7% of patients. The incidence of acute (a) graft versus host disease (GVHD) grades II-IV and III-IV was 23.2 and 8.1%. 5-year total and extensive chronic (c) GVHD was 22.3 and 10.1%. 5-year nonrelapse mortality (NRM), relapse incidence (RI), leukemia-free survival (LFS), overall survival (OS) and GVHD free, relapse-free survival (GRFS) was 51.6, 18.8, 29.6, 30.7 and 22.4%, respectively. Infections were the main cause of death. In multivariable analysis, being transplanted at second vs. first remission, lower Karnofsky performance status (KPS; <90) and receiving MAC at HSCT1 were adverse prognostic factors for NRM, LFS, OS, and GRFS, as was increased age for NRM, LFS, OS. We conclude that HSCT2 can rescue about a third of the patients who experienced pGF, but NRM is as high as 50%.

Complement Inhibition in Paroxysmal Nocturnal Hemoglobinuria (PNH): A Systematic Review and Expert Opinion from Central Europe on Special Patient Populations

INTRODUCTION

Hemolysis in paroxysmal nocturnal hemoglobinuria (PNH) is complement-mediated due to the lack of complement inhibitors in the hemopoietic cell membranes, making complement inhibition the best approach to manage PNH. Three complement inhibitors are approved by the European Medicines Agency as targeted therapy for PNH: eculizumab and ravulizumab, two humanized monoclonal antibodies targeting the same complement 5 (C5) epitope, approved in 2007 and 2019, respectively, and the more recently approved cyclic peptide, the complement 3 (C3) inhibitor pegcetacoplan. Although national and international PNH treatment guidelines exist, they do not take into consideration the latest clinical trial evidence. Given the lack of evidence-based data for some clinical situations encountered in real life, we identified specific populations of patients who may benefit from switching to proximal C3 from terminal C5 inhibition.

METHODS

The expert recommendations presented here were created using a Delphi-like process by a group of expert PNH specialists across Central Europe. Based on an initial advisory board meeting discussion, recommendations were prepared and reviewed as part of a Delphi survey to test agreement.

RESULTS

Using a systematic approach, literature databases were searched for relevant studies, and 50 articles were reviewed by the experts and included as supporting evidence.

CONCLUSION

Implementation of these recommendations uniformly across healthcare institutions will promote the best use of complement inhibition in managing PNH, and has the potential to positively impact patient outcomes in Central Europe and worldwide.

Non-T-depleted haploidentical transplantation with post-transplant cyclophosphamide in patients with secondary versus de novo AML in first complete remission: a study from the ALWP/EBMT

We compared outcomes of adult patients with secondary acute myeloid leukemia (sAML) versus de novo AML after non-T-depleted haploidentical stem cell transplant (HaploSCT) with post-transplant cyclophosphamide (PTCy). Seventeen hundred and eleven AML patients (sAML-231, de novo-1480) in first complete remission transplanted from 2010 to 2021, were included. Patients with de novo AML were younger, median age 55.8 versus 60.8 years, p < 0.0001, had better transplantation comorbidity index (HCT-CI) ≥ 3 21.3% versus 40.8%, p < 0.0001 and Karnofsky performance status (KPS) with KPS ≥ 90 in 78% versus 68.5%, respectively, p = 0.002. The two patient groups did not differ with respect to gender, cytomegalovirus serostatus, and cell source. Median time from diagnosis to HaploSCT was 5.2 versus 4.9 months, respectively, p = 0.005. Fewer sAML patients received myeloablative conditioning 35.1% versus 50.1%, p < 0.0001. Two hundred and eleven sAML and 410 de novo AML patients were included in the matched-pair analysis matching two de novo AML with each sAML. No significant difference was observed in any transplantation outcome parameter between the sAML versus de novo AML groups. Two-year non-relapse mortality and relapse incidence did not differ with HaploSCT for de novo versus sAML; 21.4% versus 21%, hazard ratio (HR) = 0.98, p = 0.9 and 23.4% versus 20.6%, HR = 0.92, p = 0.67, respectively. Two-year leukemia-free survival, overall survival, and graft-versus-host disease (GVHD)-free, relapse-free survival were also not different between the de novo AML and sAML groups 55.2% versus 58.4%, HR = 0.95, p = 0.67; 61.4% versus 66.4%, HR = 0.91, p = 0.51 and 46.3% versus 48.2%, HR = 0.92, p = 0.48, respectively. Similarly, the incidence of engraftment as well as acute and chronic GVHD was similar between the 2 cohorts. In conclusion, HaploSCT with PTCy may be able to overcome the bad prognosis of sAML as results are not significantly different to those of HaploSCT in de novo AML.

Improved outcomes over time and higher mortality in CMV seropositive allogeneic stem cell transplantation patients with COVID-19; An infectious disease working party study from the European Society for Blood and Marrow Transplantation registry

Introduction

COVID-19 has been associated with high morbidity and mortality in allogeneic hematopoietic stem cell transplant (allo-HCT) recipients.

Methods

This study reports on 986 patients reported to the EBMT registry during the first 29 months of the pandemic.

Results

The median age was 50.3 years (min - max; 1.0 - 80.7). The median time from most recent HCT to diagnosis of COVID-19 was 20 months (min - max; 0.0 - 383.9). The median time was 19.3 (0.0 - 287.6) months during 2020, 21.2 (0.1 - 324.5) months during 2021, and 19.7 (0.1 - 383.9) months during 2022 (p = NS). 145/986 (14.7%) patients died; 124 (12.6%) due to COVID-19 and 21 of other causes. Only 2/204 (1%) fully vaccinated patients died from COVID-19. There was a successive improvement in overall survival over time. In multivariate analysis, increasing age (p<.0001), worse performance status (p<.0001), contracting COVID-19 within the first 30 days (p<.0001) or 30 - 100 days after HCT (p=.003), ongoing immunosuppression (p=.004), pre-existing lung disease (p=.003), and recipient CMV seropositivity (p=.004) had negative impact on overall survival while patients contracting COVID-19 in 2020 (p<.0001) or 2021 (p=.027) had worse overall survival than patients with COVID-19 diagnosed in 2022.

Discussion

Although the outcome of COVID-19 has improved, patients having risk factors were still at risk for severe COVID-19 including death.

Biosimilars in rare diseases - a focus on paroxysmal nocturnal hemoglobinuria

Biologics, a class of medicines grown in and purified from genetically engineered cell cultures, have transformed the management of many cancers and rare diseases, such as paroxysmal nocturnal hemoglobinuria. As prescription drug spending has increased and exclusivity periods have expired, manufacturers have developed biosimilars—biologics that may be more affordable and highly similar to a licensed biological therapeutic, with no clinically meaningful differences in safety or efficacy. With biosimilars gaining regulatory approval around the globe and broadening patient access to biologics, this review aims to help rare disease healthcare providers familiarize themselves with biosimilars, understand their development and regulatory approval process, and address practical considerations that may facilitate their use.

Comparison of HLA-mismatched unrelated donor transplantation with post-transplant cyclophosphamide versus HLA-haploidentical transplantation in patients with active acute myeloid leukemia

HLA-haploidentical allogeneic hematopoietic stem cell transplantation (Haplo-HCT) is frequently used as treatment for patients with active acute myeloid leukemia (AML). Here, we investigated whether 9/10 HLA-mismatched unrelated donor transplantation (MMUD-HCT) with post-transplant cyclophosphamide (PTCy) is an adequate alternative. Inclusion criteria in this retrospective registry study consisted of adult patients, first HCT with a Haplo donor or MMUD between 2010 and 2020 using PTCy as graft-versus-host disease (GVHD) prophylaxis, and primary refractory or relapsed disease. MMUD patients were pair-matched 1 to 2 with Haplo-recipients. A total of 73 MMUD patients met the inclusion criteria. Their data were compared to those of 146 Haplo patients in a matched-pair analysis. Median follow-up was 27 months in MMUD patients and 36 months in Haplo recipients. Two-year incidences of relapse and non-relapse mortality (NRM) were 40% and 18% in MMUD patients, respectively, versus 50% (P = 0.23) and 24% (P = 0.18) in Haplo recipients. Two-year leukemia-free survival (LFS) and overall survival (OS) was 42% and 46% in MMUD recipients, respectively, versus 26% (P = 0.1) and 28% (P = 0.061) in Haplo-patients. In conclusions, in AML patients with active disease at transplantation, MMUD-HCT results in at least comparable outcomes to Haplo-HCT when PTCy is applied.

Favorable outcomes of allogeneic hematopoietic stem cell transplantation with fludarabine-bendamustine conditioning and posttransplantation cyclophosphamide in classical Hodgkin lymphoma

INTRODUCTION

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for patients with relapsed and refractory classic Hodgkin lymphoma (rrHL). However, the optimal conditioning regimen and GVHD prophylaxis for rrHL remain undetermined. The aim of this study was to investigate outcomes of allo-HSCT with a fludarabine plus bendamustine (FluBe) conditioning regimen and GVHD prophylaxis with posttransplantation cyclophosphamide (PTCY) in patients with rrHL.

METHODS

Allo-HSCT results in 58 adult patients with rrHL were analyzed retrospectively.

RESULTS

Three-year overall survival and event-free survival were 81% (95% CI 65-91) and 55% (95% CI 38-72), respectively. The cumulative incidence of relapse (CIR) at 3 years was 33% (95% CI 13-51). The cumulative incidence of aGVHD grade II-IV and severe aGVHD grade III-IV was 36% (95% CI 22-48) and 22% (95% CI 9-33), respectively. The cumulative incidence of cGVHD was 32% (95% CI 17-45), including moderate or severe cGVHD in 17% (95% CI 4-28). Patients who developed aGVHD after allo-HSCT had significantly lower CIR (24% vs 49%, p = 0.004). The use of PBSC as a graft source also significantly reduced CIR (4% vs 61%, p = 0.002).

CONCLUSIONS

FluBe-PTCY allo-HSCT facilitates favorable outcomes, low toxicity, and mortality in rrHL.

Long-term safety and efficacy of ravulizumab in patients with paroxysmal nocturnal hemoglobinuria: 2-year results from two pivotal phase 3 studies

OBJECTIVES

The complement component 5 (C5) inhibitor ravulizumab demonstrated non-inferiority to eculizumab following 26 weeks of treatment in complement inhibitor-naïve and complement inhibitor-experienced patients with paroxysmal nocturnal hemoglobinuria (PNH; studies 301 and 302, respectively). This study aims to describe the results of both studies from 27 weeks to 2 years.

METHODS

Patients (N = 441) continued to receive ravulizumab throughout the extension period. Efficacy endpoints included lactate dehydrogenase (LDH) normalization, transfusion avoidance and fatigue score (FACIT-F). Safety analyses were also performed.

RESULTS

From 27 weeks to 2 years, improvements in LDH levels were maintained in both study populations. Transfusion avoidance was maintained in 81.9% (study 301) and 85.6% (study 302) of patients, and FACIT-F scores remained stable. Ravulizumab was well tolerated, and the incidence of adverse events (AEs) were similar between patients of both studies. Incidence of serious AEs deemed related to ravulizumab treatment was low (<3%).

CONCLUSIONS

This study reports, to date, the longest period of follow-up in over 400 patients with PNH treated with ravulizumab (662 patient-years). Long-term, ravulizumab demonstrated durable efficacy and was well tolerated, highlighting the importance of C5 inhibitors as the mainstay of PNH treatment.

Immunosuppressive Microenvironment and Efficacy of PD-1 Inhibitors in Relapsed/Refractory Classic Hodgkin Lymphoma: Checkpoint Molecules Landscape and Macrophage Populations

Simple Summary

Classic Hodgkin lymphoma contains rare malignant Hodgkin/Reed–Sternberg cells and abundant reactive populations in the tumor microenvironment. Many aspects of the interaction between tumor cells and immune cells remain unclear. Nevertheless, the microenvironment is believed to play a crucial role in tumor resistance and progression. Current knowledge about the role and dynamics of the tumor microenvironment in Hodgkin lymphoma during anti-PD-1 treatment is limited. The aim of this study was to identify possible predictive and prognostic morphological markers in the treatment of patients with relapsed or refractory classic Hodgkin lymphoma treated with nivolumab and to assess the variability of reactive cell populations after nivolumab therapy. The study was aimed to optimize therapeutic strategy in patients with relapsed or refractory classic Hodgkin lymphoma.

Abstract

To date, the impact of the tumor microenvironment on the prognosis of patients with classic Hodgkin lymphoma (cHL) during anti-PD-1 therapy has been studied insufficiently. This retrospective study included 61 primary samples of lymph nodes from patients who had relapsed/refractory (r/r) cHL and were treated with nivolumab. Repeated samples were obtained in 15 patients at relapse or disease progression after immunotherapy. Median follow-up was 55 (13–63) months. The best overall response rate and progression-free survival (PFS) were analyzed depending on the expression of CD68, CD163, PD-1, LAG-3, TIM-3, CTLA-4, TIGIT, CD163/c-maf in the tumor microenvironment in primary and sequential biopsies. The combination of CD163/c-maf antibodies was used for the identification of M2 macrophages (M2). A low number of macrophages in primary samples was associated with inferior PFS during nivolumab treatment (for CD163-positive cells p = 0.0086; for CD68-positive cells p = 0.037), while a low number of M2 with higher PFS (p = 0.014). Complete response was associated with a lower level of M2 (p = 0.011). In sequential samples (before and after nivolumab therapy) an increase in PD-1 (p = 0.011) and LAG-3 (p = 0.0045) and a depletion of CD68 (p = 0.057) and CD163 (p = 0.0049)-positive cells were observed. The study expands understanding of the cHL microenvironment structure and dynamics during nivolumab therapy in patients with r/r cHL.

Extracorporeal Photopheresis in Children with Chronic Graft-Versus-Host Disease

Chronic graft versus host disease (cGVHD) remains a major complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). It significantly decreases survival and quality of life. The present study demonstrates retrospective data on extracorporeal photopheresis (ECP) in children with cGVHD. A total of 42 children with steroid-refractory cGVHD were enrolled in the study. The majority of patients had acute leukemia (n = 32, 76%). All patients received ECP as second (n = 18, 43%) or third (n = 24, 57%) line of therapy. Initial ECP schedule consisted of bimonthly regimen for two consecutive days with possibility of further tapering according to response. Any concurrent treatment administered before ECP could be continued if considered necessary. Complete response to ECP was registered in seven (17%) patients and partial response in 24 (57%). Overall response according to organ involvement was as follows: skin (n = 24, 75%), mucous membranes (n = 16, 73%), liver (n = 8, 80%), gut (n = 4, 80%), lungs (n = 2, 22%) and joints (n = 2, 67%). Five-year overall, progression-free and failure-free survival was 57%, 56% and 30%, respectively. Non-relapse mortality at 5 years was 14%. We didn't observe any clinically significant complications in children that could be attributed to the procedure. ECP remains important and safe treatment option in children with cGVHD.