Clinical Practice Recommendations for Hematopoietic Cell Transplantation and Cellular Therapies in Follicular Lymphoma: A Collaborative Effort on Behalf of the American Society for Transplantation and Cellular Therapy and the European Society for Blood and Marrow Transplantation.

Follicular lymphoma (FL) is the most common indolent B-cell non-Hodgkin lymphoma (NHL), accounting for nearly one-third of all NHL. The therapeutic landscape for patients with FL has significantly expanded over the past decade, but the disease continues to be considered incurable. Hematopoietic cell transplantation (HCT) is potentially curative in some cases. Recently, the emergence of chimeric antigen receptor T-cell therapy (CAR-T) for patients with relapsed/refractory (R/R) FL has yielded impressive response rates and long-term remissions, but definitive statement on the curative potential of CAR-T is currently not possible due to limited patient numbers and relatively short follow up. A consensus on the contemporary role, optimal timing, and sequencing of HCT (autologous or allogeneic) and cellular therapies in FL is needed. As a result, the American Society of Transplantation and Cellular Therapy (ASTCT) Committee on Practice Guidelines endorsed this effort to formulate consensus recommendations to address this unmet need. The RAND-modified Delphi method was used to generate 15 consensus statements/recommendations. These clinical practice recommendations will help guide clinicians managing patients with FL. Of note, the use of bispecific antibodies in R/R FL was not in the scope of this project.

Updated Indications for Immune Effector Cell Therapy: 2023 Guidelines from the American Society for Transplantation and Cellular Therapy.

The American Society for Transplantation and Cellular Therapy (ASTCT) published its guidelines on indications for autologous and allogeneic hematopoietic cell transplantation (HCT) and immune effector cell therapy (IECT) in 2020. Since then, we have witnessed rapid advancements in the field of IECT, resulting in several new chimeric antigen receptor T cell (CAR-T) products and disease indications being approved by the US Food and Drug Administration (FDA). To keep abreast of these practice changes, the ASTCT Committee on Practice Guidelines commissioned a focused update covering CAR-T therapy indications. Here we present updated ASTCT recommendations on indications for CAR-T therapy. Only FDA-approved indications for CAR-T were recommended and categorized as "standard of care," where the indication is well defined and supported by evidence. The ASTCT will continue to periodically review these guidelines and update them as new evidence becomes available.

Haploidentical Versus Matched Unrelated Donor Transplants Using Post-Transplantation Cyclophosphamide for Lymphomas.

When using post-transplantation cyclophosphamide (PTCy) graft-versus-host disease (GVHD) prophylaxis for lymphoma patients, it is currently unknown whether a matched unrelated donor (MUD) or a haploidentical related donor is preferable if both are available. In this study we wanted to test whether using a haploidentical donor has the same results of a MUD. A total of 2140 adults (34% Center for International Blood and Marrow Transplant Research, 66% European Society for Blood and Marrow Transplantation registry) aged ≥18 years who received their first haploidentical hematopoietic cell transplantation (haplo-HCT) or MUD-HCT (8/8 match at HLA-loci A, B, C, and DRB1) for lymphoma using PTCy-based GVHD prophylaxis from 2010 to 2019 were retrospectively analyzed. The majority of both MUD and haploidentical HCTs received reduced intensity/nonmyeloablative conditioning (74% and 77%, respectively) and used a peripheral blood stem cell graft (91% and 60%, respectively) and a 3-drug GVHD prophylaxis (PTCy + calcineurin inhibitor + MMF in 54% and 90%, respectively). Haploidentical HCT has less favorable results versus MUD cohort in terms of overall mortality (hazard ratio [HR= = 1.69; 95% confidence interval [CI], 1.30-2.27; P < .001), progression-free survival (HR=1.39; 95% CI, 1.10-1.79; P = .008), nonrelapse mortality (HR = 1.93; 95% CI, 1.21-3.07; P = .006), platelet engraftment (HR = 0.69; 95% CI, 0.59-0.80; P < .001), acute grade 2-4 GVHD incidence (HR = 1.65; 95% CI, 1.28-2.14; P < .001), and chronic GVHD (HR = 1.79; 95% CI, 1.30-2.48, P < .001). No significant differences were observed in terms of relapse and neutrophil engraftment. Adjusting for propensity score yielded similar results. Whenever MUD is available in a timely manner, it should be preferred over a haploidentical donor when using PTCy-based GVHD prophylaxis for patients with lymphoma.

Pembrolizumab for patients with non-Hodgkin lymphoma: phase 1b KEYNOTE-013 study.

The multicohort phase 1b KEYNOTE-013 study (NCT01953692) evaluated the safety and efficacy of pembrolizumab in patients with relapsed or refractory NHL who were ineligible for or failed hematopoietic cell transplantation (HCT). Patients received pembrolizumab (cohort 4) or pembrolizumab plus lenalidomide (cohort 5). Primary end points were safety and objective response rate (ORR) per IWG 2007 criteria. Cohort 4 included 89 patients. ORR was 22% (19/86; 90% CI 15-31; 10 CR, nine PR); ORRs by disease type were 48% (10/21), 10% (2/20), 12% (5/41), and 50% (2/4), for PMBCL, FL, DLBCL, and 'other' NHL, respectively. Toxicity was as predicted. Cohort 5 included 19 patients. ORR was 39% (90% CI 20-61; four CR, three PR). Hematologic toxicities were the most common treatment-related AEs. In conclusion, pembrolizumab following HCT ineligibility/failure confirms prior experience in PMBCL but not with NHL subtypes in this study. Additional analyses in DLBCL may not be warranted.

Anti-CD20-atezolizumab-polatuzumab vedotin in relapsed/refractory follicular and diffuse large B-cell lymphoma.

PURPOSE: New therapies are needed for relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma. This phase 1b, open-label trial evaluated two anti-CD20-based triplet combinations. METHODS: Patients with R/R follicular lymphoma (FL; n = 13) were treated with obinutuzumab, atezolizumab, and polatuzumab vedotin (G-atezo-pola; 1.4 mg/kg/1.8 mg/kg) and patients with R/R diffuse large B-cell lymphoma (DLBCL; n = 23) received rituximab (R)-atezo-pola. The primary efficacy endpoint was complete response (CR) at end of induction (EOI) by PET-CT (investigator assessed; modified Lugano 2014 criteria). Safety endpoints were also assessed. RESULTS: 13 FL patients were treated and evaluable for safety; 2/23 DLBCL patients did not receive treatment and were not included in the safety population. Median observation time was 23.3 and 5.7 months in the FL and DLBCL cohorts, respectively. At EOI, CR rates in FL patients treated with G-atezo-pola at pola doses of 1.4 mg/kg (N = 3) and 1.8 mg/kg (N = 7) were 33% and 14%, respectively. In DLBCL patients receiving R-atezo-pola, the CR rate at EOI was 13%. In the FL cohort, 62% of patients experienced a grade 3-5 adverse event (AE; including two deaths) and 31% developed a serious AE (SAE). In DLBCL patients, R-atezo-pola was associated with a lower incidence of grade 3-5 AEs (24%; one death) and SAEs (10%). In both cohorts, the most common grade 3-5 AEs were hematologic toxicities. CONCLUSION: Based on these safety issues, considered as related specifically to G-atezo-pola, and limited efficacy, no further development of either combination is planned. TRIAL REGISTRATION: NCT02729896; Date of registration: April 6, 2016.

Phase 1 Study Evaluating Pharmacokinetics and Tolerability of Ofatumumab Combined With Bendamustine in Patients With Indolent B-Cell Non-Hodgkin's Lymphoma.

The pharmacokinetics (PK) and safety of ofatumumab and bendamustine alone and in combination were evaluated in patients with treatment-naive or relapsed indolent B-cell non-Hodgkin lymphoma (iNHL). Patients were randomly assigned to ofatumumab and bendamustine or ofatumumab alone. Ofatumumab PK concentration profiles and parameters were similar, alone or in combination with bendamustine. A decrease of 14% in the maximum observed plasma concentration (Cmax ) and 15% in the area under the plasma concentration-time curve (AUC) from time 0 to the last measurable concentration sampling time (AUClast ) was observed for ofatumumab coadministered with bendamustine, which was not considered clinically relevant. Bendamustine PK concentration profiles and parameters were similar with or without ofatumumab. The most frequent treatment-related adverse event was infusion-related reaction in 53% in the combination arm and 47% in the ofatumumab arm. No relevant drug-drug interaction was observed between ofatumumab and bendamustine. Ofatumumab alone or in combination with bendamustine had a manageable safety profile.

Pomalidomide, bortezomib, and dexamethasone at first relapse in lenalidomide-pretreated myeloma: A subanalysis of OPTIMISMM by clinical characteristics.

OBJECTIVE: We evaluated the efficacy and safety of pomalidomide, bortezomib, and dexamethasone (PVd) vs bortezomib and dexamethasone (Vd) by age, renal function, and high-risk cytogenetic abnormalities in lenalidomide-pretreated patients with multiple myeloma at first relapse. METHODS: OPTIMISMM was a phase 3, multicenter, open-label, randomized study (NCT01734928; N = 559). The primary endpoint was progression-free survival (PFS). RESULTS: Overall, 226 patients had received one prior line of therapy. PVd significantly prolonged PFS vs Vd in patients aged ≤65 years (median, 22.0 vs 13.1 months; P = .0258) and >65 years (median, 17.6 vs 9.9 months; P = .0369). Median PFS in patients with renal impairment (RI; creatinine clearance <60 mL/min) was 15.1 months with PVd vs 9.5 months with Vd (hazard ratio [HR], 0.67 [95% CI, 0.34-1.34]). In patients without RI, median PFS was 22.0 vs 13.1 months (HR, 0.45 [95% CI, 0.27-0.76]). In patients with high-risk cytogenetics, median PFS was 14.7 vs 9.9 months (HR, 0.39 [95% CI, 0.13-1.17]). PVd significantly improved overall response rate vs Vd in all subgroups. The safety profile of PVd was consistent with previous reports. CONCLUSIONS: These findings confirmed the benefits of PVd at first relapse, including in patients with poor prognostic factors.

Pre-existing cardiovascular disease increases risk of atrial arrhythmia and mortality in cancer patients treated with Ibrutinib.

BACKGROUND: Ibrutinib is a Bruton's tyrosine kinase inhibitor used in the treatment of hematological malignancies. The most common cardiotoxicity associated with ibrutinib is atrial arrhythmia (atrial fibrillation and flutter). It is known that patients with cardiovascular disease (CVD) are at an increased risk for developing atrial arrhythmia. However, the rate of atrial arrhythmia in patients with pre-existing CVD treated with ibrutinib is unknown. OBJECTIVE: This study examined whether patients with pre-existing CVD are at a higher risk for developing atrial arrhythmias compared to those without prior CVD. METHODS: A single-institution retrospective chart review of patients with no prior history of atrial arrhythmia treated with ibrutinib from 2012 to 2020 was performed. Patients were grouped into two cohorts: those with CVD (known history of coronary artery disease, heart failure, pulmonary hypertension, at least moderate valvular heart disease, or device implantation) and those without CVD. The primary outcome was incidence of atrial arrhythmia, and the secondary outcomes were all-cause mortality, risk of bleeding, and discontinuation of ibrutinib. The predictors of atrial arrhythmia (namely atrial fibrillation) were assessed using logistic regression. A Cox-Proportional Hazard model was created for mortality. RESULTS: Patients were followed for a median of 1.1 years. Among 217 patients treated with ibrutinib, the rate of new-onset atrial arrhythmia was nearly threefold higher in the cohort with CVD compared to the cohort without CVD (17% vs 7%, p = 0.02). Patients with CVD also demonstrated increased adjusted all-cause mortality (OR 1.9, 95% CI 1.06-3.41, p = 0.01) and decreased survival probability (43% vs 54%, p = 0.04) compared to those without CVD over the follow-up period. There were no differences in risk of bleeding or discontinuation between the two cohorts. CONCLUSIONS: Pre-existing cardiovascular disease was associated with significantly higher rates of atrial arrhythmia and mortality in patients with hematological malignancies managed with ibrutinib.

Standardizing Definitions of Hematopoietic Recovery, Graft Rejection, Graft Failure, Poor Graft Function, and Donor Chimerism in Allogeneic Hematopoietic Cell Transplantation: A Report on Behalf of the American Society for Transplantation and Cellular Therapy.

Allogeneic hematopoietic cell transplantation (allo-HCT) is potentially curative for certain hematologic malignancies and nonmalignant diseases. The field of allo-HCT has witnessed significant advances, including broadening indications for transplantation, availability of alternative donor sources, less toxic preparative regimens, new cell manipulation techniques, and novel GVHD prevention methods, all of which have expanded the applicability of the procedure. These advances have led to clinical practice conundrums when applying traditional definitions of hematopoietic recovery, graft rejection, graft failure, poor graft function, and donor chimerism, because these may vary based on donor type, cell source, cell dose, primary disease, graft-versus-host disease (GVHD) prophylaxis, and conditioning intensity, among other variables. To address these contemporary challenges, we surveyed a panel of allo-HCT experts in an attempt to standardize these definitions. We analyzed survey responses from adult and pediatric transplantation physicians separately. Consensus was achieved for definitions of neutrophil and platelet recovery, graft rejection, graft failure, poor graft function, and donor chimerism, but not for delayed engraftment. Here we highlight the complexities associated with the management of mixed donor chimerism in malignant and nonmalignant hematologic diseases, which remains an area for future research. We recognize that there are multiple other specific, and at times complex, clinical scenarios for which clinical management must be individualized.

Impact of anti-anaerobic antibiotic activity on graft-versus-host disease in allogeneic hematopoietic stem cell transplant (HSCT) recipients at an institution that utilizes antibiotic cycling.

BACKGROUND: At our institution, antibiotic cycling for febrile neutropenia is utilized to increase heterogeneity of antibiotic exposure in patients who have undergone an allogeneic hematopoietic stem cell transplantation (allo-HSCT). Development of acute graft-versus-host disease (aGVHD) has been associated with low diversity within stool microbiota. To date, discordant outcomes have been reported implicating anti-anaerobic antibiotic use with the development of aGVHD, and there is currently a lack of published data available in an antibiotic cycled environment. The objective of this study was to determine if there is a difference in the rate of aGVHD in patients who receive anti-anaerobic cycled antibiotics compared with other cycled antibiotics. METHODS: This was a retrospective, observational study evaluating rates of aGVHD in patients who received antibiotics with anaerobic vs non-anaerobic coverage post-allo-HSCT from January 2008 to January 2018. Univariate and multivariable analyses were performed to assess associations with aGVHD. Secondary outcomes include rate of all stages of aGVHD, progression-free survival, overall survival, 100-day treatment-related mortality (TRM), and 1-year TRM. RESULTS: A total of 273 patients were included in the study. Baseline characteristics were similar between groups, except patients who received anti-anaerobic antibiotics had more unrelated donors (P = .002), were more likely to get myeloablative preparatory regimens (P = .009), had less subtherapeutic calcineurin inhibitor serum concentrations (P = .001), and more often received T-cell depletion (P = .004). The incidence of grades II-IV aGVHD post-HSCT in patients who received anti-anaerobic antibiotics was 32.6% compared with 18.8% in patients who received other antibiotics (P = .015). Multivariable analysis showed that the occurrence of grades II-IV aGVHD was associated with cytomegalovirus reactivation (OR = 2.1, 95% CI = 1.0-4.5, P = .047), unrelated donors (OR = 6.1, 95% CI = 2.3-16.6, P < .001), and use of anti-anaerobic antibiotics (OR = 2.3, 95% CI = 1.1-4.8, P = .021). A 100-day TRM in patients who received anti-anaerobic antibiotics was 9.6% compared with 3.6% in patients who received other antibiotics (P = .046). One-year TRM in patients who received anti-anaerobic antibiotics was 25.2% compared with 13.8% in patients who received other antibiotics (P = .017). There was no statistically significant difference seen between groups in progression free survival or overall survival. CONCLUSION: Variability in baseline characteristics limits ability to make strong conclusions, but patients who received antibiotics with anaerobic coverage during the first 30 days after an allogeneic HSCT appeared to be at an increased risk of developing aGVHD and TRM. Larger well-controlled trials are warranted to further clarify these relationships.

Post-transplant cyclophosphamide versus anti-thymocyte globulin for graft-versus-host disease prevention in haploidentical transplantation for adult acute lymphoblastic leukemia.

Graft-versus-host disease (GVHD) prophylaxis for unmanipulated haploidentical hematopoietic cell transplantation (haplo-HCT) include post-transplant cyclophosphamide (PTCy) and anti-thymocyte globulin (ATG). Utilizing EBMT registry, we compared ATG versus PTCy based GVHD prophylaxis in adult acute lymphoblastic leukemia (ALL) patients undergoing haplo-HCT. Included were 434 patients; ATG (n=98) and PTCy (n=336). Median follow-up was ~2 years. Baseline characteristics were similar between the groups except that the ATG-group was more likely to have relapsed/refractory ALL (P=0.008), non-TBI conditioning (P<0.001), peripheral blood graft source (P=<0.001) and transplanted at an earlier time-period (median year of HCT 2011 vs. 2015). The 100-day grade II-IV and III-IV acute-GVHD was similar between ATG and PTCy, as was 2-year chronic-GVHD. On multivariate analysis (MVA), leukemia-free survival (LFS) and overall survival (OS) was better with PTCy compared to ATG prophylaxis. Relapse incidence (RI) was lower in the PTCy group (P=0.03), while non-relapse mortality (NRM) was not different. Advanced disease and lower performance score were associated with poorer LFS and OS and advanced disease with inferior GVHD-free/relapse-free survival (GRFS). Peripheral grafts were associated with higher GVHD compared to bone marrow grafts. In ALL patients undergoing unmanipulated haplo-HCT, PTCy for GVHD prevention resulted in lower RI and improved LFS and OS compared to ATG.

Prospective assessment of Clostridioides (formerly Clostridium) difficile colonization and acquisition in hematopoietic stem cell transplant patients.

BACKGROUND: Patients undergoing hematopoietic stem cell transplant (HSCT) possess numerous risk factors for Clostridioides (formerly Clostridium) difficile infection (CDI) and experience a high rate of diarrhea. Colonization rates of Clostridium difficile vary greatly among subgroup analyses with recent studies demonstrating colonization rates in the blood and marrow transplant units up to nine times that of the general population. METHODS: The primary objectives of this study were to identify the rate of C difficile colonization and acquisition in HSCT patients admitted to the blood and marrow transplant unit. This was a prospective study that included all adult patients admitted for hematopoietic stem cell transplantation. Stool specimens were routinely collected on admission and weekly thereafter for a maximum of six samples per patient. RESULTS: Forty-two patients met inclusion criteria and had baseline samples available for analysis. The rate of C difficile colonization on admission was 24%, and an additional 9% of patients acquired the organism during admission. Twelve percent of patients developed CDI that was diagnosed clinically. Univariate analysis showed an increased risk of colonization for patients with three or more prior chemotherapy cycles. CONCLUSIONS: Given high colonization rates coupled with high risk of CDI in this population, providers must be judicious when testing for CDI and interpreting test results for HSCT patients.

Eligibility Criteria for Patients Undergoing Allogeneic Hematopoietic Cell Transplantation.

Eligibility assessment of a potential candidate for allogeneic hematopoietic cell transplantation (allo-HCT) is a complex yet vital component of pretransplant evaluation. Although no formal standardized consensus exists to guide this process, transplant centers follow institutional standard operating procedures and parameters to approve candidacy of an individual patient. Consideration for allo-HCT is dependent on a myriad of interrelated factors, including disease-related (eg, appropriate indication, disease status, prior therapies), patient-related (eg, age, functional status, frailty, comorbidities), psychosocial, and economic factors. A multidisciplinary approach is optimal for patient selection and requires the efforts of transplant coordinators, nurses, advanced practice providers, social workers, psychologists, financial specialists, and physicians. This article reviews the data and provides general guidelines that may be used in making an informed decision when evaluating a prospective candidate for allo-HCT. These recommendations are based on published data, expert commentary, reviews, and institutional practices. In the end, the eligibility assessment and decision to consider allo-HCT as the optimal choice of treatment for an individual patient are truly as much an "art" as it is the "science" of medicine, encompassing a multidisciplinary approach to minimize harm without compromising the curative potential-all essential doctrines of the Hippocratic Oath.

Hematopoietic cell transplantation utilization and outcomes for primary plasma cell leukemia in the current era.

The outcomes of patients with primary plasma cell leukemia (pPCL) after undergoing hematopoietic cell transplantation (HCT) in the novel agent era are unknown. We report outcomes of 348 patients with pPCL receiving autologous (auto-) HCT (n = 277) and allogeneic (allo-) HCT (n = 71) between 2008 and 2015. Median age was 60 years and 56 years for auto- and allo-HCT respectively. For auto-HCT, the 4-year outcomes were: non-relapse mortality (NRM) 7% (4-11%), relapse (REL) 76% (69-82%), progression-free survival (PFS) 17% (13-23%), and overall survival (OS) 28% (22-35%). Karnofsky performance status (KPS) > 90 and ≥very good partial response (VGPR) predicted superior OS in multi-variate analysis for auto-HCT. For allo-HCT, the 4-year outcomes were: NRM 12% (5-21%), REL 69% (56-81%), PFS 19% (10-31%), and OS 31% (19-44%). Compared with prior CIBMTR pPCL patients (1995-2006), inferior survival was noted in the current cohort (3-year OS, 39% vs. 38% in allo-HCT, and 62% vs. 35% in auto-HCT) respectively. However, we noted an increased HCT utilization, from 12% (7-21%) in 1995 to 46% (34-64%) in 2009 using SEER data (available till 2009). Despite modern induction translating to higher proportion receiving HCT, the outcomes remain poor in pPCL patients, mainly derived by high relapse rates post-HCT.

Health-related quality-of-life results from the phase 3 OPTIMISMM study: pomalidomide, bortezomib, and low-dose dexamethasone versus bortezomib and low-dose dexamethasone in relapsed or refractory multiple myeloma.

In the randomized phase-3 OPTIMISMM study, the addition of pomalidomide to bortezomib and low-dose dexamethasone (PVd) resulted in significant improvement in progression-free survival (PFS) in lenalidomide-pretreated patients with relapsed or refractory multiple myeloma (RRMM), including lenalidomide refractory patients. Here, we report health-related quality of life (HRQoL) results from this trial. Patients received PVd or Vd in 21-day cycles until disease progression or discontinuation. HRQoL was assessed using the EORTC QLQ-C30, QLQ-MY20, and EQ-5D-3L instruments on day 1 of each treatment cycle. Mean score changes for global QoL, physical functioning, fatigue, side effects of treatment domains, and EQ-5D-3L index were generally stable over time across treatment arms. The proportion of patients who experienced clinically meaningful worsening in global QoL and other domains of interest was similar. These HRQoL results with PVd along with previously demonstrated improvement in PFS vs Vd continue to support its use in patients with RRMM.

Novel Targeted Therapies for Chronic Lymphocytic Leukemia in Elderly Patients: A Systematic Review.

Chronic lymphocytic leukemia (CLL) typically affects older patients; administration of traditional cytotoxic therapies in old patients has very modest benefit with no survival improvement. With better understanding of CLL biology, trends are shifting towards the use of targeted therapies. The objective of this article is to review the safety and efficacy of various novel agents that specifically target the dysregulated pathways, with particular attention to elderly patients. Agents like B-cell receptor (BCR) inhibitors (Bruton's tyrosine kinase inhibitors [ibrutinib]), phosphatidylinositol 3-kinase inhibitors (idelalisib), spleen tyrosine kinase inhibitors (entospletinib), Bcl-2 inhibitors (venetoclax), immunomodulators (lenalidomide), and monoclonal antibodies (obinutuzumab, ofatumumab) have shown activity in CLL with a very favorable toxicity profile. Newer agents have improved clinical outcomes, and have tolerable toxicity profiles in elderly patients, resulting in the treatment with individualized therapy approach for CLL.

Indications for Hematopoietic Cell Transplantation and Immune Effector Cell Therapy: Guidelines from the American Society for Transplantation and Cellular Therapy.

The American Society for Transplantation and Cellular Therapy (ASTCT) published its first white paper on indications for autologous and allogeneic hematopoietic cell transplantation (HCT) in 2015. It was identified at the time that periodic updates of indications would be required to stay abreast with state of the art and emerging indications and therapy. In recent years the field has not only seen an improvement in transplantation technology, thus widening the therapeutic scope of HCT, but additionally a whole new treatment strategy using modified immune effector cells, including chimeric antigen receptor T cells and engineered T-cell receptors, has emerged. The guidelines review committee of the ASTCT deemed it optimal to update the ASTCT recommendations for indications for HCT to include new data and to incorporate indications for immune effector cell therapy (IECT) where appropriate. The guidelines committee established a multiple stakeholder task force consisting of transplant experts, payer representatives, and a patient advocate to provide guidance on indications for HCT and IECT. This article presents the updated recommendations from the ASTCT on indications for HCT and IECT. Indications for HCT/IECT were categorized as (1) Standard of care, where indication is well defined and supported by evidence; (2) Standard of care, clinical evidence available, where large clinical trials and observational studies are not available but have been shown to be effective therapy; (3) Standard of care, rare indication, for rare diseases where demonstrated effectiveness exists but large clinical trials and observational studies are not feasible; (4) Developmental, for diseases where preclinical and/or early-phase clinical studies show HCT/IECT to be a promising treatment option; and (5) Not generally recommended, where available evidence does not support the routine use of HCT/IECT. The ASTCT will continue to periodically review these guidelines and update them as new evidence becomes available.

Summary of Scientific and Statistical Methods, Study Endpoints and Definitions for Observational and Registry-Based Studies in Hematopoietic Cell Transplantation.

Due to the increasingly strict word/character restrictions enforced by most scientific publications, we identified a need for a master document illustrating the "Scientific Methods" that may be applicable to the majority of observational and registry-based studies in hematopoietic cell transplantation (HCT). The purpose of this study is to serve as a reference document that describes the data source, study endpoints and statistical analyses utilized most commonly in retrospective studies in HCT. To this end we compile, define and reference the methodology commonly used in HCT research. While it is recognized that the scientific methodology may periodically require updates due to the evolving landscape of transplant research, such as newer study endpoints and statistical methods, this manuscript describes frequently used methodologies.