Furqan, Fateeha

7023 Background: Axi-cel is an autologous chimeric antigen receptor (CAR) T-cell therapy approved for adults with R/R LBCL after ≥ 1 prior line of therapy (LoT). Adverse events, such as cytokine release syndrome (CRS) and neurologic events (NEs), may deter centers from using axi-cel in an outpatient (OPT) setting, though individual centers have observed comparable safety and effectiveness in OPT and inpatient (IPT) care (Furqan et al. Blood Adv . 2024). Here, we present safety and effectiveness outcomes of axi-cel by intention to treat in OPT and IPT settings in a multicenter real-world dataset. Methods: Pts receiving axi-cel for R/R LBCL in the US from 01/2021-07/2023 with data in the Center for International Blood and Marrow Transplant Research (CIBMTR) registry were eligible for analysis. Pts with prior allogeneic transplant or unknown intended care setting were excluded. Of potential pts, 119 OPT pts were identified from 29 centers where an increasing trend was seen (9.6% of pts in 2021 were OPT, 13.5% in 2022, 22.8% in 2023). Pts were matched to 119 IPT pts by propensity score matching on age, sex, comorbidities, lactate dehydrogenase (LDH), bulky disease, prior LoT, chemosensitivity, and infusion year (see table). Results: OPT pts had median age of 63 y (25% ≥ 70), 66% were male, and 67% had ≥ 1 comorbidity. Half (50%) had elevated LDH and 73% had 1 prior LoT. Bulky disease was reported in 3%, and 60% had chemo-resistant disease. Outcomes were analyzed at median follow-up of 12 mo. Safety and effectiveness outcomes were similar between OPT and IPT pts (see table). In multivariate analyses, no differences were found between intended care setting and CRS (odds ratio [OR] 1.09 [95% CI 0.51-2.35]), CRS Gr ≥ 3 (OR 0.57 [0.12-2.60]), NEs (OR 1.14 [0.65-2.00]), or NEs Gr ≥ 3 (OR 0.98 [0.48-2.00]). Among OPT pts, 24% and 50% did not require hospital admission within 30 d and 3 d, respectively. In pts aged ≥ 70 y, only any Gr NEs were higher in the OPT group. Conclusions: After matching on key factors that may be used to select pts for OPT infusion, outcomes were comparable between intended care settings. These findings corroborate prior results and support the consideration of axi-cel in appropriate OPT care settings. Outcomes between matched pts with R/R LBCL receiving axi-cel intended for OPT or IPT. OPT (n=119) a IPT (n=119) a CRS any Gr / Gr ≥ 3 83 (75−89) / 3 (<1−7) 83 (74−89) / 4 (1−10) NE any Gr / Gr ≥ 3 47 (38−57) / 19 (12−27) 46 (37−56) / 21 (14−30) Overall / complete response rates 78 (69−85) / 68 (59−76) 76 (67−83) / 62 (52-70) Duration of response @ 12 mo 64 (52−74) 69 (58−78) Progression-free survival @ 12 mo 53 (43−62) 53 (43−61) Overall survival @ 12 mo 71 (61−78) 72 (62−79) Non-relapse mortality @ 12 mo 6 (2−11) 4 (1−8) Hospital admission within 30 days of infusion / median duration (range), d 76 (67−83) / 9 (2−53) Not Applicable a Percent (95% CI) unless otherwise specified.

ABSTRACTAlthough recent studies have demonstrated the efficacy of chimeric antigen receptor T‐cell (CAR‐T) therapy in relapsed large B‐cell lymphoma (LBCL) with MYC rearrangement (R‐MYC), the data comparing CAR‐T to autologous hematopoietic cell transplant (auto‐HCT) in such patients who achieve a complete or partial response (CR/PR) after salvage therapies are limited. We compared the clinical outcomes of patients with R‐MYC LBCL (including double and triple hit lymphomas) who underwent CAR‐T or auto‐HCT after achieving a CR/PR with salvage therapies using the Center for International Blood & Marrow Transplant Research registry. Among the 252 patients (auto‐HCT = 98, CAR‐T = 154), relative to auto‐HCT, CAR‐T was associated with significantly lower overall survival (OS) (Hazard Ratio [HR] 2.09, 95% CI 1.38–3.15, p < 0.001) on multivariate analysis. There were no differences in progression‐free survival (PFS) (HR 1.21, 95% CI 0.81–1.8 p = 0.36), risk of relapse (HR 1.1, 95% CI 0.71–1.69 p = 0.68), nonrelapse mortality (NRM) (HR 1.74, 95% CI 0.64–4.7 p = 0.28) while the post‐relapse survival was longer in auto‐HCT relative to CAR‐T (HR 1.93, 95% CI 1.21–3.06 p = 0.01). On propensity score matched analysis accounting for differences in characteristics across the two cohorts, we detected no significant differences in OS (HR 1.72, 95% CI 0.92–3.21 p = 0.09), PFS (HR 1.04, 95% CI 0.64–1.68 p = 0.88), NRM (HR 1.22, 95% CI 0.35–4.2 p = 0.76), relapse (HR = 0.93, 95% CI 0.54–1.6 p = 0.8) and post‐relapse survival (HR 2.25, 95% CI 0.98–5.17, p = 0.06). These data, although retrospective, support consideration for auto‐HCT in patients with R‐MYC LBCL who achieve a CR/PR after salvage therapies, particularly in regions with no or limited access to CAR‐T.

Summary The prognosis of relapsed/refractory (R/R) anaplastic large cell lymphoma (ALCL) is poor. Large studies evaluating outcomes of allogeneic haematopoietic cell transplantation (allo‐HCT) in systemic R/R ALCL are not available. Using the Center for International Blood and Marrow Transplant Research (CIBMTR) database, we evaluated outcomes of 182 adults (aged ≥18 years) with R/R ALCL undergoing allo‐HCT between 2008 and 2019. Non‐relapse mortality (NRM), disease relapse/progression (REL), progression‐free survival (PFS), and overall survival (OS) were modelled using Cox proportional hazards models. The median (range) follow‐up of survivors was 62 (3–148) months. The 1‐year NRM was 18%. The 5‐year REL, PFS and OS were 32%, 41% and 56% respectively. On multivariable regression analysis African American race (hazard ratio [HR] 2.7, 95% confidence interval [CI] 1.6–4.8; p < 0.001) and refractory disease at allo‐HCT (HR 3.2, 95% CI 1.6–6.2; p < 0.001) were predictive of inferior OS. Similarly, African‐American race (HR 2.1, 95% CI 1.3–3.4; p = 0.003), other minority race (HR 2.5, 95% CI 1.2–5.3; p = 0.02) and refractory disease (HR 2.2, 95% CI 1.2–4.3; p = 0.01) were predictive of inferior PFS. These data, demonstrate that allo‐HCT can result in durable disease control in a sizable proportion of patients with R/R ALCL. Refractory disease and racial minority status predicted inferior allo‐HCT outcomes. Whether the inferior outcomes of racial minorities with R/R ALCL after allo‐HCT are driven by differences in disease biology or disparities in post allo‐HCT care, or both, requires further investigation.

Introduction: Fecal microbiota transplant (FMT) has been shown to be an effective treatment for recurrent Clostridioides difficile infection (CDI). Immunosuppression is one of the risk factors for CDI. However, most of the trials evaluating efficacy of FMT have excluded immunocompromised patients. Patients with hematological cancers represent a major class of immunocompromised patients. Hence, we performed a meta-analysis to evaluate the efficacy of FMT in patients with hematological cancer for the treatment of recurrent CDI. Methods: A systematic search of Medline, Embase, and Web of Science was performed from January 2000 up to December 2018. Articles included for meta-analysis were case series and case reports that assessed efficacy of FMT in hematological cancer patients were included. Study quality was assessed using the Newcastle-Ottawa scale. The main outcomes were pooled proportions of patients achieving cure after first FMT. The cure rate was defined as resolution of diarrhea without any recurrence. Results: 10 studies (5 case series and 5 case reports) were included in the analysis, making up 29 patients who underwent 38 total FMT procedures. The follow up period ranged from 1- 14 months. Of the included patients, 17 had leukemia, 10 had lymphoma and 2 patients had multiple myeloma and myelodysplastic syndrome each. 7 of these patients had undergone hematopoietic stem cell transplant. The pooled cure rate was 82% [confidence interval (CI) 67-94%] after 1 FMT with no heterogeneity (I2=0%). Minor publication bias was seen on visual inspection of funnel plot. FMT was generally well tolerated by these patients. No serious side effects were reported in any study. One of the studies reported death due to cardiac arrest 5 days after FMT which was thought to be unrelated to the procedure. Mild side effects including mild abdominal pain, transient diarrhea, fecal urgency, constipation and nausea were reported in 5 patients. Conclusion: Based on limited observational data, FMT seems to be an effective and safe modality for management of recurrent CDI in patients with hematological cancers. However, further prospective clinical trials are needed to establish its safety as a first line therapy for recurrent CDI in this population. Figure Disclosures Jamshed: Takeda Pharmaceutical: Honoraria. Khanna:Rebiotix, Inc: Research Funding; Probio Tech, LLC: Consultancy; Facile Therapeutics: Consultancy; Shire, Plc: Consultancy.

Abstract Introduction: C. difficile infection (CDI) is a common nosocomial infection. Immune suppression is thought to be a major risk factor for CDI. Hematopoietic stem cell transplant (HSCT) recipients represent a major subgroup of immunologically vulnerable patients. It is unclear if these patients have novel risk factors for CDI development. We, therefore, performed a systematic review and meta-analysis to evaluate the predictors of CDI in HSCT recipients. Methods: A systematic search of Medline, Embase, and Web of Science was performed from January 2000 up to June 2018. All studies that assessed risk factors associated with CDI development in HSCT recipients were eligible for inclusion. Data on clinical characteristics and risk factors associated with CDI development were collected. Study quality was assessed using the Newcastle-Ottawa scale. Meta-analyses were performed using random effects models and pooled odds ratios with 95% confidence interval (CI) for risk factors reported in ≥ 2 studies were calculated. Results: Overall, 17 studies, including 6328 HSCT patients were included. Of those 874 patients developed CDI. The rate of CDI development in these patients was 13.81% with a follow up ranging from 1- 36 months. A total of 34 different risk factors were studied, of which 20 were identified in ≥ 2 studies. Our analysis showed that cephalosporin use (Odds ratio [OR] 2.21, 95% confidence interval [CI] 1.26-3.87), cord blood transplant (OR 1.36, 95% CI 1.01-1.83), graft versus host disease (GVHD) (OR 1.63, 95% CI 1.07-2.48) & prior hospitalization within 90 days of HSCT (OR 1.85, 95% CI 1.21-2.83) were associated with statistically significant increased risk of CDI in HSCT patients (Figure 1). On the other hand, many characteristics of HSCT patients including age, diabetes, lung disease, fluoroquinolones, proton pump inhibitors, rituximab, mucositis, myeloablative therapy, melphalan use before BMT, total body irradiation, growth factor use during admission, neutropenia, autologous vs allogenic transplant and use of matched related donor were not associated with increased risk of CDI. Conclusion: HSCT recipients are at an increased risk of CDI compared to general population. In addition to the common risk factors like cephalosporin use and prior hospitalization, these patients have novel characteristics including presence of GVHD and cord blood transplant that puts them at a higher risk of CDI. HSCT patients with these risk factors may warrant a closer surveillance for early detection and treatment of CDI. Table 1. Table 1. Disclosures No relevant conflicts of interest to declare.

INTRODUCTION: Graft versus Host disease (GVHD) is a major cause of mortality and morbidity in allogenic hematopoietic stem cell transplant recipients (HSCT). Gut microbiome dysbiosis secondary to conditioning regimens (which include antibiotics) in HSCT, appears to play a significant role in gut GVHD development through its interaction with the immune system. Fecal Microbiota Transplantation (FMT) has been explored for the treatment of gut GVHD owing to its ability to restore the gut microbiome. We performed a systemic review and meta-analysis to review the efficacy and safety of FMT for gut GVHD. METHODS: A systematic search of Medline, Embase, and Web of Science was performed from January 2000 through May 2019. Articles included for meta-analysis were observational studies which included patients with steroid-dependent or resistant gut GVHD after HSCT who underwent one or more FMTs. The main outcomes were pooled proportions of patients achieving response defined as a decrease in gastrointestinal symptoms including stool volume and frequency or reduction of steroid or immunosuppressant dose. Partial response was defined as a decrease of gastrointestinal symptoms followed by recurrence of symptoms. RESULTS: Five studies (4 prospective single arm pilot studies and 1 retrospective case series) including 37 patients were included with follow up ranging from 1–13 months. Three studies used naso-duodenal route, one used oral capsules and one used colonoscopy for FMT. Median number of FMTs per study was 2 (range, 1–6). Unrelated donors were used in 4 studies. A total of 23/37 patients achieved complete response with a pooled proportion of 61.0% (95% confidence interval [CI] 46–76.0), with no heterogeneity (I 2 = 0%). Partial response was seen in 3 patients. Hence, the overall response rate was 74.0% (95% CI 49–93, I 2 53%). FMT was generally well tolerated. No treatment-related mortality was reported by any study. Serious adverse events were reported in 3 patients (hypoxia in one patient and bacteremia in two patients) but were not directly attributed to FMT. CONCLUSION: FMT is a promising modality for management of gut GVHD and appears to be safe as a salvage therapy based on the current limited data. Ongoing placebo-controlled prospective clinical trials will help to further establish its safety and efficacy.

e18244 Background: Clostridioides difficile infection (CDI) has higher incidence in cancer patients. To characterize the extent of CDI burden among hematologic cancer patients, we used the National Hospital Discharge Survey (NHDS) to report the incidence and outcomes of CDI. Methods: NHDS data from 2001-2010 were analyzed using diagnosis codes to identify patients with hematologic cancers and CDI. Demographics and discharge information were compared amongst hematologic cancer patients with and without CDI. Logistic regression models were runto estimate the impact of CDI on hematologic cancer patient outcomes, using STATA 12.0. Results: During the years 2001-2010, about 3.7 million patients (weighted data) were discharged with hematologic cancer. Among them, the incidence of CDI was 2.3%. Hematologic cancer patients with CDI were younger (mean age 66 vs 68 years), more likely to be men (66% vs 64.5%), to be of white race (68.1% vs 67.7%) and to have emergent admissions (73% vs 69%), all p values < 0.001. CDI incidence in these patients showed a steeper increase than non-cancer patients, with highest incidence in 2008-2009. Hematologic cancer patients with CDI had a longer mean Length of stay (16.9 vs 7.1 days; adjusted odds ratio (aOR) 9.5, 95% CI 9.4-9.6), all cause hospital mortality (11.3% vs 6.3%; aOR 1.92, 95% CI 1.88-1.97) and discharge to a care facility (28.4% vs 18.8%; aOR 2.06, 95% CI 2.02-2.10) compared to non-CDI cancer patients. Conclusions: CDI incidence is higher in patients with hematologic malignancy. They also have worse outcomes including overall mortality, longer hospitalizations and discharge to healthcare facility. These patients warrant closer screening and prompt treatment of CDI as they are at greater risk of unfavorable outcomes. [Table: see text]