Allogeneic transplantation in elderly patients ≥65 years with non-Hodgkin lymphoma: a time-trend analysis

Age barriers in allogeneic hematopoietic cell transplantation: Raising the silver curtain

Allogeneic hematopoietic cell transplantation (HCT) is no longer exclusively for the young. With an aging population, development of non-intensive remission-inducing strategies for hematologic malignancies, and novel graft-versus-host disease-prevention platforms, an older population of patients is pursuing HCT. The evolving population of HCT recipients requires an overhaul in the way we risk-stratify and optimize patients prior to HCT. Here, we review the history and current state of HCT for older adults and propose an assessment and intervention flow to bridge the gaps in today's clinical guidelines.

The association of body composition and outcomes following autologous hematopoietic stem cell transplantation in patients with non-Hodgkin lymphoma

Recently there has been a growing interest in evaluating body composition as a marker for prognosis in cancer patients. The association of body composition parameters and outcomes has not been deeply investigated in patients with autologous hematopoietic stem cell transplantation (HSCT) recipients with non-Hodgkin lymphoma (NHL). We conducted a retrospective cohort study of 264 NHL patients who received autologous HSCT. PreHSCT abdominal CT scans at the levels of L3 were assessed for body composition measures. We evaluated sarcopenia, myosteatosis, high visceral adipose tissue (VAT) and high visceral adipose tissue density (VATD). Using multivariable Cox proportional regression, we analyzed the association of clinical and transplant-related characteristics with overall survival (OS), relapse-free survival (RFS), and non-relapse mortality (NRM). In a multivariate regression model, patients with higher VATD had worse OS (HR 1.78; 95% confidence intervals CI 1.08-2.95, p = 0.02) and worse NRM (HR 2.31 95% CI 1.08-4.95, p = 0.02) than with lower VATD. Patients with lower levels of VAT also had worse RFS (HR 1.49 95% CI 1.03-2.15, p = 0.03). Sarcopenia and myosteatosis were not associated with outcomes. High pre-transplant VATD was associated with lower OS and higher NRM, and low pre-transplant VAT was associated with worse RFS in patients with NHL undergoing autologous HSCT.

Trends in Allogeneic Hematopoietic Cell Transplantation Utilization and Estimated Unmet Need Among Medicare Beneficiaries with Acute Myelogenous Leukemia

Allogeneic hematopoietic cell transplantation (alloHCT) is a resource-intensive procedure and the sole potentially curative treatment available for patients with acute myelogenous leukemia (AML). Although Medicare coverage may help address a major financial barrier to accessing alloHCT, there remains an unmet need for alloHCT owing to sociodemographic disparities. This study examined trends and factors associated with the utilization of alloHCT and the estimated unmet need for alloHCT among Medicare beneficiaries with AML. This retrospective cohort study included patients (age 65 to 74 years) with a diagnosis of AML identified in Medicare claims data from 2010 through 2016. To study trends in utilization, transplantation rates were calculated as the number of patients who underwent alloHCT within 180 days and 1 year of diagnosis (numerator) divided by the total number of patients with AML within each diagnosis year (denominator). A multivariable logistic regression was used to identify factors associated with the likelihood of undergoing alloHCT within 1 year of diagnosis. Two approaches were applied to estimate the unmet need for alloHCT. The first approach used claims data to identify the potential need for alloHCT among patients who achieved complete remission for at least 90 days. The second approach used established National Marrow Donor Program (NMDP) methodology, which considers estimates of risk level, response to treatment, comorbidity, and early mortality, to identify the potential and unmet need for alloHCT. The overall estimated need and unmet need from 2010 to 2015 and over different time periods were evaluated for both approaches. The alloHCT rate within 180 days of diagnosis increased from 8% in 2010 to 15.8% in 2016 (P < .001), and the 1-year alloHCT rate also increased over time, from 11.9% in 2010 to 20.0% in 2015 (P < .001). The likelihood of undergoing alloHCT within 1 year of diagnosis was associated with diagnosis year, age, race, geographic region, Elixhauser Comorbidity Index, and population-level median household income. Between 2010 and 2015, the claims data approach estimated a lower potential need for alloHCT compared with the NMDP methodology estimate (27% versus 36%); both approaches estimated that 43% to 44% of patients with a potential need for alloHCT had an unmet treatment need. Despite the differences in estimated potential need between the 2 approaches, both showed a sustained unmet need but with a downward trend over time. Our data show that utilization of alloHCT has increased over time among Medicare beneficiaries with AML. Two approaches of need analysis were conducted for validation of estimated need and unmet need for alloHCT using claim-identified remission status, given the lack of cytogenetics and molecular information in claims data. Both approaches to estimating the unmet need for alloHCT found a downward trend over time; however, there are differences in utilization of alloHCT by age, race, geographic region, comorbidity, and socioeconomic status, indicating disparities in access to alloHCT among Medicare beneficiaries with AML. This suggests the need for policy efforts, research, and continued education to improve access to alloHCT and to close the gap between the actual utilization of alloHCT and the unmet need.

Trends in the risk of second primary malignances after non-Hodgkin's lymphoma

Patients with non-Hodgkin's lymphoma (NHL) have an increased risk of developing second primary malignances (SPMs). In the current study, we aimed to evaluate the trends and relative clinical variables of SPM risk among NHL survivors over the past four decades. Standardized incidence ratio (SIR) and cumulative incidence frequency (CIF) were assessed in patients diagnosed with first primary NHL between 1975-2016 from the Surveillance, Epidemiology, and End Results (SEER) database. As a result, the overall SIR was 1.13 for SPMs of all sites among NHL survivors. Risk factors included male patients, "other" races, chemotherapy and radiation, and younger age at the time of NHL diagnosis. The relative and cumulative risk for both hematological and solid second cancers after NHL increased over time, whereas the increasing trend was more remarkable for hematological malignances compared with solid tumors. For individual cancer sites, the trends of SIRs varied. A significantly increasing trend of SPM risk was observed in the group receiving chemotherapy and those younger than 40 years at the time of NHL diagnosis. Recent calendar years was not an independent risk factor after adjusting age, race, gender, and therapies in the multivariate Cox proportional hazard regression. To conclude, the current study showed that the relative and cumulative risk of developing SPMs significantly increased in patients diagnosed with NHL in recent years. The trend of SPM risk was associated with certain clinical and demographic variables, and might vary according to different cancer types.

A calibrated Bayesian method for the stratified proportional hazards model with missing covariates

Missing covariates are commonly encountered when evaluating covariate effects on survival outcomes. Excluding missing data from the analysis may lead to biased parameter estimation and a misleading conclusion. The inverse probability weighting method is widely used to handle missing covariates. However, obtaining asymptotic variance in frequentist inference is complicated because it involves estimating parameters for propensity scores. In this paper, we propose a new approach based on an approximate Bayesian method without using Taylor expansion to handle missing covariates for survival data. We consider a stratified proportional hazards model so that it can be used for the non-proportional hazards structure. Two cases for missing pattern are studied: a single missing pattern and multiple missing patterns. The proposed estimators are shown to be consistent and asymptotically normal, which matches the frequentist asymptotic properties. Simulation studies show that our proposed estimators are asymptotically unbiased and the credible region obtained from posterior distribution is close to the frequentist confidence interval. The algorithm is straightforward and computationally efficient. We apply the proposed method to a stem cell transplantation data set.

GITMO Registry Study on Allogeneic Transplantation in Patients Aged ≥60 Years from 2000 to 2017: Improvements and Criticisms

Today, allogeneic stem cell transplantation (allo-SCT) can be offered to patients up to age 70 to 72 years and represents one of the most effective curative treatments for many hematologic malignancies. The primary objective of the study was to collect data from the allo-SCTs performed in Italy between 2000 and 2017 in patients aged ≥60 years to evaluate the changes in safety and efficacy outcomes, as well as their distribution and characteristics over time. The Italian Group for Bone Marrow Transplantation, Hematopoietic Stem Cells and Cell Therapy (GITMO) AlloEld study (ClinicalTrials.gov identifier NCT04469985) is a retrospective analysis of allo-SCTs performed at 30 Italian transplantation centers in older patients (age ≥60 years) between 2000 and 2017 (n = 1996). For the purpose of this analysis, patients were grouped into 3 time periods: time A, 2000 to 2005 (n = 256; 12%); time B, 2006 to 2011 (n = 584; 29%); and time C, 2012 to 2017 (n = 1156; 59%). After a median follow-up of 5.6 years, the 5-year nonrelapse mortality (NRM) remained stable (time A, 32.8%; time B, 36.2%; and time C, 35.0%; P = .5), overall survival improved (time A, 28.4%; time B, 31.8%; and time C, 37.3%; P = .012), and the cumulative incidence of relapse was reduced (time A, 45.3%; time B, 38.2%; time C, 30.0%; P < .0001). The 2-year incidence of extensive chronic graft-versus-host disease was reduced significantly (time A, 17.2%; time B, 15.8%; time C, 12.2%; P = .004). Considering times A and B together (2000 to 2011), the 2-year NRM was positively correlated with the Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) score; NRM was 25.2% in patients with an HCT-CI score of 0, 33.9% in those with a score of 1 or 2, and 36.1% in those with a score of 3 (P < .001). However, after 2012, the HCT-CI score was not significantly predictive of NRM. This study shows that the transplantation procedure in elderly patients became more effective over time. Relapse incidence remains the major problem, and strategies to prevent it are currently under investigation (eg, post-transplantation maintenance). The selection of patients aged ≥60 could be improved by combining HCT-CI and frailty assessment to better predict NRM.

CAR T cells or allogeneic transplantation as standard of care for advanced large B-cell lymphoma: an intent-to-treat comparison

CD19-directed chimeric antigen receptor (CAR) T-cell treatment has evolved as standard of care (SOC) for multiply relapsed/refractory (R/R) large B-cell lymphoma (LBCL). However, its potential benefit over allogeneic hematopoietic cell transplantation (alloHCT) remains unclear. We compared outcomes with both types of cellular immunotherapy (CI) by intention to treat (ITT). Eligble were all patients with R/R LBCL and institutional tumor board decision recommending SOC CAR T-cell treatment between July 2018 and February 2020, or alloHCT between January 2004 and February 2020. Primary end point was overall survival (OS) from indication. Altogether, 41 and 60 patients for whom CAR T cells and alloHCT were intended, respectively, were included. In both cohorts, virtually all patients had active disease at indication. CI was recommended as part of second-line therapy for 21 alloHCT patients but no CAR T-cell patients. Median OS from indication was 475 days with CAR T cells vs 285 days with alloHCT (P = .88) and 222 days for 39 patients for whom alloHCT beyond second line was recommended (P = .08). Of CAR T-cell and alloHCT patients, 73% and 65%, respectively, proceeded to CI. After CI, 12-month estimates for nonrelapse mortality, relapse incidence, progression-free survival, and OS for CAR T cells vs alloHCT were 3% vs 21% (P = .04), 59% vs 44% (P = .12), 39% vs 33% (P = .97), and 68% vs 54% (P = .32), respectively. In conclusion, CAR T-cell outcomes were not inferior to alloHCT outcomes, whether measured by ITT or from CI administration, supporting strategies preferring CAR T cells over alloHCT as first CI for multiply R/R LBCL.

Allogeneic stem cell transplantation for chronic lymphocytic leukemia in the era of novel agents

Although novel agents (NAs) have improved outcomes for patients with chronic lymphocytic leukemia (CLL), a subset will progress through all available NAs. Understanding outcomes for potentially curative modalities including allogeneic hematopoietic stem cell transplantation (alloHCT) following NA therapy is critical while devising treatment sequences aimed at long-term disease control. In this multicenter, retrospective cohort study, we examined 65 patients with CLL who underwent alloHCT following exposure to ≥1 NA, including baseline disease and transplant characteristics, treatment preceding alloHCT, transplant outcomes, treatment following alloHCT, and survival outcomes. Univariable and multivariable analyses evaluated associations between pre-alloHCT factors and progression-free survival (PFS). Twenty-four-month PFS, overall survival (OS), nonrelapse mortality, and relapse incidence were 63%, 81%, 13%, and 27% among patients transplanted for CLL. Day +100 cumulative incidence of grade III-IV acute graft-vs-host disease (GVHD) was 24%; moderate-severe GVHD developed in 27%. Poor-risk disease characteristics, prior NA exposure, complete vs partial remission, and transplant characteristics were not independently associated with PFS. Hematopoietic cell transplantation-specific comorbidity index independently predicts PFS. PFS and OS were not impacted by having received NAs vs both NAs and chemoimmunotherapy, 1 vs ≥2 NAs, or ibrutinib vs venetoclax as the line of therapy immediately pre-alloHCT. AlloHCT remains a viable long-term disease control strategy that overcomes adverse CLL characteristics. Prior NAs do not appear to impact the safety of alloHCT, and survival outcomes are similar regardless of number of NAs received, prior chemoimmunotherapy exposure, or NA immediately preceding alloHCT. Decisions about proceeding to alloHCT should consider comorbidities and anticipated response to remaining therapeutic options.