Bansal, Radhika

e19556 Background: CD19 chimeric antigen receptor T cell therapy possesses unique side effects including cytokine release syndrome (CRS) and immune effector cell associated neurotoxicity syndrome (ICANS). Age is a major risk factor for ICANS. However, whether ICANS in older patients is different compared to younger patients is unknown. Herein, we report clinical course, outcomes and risk factors for ICANS in older patients with large B cell lymphoma (LBCL) treated with axicabtagene ciloleucel (axi-cel). Methods: We comprehensively reviewed detailed clinical courses of ICANS in 78 adult patients with LBCL treated with axi-cel between June 2016 and October 2020. Incidence, manifestation, risk factors, treatment, and outcomes of ICANS were compared between patients age ≥60 (n=32) and <60 (n=46) years old. Results: Baseline characteristics were comparable between older and younger patients except higher proportion of high international prognostic index and underlying cerebral microvascular disease in older patients. ICANS was observed in 16 patients in the older and 24 patients in the younger age group, with a 30-day incidence of 52% and 50%, respectively. Median time to CRS and ICANS were similar between 2 age groups. The most common initial neurological findings included aphasia, dysgraphia and encephalopathy in both age groups. Table summarizes the characteristics, clinical course and interventions of ICANS in older and younger patients. In Cox regression model, the presence of CRS was the only factor associated with ICANS in both age groups. Age, history of central nervous system involvement and cerebral microvascular disease were not associated with ICANS. Importantly, all patients had complete resolution of ICANS. No elderly patients in our cohort experienced seizure as a manifestation of ICANS. Conclusions: In our study, older age was not a risk factor for ICANS. CRS was the only factor associated with ICANS in both younger and older patients. Incidence, clinical course and neurological outcomes of ICANS in older patients treated with axi-cel were comparable to younger patients. [Table: see text]

e19554 Background: Obesity is associated with a pro-inflammatory state and immune dysregulation. Retrospective studies indicate that obesity could affect toxicities and outcomes after immunotherapies including checkpoint inhibitors and allogeneic stem cell transplant. Currently, there are no data specifically on outcomes for obese patients who receive chimeric antigen receptor T (CAR-T) cells. We described the clinical outcome in obese patients with large B cell lymphoma (LBCL) who received axicabtagene ciloleucel (axi-cel). Methods: We analyzed the effect of body weight (BW) and body mass index (BMI) on toxicities and outcomes of 78 adults with LBCL who received axi-cel between June 2016 and October 2020 at Mayo Clinic. Obesity was defined as having BMI of 30 or higher. Results: Of 78 patients, 22 (28%) and 19 (24%) were classified as overweight (BMI 25-29.99 kg/m2) and obese (BMI ≥30 kg/m2), respectively. Baseline characteristics were not statistically significantly different between non-obese and obese patients. The median delivered dose of fludarabine was similar between non-obese and obese patients (89 [0-105] vs 88 [56-94] mg/m2, P=0.32) whereas the median delivered dose of cyclophosphamide was lower in non-obese patients (1503 [1077-1525] vs 1512 [1021-1660] mg/m2, P=0.01). The 30-days cumulative incidence of CRS and ICANS were similar between non-obese and obese patients. BW and BMI were not associated with CRS or ICANS. The overall response rate was 66% (CR 47%) and 68% (CR 53%) in non-obese and obese group, respectively ( P=0.83). The 1-year event free survival (EFS) and overall survival (OS) was 34.6% and 64.5%, neither were different between non-obese and obese patients (EFS 35.8% vs. 30.7%, P=0.60; OS 59.4% vs. 83.9%, P=0.18). The 1-year cumulative incidence of relapse and non-relapse mortality was comparable (60.8% vs. 69.0%, P=0.40 and 3.4% vs. 0%, P=0.42). In the Cox proportional hazards model, higher dose of fludarabine, but not cyclophosphamide, was associated with better EFS and OS; however, neither obesity nor BW were associated with toxicities and outcomes. Conclusions: In our study, Obesity was not associated with risk of toxicities or adverse survival outcomes. The effect of obesity on the pattern of LD chemotherapy dosing including toxicities and outcomes after CAR-T warrants further exploration. [Table: see text]

7558 Background: A low absolute lymphocyte to monocyte ratio (ALC/AMC) has been found to predict decreased survival in lymphoma patients receiving chemotherapy and stem cell transplant. We report its clinical significance and additional cellular phenotype changes in patients receiving chimeric antigen receptor T-cell (CART) therapy. Methods: Records were reviewed for patients (pts) who received axicabtagene ciloleucel between 6/2016 and 12/2020. Receiver operator curve was generated using nominal logistic regression to predict CR as best response. Survivals were calculated using Kaplan- Meier method. Blood immune phenotype were assayed by multiparametric flow. Principle component analysis (PCA) was performed using ClusterVis. Results: Low ALC/AMC (≤0.8) prior to lymphodepletion (LD) chemotherapy on day -5 was associated with lower CR rate (AUC=0.68, Table). Our cohort of 81 pts had similar baseline characteristics except that noted in Table. Low ALC/AMC ratio is associated with shorter EFS and OS (EFS: 2.6 vs. 6.4 months, P<0.0001; OS: 5.3 months vs. not reached, P=0.0006), respectively. Prognostic association remained significant in multivariate analysis including ASCT, bridging therapy and CRP. Interestingly, compared to the high ALC/AMC group, the low ALC/AMC group had decreased CD8 Tem, increased CD16+CCR2+ monocytes and increased monocytes’ producing IL12, IL-10, and IL-1β (n=26). Unsupervised PCA identified 3 clusters: 1. Low ALC/AMC, all non-CR; 2. High ALC/AMC, some non-CR; 3. High ALC/AMC, all CR. Compared to cluster 1 and 2, cluster 3 had increased CD4 Tnaive, CD8 Tcm and IL-17 producing CD4 T and NK cells. Conclusions: ALC/AMC is a clinically accessible test that is strongly associated with CAR-T response and survival. Immune characterization revealed that the biologic effect is not just associated with cell ratio. Increased inflammation has been found to negatively impact CAR-T response, with some cytokines known to be from the myeloid lineage. We show that CRP is elevated in the low ALC/AMC group with increased cytokine production by monocytes. In addition, presence of T cell subset and IL-17 producing cells, before LD, are associated with clinical response. Further investigation on optimizing host immunity may help improve clinical outcome with CAR-T.[Table: see text]

7555 Background: While CAR-T therapy is not myelo-ablative, patients with aggressive lymphoma treated with CD19 chimeric antigen receptor T cell therapy (CAR-T) are lymphodepleted and have prolonged B cell aplasia. The impact of CAR-T on immunologic protection from vaccine-preventable diseases (and thus the need to revaccinate) is not known. We report the vaccine titers of patients treated with axicabtagene ciloleucel (axi-cel) at Mayo Clinic. Methods: Retrospective chart review of adult lymphoma patients who received axi-cel from 9/2018 to 9/2020 for anti-viral and anti-bacterial titers prior to CAR-T infusion and at month 3 (MO3) post CAR-T. Results: Prior to CAR-T therapy, positive titer rate was highest for tetanus and lowest for Strep pneumoniae (Strep PNA) (Table). Similar trends were seen whether patients had stem cell transplant (ASCT) within 2 years of CAR-T (i.e. within immunization timeframe post ASCT) or not (Table). Compared to patients who had ASCT, those who did not had higher rate of positive titer for Strep PNA and lower rate for hepatitis B, Mumps, and VZV. The same trend for sero-positive rate were observed at MO3 post CAR-T. Patients with IgG<400 mg/dl received IVIG supplement for prophylaxis. Among the 23 patients who received IVIG, variable rate of conversion from negative to positive titers were seen for measles (1/2, 50%), mumps (2/3, 67%), rubella (2/3, 67%), varicella-zoster (VZV, 3/3, 100%), hepatitis A (6/6, 100%), hepatitis B (6/7, 86%) and Strep PNA (0/10, 0%). For patients who did not receive IVIG prophylaxis, there was one loss of seropositivity for Strep PNA (1/4, 25%). Conclusions: The presence of protective vaccine titers is variable for patients receiving CAR-T, regardless of recent ASCT. The loss of protective titers post CART was low. IVIG variably impacted vaccine titer status. Immunization remains important for patients with ASCT prior to CART, without completion of post ASCT immunization protocol. Further study is needed to inform the need for immunization and optimal timing post CART.[Table: see text]

7554 Background: Chimeric antigen receptor T-cell therapy (CAR-T) are commonly administered inpatient due to concern for early onset cytokine release syndrome (CRS), especially with axicabtagene ciloleucel (axi-cel). We report Mayo Clinic Rochester experience for hospital-based outpatient (HBO) management of patients (pts) receiving axi-cel and identify opportunities for improvement. HBO is closely integrated with inpatient practice and includes the same specialty trained clinical team. It is the first point of contact 24/7 for pts and triage evaluations. Lymphodepletion chemotherapy and CAR-T infusion is given on HBO followed by daily monitoring till day 8 and thereafter, as clinically needed until admission criteria is met. Methods: We retrospectively analyzed database of pts who received axi-cel between 1/2018 and 1/2021. After 06/2020, remote patient monitoring (RPM) tools were implemented to collect patient-reported neurologic symptoms and vital signs via bluetooth-enabled devices 4 times daily through month 1. Adverse data trends are addressed by the HBO team. Results: Among 72 recipients, 89% received their cells outpatient; 8% remained outpatient for the entire month. CRS and neurotoxicity incidence were comparable to those reported from CIBMTR. Median time to first admission was 2 days (Table). Use of bridging therapy, increased CRP and LDH were associated with early admission (≤3 days). Median time to tocilizumab, steroid, oxygen support, vasopressor was 4 days after admission. Half of HBO visits required intervention such as blood transfusions, IV medications through the first month. Nine pts had enrolled in RPM to date; with 8 having evaluable data. With 4 scheduled entries/day, a median of 1 entry/day was skipped and 2 entries/day were answered incompletely. An average of 57 additional unscheduled entries were generated per pt. Among a median of 373 (range 91-522) readings per pt over the first month, 4% (2%-20%) of the readings generated alerts. An average of 4 alerts were seen within 48 hours prior to admission. Data including additional subjects will be presented at ASCO meeting. Conclusions: We report a feasible outpatient care model for management of axi-cel recipients with safe outcomes. Clinical characteristics associated with more aggressive disease are associated with likelihood of early admission. Early RPM experience suggest use of digital tools could improve monitoring compliance and may predict evolution to symptoms requiring escalation of care.[Table: see text]

Background: Lytic bone lesions are one of the most common clinical characteristics of patients with multiple myeloma (MM) and identification of bone lesions help distinguish between patients with smoldering multiple MM and active MM. Given this, the most recent update of the diagnostic criteria for MM incorporates advanced imaging approaches for distinguishing between the two entities. Several small retrospective studies have compared conventional skeletal survey (SS) with whole-body low dose computed tomography (WBLDCT) scan or the CT portion of a positron emission tomography (PET) scan. Conducting prospective studies comparing these two modalities side by side is limited by the radiation exposure. We undertook this study to provide a comparison between these two imaging modalities in terms of their ability to recognize lytic bone lesions in patients with MM. Patients and methods: This was a retrospective study of consecutive patients with the diagnosis of MM treated at Mayo Cinic Hospital during 2004- 2018. Patients were included if they had a conventional skeletal survey no more than 3 months before MM diagnosis or any time after diagnosis and also had a WBLDCT or PET-CT within a 12-month period following the skeletal survey. We chose this approach since it is unlikely that a patient would have had both modalities done at the same time as part of standard of care (SOC). This approach was also facilitated by a gradual change in our SOC for skeletal imaging from conventional skeletal survey to WBLDCT. To measure the robustness of our findings, we performed a sensitivity analysis in patients who had the exam ≤6 months apart. Proportions were compared using a chi-square test and survival estimates were calculated using the Kaplan- Meier methodology and compared using log rank test. Results: The overall study cohort had 1040 patients, median age was 62 years at diagnosis (range, 24-94), 61% were male and 39% were female. The median time to the skeletal survey was 8 months from diagnosis (range, 0-160) and the median time to WBLDCT or PET-CT from SS was 2 months (0-12). A PET-CT was available in 789 (76%) of patients and WBLDCT in 251 (24%) of patients. Among the 300 patients with no lesions identified by SS, 188 (63%) had lytic lesions identified by CT, while in 60/740 (8%) patients with a positive SS did not have lytic lesions observed on the CT (p&lt;0.0001). Overall, CT identified lytic lesions in 868 (84%) patients compared with 740 (71%) patients with lytic lesions seen on SS. Although the proportion of lytic lesions was slightly higher with PET compared to WBLDCT, the analysis did not reach statistical significance (65% vs. 56%; p = 0.17; Table 1a). After restricting the analysis to those with ≤6 months gap between low dose CT and SS (n=737), the result did not change (Table 1b). Further examination demonstrated that presence of lytic lesions by SS had no impact on OS from diagnosis, detection of lesions on the CT exam was associated with an inferior survival (112 vs. 81 months, p&lt;0.0001). (Figure 1) Conclusion: Skeletal survey has been the screening technique of choice for evaluation of bone involvement in MM for decades. However, CT based approaches have higher sensitivity with lytic lesions identified in a higher proportion of patients. The prognostic value of lytic disease is evident with CT based detection, again suggesting that this provides a more accurate estimate of the skeletal disease burden. Low dose CT rather than conventional radiographs should be the modality of choice for monitoring disease-progression and diagnosing active multiple myeloma. Disclosures Kapoor: Cellectar: Consultancy; Janssen: Research Funding; Sanofi: Consultancy, Research Funding; Amgen: Research Funding; Takeda: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Celgene: Honoraria. Gertz:Abbvie: Other; Celgene: Other; Physicians Education Resource: Other: personal fee; Medscape: Other: personal fee, Speakers Bureau; Janssen: Other: personal fee; Spectrum: Other: personal fee, Research Funding; Johnson and Johnson: Speakers Bureau; Teva: Speakers Bureau; Annexon: Other: personal fee; Research to Practice: Other; Sanofi: Other; Proclara: Other; DAVA oncology: Speakers Bureau; Springer Publishing: Patents & Royalties; Appellis: Other: personal fee; Amgen: Other: personal fee; Prothena: Other: personal fee; Aurora Bio: Other; Alnylam: Other: personal fee; Ionis/Akcea: Other: personal fee. Dispenzieri:Takeda: Research Funding; Pfizer: Research Funding; Janssen: Research Funding; Intellia: Research Funding; Alnylam: Research Funding; Celgene: Research Funding. Dingli:Alexion: Consultancy; Janssen: Consultancy; Sanofi-Genzyme: Consultancy; Millenium: Consultancy; Bristol Myers Squibb: Research Funding; Rigel: Consultancy; Apellis: Consultancy; Karyopharm Therapeutics: Research Funding. Lin:Merck: Research Funding; Takeda: Research Funding; Legend BioTech: Consultancy; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Vineti: Consultancy; Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gamida Cells: Consultancy. Kumar:Dr. Reddy's Laboratories: Honoraria; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Sanofi: Research Funding; Novartis: Research Funding; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Merck: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Carsgen: Other, Research Funding; Cellectar: Other; MedImmune: Research Funding; Karyopharm: Consultancy; BMS: Consultancy, Research Funding; Tenebio: Other, Research Funding; Genecentrix: Consultancy; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Kite Pharma: Consultancy, Research Funding.