Exposure to antibiotics with anaerobic activity before respiratory viral infection is associated with respiratory disease progression after hematopoietic cell transplant.

We examined associations between specific antibiotic exposures and progression to lower respiratory tract disease (LRTD) following individual respiratory viral infections (RVIs) after hematopoietic cell transplantation (HCT). We analyzed allogeneic HCT recipients of all ages with their first RVI during the first 100 days post-HCT. For the 21 days before RVI onset, we recorded any receipt of specific groups of antibiotics, and the cumulative sum of the number of antibiotics received for each day (antibiotic-days). We used Cox proportional hazards models to assess the relationship between antibiotic exposure and progression to LRTD. Among 469 patients with RVI, 124 progressed to LRTD. Compared to no antibiotics, use of antibiotics with broad anaerobic activity in the prior 21 days was associated with progression to LRTD after adjusting for age, virus type, hypoalbuminemia, neutropenia, steroid use, and monocytopenia (HR 2.2, 95% CI 1.1-4.1). Greater use of those antibiotics (≥7 antibiotic days) was also associated with LRTD in adjusted models (HR 2.2, 95% CI 1.1-4.3). Results were similar after adjusting for lymphopenia instead of monocytopenia. Antibiotic use is associated with LRTD after RVI across different viruses in HCT recipients. Prospective studies using anaerobe-sparing antibiotics should be explored to assess impact on LRTD in patients undergoing HCT.

Predictors of cytopenias after treatment with axicabtagene ciloleucel in patients with large B-cell lymphoma.

Cytopenias are important but less studied adverse events following chimeric antigen receptor-engineered T cell (CAR-T) therapy. In our analysis of patients with large cell lymphoma who received axicabtagene ciloleucel (axi-cel), we sought to determine the rate and risk factors of clinically significant short term cytopenias defined as grade ≥3 neutropenia, anemia, or thrombocytopenia, or treatment with growth factors or blood product transfusions between days 20-30 after axi-cel. Fifty-three pts received axi-cel during the study period and severe cytopenias were observed in 32 (60%) pts. Significant cytopenias were more common in non-responders (stable or progressive disease) vs. responders (partial or complete response) (100% vs. 70%; p = .01). In the multivariable model, platelet transfusion within a month before leukapheresis, number of red blood cell and platelet transfusions between leukapheresis to lymphodepletion, pre-lymphodepletion absolute neurophil count, pre-lymphodepletion lactate dehydrogenase, and number of dexamethasone treatments after CAR-T were significantly associated with severe cytopenias after axi-cel.

Impact of CD19 CAR T-cell product type on outcomes in relapsed or refractory aggressive B-NHL.

CD19-targeted chimeric antigen receptor-engineered (CD19 CAR) T cells are novel therapies showing great promise for patients with relapsed or refractory (R/R) aggressive B-cell non-Hodgkin lymphoma (B-NHL). Single-arm studies showed significant variations in outcomes across distinct CD19 CAR T-cell products. To estimate the independent impact of the CAR T-cell product type on outcomes, we retrospectively analyzed data from 129 patients with R/R aggressive B-NHL treated with cyclophosphamide and fludarabine lymphodepletion followed by either a commercially available CD19 CAR T-cell therapy (axicabtagene ciloleucel [axicel] or tisagenlecleucel [tisacel]), or the investigational product JCAR014 on a phase 1/2 clinical trial (NCT01865617). After adjustment for age, hematopoietic cell transplantation-specific comorbidity index, lactate dehydrogenase (LDH), largest lesion diameter, and absolute lymphocyte count (ALC), CAR T-cell product type remained associated with outcomes in multivariable models. JCAR014 was independently associated with lower cytokine release syndrome (CRS) severity compared with axicel (adjusted odds ratio [aOR], 0.19; 95% confidence interval [CI]; 0.08-0.46), with a trend toward lower CRS severity with tisacel compared with axicel (aOR, 0.47; 95% CI, 0.21-1.06; P = .07). Tisacel (aOR, 0.17; 95% CI, 0.06-0.48) and JCAR014 (aOR, 0.17; 95% CI, 0.06-0.47) were both associated with lower immune effector cell-associated neurotoxicity syndrome severity compared with axicel. Lower odds of complete response (CR) were predicted with tisacel and JCAR014 compared with axicel. Although sensitivity analyses using either positron emission tomography- or computed tomography-based response criteria also suggested higher efficacy of axicel over JCAR014, the impact of tisacel vs axicel became undetermined. Higher preleukapheresis LDH, largest lesion diameter, and lower ALC were independently associated with lower odds of CR. We conclude that CD19 CAR T-cell product type independently impacts toxicity and efficacy in R/R aggressive B-NHL patients.

Megadose 90Y-ibritumomab tiuxetan prior to allogeneic transplantation is effective for aggressive large B-cell lymphoma.

Allogeneic hematopoietic cell transplantation (allo-HCT) can be curative for relapsed or refractory B-cell lymphomas (BCLs), although outcomes are worse in aggressive disease, and most patients will still experience relapse. Radioimmunotherapy using 90Y-ibritumomab tiuxetan can induce disease control across lymphoma subtypes in a dose-dependent fashion. We hypothesized that megadoses of 90Y-ibritumomab tiuxetan with reduced-intensity conditioning could safely produce deeper remissions in aggressive BCL further maintained with the immunologic effect of allo-HCT. In this phase 2 study, CD20+ BCL patients received outpatient 90Y-ibritumomab tiuxetan (1.5 mCi/kg; maximum, 120 mCi), fludarabine, and then 2 Gy total body irradiation before HLA-matched allo-HCT. Twenty patients were enrolled after a median of 4.5 prior lines of therapy, including 14 with prior autologous transplant and 4 with prior anti-CD19 chimeric T-cellular therapy. A median 90Y-ibritumomab tiuxetan activity of 113.6 mCi (range, 71.2-129.2 mCi) was administered, delivering a median of 552 cGy to the liver (range, 499-2411 cGy). The estimated 1- and 5-year progression-free survival was 55% (95% confidence interval [CI], 31-73) and 50% (95% CI, 27-69) with a median progression-free survival of 1.57 years. The estimated 1- and 5-year overall survival was 80% (95% CI, 54-92) and 63% (95% CI, 38-81) with a median overall survival of 6.45 years. Sixteen patients (80%) experienced grade 3 or higher toxicities, although nonrelapse mortality was 10% at 1 year. No patients developed secondary acute myeloid leukemia/myelodysplastic syndrome. Megadose 90Y-ibritumomab tiuxetan, fludarabine, and low-dose total body irradiation followed by an HLA-matched allo-HCT was feasible, safe, and effective in treating aggressive BCL, exceeding the prespecified end point while producing nonhematologic toxicities comparable to those of standard reduced-intensity conditioning regimens.

Outcomes Associated With Thiotepa-Based Conditioning in Patients With Primary Central Nervous System Lymphoma After Autologous Hematopoietic Cell Transplant.

IMPORTANCE: Primary central nervous system lymphoma (PCNSL) requires induction and consolidation to achieve potential cure. High-dose therapy and autologous hematopoietic cell transplant (AHCT) is an accepted and effective consolidation strategy for PCNSL, but no consensus exists on the optimal conditioning regimens. OBJECTIVE: To assess the outcomes in patients with PCNSL undergoing AHCT with the 3 most commonly used conditioning regimens: thiotepa/busulfan/cyclophosphamide (TBC), thiotepa/carmustine (TT-BCNU), and carmustine/etoposide/cytarabine/melphalan (BEAM). DESIGN, SETTING, AND PARTICIPANTS: This observational cohort study used registry data from the Center for International Blood and Marrow Transplant Research registry. The Center is a working group of more than 380 transplantation centers worldwide that contributed detailed data on HCT to a statistical center at the Medical College of Wisconsin, Milwaukee. The participant data were from 603 adult patients with PCNSL who underwent AHCT as initial, or subsequent, consolidation between January 2010 and December 2018. Patients were excluded if they had a non-Hodgkin lymphoma subtype other than diffuse large B-cell lymphoma, systemic non-Hodgkin lymphoma, or HIV; received an uncommon conditioning regimen; or were not in partial remission or complete remission prior to AHCT. Statistical analysis was performed from July 5, 2020, to March 1, 2021. INTERVENTIONS: Patients received 1 of 3 conditioning regimens: TBC (n = 263), TT-BCNU (n = 275), and BEAM (n = 65). MAIN OUTCOMES AND MEASURES: The primary outcome was progression-free survival. Secondary outcomes included hematopoietic recovery, incidence of relapse, nonrelapse mortality, and overall survival. RESULTS: Of 603 patients, the mean age was 57 (range, 19-77) years and 318 (53%) were male. The 3-year adjusted progression-free survival rates were higher in the TBC cohort (75%) and TT-BCNU cohort (76%) compared with the BEAM cohort (58%) (P = .03) owing to a higher relapse risk in the BEAM cohort (hazard ratio [HR], 4.34; 95% CI, 2.45-7.70; P < .001). In a multivariable regression analysis, compared with the TBC cohort, patients who received TT-BCNU had a higher relapse risk (HR, 1.79; 95% CI, 1.07-2.98; P = .03), lower risk of nonrelapse mortality (NRM) (HR, 0.50; 95% CI, 0.29-0.87; P = .01), and similar risk of all-cause mortality more than 6 months after HCT (HR, 1.54; 95% CI, 0.93-2.55; P = .10). Age of 60 years or older, Karnofsky performance status less than 90, and an HCT-comorbidity index greater than or equal to 3 were associated with lower rates of survival across all 3 cohorts. Subgroup analyses demonstrated that patients aged 60 years and older had considerably higher NRM with TBC. CONCLUSIONS AND RELEVANCE: In this cohort study, thiotepa-based conditioning regimen was associated with higher rates of survival compared with BEAM, despite higher rates of early toxic effects and NRM; these findings may assist clinicians in choosing between TBC or TT-BCNU based on patient and disease characteristics.

Yttrium-90 Anti-CD45 Immunotherapy Followed by Autologous Hematopoietic Cell Transplantation for Relapsed or Refractory Lymphoma.

Autologous hematopoietic cell transplantation (AHCT) is a standard of care for several subtypes of high-risk lymphoma, but durable remissions are not achieved in the majority of patients. Intensified conditioning using CD45-targeted antibody-radionuclide conjugate (ARC) preceding AHCT may improve outcomes in lymphoma by permitting the delivery of curative doses of radiation to disease sites while minimizing toxicity. We performed sequential phase I trials of escalating doses of yttrium-90 (90Y)-labeled anti-CD45 antibody with or without BEAM (carmustine, etoposide, cytarabine, melphalan) chemotherapy followed by AHCT in adults with relapsed/refractory or high-risk B cell non-Hodgkin lymphoma (NHL), T cell NHL (T-NHL), or Hodgkin lymphoma (HL). Twenty-one patients were enrolled (16 NHL, 4 HL, 1 T-NHL). Nineteen patients received BEAM concurrently. No dose-limiting toxicities were observed; therefore, the maximum tolerated dose is estimated to be ≥34 Gy to the liver. Nonhematologic toxicities and engraftment kinetics were similar to standard myeloablative AHCT. Late myeloid malignancies and 100-day nonrelapse deaths were not observed. At a median follow-up of 5 years, the estimates of progression-free and overall survival of 19 patients were 37% and 68%, respectively. Two patients did not receive BEAM; one had stable disease and the other progressive disease post-transplant. The combination of 90Y-anti-CD45 with BEAM and AHCT was feasible and tolerable in patients with relapsed and refractory lymphoma. The use of anti-CD45 ARC as an adjunct to hematopoietic cell transplantation regimens or in combination with novel therapies/immunotherapies should be further explored based on these and other data.

A phase II trial evaluating the efficacy of high-dose Radioiodinated Tositumomab (Anti-CD20) antibody, etoposide and cyclophosphamide followed by autologous transplantation, for high-risk relapsed or refractory non-hodgkin lymphoma.

Radiation is the most effective treatment for localized lymphoma, but treatment of multifocal disease is limited by toxicity. Radioimmunotherapy (RIT) delivers tumoricidal radiation to multifocal sites, further augmenting response by dose-escalation. This phase II trial evaluated high-dose RIT and chemotherapy prior to autologous stem-cell transplant (ASCT) for high-risk, relapsed or refractory (R/R) B-cell non-Hodgkin lymphoma (NHL). The primary endpoint was progression free survival (PFS). Secondary endpoints were overall survival (OS), toxicity, and tolerability. Patients age < 60 years with R/R NHL expressing CD20 were eligible. Mantle cell lymphoma (MCL) patients could proceed to transplant in first remission. Patients received I-131-tositumomab delivered at ≤25Gy to critical normal organs, followed by etoposide, cyclophosphamide and ASCT. A group of 107 patients were treated including aggressive lymphoma (N = 29), indolent lymphoma (N = 45), and MCL (N = 33). After a median follow-up of 10.1 years, the 10-year PFS for the aggressive, indolent, and MCL groups were 62%, 64%, 43% respectively. The 10-year OS for the aggressive, indolent, and MCL groups were 61%, 71%, 48% respectively. Toxicities were similar to standard conditioning regimens and non-relapse mortality at 100 days was 2.8%. Late myeloid malignancies were seen in 6% of patients. High-dose I-131-tositumomab, etoposide and cyclophosphamide followed by ASCT appeared feasible, safe, and effective in treating NHL, with estimated PFS at 10-years of 43%-64%. In light of novel cellular therapies for R/R NHL, high-dose RIT-containing regimens yield comparable efficacy and safety and could be prospectively compared.

Higher Total Body Irradiation Dose Intensity in Fludarabine/TBI-Based Reduced-Intensity Conditioning Regimen Is Associated with Inferior Survival in Non-Hodgkin Lymphoma Patients Undergoing Allogeneic Transplantation.

Disease relapse is the most common cause of therapy failure in patients with non-Hodgkin lymphoma (NHL) undergoing reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (allo-HCT). It is not known whether or not increasing total body irradiation (TBI) dose from 2 to 4 Gy in a RIC platform can provide improved disease control without increasing nonrelapse mortality (NRM). Using the Center for International Blood & Marrow Transplant Research (CIBMTR) database, we evaluated the outcomes of patients with NHL receiving RIC allo-HCT with either fludarabine (Flu)/2-Gy TBI versus Flu/4-Gy TBI. In the CIBMTR registry, 413 adult patients with NHL underwent a first allo-HCT using either a matched related or unrelated donor between 2008 and 2017, using a RIC regimen with either Flu/2-Gy TBI (n = 349) or Flu/4-Gy TBI (n = 64). The primary endpoint was overall survival (OS). Secondary endpoints included acute (a) and chronic (c) graft-versus-host disease (GVHD), NRM, relapse/progression, and progression-free survival (PFS). At baseline, the Flu/2-Gy TBI cohort had significantly fewer patients with Karnofsky performance status ≥90 and significantly more patients had a higher HCT-comorbidity index. On multivariate analysis, the 2 conditioning cohorts were not significantly different in terms of risk of grade 3 to 4 aGVHD or cGVHD. Compared to Flu/2-Gy TBI, the Flu/4-Gy TBI conditioning was associated with a significantly higher risk of NRM (hazard ratio [HR], 1.79; 95% confidence interval [CI], 1.11 to 2.89; P = .02) and inferior OS (HR, 1.51; 95% CI, 1.03 to 2.23, P = .03). No significant differences were seen in the risk of relapse/progression (HR, 0.78; 95% CI, 0.47 to 1.29, P = .33) or PFS (HR, 1.09; 95% CI, 0.78 to 1.54, P = .61) between the 2 regimens. Comparing Flu/2-Gy TBI versus Flu/4-Gy TBI cohorts, the 5-year adjusted outcomes were NRM (28% versus 47%; P = .005), relapse/progression (35% versus 29%; P = .28), PFS (37% versus 24%; P = .03), and OS (51% versus 31%; P = .001), respectively. Relapse was the most common cause of death in both cohorts. In patients with NHL undergoing Flu/TB I-based conditioning, augmenting TBI dose from 2 to 4 Gy is associated with higher NRM and inferior OS, without any significant benefit in terms of disease control. The optimal dose is 2-Gy in the RIC Flu/TBI platform for lymphomas.

Where does transplant fit in the age of targeted therapies?

The role of hematopoietic cell transplantation (HCT) for indolent lymphoma has evolved over the last 5 years with the availability of novel low-toxicity therapies and a better understanding of the prognosis of these entities. However, despite numerous treatment options for patients with follicular lymphoma, none are thought to be curative, and many require ongoing therapy with chronic toxicity. Historical trials indicate that autologous HCT as initial consolidation leads to improved progression-free survival, but not overall survival (OS) and, thus, is not typically recommended. However, autologous HCT for chemosensitive relapse can be carried out with ∼1% early mortality risk, affording disease control lasting a median of 3 to 5 years and the potential to improve OS. These results may compare favorably in efficacy, toxicity, and cost vs multiple sequential novel therapies with shorter durations of benefit. Recent data indicate that autologous HCT in follicular lymphoma patients with early initial progression will result in more than one third being alive and without relapse at 5 years, leading to improved OS when used within a year of the first recurrence. Unlike other available therapies, allogeneic HCT has the potential to cure up to one half of those transplanted with indolent B-cell non-Hodgkin lymphoma, although the risks need to be recognized and appropriate patient and donor selection is critical to ensure the best outcomes. HCT continues to remain a viable option in the current era of multiple targeted agents.

Limited Utility of Outpatient Surveillance Blood Cultures in Hematopoietic Cell Transplant Recipients on High-Dose Steroids for Treatment of Acute Graft-versus-Host-Disease.

Steroids used to treat acute graft-versus-host-disease (GVHD) are believed to blunt clinical symptoms of infection. We aimed to assess the value of weekly surveillance blood cultures (SBCs) drawn in an outpatient setting from hematopoietic cell transplant (HCT) patients receiving high-dose steroids. We hypothesized that most positive outpatient surveillance cultures would be low-pathogenicity, gram-positive organisms and would lead to excess vancomycin therapy. We conducted a retrospective review of blood cultures collected from a cohort of adult HCT patients enrolled in a clinical trial of acute GVHD therapy with high-dose steroids (prednisone-equivalent doses ≥ .5 mg/kg/day) between April 2009 and May 2013. SBCs were defined as those collected weekly from central venous catheters in the outpatient setting while patients were receiving high-dose steroids. Cultures obtained as part of a symptom workup or as follow-up for documented bacteremia were excluded. Clinical data were collected using center databases supplemented by medical record review. One hundred twenty-seven HCT recipients were eligible for inclusion in the study. A total of 1015 SBCs were obtained, with a median of 8 cultures (interquartile range, 5 to 10) per patient. Forty-two organisms were isolated from 36 of 1015 cultures (3.5%) in 30 unique patients, or 1 positive culture per 28 blood cultures drawn. The most frequently detected organisms were coagulase-negative Staphylococci (25/1015 [2.5%]). Gram-negative organisms were rare (4/1015 [.4%]. Antibiotics were administered to most patients with positive surveillance cultures (33/36 [92%]). Six were admitted to the hospital for treatment; none needed intensive care or died from their bacteremia. Vancomycin was the most frequently administered antibiotic, comprising 256 of 376 total days (68%) of antibiotic received by the cohort with a median duration of 10 days ((interquartile range, 7 to 14). Weekly outpatient SBCs obtained from asymptomatic patients on high-dose glucocorticoids for treatment of acute GVHD after allogeneic HCT were infrequently positive, and most organisms were low-pathogenicity organisms. SBCs also led to excess antibiotic exposure and costs, suggesting benefits of such ambulatory screening may be of limited value in this setting.

Translating anti-CD19 CAR T-cell therapy into clinical practice for relapsed/refractory diffuse large B-cell lymphoma.

Chimeric antigen receptor T cells demonstrate efficacy in B-cell malignancies, leading to US Food and Drug Administration approval of axicabtagene ciloleucel (October 2017) and tisagenlecleucel (May 2018) for large B-cell lymphomas after 2 prior lines of therapy. Durable remissions are seen in 30% to 40% of study-treated patients, but toxicities of cytokine release syndrome and neurotoxicity require administration in specialized centers. This article reviews data of current diffuse large B-cell lymphoma management, focusing on axicabtagene ciloleucel, tisagenlecleucel, and lisocabtagene maraleucel.