Comparative outcome of nonmyeloablative and myeloablative allogeneic hematopoietic cell transplantation for patients older than 50 years of age

Allogeneic blood or marrow transplantation using haploidentical grandchildren donors and post-transplant cyclophosphamide-based graft-versus-host disease prophylaxis

BACKGROUND

High-dose post-transplant cyclophosphamide allows safe and effective use of allografts from haploidentical relatives (siblings, parents and children) in patients undergoing allogeneic blood or marrow transplant (alloBMT). More recently, second- and third-degree relatives have also been shown to be safe allograft donors. An increasing number of older patients undergoing alloBMT have been receiving allografts from haploidentical donors. However, older patients are more likely to have older siblings and children, and older donor age is associated with worse outcomes.

OBJECTIVE

In the current study, we report the safety and utility of grandchildren as haploidentical donors and compared with children as donors in patients undergoing alloBMT.

METHODS

We compared characteristics and outcomes of alloBMT patients aged 55 years and older with children older than 30 years as donors (C group; n = 276) and those with grandchildren as donors (GC group; n = 40). Because many important baseline characteristics predict outcomes after alloBMT, we performed propensity score matched analysis based on recipient age, alloBMT year, disease, graft source and haematopoietic cell transplantation comorbidity index (HCT-CI).

RESULTS

The median age of recipients was 67 years (range 55-79) in the C group and 73 years (range 57-78) in the GC group. More than 70% of recipients in the GC group were older than 70 years, compared with 27% in the C group. The median donor age was 37 years (range 31-52) in the C group and 20 years (range 14-34) in the GC group. More patients in the GC group had HCT-CI scores ≥3 than in the C group (32.5% vs. 23%, p = 0.27). Two-year overall survival did not differ between the two groups (GC 62% vs. C 60%, hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.53-1.75, p = 0.90) despite recipients of allografts from grandchildren being older. The 2-year RFS was 55% in the C group compared with 50% in the GC group (HR 1.05, 95% CI 0.62-1.77, p = 0.85). Non-relapse mortality subdistribution [SD] (SDHR 1.36, 95% 0.70-2.63, p = 0.36), relapse (SDHR 0.72, 95% CI 0.33-1.58, p = 0.42) or relapse-free survival (HR 1.05, 95% CI 0.62-1.77, p = 0.85). Propensity score matching analysis showed no significant differences in 2-year overall survival (GC 64% vs. C 53%; HR 0.77, 95% CI 0.42-1.42, p = 0.40), non-relapse mortality (SDHR 1.26, 95% 0.66-2.41, p = 0.48), relapse (SDHR 0.57, 95% CI 0.21-1.52, p = 0.26) or relapse-free survival (HR 0.94, 95% CI 0.57-1.54, p = 0.81).

CONCLUSION

Our results indicate that outcomes of alloBMT patients with grandchild donors are similar to those with child donors, despite recipients' older age and higher comorbidities in the GC group. Grandchildren should be considered when selecting a donor for older alloBMT recipients.

Fludarabine Melphalan, Reduced-dose Busulfan Versus Fludarabine, Melphalan, Full-dose Busulfan in Patients Receiving Cord Blood Transplantation

BACKGROUND

Various reduced-intensity conditioning/reduced-toxicity conditioning regimens have been developed for patients receiving allogeneic hematopoietic cell transplantation. The balance between disease relapse and toxicity can be partly dependent on reduced-intensity conditioning/reduced-toxicity conditioning regimens. This retrospective study aimed to compare the nonrelapse mortality, relapse incidence, progression-free survival, and overall survival rates between the fludarabine/melphalan/reduced-dose busulfan (Flu/Mel/Bu2; busulfan at a dose of 6.4 mg/kg intravenously) and fludarabine/melphalan/full-dose busulfan (Flu/Mel/Bu4; busulfan at a dose of 12.8 mg/kg intravenously) regimens in patients receiving umbilical cord blood transplantation.

METHOD

Eighty-seven adult patients who received the Flu/Mel/Bu2 (n = 45) or Flu/Mel/Bu4 (n = 42) regimen as a conditioning regimen before umbilical cord blood transplantation at our institution between January 2013 and December 2022 were included in this study.

RESULTS

There were no significant differences in terms of clinical outcomes including nonrelapse mortality, relapse incidence, progression-free survival, and overall survival rates between the two regimens. Further, even in higher-risk patients classified according to the Refined Disease Risk Index, the Flu/Mel/Bu2 regimen was comparable to the Flu/Mel/Bu4 regimen.

CONCLUSION

The novel Flu/Mel/Bu2 regimen could be applied in clinical settings as it can be tolerated and effective in older patients.

Evaluating targeted therapies in older patients with TP53-mutated AML

Mutation of thetumor suppressor gene, TP53 (tumor protein 53), occurs in up to 15% of all patients with acute myeloid leukemia (AML) and is enriched within specific clinical subsets, most notably in older adults, and including secondary AML cases arising from preceding myeloproliferative neoplasm (MPN), myelodysplastic syndrome (MDS), patients exposed to prior DNA-damaging, cytotoxic therapies. In all cases, these tumors have remained difficult to effectively treat with conventional therapeutic regimens. Newer approaches fortreatmentofTP53-mutated AML have shifted to interventions that maymodulateTP53 function, target downstream molecular vulnerabilities, target non-p53 dependent molecular pathways, and/or elicit immunogenic responses. This review will describe the basic biology of TP53, the clinical and biological patterns of TP53 within myeloid neoplasms with a focus on elderly AML patients and will summarize newer therapeutic strategies and current clinical trials.

Prognostic impact of the conditioning intensity on outcomes after allogeneic transplantation for MDS with low blasts: a nationwide retrospective study by the adult MDS working group of the Japan Society for Transplantation and Cellular Therapy

Poor prognostic factors, such as transfusion dependency and chromosomal risk, need to be considered in the indication of allogeneic hematopoietic cell transplantation (allo-HCT) for patients harboring myelodysplastic syndromes with less than 5% marrow blasts (MDS-Lo). We analyzed the post-transplant outcomes of 1229 MDS-Lo patients who received myeloablative (MAC)(n = 651), reduced-intensity (RIC)(n = 397), and non-myeloablative conditioning (NMAC) regimens (n = 181). The multivariate analysis revealed that the RIC group had better chronic graft-versus-host disease (GVHD)- and relapse-free survival (CRFS) (P = 0.021), and GVHD- and relapse-free survival (GRFS) than the MAC group (P = 0.001), while no significant differences were observed between the NMAC and MAC groups. In the subgroup analysis, the MAC group has better overall survival (P = 0.008) than the RIC group among patients with an HCT-comorbidity index (HCT-CI) score of 0, while the RIC group had better overall survival (P = 0.029) than the MAC group among those with an HCT-CI score ≥3. According to the type of conditioning regimen, total body irradiation 12 Gy-based MAC regimen showed better OS and CRFS than the other MAC regimen, and comparable outcomes to the RIC regimen. In conclusion, the RIC and NMAC regimens are promising options for MDS-Lo patients in addition to the MAC regimen.

Impact of chronic graft-versus-host disease on non-relapse mortality and survival

Chronic graft-versus-host-disease (cGVHD) is one of the primary causes of morbidity and mortality for patients who undergo allogeneic hematopoietic stem cell transplantation (allo-HCT). In recent years, advancements in allo-HCT have allowed a broader range of patients to receive transplant, particularly older patients. We sought to assess the impact of cGVHD on outcomes in patients undergoing allo-HCT, for older patients as compared to their counterparts. We performed a retrospective analysis of all patients who underwent allo-HCT 1999-2018. Our results showed that those patients who developed cGVHD by D + 180 had an increased risk and incidence of NRM as compared to those patients without cGVHD. There was no significant difference in outcomes for those patients with cGVHD by age (≥60 years old [yo] and <60 yo). These findings suggest the significant morbidity of cGVHD, regardless of age.

Competing risks data in clinical oncology

Competing risks data analysis plays a critical role in the evaluation of clinical utility of specific cancer treatments and can inform the development of future treatment approaches. Although competing risks data are ubiquitous in cancer studies, competing risks data are infrequently recognized and competing risks data analysis is not commonly performed. Consequently, efficacy of specific treatments is often incompletely and inaccurately presented and thus study results may be interpreted improperly. In the present article, we aim to enhance awareness of competing risks data and provide a general overview and guidance on competing risks data and its analysis using cancer clinical studies.

Development of an umbilical cord blood transplantation-specific nonrelapse mortality risk assessment score

ABSTRACT

Higher rate of nonrelapse mortality (NRM) remains yet to be resolved in umbilical cord blood transplantation (UCBT). Considering that UCBT has some unique features compared with allogeneic hematopoietic cell transplantation from other graft sources, a UCBT-specific NRM risk assessment system is required. Thus, in this study, we sought to develop a UCBT-specific NRM Risk Assessment (CoBRA) score. Using a nationwide registry database, we retrospectively analyzed 4437 recipients who had received their first single-unit UCBT. Using the backward elimination method, we constructed the CoBRA score in a training cohort (n = 2687), which consisted of recipients age ≥55 years (score 2), hematopoietic cell transplantation-specific comorbidity index ≥3 (score 2), male recipient, graft-versus-host disease prophylaxis other than tacrolimus in combination with methotrexate, performance status (PS) 2 to 4, HLA allele mismatch ≥ 2, refined Disease Risk Index high risk, myeloablative conditioning, and CD34+ cell doses < 0.82 × 105/kg (score 1 in each). The recipients were categorized into 3 groups: low (0-4 points), intermediate (5-7 points), and high (8-11 points) groups according to the CoBRA score. In the validation cohort (n = 1750), the cumulative incidence of NRM at 2 years was 14.9%, 25.5%, and 47.1% (P < .001), and 2-year overall survival (OS) was 74.2%, 52.7%, and 26.3% (P < .001) in the low, intermediate, and high groups, respectively. In summary, the CoBRA score could predict the NRM risk as well as OS after UCBT. Further external validation will be needed to confirm the significance of the CoBRA score.

Stem cell therapy for HTLV-1 induced adult T-cell leukemia/lymphoma (ATLL): A comprehensive review

Adult T-cell leukemia/lymphoma (ATLL) is a rare and aggressive form of cancer associated with human T-cell lymphotropic virus type 1 (HTLV-1) infection. The emerging field of stem cell therapies for ATLL is discussed, highlighting the potential of hematopoietic stem cell transplantation (HSCT) and genetically modified stem cells. HSCT aims to eradicate malignant T-cells and restore a functional immune system through the infusion of healthy donor stem cells. Genetically modified stem cells show promise in enhancing their ability to target and eliminate ATLL cells. The article presents insights from preclinical studies and limited clinical trials, emphasizing the need for further research to establish the safety, efficacy, and long-term outcomes of stem cell therapies for ATLL and challenges associated with these innovative approaches are also explored. Overall, stem cell therapies hold significant potential in revolutionizing ATLL treatment, and ongoing clinical trials aim to determine their benefits in larger patient populations.

Role of Bcl-2 inhibition in myelodysplastic syndromes

Myelodysplasic syndromes (MDS) are diseases occurring mainly in the elderly population. Although hematopoietic stem cell transplantation is the only hope for cure, a majority of the patients suffering from MDS are too old or frail for intensive treatment regimens such as intensive chemotherapy and transplantation. The gold standard for those patients is currently treatment with hypomethylating agents, although real-life data could not reproduce the overall survival rates reported for the pivotal azacitidine phase III study. MDS treatment is often inspired by treatment for acute myeloid leukemia (AML). The new gold standard for elderly and frail patients not able to undergo intensive treatment regimens in AML is the combination of hypomethylating agents with venetoclax, a BCL-2 inhibitor that also showed excellent treatment outcomes in other hematological malignancies. In this review, we explain the rationale for the use of venetoclax in hematological malignancies, study outcomes available so far and the current knowledge of its use in MDS.

Implementation of Routine Endoscopy with Narrow Band Imaging in the Evaluation of Oral and Upper Airways Lesions in Oral Chronic Graft-Versus-Host Disease: A Preliminary Study

(1) Background: The aim of our study is to investigate the main oral lesion patterns in patients with oral graft-versus-host disease and to describe and validate the use of endoscopy enhanced with narrow-band imaging (NBI) as a personalized, reliable and user-friendly tool for the early detection of oral potentially diseases. (2) Methods: We retrospectively evaluated the medical records of 20 patients with chronic GVHD and with oral manifestations, who were referred to our “Interdisciplinary Center for Oropharyngeal Pathology (CIPO)” from January 2017 to July 2022. (3) Results: Data on GVHD, oral localization and NBI endoscopic evaluation are collected. A total of six mucositis, one mucosal erythematous change, ten lichenoid-like changes, eight erosive lesions, one leukoplakia, two erythroplakia and two case of blisters were observed. Two vascular abnormalities were seen with NBI, leading to one excisional biopsy. The patient was diagnosed with squamous cell carcinoma. (4) Conclusion: Our study is the first to highlight the relevance of the routine use of endoscopy with NBI in patients with oral chronic GVHD. We highlighted its role as a reliable, reproducible, easy-to-use and tailor-made tool in the follow-up of those patients and to allow an earlier identification of aberrant neoangiogenesis related to oral potentially malignant disorders and oral cancer.

Insights into mechanisms of graft-versus-host disease through humanised mouse models

Graft-versus-host disease (GVHD) is a major complication that occurs following allogeneic haematopoietic stem cell transplantation (HSCT) for the treatment of haematological cancers and other blood-related disorders. GVHD is an inflammatory disorder, where the transplanted donor immune cells can mediate an immune response against the recipient and attack host tissues. Despite over 60 years of research, broad-range immune suppression is still used to prevent or treat GVHD, leading to an increased risk of cancer relapse and infection. Therefore, further insights into the disease mechanisms and development of predictive and prognostic biomarkers are key to improving outcomes and reducing GVHD development following allogeneic HSCT. An important preclinical tool to examine the pathophysiology of GVHD and to understand the key mechanisms that lead to GVHD development are preclinical humanised mouse models. Such models of GVHD are now well-established and can provide valuable insights into disease development. This review will focus on models where human peripheral blood mononuclear cells are injected into immune-deficient non-obese diabetic (NOD)-scid-interleukin-2(IL-2)Rγ mutant (NOD-scid-IL2Rγ^null) mice. Humanised mouse models of GVHD can mimic the clinical setting for GVHD development, with disease progression and tissues impacted like that observed in humans. This review will highlight key findings from preclinical humanised mouse models regarding the role of donor human immune cells, the function of cytokines and cell signalling molecules and their impact on specific target tissues and GVHD development. Further, specific therapeutic strategies tested in these preclinical models reveal key molecular pathways important in reducing the burden of GVHD following allogeneic HSCT.

Outcomes of non-myeloablative allogeneic stem cell transplant in older patients with acute myeloid leukaemia in first remission

The benefits of non-myeloablative stem cell transplant in older patients with acute myeloid leukaemia are unclear. We compare the long-term outcomes of this regimen in those aged 55-65 years in first remission with a chemotherapy only cohort that achieved durable morphologic remission. Five-year overall survival was similar (32% vs 33%, P = 0.90), as was relapse-free survival (23% vs 20%, P = 0.37). There was a trend for decreased relapse that was balanced against increased non-relapse mortality with transplantation.

Myeloablative Fractionated Busulfan With Fludarabine in Older Patients: Long Term Disease-Specific Outcomes of a Prospective Phase II Clinical Trial

Compared to reduced-intensity conditioning regimen, myeloablative conditioning (MAC) for hematopoietic stem cell transplantation (HCT) reduces relapse but is avoided in older patients because of higher non-relapse mortality (NRM). To meet the need for a myeloablative regimen for older patients, we developed a novel fludarabine and busulfan MAC regimen. We fractionated the dose of busulfan and gave it for 6 days over a 2-week period and demonstrated the feasibility and safety of this approach. However, the disease-specific efficacy of this regimen is not known. The purpose of this study was to estimate the efficacy of fractionated busulfan regimen by estimating diseases specific survival outcomes. The conditioning regimen consisted of busulfan and fludarabine. On days -13 and -12 before HCT, patients received 80 mg/m² busulfan intravenously (IV) daily in an outpatient clinic. Additional chemotherapy was administered during inpatient treatment from day -6 through day -3, including fludarabine 40 mg/m² and busulfan IV once daily. The dosing of busulfan was determined from pharmacokinetic analyses to achieve for the course a target area under the curve of 20,000 ± 12% μmol/min, which is close to the average exposure of myeloablative dose of busulfan. One hundred fifty patients with high-risk hematological malignancies up to 75 years were enrolled in this prospective phase II study. The objective was to evaluate NRM, relapse, survival, the rates of graft-versus-host disease (GVHD), and long-term complications. The median age of the patient population was 61 years (interquartile range, 55-67). The most common diagnoses were acute myeloid leukemia (AML; N = 59 [39.3%]), myelodysplastic syndrome (MDS; n = 29 [19.3%]), and myelofibrosis (MF; N = 22 [14.7%]). Most had an unrelated donor (n = 93 [62%]) and received peripheral blood graft (n = 110 [73.3%]). Over half had an HCT-specific comorbidity index of ≥3 (n = 79 [52.7%]). The median follow-up among survivors was 43.4 months (interquartile range, 38.9-50.4). In patients with AML in complete remission, MDS, and myelofibrosis, 3-year overall survival was 66.7% (95% confidence interval [CI], 50.2-88.5%), 43.6% (95% CI, 28.6-66.4%), and 59.1% (95% CI, 41.7-83.7%) respectively. The cumulative incidence of NRM was 22% (15.3%-28.7%), extensive chronic GVHD was 27% (95% CI, 20-34%), bronchiolitis obliterans was 4.7% (95% CI, 1.3-8.1%), and secondary malignancy was 8.7% (95% CI, 4.1-13.2%) at 3 years. Lengthening the duration of busulfan (fractionation) permits safe delivery of myeloablative conditioning in older patients, leading to prolonged survival. © 2021 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Understanding the Process and Challenges for Return-to-Work Post-Hematopoietic Cell Transplantation from a Musculoskeletal Perspective: A Narrative Review

The current paper seeks to inform healthcare professionals on how adapting various components of return to work (RTW) programs that are already in use by other musculoskeletal rehabilitation settings can help optimize return to work process for patients with or without musculoskeletal manifestations, posthematopoietic cell transplantation. Since there is no universally agreed RTW structure for hematopoietic cell transplant patients, a narrative approach has been taken utilizing evidence from the existing musculoskeletal return to work assessment publications to help draw parallel for the hematopoietic cell transplant patients. Databases were searched including PUBMED, CINHAL, AMED, SCOPUS, and Cochrane using keywords RTW, functional restoration program, hematopoietic cell transplant, bone marrow transplant, stem cell transplant, and musculoskeletal functional assessment. The authors have managed to outline and propose a structured RTW assessment and monitoring program which can aid in getting patients back to employment by utilizing the functional capacity and job evaluation to help hematopoietic cell transplantation patients reintegrate socially. Patients undergoing hematopoietic cell transplant require additional support and a robust assessment system to allow safe RTW. The proposed model of RTW assessment can prove to be beneficial in helping patients return to work safely. Clinical Significance. To acknowledge the individuality in functional limitation is important in determining not only the rehab needs but also the RTW capabilities. The proposed RTW plan not only promotes an individualized approach to patients but also provides a structure for return to work assessments for hematopoietic cell transplantation patients, thus, eliminating the need for guess work by healthcare professionals. In line with the International Classification of Functioning, Disability, and Health (ICF) recommendations, a RTW assessment combined with a job evaluation helps healthcare professionals and stakeholders to understand the unique challenges and strengths of a patient and thereby design an individualized therapy approach.

Outcomes of Fludarabine, Melphalan and Total Body Irradiation as a Reduced Intensity Conditioning Regimen in Matched Donor Allogeneic Peripheral Blood Stem Cell Transplantation

Fludarabine 30 mg/m²/d × 5 and melphalan 140 mg/m² × 1 (Flu-Mel140) is a commonly used reduced-intensity conditioning regimen. We hypothesized that addition of 200cGy total body irradiation (TBI) to Flu-Mel140 may improve antitumor activity and transplant outcomes. Primary objectives was overall survival (OS) at 3 years. Secondary objectives were to assess the cumulative incidences of acute and chronic GVHD, relapse-free survival (RFS), relapse rate, and nonrelapse mortality (NRM). We retrospectively evaluated outcomes of patients receiving Flu-Mel140-TBI followed by HLA-matched donor allogeneic hematopoietic stem cell transplantation (alloSCT) using peripheral blood stem cells. Eighty-one patients (median age, 58 years) underwent alloSCT between January 2008 and December 2018. Thirty-one percent of patients had a prior transplant, 32% had high or very-high disease risk index, and the donor was unrelated in 70% of patients. Grade 3 to 4 regimen-related toxicities were mucositis (37%), cardiac toxicity (17%), and renal toxicity (10%). The cumulative incidence of grade III to IV acute GVHD at day +100 was 24.7% and chronic GVHD at 1 year was 51.3%. Median follow-up for survival was 6.1 years. At 3 years, OS was 39.81%, RFS was 31.47%, and relapse rate was 30.5%. One-year NRM was 29.9%. Patients undergoing first transplantation experienced improved OS compared with second or beyond (63.08% versus 42.31%, P = .02). After adjusting for disease subtypes, age (≤55 versus 55), comorbidity index (CI), number of transplant and GVHD prophylaxis, multivariable analysis did not demonstrate any survival difference among disease subtypes. High CI (≥3) was predictive of adverse OS and NRM, whereas older age (>55 years) was associated with high NRM. Our study shows that Flu-Mel140-TBI seems feasible and provides durable disease control. Addition of TBI did not appear to improve outcomes compared to previously published reports of Flu-Mel140. Considerable NRM could result from the inclusion of patients with older age and prior transplants.

Should patients receive consolidation chemotherapy before reduced intensity allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia in first complete remission?

Background:

For acute myeloid leukemia (AML) patients, the role of bridging consolidation chemotherapy after achieving first complete remission (CR1) in the transplant setting is a frequently debated issue. The lack of data from Asian patients led us to conduct this study.

Methods:

We retrospectively studied outcomes of 106 patients in CR1 undergoing allogeneic stem cell transplantation (alloSCT) with reduced intensity conditioning (RIC) based on their exposure to pre-transplant consolidation chemotherapy. There were 35 in the no consolidation group versus 71 in the consolidation group.

Results:

The median relapse free survival (RFS) was 9 months for the no consolidation group and 51 months for consolidation group (p = 0.023). The median overall survival was 32 months for the no consolidation group and not reached for the consolidation group (p = 0.034). Multivariate analysis recognized consolidation and poor cytogenetics as adverse prognostic factors for RFS. Moreover, RFS was better in patients with a shorter time lapse between last chemotherapy and alloSCT in both the no consolidation group and the consolidation group. Consolidation chemotherapy did not negatively affect neutrophil and platelet engraftment, infection rates, or acute graft-versus-host disease (GVHD) incidence. On the other hand, patients undergoing consolidation chemotherapy showed trends towards a more severe degree of chronic GVHD.

Conclusion:

The exposure to consolidation chemotherapy in CR1 prior to alloSCT with RIC conditioning did not negatively impact the outcomes in Korean AML patients, for whom a suitable donor is rarely immediately available. Therefore, post-remission consolidation chemotherapy is a reasonable option if required.

Comparison of myeloablative and reduced intensity conditioning unrelated donor allogeneic peripheral blood stem cell transplant outcomes for AML using thymoglobulin for GVHD prophylaxis

A head-to-head comparison of outcomes of unrelated donor allogeneic peripheral blood stem cell transplantation for AML between reduced intensity conditioning (RIC) and myeloablative conditioning (MAC) regimens using thymoglobulin for GVHD prophylaxis is limited. We evaluated outcomes of 122 AML patients who received either busulfan (Bu)/fludarabine (Flu)/low-dose total body irradiation (TBI) as RIC (n = 64, 52%) or Bu/Flu as MAC (n = 58, 48%), and thymoglobulin 4.5 mg/kg total dose between day - 3 to - 1 for GVHD prophylaxis. Grades III-IV acute GVHD (aGVHD) was lower with Bu/Flu/TBI compared with Bu/Flu (6.2% vs 26.1%, p = 0.009). At 1 year, Bu/Flu/TBI was associated with similar chronic GVHD (41.2% vs 44.8%, p = 0.75), OS (61.9% vs 56.9%, p = 0.69), relapse rate (29.9% vs 20.7%, p = 0.24), relapse-free survival (52.8% vs 50%, p = 0.80), non-relapse mortality (17.4% vs 29.3%, p = 0.41), and GVHD-free relapse-free survival (24.2% vs 27.5%, p = 0.80) compared with Bu/Flu. Multivariable analysis did not reveal any difference in outcomes between both regimens. In summary, thymoglobulin at 4.5 mg/kg did not have any adverse impact on survival when used with RIC regimen. Both Bu/Flu/TBI and Bu/Flu conditioning regimens yielded similar survival.

Increased overall and bacterial infections following myeloablative allogeneic HCT for patients with AML in CR1

Presumably, reduced-intensity/nonmyeloablative conditioning (RIC/NMA) for allogeneic hematopoietic cell transplantation (alloHCT) results in reduced infections compared with myeloablative conditioning (MAC) regimens; however, published evidence is limited. In this Center for International Blood and Marrow Transplant Research study, 1755 patients (aged ≥40 years) with acute myeloid leukemia in first complete remission were evaluated for infections occurring within 100 days after T-cell replete alloHCT. Patients receiving RIC/NMA (n = 777) compared with those receiving MAC (n = 978) were older and underwent transplantation more recently; however, the groups were similar regarding Karnofsky performance score, HCT-comorbidity index, and cytogenetic risk. One or more infections occurred in 1045 (59.5%) patients (MAC, 595 [61%]; RIC/NMA, 450 [58%]; P = .21) by day 100. The median time to initial infection after MAC conditioning occurred earlier (MAC, 15 days [range, <1-99 days]; RIC/NMA, 21 days [range, <1-100 days]; P < .001). Patients receiving MAC were more likely to experience at least 1 bacterial infection by day 100 (MAC, 46% [95% confidence interval (CI), 43-49]; RIC/NMA, 37% [95% CI, 34-41]; P = .0004), whereas at least a single viral infection was more prevalent in the RIC/NMA cohort (MAC, 34% [95% CI, 31-37]; RIC/NMA, 39% [95% CI, 36-42]; P = .046). MAC remained a risk factor for bacterial infections in multivariable analysis (relative risk, 1.44; 95% CI, 1.23-1.67; P < .0001). Moreover, the rate of any infection per patient-days at risk in the first 100 days (infection density) after alloHCT was greater for the MAC cohort (1.21; 95% CI, 1.11-1.32; P < .0001). RIC/NMA was associated with reduced infections, especially bacterial infections, in the first 100 days after alloHCT.

Donor Evaluation for Hematopoietic Stem and Progenitor Cell Collection

With the increasing incidence of hematopoietic allogeneic cell transplantation (allo-HCT), the importance of securing a cellular product, safely from a donor, and ensuring that the product is without additional risk to the recipient, continues to be of paramount importance. The evaluation of the donor’s medical eligibility and suitability is designed to identify and limit the risk of transmitting infectious, genetic, or neoplastic diseases to the recipient through the product. It also aims to ensure a maximum level of safety for the donor and informs them of the risks of donation. Several regulatory agencies, national and international registries, and accreditation bodies have facilitated the availability and safe provision of human cells, tissues, and cellular- and tissue-based products not only at local institutions but also through international exchange.

Haploidentical transplantation using posttransplant cyclophosphamide as GVHD prophylaxis in patients over age 70

Hematologic malignancies in older people are unlikely to be cured with chemotherapy alone. Advances in allogeneic blood or marrow transplantation (alloBMT), especially nonmyeloablative (NMA) conditioning and the use of haploidentical donors, now make this therapy available to older people; however, long-term outcomes and predictors of success are unclear. We reviewed the outcomes of 93 consecutive patients aged 70 and older (median, 72; range, 70-78), who underwent haploidentical BMT at Johns Hopkins Hospital between 1 September 2009 and 1 April 2018. All patients received NMA conditioning and posttransplantation cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis. The 2-year overall survival was 53%, and 2-year event-free survival was 43%. The 180-day cumulative incidence (CuI) of nonrelapse mortality (NRM) was 14%, and the 2-year CuI was 27%. The 2-year CuI of relapse was 30%. Of 78 patients who were alive and had their weight recorded on day 180, weight loss predicted subsequent NRM (subdistribution hazard ratio, 1.0; 95% CI, 1-1.13; P = .048). In conclusion, haploidentical BMT with PTCy is feasible and relatively safe in septuagenarians. Although early, 6-month NRM was relatively low at 14%, but overall NRM continued to climb to 27% at 2 years, at least in part because of late deaths that appeared to be somewhat age related. Further studies to elucidate predictors of NRM are warranted.

Extension of Maximal Lifespan and High Bone Marrow Chimerism After Nonmyeloablative Syngeneic Transplantation of Bone Marrow From Young to Old Mice

The goal of this work was to determine the effect of nonablative syngeneic transplantation of young bone marrow (BM) to laboratory animals (mice) of advanced age upon maximum duration of their lifespan. To do this, transplantation of 100 million nucleated cells from BM of young syngeneic donors to an old nonablated animal was performed at the time when half of the population had already died. As a result, the maximum lifespan (MLS) increased by 28 ± 5%, and the survival time from the beginning of the experiment increased 2.8 ± 0.3-fold. The chimerism of the BM 6 months after the transplantation was 28%.

FLT3 internal tandem duplication does not impact prognosis after haploidentical allogeneic hematopoietic stem cell transplantation in AML patients

Acute myelogenous leukemia (AML) patients with fetal liver tyrosine kinase 3 (FLT3) internal tandem duplications (ITDs) have poor prognoses if treated with chemotherapy only, primarily as they experience increased relapse rates. To determine whether this alteration also affects outcomes after haploidentical donor (HID) allogeneic hematopoietic stem cell transplantation (allo-HSCT), we compared 334 consecutive FLT3-ITD-positive vs -negative patients with AML (other than acute promyelocytic leukemia) who underwent HID-HSCT. FLT3-ITD was detected in 39 of 334 patients (11.7%). The 2-year relapse rates for FLT3-ITD-positive and -negative patients were 16% and 17%, respectively (P = 0.774). The 3-year disease-free survival (DFS) rates for FLT3-ITD-positive and -negative patients were 74% (95% confidence interval [CI]: 64-81) and 73% (95% CI: 70-81), respectively; P = 0.872); while the 3-year overall survival (OS) rates were 72% (95% CI: 67-81) and 77% (95% CI: 72-84), respectively (P = 0.862). FLT3-ITD mutation had no influence on non-relapse mortality (NRM 15% vs 14%, P = 0.463). Multivariate analyses showed that disease status at HSCT and white blood cell count at diagnosis were independent risk factors associated with relapse, DFS, and OS. In conclusion, FLT3 mutation status has no impact on outcomes after HID-HSCT in patients with AML. HID-HSCT is therefore a valid option for AML patients with FLT3-ITD mutation.

Fludarabine with a higher versus lower dose of myeloablative timed-sequential busulfan in older patients and patients with comorbidities: an open-label, non-stratified, randomised phase 2 trial

BACKGROUND

Haemopoietic stem-cell transplantation (HCT) conditioning regimens that can reduce risk of relapse without increasing non-relapse mortality are needed. We aimed to test the safety of timed-sequential delivery of low-dose versus high-dose myeloablative busulfan in older patients and patients with comorbidities.

METHODS

This non-stratified, open-label, randomised phase 2 trial was done at The University of Texas MD Anderson Cancer Center (Houston, TX, USA). Patients with haematological cancers aged between 5 and 75 years were eligible to participate in the study. Patients who had HIV or uncontrollable infections were excluded. Eligible patients were randomly assigned (1:1 by a computer-generated programme in block sizes of four) to receive a total intravenous busulfan dose to achieve an area under the curve of 16 000 μmol/min (16K group) or 20 000 μmol/min (20K group) on the basis of pharmacokinetic analysis, plus intravenous fludarabine 40 mg/m² for 4 days. The investigators and the research nurses were masked to the block size to conceal allocation. The primary outcome was day 100 non-relapse mortality. All analyses were by modified intention to treat, including only patients who received at least one dose of the study drug. No interim analyses were planned and accrual is complete. This study is registered with ClinicalTrials.gov, number NCT01572662.

FINDINGS

Between April 18, 2012, and Dec 9, 2015, 98 patients were enrolled. 49 patients were randomly assigned to the 16K group and 49 to the 20K group, one of which was removed from the study before starting the intervention. Median age was 60 years (IQR 54-67). 50 (52%) patients had an HCT-specific comorbidity index score of 3 or more, and 41 (42%) had a high or very high Disease Risk Index score. Day 100 non-relapse mortality was 4% (95% CI 0-10) in the 16K group and 6% (0-13) in the 20K group (p=0·65). Infection was the most common grade 3-5 toxicity in both the 20K group (25 [52%] of 48 patients) and the 16K group (24 [49%] of 49 participants). Mucositis (nine [19%] of 48 patients vs three [6%] of 49 patients), idiopathic pneumonia syndrome (nine [19%] of 48 patients vs two [4%] of 49 patients), and culture-negative neutropenic fever (16 [33%] of 48 patients vs eight [16%] of 49 patients) were more common in the 20K group than in the 16K group.

INTERPRETATION

Myeloablative doses of busulfan administered in a timed-sequential manner with fludarabine is associated with low non-relapse mortality in older patients and patients with comorbidities. Additional studies are required to show whether this approach can reduce the risk of relapse.

FUNDING

Cancer Center Support Grant (US National Cancer Institute, National Institutes of Health).

Allogeneic Hematopoietic Stem Cell Transplantation for Older Patients With Acute Myeloid Leukemia

OPINION STATEMENT

Acute myelogenous leukemia (AML) in the elderly is complex and has a poor prognosis, often characterized by higher risk cytogenetic and molecular features compared to that in younger patients. Rates of transplant have been limited by concern related to non-relapse mortality, as older patients have historically been considered medically unfit for the transplantation process. Reduced-intensity conditioning (RIC) for hematopoietic stem cell transplantation (HSCT) has been shown to provide similar efficacy to myeloablative methods, with decreased non-relapse mortality in the elderly and improved efficacy over non-transplant approaches with cytotoxic chemotherapy alone. Targeted non-cytotoxic and modified cytotoxic agents have emerged to further improve transplant outcomes for older AML patients. Validated comorbidity indices are useful tools to assess an individual's fitness for undergoing HSCT rather than chronological age alone. We believe HSCT is the primary curative treatment approach for many older AML patients, taking into account risk and comorbidities, particularly given the tendency of leukemia in this population to harbor an unfavorable disease profile. We use RIC and advocate for the addition of targeted agents if applicable. With continuing data in support of transplant for older AML patients, we anticipate that transplant rates in this population will continue to rise.

Myelodysplastic syndrome from theoretical review to clinical application view

Myelodysplastic syndromes (MDS), called ineffective hematopoiesis is indicated by bone marrow failure and tendency to acute myeloid leukemia transformation. Since the disease is more common in elderly with non- hematology co-morbidities, the research for less toxic and curative novel agents is essential. More than 12 years without new Food and Drug Administration approved drugs in MDS management through the whole course, only 5 drugs. We summarized the basic data in diagnosis, treatment guidelines and future direction.

Volumetric modulated arc therapy for total body irradiation: A feasibility study using Pinnacle3 treatment planning system and Elekta Agility™ linac

A study was undertaken to explore the use of volumetric modulated arc therapy (VMAT) for total body irradiation (TBI). Five patient plans were created in Pinnacle3 using nine 6 MV photon dynamic arcs. A dose of 12 Gy in six fractions was prescribed. The planning target volume (PTV) was split into four subsections for the head, chest, abdomen, and pelvis. The head and chest beams were optimized together, followed by the abdomen and pelvis beams. The last stage of the planning process involved turning all beams on and performing a final optimization to achieve a clinically acceptable plan. Beam isocenters were shifted by 3 or 5 mm in the left-right, anterior-posterior, and superior-inferior directions to simulate the effect of setup errors on the dose distribution. Treatment plan verification consisted of ArcCheck measurements compared to calculated doses using a global 3%/3 mm gamma analysis. All five patient plans achieved the planning aim of delivering 12 Gy to at least 90% of the target. The mean dose in the PTV was 12.7 Gy. Mean lung dose was restricted to 8 Gy, and a dose reduction of up to 40% for organs such as the liver and kidneys proved feasible. The VMAT technique was found to be sensitive to patient setup errors particularly in the superior-inferior direction. The dose predicted by the planning system agreed with measured doses and had an average pass rate of 99.2% for all arcs. VMAT was found to be a viable treatment technique for total body irradiation.

Prognostic Factors for Mortality among Day +100 Survivors after Allogeneic Hematopoietic Cell Transplantation

Although day +100 survival among allogeneic hematopoietic cell transplantation (HCT) recipients has improved over time, longer-term survival remains a challenge. The aim of this study was to identify prognostic factors for survival among patients surviving longer than 100 days using baseline characteristics and factors identified within the first 100 days after transplantation. Of 413 patients undergoing a first allogeneic HCT between 2006 and 2014, 335 survived >100 days post-transplantation. The majority underwent a myeloablative transplantation (75%) with a bone marrow (BM) (52%) graft source. One-year all-cause mortality (ACM) was 29%, with 16% relapse mortality (RM) and 12% nonrelapse mortality. In multivariable analysis, high-risk disease (hazard ratio [HR], 1.55; P = .003), non-cytomegalovirus infection (HR, 1.79; P = .003), more days hospitalized (HR, 1.16; P < .001), and relapse (HR, 4.38; P < .001) within the first 100 days were associated with increased risk of ACM. Patients with higher income (HR, .89; P = .024) and those who received BM (HR, .52; P < .001) or umbilical cord blood (HR, .40; P = .002) relative to peripheral blood stem cells had lower risk of ACM. Our study identifies risk factors for adverse long-term survival in 100-day survivors, a time point when patients frequently are discharged from transplantation centers. In addition to disease- and transplantation-related factors, low socioeconomic status was associated with worse long-term survival, highlighting the need for focused efforts to improve outcomes in vulnerable patient populations.

Population pharmacokinetics analysis of intravenous busulfan in Chinese patients undergoing hematopoietic stem cell transplantation

There are several reports describing population pharmacokinetic (popPK) models of busulfan (BU). However, limited information is available in Chinese hematopoietic stem cell transplantation (HSCT) patients. The present study aimed to establish a popPK model of intravenous BU in Chinese HSCT patients for individualized drug therapy. The popPK model of BU was developed from a total of 284 concentration-time points from 53 patients. The effects of demographic and biochemical covariates were investigated by nonlinear mixed effect model (NONMEM) software. Plots, visual predictive check (VPC), bootstrap and normalized prediction distribution error (NPDE) were performed to determine the stability and the reliability of the final model. A one-compartment model with first-order elimination process was confirmed as the final structural model for BU. For a typical patient whose body surface area (BSA) is 1.7 m² , the population typical values of CL and Vd were 11.86 L/h, and 48.2 L, respectively. The result suggested BSA showed significant influence on CL and Vd (P<.001). Plots revealed the final model was performing a goodness fit. The steady rate verified by bootstrap was 100%, relative deviation was less than 4.00%, estimated value of final model was in the 95% confidence interval (CI). The VPC results showed the observed values were almost all positioned within the 5th and 95th CIs. The mean and variance of the NPDE were 0.0363 (Wilcoxon signed-rank test, 0.298) and 0.877 (Fisher variance test, 0.134; SW test of normality, 0.108), respectively. The global adjusted P value was 0.305, which indicated that the prediction of the BU popPK model was adequate. A physician-friendly Microsoft Excel-base tool was implemented using the final popPK model for designing individualized dosing regimens.

Immune Checkpoint Blockade and Hematopoietic Stem Cell Transplant

Allogeneic hematopoietic stem cell transplant (HSCT) relies primarily upon graft-versus-tumor activity for cancer eradication. Relapse remains the principal cause of treatment failure after HSCT, implying frequent immune escape, which in at least some cases, appears to be mediated by increased expression of inhibitory immune checkpoints. In an attempt to restore anti-tumor immunity, checkpoint blockade therapy (CBT) targeting PD-1 and CLTA-4 has been used in conjunction with both allogeneic and autologous HSCT. Clinical experience in this setting is limited to several small clinical trials and case series, but together they suggest that treatment with CBT can effectively amplify anti-tumor immune responses. However, intrinsic to its mechanism is also the risk that CBT in the HSCT setting may also cause significant immune toxicity. Fatal immune-related adverse events and graft-versus-host disease have been observed, but in most cases, immune side effects appear to be reversible with steroids and CBT discontinuation. As clinical investigation continues, improved understanding of immune checkpoint biology will be critical to optimize safe and efficacious treatment strategies.

Age does not adversely influence outcomes among patients older than 60 years who undergo allogeneic hematopoietic stem cell transplant for AML and myelodysplastic syndrome

Allogeneic hematopoietic stem cell transplant (AHSCT) outcomes data of older AML/myelodysplastic syndrome (MDS) patients are limited. We retrospectively evaluated consecutive patients ⩾60 years old with AML/MDS who underwent AHSCT between January 2005 and December 2014. The primary objectives were to determine nonrelapse mortality (NRM), relapse, relapse-free survival (RFS) and overall survival (OS) at 1 year post AHSCT. A total of 159 patients underwent AHSCT with a median age of 64 (range, 60-75) years. Of these, 103 patients (65%) had AML and 56 patients (35%) had MDS. At 1 year post AHSCT, grade III-IV acute GvHD and chronic GvHD occurred in 20.8% (95% confidence interval (CI), 14.9-27.5%) and 54.1% (95% CI, 46.0-61.5%) of patients, respectively. NRM, RFS, relapse rate and OS at 1 year post AHSCT were 25.3% (95% CI, 18.8-32.3%), 53.3% (95% CI, 46.1-61.7%), 21.4% (95% CI, 15.4-28.1%) and 56.4% (95% CI, 49.2-54.7%), respectively. High disease risk index was associated with poor RFS, OS and higher relapse rate (P<0.03), whereas non-thymoglobulin-based GvHD prophylaxis, higher comorbidity index (⩾3) and MDS were associated with higher NRM (P<0.03). Importantly, age did not have an adverse effect on NRM, relapse, RFS and OS. AHSCT was well tolerated. Hence, older age alone should not be considered a contraindication to AHSCT.

Emerging cell cycle inhibitors for acute myeloid leukemia

INTRODUCTION

AML therapy remains very challenging despite our increased understanding of its molecular heterogeneity. Outcomes with chemotherapy and targeted therapy remain poor. Targeting cell cycle regulators might complement chemotherapy and targeted therapy and help in improving outcomes. Areas covered: Here we cover the pre-clinical and clinical data for both for cyclin dependent kinase (CDK) and cell-cycle checkpoint inhibitors. While CDK inhibition can inhibit proliferation, checkpoint inhibitors can facilitate cell cycle progression in presence of DNA damage and can induce mitotic catastrophe. Expert opinion: Though the preclinical data for cell cycle inhibitors in AML is compelling, the clinical translation so far has proven to be challenging. This is a reflection of the complexity of both, AML and cell cycle regulators. However, early introduction of cell-cycle active agents in combination with chemotherapy or targeted agents, identifying right sequence of use and identifying right biomarkers might pave the way into successful clinical translation.

Phase I Study of Clofarabine and 2-Gy Total Body Irradiation as a Nonmyeloablative Preparative Regimen for Hematopoietic Stem Cell Transplantation in Pediatric Patients with Hematologic Malignancies: A Therapeutic Advances in Childhood Leukemia Consortium Study

Clofarabine is a purine nucleoside analog with immunosuppressive and antileukemic activity and its inclusion in reduced-intensity regimens could potentially improve outcomes. We performed a prospective phase I study of clofarabine combined with 2 Gy total body irradiation (TBI) as a nonmyeloablative preparative regimen for allogeneic stem cell transplantation in pediatric patients who were considered at high risk of mortality from standard myeloablative regimens. The main goal of the study was to delineate the maximum feasible dose (MFD) of clofarabine in combination with 2 Gy TBI. Eighteen patients, 1 to 21 years of age and in complete remission, were enrolled in 2 strata (matched related donor and unrelated donor) and evaluated for day100 dose-limiting events (DLE) (nonengraftment, nonrelapse mortality [NRM], and severe renal insufficiency) after receiving clofarabine at the starting dose level of 40 mg/m². All 6 patients (3 in each stratum) engrafted with no day 100 DLE seen in the first cohort. The dose was increased to 52 mg/m² in the next and an expanded cohort (total of 12 patients) and no DLE were observed at day 100 and at the 1-year study endpoint. The regimen was well tolerated with transient transaminitis and gastrointestinal and skin reactions as the common reversible toxicities observed with clofarabine. The dose of 52 mg/m² of clofarabine was deemed the MFD. Disease relapse led to mortality in 6 (33%) patients during follow-up with 1-year event-free survival and overall survival of 60% (95% confidence interval [CI], 34 to 79) and 71% (95% CI, 44 to 87), respectively. This regimen leads to successful engraftment using both related and unrelated donors with exceptionally low rates of NRM.

The long-term outcome of reduced-intensity allogeneic stem cell transplantation from a matched related or unrelated donor, or haploidentical family donor in patients with leukemia: a retrospective analysis of data from the China RIC Cooperative Group

This study compared 6-year follow-up data from patients undergoing reduced-intensity conditioning (RIC) transplantation with an HLA-matched related donor (MRD), an HLA-matched unrelated donor (MUD), or an HLA-haploidentical donor (HID) for leukemia. Four hundred and twenty-seven patients from the China RIC Cooperative Group were enrolled, including 301 in the MRD, 79 in the HID, and 47 in the MUD groups. The conditioning regimen involved fludarabine combined with anti-lymphocyte globulin and cyclophosphamide. Graft-versus-host disease (GVHD) prophylaxis was administered using cyclosporin A (CsA) and mycophenolate mofetil (MMF). Four hundred and nineteen patients achieved stable donor chimerism. The incidence of stage II-IV acute GVHD in the HID group was 44.3 %, significantly higher than that in the MRD (23.6 %) and MUD (19.1 %) groups. The 1-year transplantation-related mortality (TRM) rates were 44.3, 17.6, and 21.3, respectively. Event-free survival (EFS) at 6 years in the HID group was 36.7 %, significantly lower than that of the MRD and MUD groups (59.1 and 66.0 %, P < 0.001 and P = 0.001, respectively). For advanced leukemia, the relapse rate of the HID group was 18.5 %, lower than that of the MRD group (37.5 %, P = 0.05), but the EFS at 6 years was 31.7 and 30.4 % (P > 0.05), respectively. RIC transplantation with MRD and MUD had similar outcome in leukemia which is better than that with HID. RIC transplantation with HID had lower relapsed with higher TRM and GVHD rate, particularly in advanced leukemias. RIC transplantation with MRD and MUD had similar outcomes in leukemia and they were better than those with HID. RIC transplantation with HID had a lower relapse rate but higher TRM and GVHD rates, particularly in cases of advanced leukemia.

Role of reduced-intensity conditioning allogeneic hematopoietic cell transplantation in older patients with de novo acute myeloid leukemia

Reduced-intensity conditioning (RIC) regimens extend the therapeutic use of allogeneic hematopoietic cell transplantation (HCT) to older patients. The survival trend in 2325 patients aged >50 years presenting with de novo acute myeloid leukemia (AML) who underwent first reduced-intensity HCT (RIC-HCT) was assessed by retrospectively analyzing outcomes between 2000 and 2013. The annual number of RIC-HCTs in Japan was higher in the 2008-2013 period (n = 205/year [1229/6 years]) than in the 2000-2007 period (n = 137/year [1096/8 years]). Overall and disease-free survival were higher in the 2008-2013 period (P < 0.001) because of the improvement in transplant-related mortality (TRM). Survival regarding RIC-HCT for AML has improved over time, with an increased number of RIC-HCTs in patients with a Karnofsky performance status (KPS) ≥80. However, TRM remains high and the relapse rate has not improved over time. Multivariate analyses showed that a KPS ≥80 and complete remission at HCT were associated with less TRM and relapse, and better survival regardless of age ≥65 years. Accurate timing and prospective identification of patients at risk of TRM may aid the development of risk-adapted strategies for RIC-HCT in AML patients regardless of age.

Unrelated donor versus matched sibling donor in adults with acute myeloid leukemia in first relapse: an ALWP-EBMT study

Background

Allogeneic stem cell transplantation is the only curative option for patients with acute myeloid leukemia (AML) experiencing relapse. Either matched sibling donor (MSD) or unrelated donor (UD) is indicated.

Methods

We analyzed 1554 adults with AML transplanted from MSD (n = 961) or UD (n = 593, HLA-matched 10/10, n = 481; 9/10, n = 112). Compared to MSD, UD recipients were older (49 vs 52 years, p = 0.001), transplanted more recently (2009 vs 2006, p = 0.001), and with a longer interval to transplant (10 vs 9 months, p = 0.001). Conditioning regimen was more frequently myeloablative for patients transplanted with a MSD (61 vs 46 %, p = 0.001). Median follow-up was 28 (range 3–157) months.

Results

Cumulative incidence (CI) of neutrophil engraftment (p = 0.07), grades II–IV acute GVHD (p = 0.11), chronic GVHD (p = 0.9), and non-relapse mortality (NRM, p = 0.24) was not different according to the type of donor. At 2 years, CI of relapse (relapse incidence (RI)) was 57 vs 49 % (p = 0.001). Leukemia-free survival (LFS) at 2 years was 21 vs 26 % (p = 0.001), and overall survival (OS) was 26 vs 33 % (p = 0.004) for MSD vs UD, respectively. Chronic GVHD as time-dependent variable was associated with lower RI (HR 0.78, p = 0.05), higher NRM (HR 1.71, p = 0.001), and higher OS (HR 0.69, p = 0.001). According to HLA match, RI was 57 vs 50 vs 45 %, (p = 0.001) NRM was 23 vs 23 vs 29 % (p = 0.26), and LFS at 2 years was 21 vs 27 vs 25 % (p = 0.003) for MSD, 10/10, and 9/10 UD, respectively. In multivariate analysis adjusted for differences between the two groups, UD was associated with lower RI (HR 0.76, p = 0.001) and higher LFS (HR 0.83, p = 0.001) compared to MSD. Interval between diagnosis and transplant was the other factor associated with better outcomes (RI (HR 0.62, p < 0.001) and LFS (HR 0.67, p < 0.001)).

Conclusions

Transplantation using UD was associated with better LFS and lower RI compared to MSD for high-risk patients with AML transplanted in first relapse.

Comparable Allogeneic Hematopoietic Cell Transplantation Outcome of a Haplo-Identical Family Donor with an Alternative Donor in Adult Aplastic Anemia

We performed a study on allogeneic hematopoietic cell transplantation (alloHCT) from an HLA-haplo-identical familial donor (haploFD) using a busulfan-fludarabine-antithymocyte globulin conditioning regimen for severe aplastic anemia (sAA) and hypoplastic myelodysplastic syndrome. For the comparison between a haploFD and an alternative donor (AD; matched unrelated or partially matched donor) for sAA in adults, we collected haploFD data retrospectively and prospectively. Forty-eight AD cases were selected for the comparison with 16 haploFD cases. All transplantation outcomes except for extensive chronic graft versus host disease (GvHD) were similar. The frequencies of hepatic sinusoidal obstruction syndrome (p = 1.000), acute GvHD (p = 0.769), grade 3/4 acute GvHD (p = 0.258), chronic GvHD (p = 0.173), extensive chronic GvHD (p = 0.099), primary neutrophil engraftment failure (p = 1.000), secondary graft failure (p = 1.000) and platelet engraftment failure (p = 0.505) were similar. Time to neutrophil engraftment was faster in haploFD (p = 0.003), while the cumulative incidence of platelet engraftment was similar (p = 0.505). Overall survival was also similar between AD and haploFD (p = 0.730). In conclusion, alloHCT from haploFD in sAA was comparable with alloHCT from AD, but extensive chronic GvHD seemed frequent in haploFD. Therefore alloHCT from haploFD could be an alternative approach for alloHCT from AD in adult sAA.

Ipilimumab for Patients with Relapse after Allogeneic Transplantation

BACKGROUND

Loss of donor-mediated immune antitumor activity after allogeneic hematopoietic stem-cell transplantation (HSCT) permits relapse of hematologic cancers. We hypothesized that immune checkpoint blockade established by targeting cytotoxic T-lymphocyte-associated protein 4 with ipilimumab could restore antitumor reactivity through a graft-versus-tumor effect.

METHODS

We conducted a phase 1/1b multicenter, investigator-initiated study to determine the safety and efficacy of ipilimumab in patients with relapsed hematologic cancer after allogeneic HSCT. Patients received induction therapy with ipilimumab at a dose of 3 or 10 mg per kilogram of body weight every 3 weeks for a total of 4 doses, with additional doses every 12 weeks for up to 60 weeks in patients who had a clinical benefit.

RESULTS

A total of 28 patients were enrolled. Immune-related adverse events, including one death, were observed in 6 patients (21%), and graft-versus-host disease (GVHD) that precluded further administration of ipilimumab was observed in 4 patients (14%). No responses that met formal response criteria occurred in patients who received a dose of 3 mg per kilogram. Among 22 patients who received a dose of 10 mg per kilogram, 5 (23%) had a complete response, 2 (9%) had a partial response, and 6 (27%) had decreased tumor burden. Complete responses occurred in 4 patients with extramedullary acute myeloid leukemia and 1 patient with the myelodysplastic syndrome developing into acute myeloid leukemia. Four patients had a durable response for more than 1 year. Responses were associated with in situ infiltration of cytotoxic CD8+ T cells, decreased activation of regulatory T cells, and expansion of subpopulations of effector T cells in the blood.

CONCLUSIONS

Our early-phase data showed that administration of ipilimumab was feasible in patients with recurrent hematologic cancers after allogeneic HSCT, although immune-mediated toxic effects and GVHD occurred. Durable responses were observed in association with several histologic subtypes of these cancers, including extramedullary acute myeloid leukemia. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT01822509.).

Reduced-intensity conditioning allogeneic hematopoietic-cell transplantation for older patients with acute myeloid leukemia

Elderly patients (>60 years) with acute myeloid leukemia have a poor prognosis with a chemotherapy-alone approach. Allogeneic hematopoietic-cell transplantation (HCT) can improve overall survival (OS). However, myeloablative regimens can have unacceptably high transplant-related mortality (TRM) in an unselected group of older patients. Reduced-intensity conditioning (RIC) or nonmyeloablative (NMA) conditioning regimens preserve the graft-versus-leukemia effects but reduce TRM. NMA regimens result in minimal cytopenia and may not require stem cell support for restoring hematopoiesis. RIC regimens, intermediate in intensity between NMA and myeloablative regimens, can cause prolonged myelosuppresion and usually require stem cell support. A few retrospective and prospective studies suggest a possibility of lower risk of relapse with myeloablative HCT in fit older patients with lower HCT comorbidity index; however, RIC and NMA HCTs have an important role in less-fit patients and those with significant comorbidities because of lower TRM. Whether early tapering of immunosuppression, monitoring of minimal residual disease, and post-transplant maintenance therapy can improve the outcomes of RIC and NMA HCT in elderly patients will require prospective trials.

Prognostic Factors on the Graft-versus-Host Disease-Free and Relapse-Free Survival after Adult Allogeneic Hematopoietic Stem Cell Transplantation

The cure of hematologic disorders by allogeneic hematopoietic stem cell transplantation (HSCT) is often associated with major complications resulting in poor outcome, including graft-versus-host disease (GVHD), relapse, and death. A novel composite endpoint of GVHD-free/relapse-free survival (GRFS) in which events include grades 3-4 acute GVHD, chronic GVHD requiring systemic therapy, relapse, or death is censored to completely characterize the survival without mortality or ongoing morbidity. In this regard, studies attempting to identify the prognostic factors of GRFS are quite scarce. Thus, we reviewed 377 adult patients undergoing allogeneic HSCT between 2003 and 2013. The 1- and 2-year GRFS were 40.8% and 36.5%, respectively, significantly worse than overall survival and disease-free survival (log-rank p < 0.001). European Group for Blood and Marrow Transplantation (EBMT) risk score > 2 (p < 0.001) and hematologic malignancy (p = 0.033) were poor prognostic factors for 1-year GRFS. For 2-year GRFS, EBMT risk score > 2 (p < 0.001), being male (p = 0.028), and hematologic malignancy (p = 0.010) were significant for poor outcome. The events between 1-year GRFS and 2-year GRFS predominantly increased in relapsed patients. With prognostic factors of GRFS, we could evaluate the probability of real recovery following HSCT without ongoing morbidity.

CD123 redirected multiple virus-specific T cells for acute myeloid leukemia

Hematopoietic stem cell transplantation (HSCT) has been increasingly used as a curative treatment for acute myeloid leukemia (AML). However, relapse rates after HSCT in complete remission (CR) are reported between 30% and 70%. In addition, numerous studies suggested that secondary viral infection from a variety of viruses including Epstein-Barr virus (EBV), adenovirus (Adv), and cytomegalovirus (CMV) are among the most common causes of death post-HSCT. Currently, chimeric antigen receptor (CAR)-based T cells have been developed to treat AML in clinical studies, while virus-specific cytotoxic T cells (VST) have been proven to be able to effectively prevent or treat viral infection after HSCT. Thus it would be desirable to develop T cells with the ability of simultaneously targeting AML relapse and viral infection. In this article, we now describe the generation of VST cells that are engineered to express CAR for a specific AML cell-surface antigen CD123 (CD123-CAR-VST). Using Dendritic cells (DCs) pulsed with EBV, Adv, and CMV peptides as sources of viral antigens, we generated VST from A2 donor peripheral mononuclear cells (PBMC). VST were then transduced with retroviral vector encoding CD123-CAR to generate CD123-CAR-VST. We demonstrated that CD123-CAR-VST recognized EBV, Adv, and CMV epitopes and had HLA-restricted virus-specific cytotoxic effector function against EBV target. In addition, CD123-CAR-VST retained the specificity against CD123-positive AML cell lines such as MOLM13 and THP-1 in vitro. Thus our results suggested that CD123-CAR-VST might be a valuable candidate to simultaneously prevent or treat relapse and viral infection in AML HSCT recipients.