Incidence Of Cytokine Release Syndrome Research Articles

B7-H3-Targeting Chimeric Antigen Receptors Epstein Barr Virus Specific T Cells Provides a Tumor Agnostic Off-The-Shelf Therapy Against B7-H3 Positive Solid Tumors.

Encouraged by our observations of pronounced B7-H3 protein over-expression in many human solid tumors compared to healthy tissues, we focused on targeting B7-H3 with CAR T cells. We utilized a nanobody as the t B7-H3 targeting domain in our CAR construct to circumvent the stability issues associated with scFv-based domains. In efforts to expand patient access to CAR T cell therapy, we engineered our nanobody-based CAR into human Epstein-Barr Virus Specific T Cells (EBVSTs), offering a readily available off-the-shelf treatment. B7H3.CAR-armored EBVSTs demonstrated potent in vitro and in vivo activities against multiple B7-H3-positive human tumor cell lines and patient-derived xenograft models. Murine T cells expressing a murine equivalent of our B7H3.CAR exhibited no life-threatening toxicities in immunocompetent mice bearing syngeneic tumors. Further in vitro evaluation revealed that while human T, B and NK cells were unaffected by B7H3.CAR EBVSTs, monocytes were targeted due to upregulation of B7-H3. Such targeting of myeloid cells, which are key mediators of cytokine release syndrome (CRS), contributed to a low incidence of CRS in humanized mice after B7H3.CAR EBVST treatment. Notably, we showed that B7H3.CAR EBVSTs can target B7-H3 expressing myeloid-derived suppressor cells (MDSCs), thereby mitigating MDSC-driven immune suppression. In summary, our data demonstrate that our nanobody-based B7H3.CAR EBVSTs are effective as an off-the-shelf therapy for B7-H3 positive solid tumors. These cells also offer an avenue to modulate the immunosuppressive tumor microenvironment, highlighting their promising clinical potential in targeting solid tumors.

The degree of HLA matching determines the incidence of cytokine release syndrome and associated nonrelapse mortality in matched related and unrelated allogeneic stem cell transplantation with post-transplant cyclophosphamide

Cytokine release syndrome (CRS) occurs frequently after haplo-identical allogeneic stem cell transplantation (alloSCT) with post-transplant cyclophosphamide (PTCy), increasing nonrelapse mortality (NRM) and decreasing survival. Data on CRS in HLA-matched alloSCT are limited and effects of specific HLA-mismatches on CRS development unknown. We hypothesized that in HLA-matched alloSCT increasing degrees of HLA-mismatching influence CRS incidence, NRM and survival. Retrospective analysis of 126 HLA-matched PTCy-alloSCT patients showed that higher degrees of HLA-mismatching significantly increased CRS incidence (26%, 75% and 90% CRS with 12/12, 10/10 and 9/10 matched donors, respectively). Maximum temperature during CRS increased with higher HLA-mismatch. Specific associations between HLA-mismatches and CRS could be determined. Grade 2 CRS and CRS-induced grade 3 fever were associated with significantly increased NRM (p < 0.001 and p = 0.003, respectively) and inferior survival (p < 0.001 and p = 0.005, respectively). NRM was mainly caused by disease conditions that may be considered CRS-induced inflammatory responses (encephalopathy, cryptogenic organizing pneumonia and multi-organ failure).

Patterns of CRS with teclistamab in relapsed/refractory multiple myeloma with or without prior T-cell redirection therapy

AbstractTeclistamab (Tec) is a first-in-class BCMA × CD3 bispecific T-cell engager antibody approved for treating multiple myeloma progressing after at least 4 lines of therapy. The objective of this study was to evaluate the rate of cytokine release syndrome (CRS) in patients who were treated with commercial Tec and had prior exposure to other T-cell redirection therapies. A retrospective chart review was performed to identify patients who completed the Tec step-up dosing phase between November 2022 and November 2023. Patients were divided into 2 cohorts based on prior exposure to T-cell redirection therapy (cohort 1: T-cell redirection therapy experienced; cohort 2: T-cell redirection therapy naïve). The primary objective was to compare the differences in the rates of CRS between the 2 cohorts. Univariate and multivariate logistic regression analyses were performed to assess the association between CRS rates with Tec and prior treatment with T-cell redirection therapy. A total of 72 patients were included in the analysis (27 in cohort 1 and 45 in cohort 2). The CRS rates were significantly lower in cohort 1 (37%, n = 10) compared with cohort 2 (80%, n = 36; P = .0004). Based on multivariate logistic regression analysis, patients without prior exposure to T-cell redirection therapy (cohort 2) had about a fourfold increase in the incidence of CRS (95% confidence interval, 1.40-14.90; P = .0002) with Tec. In our study, prior exposure to T-cell redirection therapy reduced the risk of CRS with Tec during the step-up dosing phase. This observation will allow for the optimization of CRS prophylactic strategies for Tec.

Associations of granulocyte colony-stimulating factor with toxicities and efficacy of chimeric antigen receptor T-cell therapy in relapsed or refractory B-cell acute lymphoblastic leukemia

Few studies have reported the associations of granulocyte colony-stimulating factor (G-CSF) with cytokine release syndrome (CRS), neurotoxic events (NEs) and efficacy after chimeric antigen receptor (CAR) T-cell therapy for relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). We present a retrospective study of 67 patients with R/R B-ALL who received anti-CD19 CAR T-cell therapy, 41 (61.2%) patients received G-CSF (G-CSF group), while 26 (38.8%) did not (non-G-CSF group). Patients had similar duration of grade 3–4 neutropenia between the two groups. The incidences of CRS and NEs were higher in G-CSF group, while no differences in severity were found. Further stratified analysis showed that the incidence and severity of CRS were not associated with G-CSF administration in patients with low bone marrow (BM) tumor burden. None of the patients with low BM tumor burden developed NEs. However, there was a significant increase in the incidence of CRS after G-CSF administration in patients with high BM tumor burden. The duration of CRS in patients who used G-CSF was longer. There were no significant differences in response rates at 1 and 3 months after CAR T-cell infusion, as well as overall survival (OS) between the two groups. In conclusion, our results showed that G-CSF administration was not associated with the incidence or severity of CRS in patients with low BM tumor burden, but the incidence of CRS was higher after G-CSF administration in patients with high BM tumor burden. The duration of CRS was prolonged in G-CSF group. G-CSF administration was not associated with the efficacy of CAR T-cell therapy.

Abstract P66: Off-The-Shelf Epstein Barr Virus Specific T Cells Armored with B7-H3-Targeting Chimeric Antigen Receptors Is an Effective and Safe Tumor- Agnostic Therapy For B7-H3 Positive Solid Malignancies

Abstract In contrast to its limited expression in normal tissues, the B7 homolog 3 protein (B7-H3) is over-expressed in many human tumors, making it an attractive target for chimeric antigen receptor (CAR) T cell therapy. To address the technical challenges limiting broader patient access to autologous CAR T cell therapy, we armoured Epstein-Barr Virus Specific T Cells (EBVSTs) with CARs as an off-the-shelf therapy against solid tumors. We identified and utilised a nanobody as the domain specifically targeting B7-H3 in our CAR construct to reduce the stability issues associated with scFv-based domains. Our B7H3.CAR armored EBVSTs demonstrated potent in-vitro and in-vivo activity against multiple B7-H3 positive tumor and patient-derived xenografts models. Analysis of human healthy tissues and tumors microarrays indicated that B7-H3 expression, while elevated in patient tumors, was differentially low in healthy tissues. Consistent with this, mouse T cells expressing a murine equivalent of our B7H3.CAR displayed good on-target off-tumor safety in immunocompetent mice bearing syngeneic tumors. Further in-vitro evaluation revealed that while human T, B and NK cells were unaffected by B7H3.CAR EBVSTs targeting, monocytes were readily targeted due to the upregulation of B7-H3. Consequent to this targeting and depletion of B7-H3 positive human myeloid cells which are key mediators of CRS, a low incidence of cytokine release syndrome was observed in humanized mice after B7H3.CAR EBVST treatment. Lastly, we showed that B7H3.CAR EBVSTs can target myeloid-derived suppressor cells (MDSCs) that express B7-H3 and in doing so, alleviate MDSC-driven immune suppression. Our findings demonstrate that our nanobody-based B7H3.CAR EBVSTs present not only an effective and safe off-the-shelf approach for targeting any B7-H3-positive solid tumor while also addressing challenges that hindered the clinical development of CAR T cells in such indications. Citation Format: Siok Ping Yeo, Lindsay Kua, Jin Wei Tan, Joanna Kristyn Lim, Fiona Wong, May Delos Santos, Chek Meng Poh, Angeline Goh XH, Xin Yu Koh, Xiao Hua Zhou, Rajarethinam R, Qing Feng Chen, Zhisheng Her, Ivan D Horak, Lionel Low, Kar Wai Tan. Off-The-Shelf Epstein Barr Virus Specific T Cells Armored with B7-H3-Targeting Chimeric Antigen Receptors Is an Effective and Safe Tumor- Agnostic Therapy For B7-H3 Positive Solid Malignancies [abstract]. In: Proceedings of Frontiers in Cancer Science; 2023 Nov 6-8; Singapore. Philadelphia (PA): AACR; Cancer Res 2024;84(8_Suppl):Abstract nr P66.

Abstract 6327: Impact of G-CSF on safety and efficacy of CAR T-cell therapy in non-Hodgkin lymphoma

Abstract Introduction: Chimeric antigen receptor T-cell (CAR-T) therapy is an established treatment modality for the management of refractory and/or relapsed non-Hodgkin lymphoma (NHL). Despite restrictions on granulocyte colony-stimulating factor (G-CSF) use in registration clinical trials due to potential worsening of cytokine release syndrome (CRS), G-CSF is often prescribed for neutrophil recovery post-CAR-T in clinical practice. We conducted a retrospective study to assess the association between G-CSF use and the safety and efficacy of CAR-T. Methods: Following Institutional Review Board approval, we retrospectively analyzed NHL patients receiving commercial CD19-targeted CAR-T across Mayo Clinic sites (Arizona, Florida, and Minnesota) between October 2017 and May 2023. Demographics, labs, and post CAR-T events were collected. Electronic medical records were reviewed for G-CSF exposure within Day 1 - 100 post-CAR T. Differences by G-CSF status were examined using a Chi-square test and Kruskal Wallis tests. Hazard ratios (HR) and 95% confidence intervals (CI) for overall survival (OS) were calculated using Cox model. Results: Among 270 CAR-T patients; 106 received G-CSF within 30 days and 164 did not. Median age was 56.9 with G-CSF and 58.3 without G-CSF. Most were male (75.2% G-CSF, 62.6% no G-CSF). Diffuse large B cell lymphoma was the predominant NHL subtype (67.0% G-CSF, 65.2% no G-CSF). G-CSF within 30 days was not associated with reduced incidence of neutropenic fever (11.7% G-CSF vs 9.9% no G-CSF, p = 0.6593) or documented infection (22.1% vs 18.3%, p = 0.4439). G-CSF correlated with decreased profound neutropenia duration (ANC &amp;lt; 100 μL, 0 vs 2 days, p &amp;lt; 0.0001) and incidence within 30 days ( 31.7% vs 60.4%, p &amp;lt; 0.0001) as well as incidence of protracted profound neutropenia (&amp;gt; 7 days, 3.8% vs 22.8%, p &amp;lt; 0.0001). G-CSF was associated with a higher incidence of cytopenias between days 30 -100: severe neutropenia (ANC &amp;lt; 500/uL, 28.8% vs 15.2%, p = 0.0075), severe anemia (Hb &amp;lt; 8 g/dL, 21% vs 9.7%, p = 0.0114), and severe thrombocytopenia (Plt &amp;lt; 50 g/L, 35.2% vs 20.9%, p = 0.0099). Logistic regression analysis showed that none of the examined covariates, including prior autologous stem cell transplant, ECOG PS score, and receipt of bridging therapy, were associated with severe neutropenia likelihood. G-CSF was associated with a higher CRS incidence (89.6% vs 79.9%, p = 0.0343), but grade 3 CRS or higher (4.7% vs 3.7%, p = 0.6675) was no different. No difference in complete response rates (66% vs 61.1%, p = 0.4707) or 2-year OS (p = 0.523) was observed between the 2 groups. Conclusion: G-CSF within 30 days was associated with reduced duration and incidence of profound neutropenia without a significant impact on incidence of neutropenic fever or documented infections. There was a signal of association between G-CSF and increased incidence of low-grade CRS and delayed cytopenias (day 30-100) that warrants confirmation in larger studies. Citation Format: Lay She Ng, Claire I. Yee, Radhika Bansal, Mohamed A. Kharfan-Dabaja, Grzegorz S. Nowakowski, Allison C. Rosenthal, Javier Munoz, Januario Castro, Wern Lynn Ng, Hemant S. Murthy, Yi Lin, Matthew R. Buras, Madiha Iqbal, Yucai Wang, Talal Hilal. Impact of G-CSF on safety and efficacy of CAR T-cell therapy in non-Hodgkin lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6327.

Early induction of cytokine release syndrome by rapidly generated CAR T cells in preclinical models

Cytokine release syndrome (CRS) is a significant side-effect of conventional chimeric antigen receptor (CAR) T-cell therapy. To facilitate patient accessibility, short-term (st) CAR T cells, which are administered to patients only 24 h after vector exposure, are in focus of current investigations. Their impact on the incidence and severity of CRS has been poorly explored. Here, we evaluated CD19-specific stCAR T cells in preclinical models. In co-culture with tumor cells and monocytes, stCAR T cells exhibited anti-tumoral activity and potent release of CRS-related cytokines (IL-6, IFN-γ, TNF-α, GM-CSF, IL-2, IL-10). When administered to NSG-SGM3 mice, stCAR T cells, but not conventional CAR T cells, induced severe acute adverse events within 24 h, including hypothermia and weight loss, as well as high body scores, independent of the presence of tumor target cells. Human (IFN-γ, TNF-α, IL-2, IL-10) and murine (MCP-1, IL-6, G-CSF) cytokines, typical for severe CRS, were systemically elevated. Our data highlight potential safety risks of rapidly manufactured CAR T cells and suggest NSG-SGM3 mice as sensitive model for their preclinical safety evaluation.

Teclistamab in relapsed refractory multiple myeloma: multi-institutional real-world study

The objective of our study was to report real-world data on the safety and efficacy of standard-of-care teclistamab in patients with relapsed/refractory multiple myeloma (MM). This is a multi-institutional retrospective cohort study and included all consecutive patients that received at least one dose of teclistamab up until August 2023. One hundred and ten patients were included, of whom, 86% had triple-class refractory disease, 76% penta-refractory disease, and 35% had prior exposure to B-cell maturation antigen (BCMA)-targeting therapies. The overall response rate (ORR) in our cohort was 62%, with a ≥ very good partial remission (VGPR) rate of 51%. The ORR in patients with and without prior BCMA-targeted therapies was 54% vs 67%, respectively (p = 0.23). At a median follow-up of 3.5 months (range, 0.39–10.92), the estimated 3 month and 6 month progression free survival (PFS) was 57% (95% CI, 48%, 68%) and 52% (95% CI, 42%, 64%) respectively. The incidence of cytokine release syndrome (CRS) and immune effector cell associated neurotoxicity syndrome (ICANS) was 56% and 11% respectively, with grade ≥3 CRS and ICANS noted in 3.5% and 4.6% of patients respectively. 78 unique infections were diagnosed in 44 patients, with the incidence of all-grade and grade ≥3 infections being 40% vs 26% respectively. Primary prophylaxis with intravenous immunoglobulin (IVIG) was associated with a significantly lower infection risk on multivariate analysis (Hazard ratio [HR] 0.33; 95% CI 0.17, 0.64; p = 0.001).

Chimeric antigen receptor-T cell therapy shows similar efficacy and toxicity in patients with diffuse large B-cell lymphoma aged 70 and older compared to younger patients: A multicenter cohort study.

CD19-directed chimeric antigen receptor (CAR)-T cell therapy has become a standard treatment for relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL). While the benefits of CAR-T cell treatment are clear in the general patient population, there remains a relative scarcity of real-world evidence regarding its efficacy and toxicity in patients (pts) aged ≥70 years with DLBCL. We conducted a multicenter retrospective analysis including 172 r/r DLBCL pts with CAR-T cell treatment, axicabtagene ciloleucel or tisagenlecleucel, between 2019 and 2023 at three tertiary centers. Pts were grouped by age at CAR-T infusion (<70 vs. ≥70 years). Subsequently, descriptive and survival analyses, including propensity score matching, were performed to compare outcomes between both age groups. We identified 109 pts aged <70 and 63 pts aged ≥70 years. Overall response rates for both age groups were comparable (77.7% vs. 78.3%; p = 0.63). With a median follow-up of 8.3 months, median progression-free survival was 10.2 months (95% confidence interval [CI]: 6.5-21.8) and 11.1 months (95% CI: 4.9-NR) (p = 0.93) for both cohorts. Median overall survival reached 21.8 months (95% CI: 11.8-NR) and 34.4 months (95% CI: 10.1-NR) (p = 0.97), respectively. No significant differences in the incidence of cytokine release syndrome (p = 0.53) or grade ≥3 neurotoxicity (p = 0.56) were observed. Relapse and nonrelapse mortality were not significantly different between both groups. Our findings provide additional support that CAR-T cell therapy is feasible and effective in patients with r/r DLBCL aged 70 years or older, demonstrating outcomes comparable to those observed in younger patients. CAR-T cell therapy should be not withheld for elderly patients with r/r DLBCL.

Reduced Cytokine Release Syndrome and Improved Outcomes with Earlier Immunosuppressive Therapy in Haploidentical Stem Cell Transplantation

The optimal timing of immunosuppression and post-transplantation cyclophosphamide (PTCy) in haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is unknown. However, cytokine release syndrome (CRS) following haplo-HSCT is associated with worse transplantation outcomes, and the incidence of CRS may be affected by the timing of immunosuppression and PTCy. In this study, we compared CRS and other transplantation outcomes in 2 cohorts receiving different immunosuppression and PTCy schedules following haplo-HSCT. This was a retrospective cohort study of 91 patients who underwent haplo-HSCT at the Intermountain Health Blood and Marrow Transplant Program. The original or standard haplo-HSCT GVHD prophylaxis regimen included PTCy on days +3 and +4, with mycophenolate mofetil (MMF) and tacrolimus starting on day +5. The modified regimen adopted in November 2020 changed PTCy to days +3 and +5, with earlier introduction of tacrolimus and MMF, on day -1 and day 0, respectively. Grade ≥1 CRS occurred in 32% of patients in the modified regimen, in 82% of patients in the standard regimen (P <.0001), and 65% overall. Likewise, grade ≥2 CRS was lower with the modified regimen (16% versus 57%; P = .0002). The mean duration of CRS symptoms was longer with the standard regimen (3.14 days versus 1.44 days; P = .0003). The incidence of acute graft-versus-host disease grade III-IV or extensive chronic GVHD (cGVHD) at 1 year was lower in the modified regimen (6% versus 32%; P = .0068). No differences between the standard and modified regimens were seen in overall survival, relapse, or GVHD-free relapse-free survival (GRFS), although there appeared to be a trend toward improved GRFS with the modified regimen. Post hoc analysis comparing GRFS in patients with CRS and those without CRS found that CRS was associated with lower GRFS at 1 year (36% versus 63%; P = .0138). The duration of broad-spectrum antibiotic therapy was decreased by 7.5 days (P = .0017) and the time to hospital discharge was reduced by 7.1 days (P = .0241) with the modified regimen. This is the first analysis to evaluate and find a difference in CRS with early initiation of immunosuppressive therapy in haplo-HSCT. Our results suggest that this modified GVHD regimen benefits patients by reducing CRS and high-grade GVHD compared to the standard PTCy-based GVHD prophylaxis regimen in haplo-HSCT. Additionally, this novel regimen did not appear to negatively impact outcomes.

Graft-Versus-Host Disease (GvHD) Prophylaxis after Haploidentical Peripheral Blood Stem Cell Transplantation (haplo-PBSCT) Using Abatacept in Combination with Post-Transplant Cyclophosphamide (PTCy)

Background: Multiple studies demonstrated the efficacy of PTCy in achieving successful multiple-HLA-antigen mismatched (haploidentical) donor transplantation. However, acute GvHD (aGvHD) remains a major cause of morbidity and mortality after transplantation. Furthermore, many patients (pts) experience severe cytokine release syndrome (CRS) immediately after haplo-donor transplantation, which may be a greater risk after haplo-PBSCT. We hypothesized that adding co-stimulation blockade with abatacept (Abat) starting before transplantation to a standard GvHD prophylaxis regimen of PTCy, tacrolimus, and mycophenolate mofetil in haplo-PBSCT would be safe and effective in aGvHD prevention and decrease the incidence of cytokine release syndrome (CRS) associated with use of this cell source. Methods: This retrospective study included 50 recipients of haplo-PBSCT between 1/1/20, and 3/31/23, who received standard PTCy GvHD prophylaxis with (PTCY/Abat, n=22) or without (PTCy, n=28) the addition of Abat at a planned dose of 10 mg/kg/dose IV on days -1, +5, +14 (n=10) and +28 (n=12). Choice of donor, conditioning regimen, and use of Abat were per physician discretion. The PTCy GvHD regimen and pre- and post-transplant care of all pts were as previously described (Baker et al. Biol Blood Marrow Transplant. 2016;22:2047-55). Survival development of aGvHD or chronic GvHD (cGvHD), and engraftment success and kinetics were evaluated. CRS (Lee, et al. Blood 2014;124:188-95), aGvHD (Magic criteria, Harris et al. Biol Blood Marrow Transplant. 2016;22:4-10) and cGvHD (NIH consensus criteria, Jagasia et al. Biol Blood Marrow Transplant 2015;21:389-401) were scored per citations. Results: In total, 22 pts received PTCy/Abat. Ten pts did not receive day +28 Abat for insurance reasons. Twenty-eight pts received PTCy without abatacept. Pt characteristics and CRS grading are described in the Table. Although distributions of diagnosis, sex, and pt or donor ages were similar between cohorts, there was some imbalance, particularly in higher use of TBI myeloablative conditioning regimen for PTCy cohort (Table). The median follow-up of survivors is 10 months. In this analysis we found a non-significant trend to lower incidence (65% vs 88% p=0.079) and severity of CRS for PTCy/Abat recipients vs PTCy recipients (Table). Only 1 of 20 evaluable PTCy/Abat recipients developed grade 2 CRS vs 6 of 26 PTCy pts. PTCy/Abat recipients achieved faster ANC engraftment (median: 15 days, 95% CI: 14-16 vs 17 days, 95% CI: 16-18; p&amp;lt;0.0001 (Figure 1A)) and platelet recovery (median: 15 days, 95% CI 13-22 vs 24 days 95% CI 19-29; p=0.002). No pt in either group developed 1 o or 2 o graft failure. Median peripheral blood CD3 chimerism at day +28 was 100% (range, 57-100%) for PTCy/Abat pts and 100% (range, 85-100%) for PTCy pts. The cumulative incidence of any aGvHD was 71% for PTCy/Abat pts vs 73% for PTCy pts, (p=0.9). Grade II or III aGvHD occurred in 13/21 and 1/21 evaluable PTCy/Abat pts, and 12/26 and 3/26 evaluable PTCy pts, respectively. No grade IV or liver aGvHD occurred in either group. The median time of onset of aGvHD was 54 days for PTCy/Abat pts and 36 days for PTCy pts (p= 0.08). The cumulative incidence of any grade cGvHD trended higher in the PTCy/Abat group (81% vs 50% p=0.052). Also, the PTCy/Abat group had a higher incidence of severe grade cGvHD (6/13 vs 2/10 evaluable pts). The 200-day cumulative incidence of relapse was 35% for PTCy/Abat and 11% for PTCy (p=0.2). No statistically significant differences in overall survival, or relapse-free survival (Figure 1B) were detected for these two populations. Conclusions:The addition of Abat starting before haplo-PBSCT did not interfere with the aGvHD and engraftment protective effects of PTCy in this cohort. Abat initiated before PBSC infusion may reduce the risk and severity of CRS and was associated with earlier neutrophil and platelet recoveries. Although the incidence of aGvHD did not differ between the two groups, time of onset trended later among PTCy/Abat recipients. Larger pt populations will be needed to determine more accurately the effects of adding Abat to PTCy on relapse risk and cGvHD incidence and severity.

Deliriogenic Medication Use in Older Adults Receiving CAR-T Correlates with Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS)

Background Chimeric Antigen Receptor T-Cell therapy (CAR-T) is increasingly used for older adults with hematologic malignancies. Real-world outcomes suggest chronological age alone does not have a strong impact on CAR-T outcomes or associated adverse effects, including cytokine release syndrome (CRS) and ICANS. A subset of CAR-T-eligible older adults have comorbidities managed with deliriogenic medications including opioids, benzodiazepines, and sedatives. Their effects may be exacerbated during prolonged hospitalizations for CAR-T therapy, precipitating delirium, which has clinical overlap with ICANS including inattention, altered sensorium, and reduced responsiveness. We hypothesized that exposure to high-risk deliriogenic medications may have an impact on observed ICANS incidence in older adults undergoing CAR-T therapy. Methods We performed a single-center retrospective analysis of all patients age 60 or older who received a FDA-approved CAR-T product for a hematologic malignancy at two UCLA Health hospitals from 8/2018 to 12/2022. We collected exposure to deliriogenic medications including opioids, benzodiazepines, sedatives/hypnotics, and anticholinergics prior to and during CAR-T hospitalization. Correlation with incidence of CRS and ICANS of any grade was modeled using logistic regression. If exposure to high-risk medication was found to be statistically significant, correlation with CRS and ICANS by each individual class of high-risk medications was analyzed. A multivariable logistic regression was performed including each predictor of CRS or ICANS that was statistically significant at the p&amp;lt;0.1 level in univariable regression. Results A total of 84 patients age 60 or older received an FDA-approved CAR-T product for a hematologic malignancy at our institution between 8/2018 to 12/2022. Patients ranged in age from 60 to 84 years (median 70). Baseline characteristics for all patients by cellular therapy target are shown inTable 1. The most common histology included was DLBCL (75%), followed by MCL (13%), MM (8%), ALL (2%), and FL (1%). With a median follow up of 9.6 months, CRS and ICANS of any grade were experienced by 76% and 45% of total patients with a median time to onset of 4 days and 5 days, and grade 3 or higher CRS and ICANS was experienced by 1% and 17% of patients, respectively. Most patients had exposure to a high-risk deliriogenic medication prior to and during their hospitalization for CAR-T infusions (57% and 74%, respectively). Age, performance status, and deliriogenic medication use prior to admission were not correlated with incidence of CRS or ICANS as shown in Table 2. However, exposure to high-risk medications during hospitalization was highly correlated with ICANS incidence (OR 2.64, p&amp;lt;0.001). In a multivariable model CAR-T product costimulatory domain (4-1BB vs. CD28, OR 6.21, p= 0.01), number of prior lines of therapy (OR 6.21, p=0.03), and exposure to opioids during admission (OR 10.5, p&amp;lt;0.001) were correlated with incidence of ICANS. Conclusion In our single-center real-world analysis of older adults receiving a FDA-approved CAR-T therapy, the CAR-T product infused, number of prior lines of therapy, and exposure to opioids during CAR-T hospitalization were correlated with incidence of ICANS. Increased incidence and severity of ICANS depending on CAR-T product has been well-described, but interestingly, our data suggest use of opioids in the immediate post-CAR-T infusion setting may also be a significant risk factor for ICANS. Limitations to our analysis include single-center practice patterns, unclear timing of exposure to deliriogenic medications to onset of ICANS, burden of comorbidities, and lack of baseline standardized cognitive and geriatric assessments in our elderly cohort. In addition to careful selection of CAR-T product in older adults, our findings support minimization of high-risk deliriogenic medications in the immediate post-CAR-T inpatient setting to mitigate risk of ICANS in this vulnerable patient population. Effects of ICANS and its treatments on outcomes and survival will be reported as this cohort matures.

Real-World Incidence, Characteristics and Management of Cytokine Release Syndrome Induced By Chimeric Antigen Receptor T-Cell Therapy across Hematologic Malignancies

Background: Cytokine release syndrome (CRS) is a potentially life-threatening, supraphysiologic response following immunotherapy resulting in the activation or engagement of endogenous or infused T cells and/or other immune effector cells. CRS occurs with varying frequency and severity, depending on the underlying disease and immunotherapy used, such as chimeric antigen receptor T-cell (CAR-T) therapy or off-the-shelf T-cell engaging bispecific antibodies. Limited research exists on the diagnosis and management of CRS in the real world. This study describes the real-world incidence, severity and clinical management of CRS induced by commercially available CAR-T therapies for diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), mantle cell lymphoma (MCL) and multiple myeloma (MM). Methods: Real-world data (RWD) were obtained from the Flatiron Health, US, nationwide electronic health record (EHR)-derived, de-identified database of cancer patients within a network comprised primarily of community cancer practices. The Flatiron Health network also includes practices designated as academic sites by the National Cancer Institute; however, relative proportions of community/academic practices may vary depending on the study cohort. Data as of August 31, 2022, on CAR-T therapy, clinical characteristics and disease outcomes specific to CAR-T therapy, as well as CRS and its clinical management, were abstracted from unstructured documents in EHRs (in addition to routinely available structured data), in a cohort of patients receiving commercial CAR-T therapy. Specifically, data for CRS including treatments and resolution were abstracted based on explicit mention of and attribution to CRS in charts. Results: Table 1 summarizes data by indication. Incidence of CRS ranged from 56% (104/185) in DLBCL to 72% (66/92) in MCL. Excluding categories with small numbers of cases (&amp;lt;15), CRS incidence also varied by individual CAR-T therapy and underlying indication and ranged from 35% for idecabtagene vicleucel in MM to 73% for brexucabtagene autoleucel in MCL. Highest incidence of Grade ≥2 CRS was observed among MCL patients, whereas Grade ≥3 CRS was most commonly observed among FL patients. Time to onset of CRS ranged from 0 to 16 days, with median onset between 3-4 days among lymphoma patients and earlier median onset of 1 day for MM patients. Median time to CRS resolution ranged from 2 to 6 days across indications. While 81-95% of patients received CAR-T therapy at an academic center, 5-14% received CAR-T therapy at a community center. Tocilizumab and corticosteroids were the most commonly used treatments for CRS, including 37-48% use of tocilizumab for Grade 1 CRS (Table 2). Discussion: This study uniquely summarizes RWD on CRS following the use of commercially available CAR-T therapies across multiple hematologic malignancies, based on information from clinical notes abstracted retrospectively from EHRs. Consistent with the timing of approval of commercially available CAR-T therapies, the sample size for MM was limited compared with other malignancies. Safety events are typically under-reported in RWD sources, specifically for CRS when relying on information documented in patients' EHRs, compared with other published literature. In accordance with other RWD on CRS, grading criteria for CRS as well as vasopressor and oxygen use were not consistently reported in patients' EHRs. CAR-T treatments were predominantly administered in academic centers. Limited use in community practices was also observed; however, further information to accurately characterize the size and capabilities of community centers was not available in this database. Data also showed considerable use of tocilizumab to treat low-grade CRS, suggesting the need for additional evidence on its role to treat CRS beyond its current regulatory approval. Increased evidence generation, specifically from usual clinical practice, can contribute to increased awareness and knowledge about CRS diagnosis and management, and in turn realize the maximum potential of T-cell therapeutics.

Excellent Safety Profile of a Low-Cost Novel Humanized CD19 CAR T-Cell Therapy, Actalycabtagene Autoleucel : Potential Impact on Access and Feasibility

Background: A high incidence of severe toxicities especially grade 3/4 immune effector cell-associated neurotoxicity syndrome (ICANS) and cytokine release syndrome (CRS), need for hospitalization, and the cost of supportive care is an hindrance to the implementation of CAR-T cell therapy for low and middle income countries (LMICs). To address these limitations, we designed a novel humanized CD19 CAR and demonstrated a favorable balance of efficacy to toxicity in the preclinical model and in the first-in-human Phase I study (Dwivedi et al. Mol Cancer Ther. 2021, Karulkar et al. ASH 2022). Here, we quantified the healthcare resource utilization (HCRU) and associated cost of clinical management of Actalycabtagene autoleucel (Actaly-cel) in India from an ongoing Phase I/II study in B-cell malignancies. Methods: This is a retrospective analysis of the HCRU costs of patients with r/r B-cell malignancies treated on Phase I/II study with Actaly-cel at 3 centers in India between June 2021 through July 2023. The key components of HCRUs are defined in Table 1 and were quantified from the electronic records from the time of enrolment till their last follow-up. Once enrolled, bridging therapy was allowed at investigator's discretion. After lymphodepletion (LD) with a fludarabine plus cyclophosphamide (FC) regimen for 3 days, patients received Actaly-cel at a target dose ≥ 5 million CAR-T cells/kg (upper limit; total 2 x10 9). The patients were monitored for toxicities particularly CRS, ICANS and cytopenias, as inpatient (non-HEPA filtered rooms) for at least a week. CRS and ICANS were graded as per ASTCT grading system and cytopenias as per CTCAE v5. Results: Total 59 patients were enrolled in this study and 47 patients received the infusion. Thirty seven patients (r/r lymphoma; n=28, r/r B-ALL; n=9) who completed 28 days post-infusion were evaluable for HCRU analysis. The median age was 37 years (16-71). The median follow-up of the cohort was 60 days (21-644); 19% (7/36) and 11% (4/36) patients completed 6 months and 12 months follow-up respectively. Among all patients (n=37) who received LD therapy, 46% of lymphoma patients received LD in the outpatient setting while 78% of B-ALL patients required hospitalization for LD. The median hospitalization period post Actaly-cel infusion was only 8 days (range: 7-17 days) in the lymphoma cohort, and 13 days (range: 7-19 days) for B-ALL patients. Importantly, none of the lymphoma patients required ICU admission, and only one B-ALL patient required ICU admission for management of adverse events. In the lymphoma cohort, 54% (15/28) of patients developed Grade 1/2 CRS and none had grade &amp;gt;/=3. A single dose of tocilizumab was given to 36% (10/28) of patients and only 4% (1/28) received tocilizumab plus corticosteroids. None of the patients required vasopressor support. Majority of B-ALL patients developed CRS. The incidence and severity of CRS was as follows: G1; 44% , G2; 11% and G3; 22%. There were no grade 4/5 CRS events. While 11% (1/9) of patients received a single dose of tocilizumab, 44% (4/9) received tocilizumab in combination with corticosteroids. Vasopressors were required in 22% of patients. None of the patients developed ICANS of any grade . Most patients (lymphoma and B-ALL) developed hematological toxicities(Table 1). The severity of Grade 3-4 was more prevalent in the B-ALL cohort. IVIG was administered to 25% of lymphoma and 22% of B-ALL patients. The induction and severity of the above toxicities were not dependent on the Actaly-cel dosage (median: 9 x 10 6 ;range: 2 x 10 6-21 x 10 6 CAR-T cells/kg). The projected production cost of Actaly-cel in the regional decentralized manufacturing model at the scale of 300 patients/year is ~15,000 USD per patient. The mean cost of HCRU for clinical management (until last follow-up) per patient was ~ 4,400 USD in an academic centre (lymphoma; ~4,000 USD, B-ALL; ~5,565 USD) and interestingly, only about 14% of these costs were incurred due to inpatient management (Figure 1). Conclusions: Actaly-cel was efficacious, with no incidence of ICANS and manageable CRS across a wide dose range. More importantly, this study reported low HCRUs due to negligible ICU admission and shorter duration of hospitalization, ensuring potential usage of Actaly-cel in outpatient settings, and ultimately improving the access and feasibility of CD19 CAR-T cell therapy in resource constrained settings such as LMICs.

Dexamethasone is Associated with a Lower Incidence and Severity of Cytokine Release Syndrome Compared with Other Corticosteroid Regimens When Given as Premedication for Glofitamab Monotherapy in Patients with Relapsed/Refractory (R/R) Large B-Cell Lymphoma (LBCL)

Background: Glofitamab, a CD20xCD3 T-cell engaging bispecific antibody with a novel 2:1 (CD20:CD3) format, induced frequent and durable complete responses (CRs) with a manageable safety profile in pivotal expansion cohorts of an ongoing Phase I/II study (NCT03075696) in patients (pts) with R/R LBCL (Dickinson et al. NEJM 2022, Falchi et al. ASCO 2023). Cytokine release syndrome (CRS) is a potentially life-threatening toxicity caused by immune activation that can be triggered non-specifically by T-cell engaging therapies. As previously reported, corticosteroid (steroid) premedication was required to prevent or mitigate CRS in pts treated with glofitamab. Dexamethasone (Dex) was mandated in one expansion cohort to assess if this could reduce the rate and severity of CRS versus other steroids. Here, we report data from the dose-escalation and expansion cohorts in pts with R/R LBCL who received Dex only versus non-Dex premedication. Methods: Pts with R/R LBCL (diffuse LBCL not otherwise specified [DLBCL NOS], high-grade B-cell lymphoma [HGBCL], primary mediastinal LBCL [PMBCL], or LBCL arising from follicular lymphoma [trFL]) and ≥2 prior therapies received 1000mg obinutuzumab pretreatment (Gpt) 7 days prior to the first glofitamab dose. IV glofitamab was administered with step-up dosing during Cycle (C) 1 (Day 8, 2.5mg; Day 15, 10mg) followed by the target dose (30mg) on Day 1 of C2-12 (21-day cycles; 8.4 months). Steroid premedication (80mg IV methylprednisolone, or equivalent dose of prednisone [100mg] or prednisolone [100mg], or 20mg IV Dex) was given at least 60 minutes prior to Gpt and each glofitamab dose. Responses were assessed using Lugano criteria (Cheson et al. JCO 2014). CRS events were graded by ASTCT criteria (Lee et al. Biol Blood Marrow Transplant 2019). Results: As of May 1, 2023, 145 pts with R/R LBCL had received glofitamab, including 33 (22.8%) pts (DLBCL NOS, n=24 [72.7%]; HGBCL, n=2 [6.1%]; trFL, n=7 [21.2%]) who received Dex premedication before each glofitamab dose (Dex only cohort) and 112 (77.2%) pts (DLBCL NOS, n=81 [72.3%]; HGBCL, n=5 [4.5%]; PMBCL, n=6 [5.4%]; trFL, n=20 [17.9%]) who had not received Dex premedication before each glofitamab dose (non-Dex cohort). In the Dex only and non-Dex cohorts, median age was 73.0 years (range: 27-86) and 66.0 years (range: 21-90), and 26/33 (78.8%) pts and 83/112 (74.1%) pts had Ann Arbor stage III/IV disease, respectively. Median number of prior therapies was 3.0 for both cohorts. Ten (30.3%) and 37 (33.0%) pts had previously received chimeric antigen receptor T-cell therapy, and 6 (18.3%) and 22 (19.6%) pts had received autologous stem cell transplant in the Dex only and non-Dex cohorts, respectively. Median number of glofitamab cycles was 5.0 in both cohorts. CRS of any grade occurred in 48.5% of pts in the Dex only cohort and 73.2% of pts in the non-Dex cohort, and CRS leading to serious adverse events occurred in 5 (15.2%) and 27 (24.1%) pts, respectively. In both cohorts, CRS events were mostly low grade and primarily occurred during C1 (Table; Figure). Recurring Grade (Gr) ≥2 CRS was not observed in the Dex only cohort and 6 (5.4%) pts had recurring Gr ≥2 CRS in the non-Dex cohort. Median time to CRS onset and median time to resolution were similar in the two cohorts. Treatment discontinuation rate was lower in the Dex only cohort (n=21, 63.6%) versus the non-Dex cohort (n=80, 71.4%), mainly due to progressive disease (Dex only cohort, n=12 [36.4%]; non-Dex cohort, n=52 [46.4%]). In the DLBCL NOS and trFL population, the best overall response assessed by Independent Review Committee was similar between the Dex only (n=31) and non-Dex (n=101) cohorts, with CR reported in 14 (45.2%) and 44 (43.6%) pts, and 12 (38.7%) and 34 (33.7%) pts remaining in CR at data cutoff, respectively. The estimated event-free rate among complete responders at 12 months after the first CR was 83.1% (95% CI: 61.5-100.0) in the Dex only cohort and 77% (95% CI: 63.8-90.2) in the non-Dex cohort. Conclusions: The incidence, severity, and seriousness of CRS after glofitamab administration in pts with R/R LBCL were numerically lower with Dex premedication versus premedication with other steroid regimens. Response rates in the Dex only cohort were similar to those reported in the non-Dex cohort. We therefore propose Dex as the steroid of choice for premedication to prevent or mitigate CRS in pts with LBCL treated with glofitamab monotherapy, considering its half-life and potency.

Matching-Adjusted Indirect Comparison (MAIC) of Efficacy and Safety of Lisocabtagene Maraleucel (liso-cel) and Mosunetuzumab for the Treatment (Tx) of Third Line or Later (3L+) Relapsed or Refractory (R/R) Follicular Lymphoma (FL)

Background:The tx landscape of R/R FL is evolving with the availability of anti-CD19 chimeric antigen receptor (CAR) T cell therapies and CD20xCD3 bispecific T-cell-engaging monoclonal antibodies (mAb). Liso-cel is an autologous, CD19-directed, 4-1BB CAR T cell therapy which recently reported a positive benefit-risk tx profile for the 3L+ tx of patients with R/R FL (Morschhauser F, et al. ICML 2023; LBA4). Mosunetuzumab, a CD20xCD3 bispecific T-cell-engaging mAb, is approved for the tx of R/R FL after 2 or more lines of therapy (LOT). In the absence of head-to-head data, we conducted an unanchored MAIC to compare the efficacy and safety of liso-cel and mosunetuzumab for the 3L+ tx of patients with R/R FL. Methods: Unanchored MAICs were used to estimate population-adjusted relative tx effects between individual patient-level data from TRANSCEND FL (NCT04245839; data as of January 27, 2023; median follow-up of 19.3 months) and aggregate data from GO29781 (NCT02500407; data as of August 27, 2021; median follow-up of 18.3 months; N = 90). For TRANSCEND FL, the leukapheresed (intention to treat [ITT]) set (N = 114) was used for primary comparisons of efficacy endpoints: Progression-free survival (PFS), objective response rate, and complete response rate (all per independent review committee assessment). Overall survival was not analyzed due to the low rate of events. The treated efficacy set (n = 101) was used for a sensitivity analysis of efficacy comparisons. The treated set (n = 107) was used for comparisons of safety endpoints: cytokine release syndrome (CRS), neurological events (NEs), serious infections, and use of corticosteroids or tocilizumab for CRS. Baseline characteristics and outcome measures in TRANSCEND FL were redefined to align with those reported in GO29781. Data from TRANSCEND FL were weighted using a method-of-moments propensity score model to match the marginal distribution (ie, mean, variance) of clinical factors among patients from GO29781. A panel of expert clinicians selected and ranked tx effect modifiers separately for efficacy and safety endpoints. For efficacy, factors adjusted for included number of prior systemic LOTs, progression of disease ≤ 24 months from initiation of immunochemotherapy, bulky disease at screening, FL International Prognostic Index risk factor, refractory to last therapy, double refractory to an anti-CD20 antibody and alkylating agent, ECOG PS at screening, sex, and prior autologous HSCT. For safety, factors adjusted for included age, bulky disease at screening, refractory to last therapy, number of prior systemic LOTs, ECOG PS at screening, Ann Arbor stage, and sex. Hazard ratios (HR) were used to compare PFS, and odds ratios (OR) were used for response rates and safety outcomes. Results: After adjusting for all available factors, when compared with mosunetuzumab, liso-cel was associated with higher objective response rate (OR, 3.78 [95% CI, 1.48‒9.67]), and complete response rate (OR, 6.46 [2.85‒14.65]), and improved PFS (HR, 0.28 [0.16‒0.49]) based on an effective sample size (ESS) of 71.4 (Figure). Results were consistent across all scenario analyses, including unadjusted comparisons and sensitivity analyses using the treated efficacy set for TRANSCEND FL. Although liso-cel was associated with higher incidence of any-grade CRS (OR, 1.86 [1.01‒3.43]) and any-grade NEs (OR, 2.16 [0.72‒6.44]), it demonstrated a lower incidence of grade ≥ 3 CRS (OR, 0.45 [0.04‒5.13]) and grade 3-4 serious infections (OR, 0.35 [0.12‒1.03]) based on an ESS of 81.9 compared with mosunetuzumab. Furthermore, liso-cel was associated with reduced use of corticosteroids for CRS management (OR, 0.14 [0.03‒0.65]), while the use of tocilizumab was higher in patients treated with liso-cel (OR, 2.27 [0.86‒5.99]). Conclusions: In this MAIC, liso-cel was associated with improved efficacy compared with mosunetuzumab. Liso-cel had a lower incidence of grade ≥ 3 CRS, grade 3-4 serious infections, and steroid use for management of CRS; however, liso-cel exhibited higher incidence of any-grade CRS, any-grade NEs, and tocilizumab use for CRS management. Safety comparisons were confounded by preventative use of corticosteroids in all patients in GO29781 and definition differences, most notably for NEs. These findings highlight a potential positive benefit-risk profile of liso-cel over mosunetuzumab as a 3L+ tx option for R/R FL.

Optec: A Phase 2 Study to Evaluate Outpatient Administration of Teclistamab, a BCMA-Targeting Bispecific Antibody, in Patients with Multiple Myeloma

Background: Teclistamab is the only approved BCMA×CD3 bispecific antibody with a personalized, weight-based dosing schedule for the treatment of triple-class exposed relapsed/refractory multiple myeloma (RRMM). It is FDA approved for patients (pts) of therapy (LOTs), including a proteasome inhibitor, immunomodulatory drug, and anti-CD38 antibody. In the pivotal MajesTEC-1 study (Moreau et al NEJM 2022), teclistamab showed deep and durable responses and a manageable safety profile in heavily pretreated pts with RRMM who had limited treatment options. The incidence of all grade cytokine release syndrome (CRS) during the first 2 cycles was 70%. Most pts experienced CRS following step-up doses 1 (42%) or 2 (35%), or the initial treatment dose (24%); 33% of pts experienced recurrent CRS. Most CRS events were grade 1/2 and fully resolved without discontinuation or dose reduction of teclistamab. One (0.6%) case of grade 3 CRS occurred in a pt who pneumonia but resolved in 2 days. No grade 4 or 5 CRS occurred. Tocilizumab is a monoclonal antibody targeting the interleukin-6 receptor (IL-6R) which is used to manage CRS resulting from T-cell redirection therapy. Preclinical data indicate that inhibition of IL-6 signaling prior to teclistamab administration can prevent CRS development without impacting anti-tumor activity (Li et al Ann. Oncol. 2019). In MajesTEC-1, pts who received a single IV dose of tocilizumab before the first teclistamab step-up dose (n=23) showed a reduction in the incidence of all grades of CRS, compared with the overall study population (26% vs 72%). Currently, there are no data on the safety of administering the step-up doses of teclistamab in the outpatient (OP) setting, but OP step-up dosing may make teclistamab more accessible. Therefore, we seek to investigate whether the use of prophylactic tocilizumab can reduce the incidence and severity of CRS associated with teclistamab and allow safe OP administration of the step-up dosing. Methods: This single-arm, non-randomized, multicenter, prospective study (NCT05972135) will evaluate CRS incidence and severity after prophylactic tocilizumab in pts treated with teclistamab in the OP setting. A target of 50 participants will be enrolled with an initial PK/PD safety cohort (n=10). Objectives through end of study include recurrent CRS, grade ≥3 and any grade infections, neurotoxicity including ICANS, neutropenia, febrile neutropenia, and efficacy. Eligible pts are ≥18 years with a documented diagnosis of RRMM who have previously received ≥4 LOTs. Pts with rapidly progressing disease, central nervous system involvement, active infection, or contraindication to tocilizumab will be excluded from the trial. Prior to the treatment phase, pts will participate in a 28-day screening phase to determine study eligibility. During the treatment phase, a single dose of tocilizumab will be administered at 8 mg/kg IV, 2 to 4 hours prior to step-up dose 1 of teclistamab (Cycle 1 Day 1) in an outpatient setting (Figure 1). Teclistamab will then be administered at step-up doses of 0.06 mg/kg subcutaneously (SC) (Cycle 1 Day 1) and 0.3 mg/kg SC (Cycle 1 Days 3-5), followed by 1.5 mg/kg SC (Cycle 1 Day 8), with weekly administration for twelve 28-day cycles or until disease progression or unacceptable toxicity. Teclistamab may be reduced to 1.5 mg/kg SC every two weeks for participants who achieve partial response or better after 6 months of therapy. Safety evaluations will include physical examination, vital sign measurements, neurological examination, assessment of ECOG performance status, and clinical safety laboratory assessments. IVIG is recommended in pts with serum IgG &amp;lt;4 g/L. Follow-up of participants during the study will include monitoring for all adverse events, disease progression, and survival until end of study. By studying the feasibility and safety of administering the step-up dosing schedule in an outpatient setting, teclistamab may become more accessible to pts with RRMM and limited treatment options.

Phase I Open-Label Single-Arm Study of Sscart-19 in Adult Patients with Relapsed/Refractory B-Cell Acute Lymphoblastic Leukemia in China

Background: Although CAR-T therapy has shown amazing efficacy in the treatment of hematologic malignancies in recent years, it is also accompanied by high-frequency of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), especially in acute lymphoblastic leukemia patients. Therefore, it is not recommended to enroll patients with active CNS involvement in CAR-T therapy. ssCART-19 is an autologous CD19-specific chimeric antigen receptor T-cell with short hairpin RNA-IL-6 gene silencing element. ssCART-19 can simultaneously express CAR structure and IL-6 silencing element. CAR structure can recognize and bind CD19 positive tumor cells, enhance T cell amplification, and finally exert T cell killing activity, such as releasing cytokines and perforin. Post-transcriptional expression of short hairpin RNA-IL-6 gene silencing element can recognize mRNA of IL-6, inhibit the expression of endogenous IL-6 in CAR-T cells through RNA interference mechanism, and then reduce the stimulation or activation intensity of downstream immune cells (mainly monocytes), with the control of the overall release intensity of cytokines, it reduces the incidence of severe CRS and ICANS, at the end reduces the clinical risk of CAR-T therapy. Methods: The trial of ssCART-19 in adult patients with R/R B-cell ALL (NCT04825496) is a single-arm, open-label Phase 1 study conducted in China. Patients underwent leukapheresis to obtain T cells for ssCART-19 manufacturing. Patients received fractionated infusions split over 3 days (10%; 30%; 60%) after lymphodepleting chemotherapy (3 days fludarabine and cyclophosphamide). Adverse events (AEs) were graded according to CTCAE, v5.0; CRS and ICANS were graded according to ASTCT Consensus Grading. The overall response rate(ORR) of complete response (CR) and CR with incomplete hematological recovery (CRi) within 3 months, duration of remission, relapse-free survival, and OS were assessed as secondary endpoints. Results : ssCART-19 was administered at 3 doses levels (DL) of 1×10 6/kg, 5×10 6/kg, or 10×10 6/kg. As of June 30th 2023 data cutoff (the median follow-up 15.9 months), 13 patients enrolled and underwent leukapheresis, 12 patients were received ssCART-19 treatment, 5 patients in DL1, 6 patients in DL2, and 1 patients in DL3. ssCART-19 was manufactured using serum-free culture system and no manufacture failure was reported. All 12 patients diagnosed with B-cell ALL were relapsed (75.0%) and refractory (25.0%) to multiple lines of prior therapy (100.0% patients had received 2 or more therapies). Five patients (41.7%) had more than 50% blasts in the bone marrow. All 12 patients did not have DLT events within 28 days. The most common ssCART-19-related AEs were transient neutropenia (100.0%), lymphopenia (100.0%), leukopenia (100.0%), anaemia (100.0%) and thrombocytopenia (83.3%). Adverse events of special interest (AESI) were CRS and ICANS. Among the 12 patients, 9 patients (75.0%) developed CRS, and 3 patients (25.0%) were grade 3 CRS. Notably, none of the 12 patients were occurred ICANS. No death cases were reported due to CRS or ICANS. A 83.3% overall response rate was achieved in efficacy-evaluable patients (n=12), with 7 complete response (CR, 58.3%), and 3 CR with incomplete hematological recovery (CRi,25.0%). The median duration of remission, relapse-free survival and OS have not been reached. Among them, 6 patients were in ongoing remission for over 12 months. Notably, one of the 12 patients (S012) had central nervous system infiltration with grade 2 before ssCART-19 infusion(Figure 1). After ssCART-19 therapy, the patient had no ICANS and got continuous remission. Robust CAR T-cell expansion occurred in all patients with a median time to T max of 12.5 days (range 9-14d), and peak copy number (C max) of 52495 (194-348000) copies/μg DNA. Conclusions ： ssCART-19 CAR-T cell therapy can effectively reduce the incidence of severe CRS and ICANS, especially control the occurrence of ICANS. And ssCART-19 achieved a high rate of remission in adult patients with R/R B-cell ALL. The ORR within 3 months were 83.3%. And, ssCART-19 shows good clinical efficacy in the treatment of leukemia patients with central nervous system infiltration. Thus, with the combination of short hairpin RNA-IL-6 gene silencing element, ssCART-19 can greatly improve the safety of CAR-T therapy, especially in central nervous system infiltration patients.

Patterns of Cytokine Release Syndrome with Teclistamab in Relapsed/Refractory Multiple Myeloma with or without Prior T-Cell Redirection Therapy

Introduction: Numerous therapeutic options with novel mechanisms of actions are currently available for treating patients with relapsed/refractory multiple myeloma (RRMM). Teclistamab (Tec) is a first-in-class BCMA X CD3 bispecific T-cell engager antibody that was recently approved for patients with RRMM who have received at least 4 lines of therapy (LOT). In the landmark MajesTEC-1 study, cytokine release syndrome (CRS) with Tec was reported at a rate of 72% (Usmani S, et al. Lancet 2021, Moreau P, et al. N Engl J Med 2022); however, patients who were previously treated with T-cell redirection therapies (TCRT) were excluded from the study [TCRT: chimeric antigen receptor (CAR) T-cells and/or other bispecific antibodies]. Given this knowledge gap, we investigated whether prior TCRT exposure impacts CRS rates with Tec in a real-world setting. Methods: Our institutional plasma cell disorders database was queried to identify RRMM patients who received commercial Tec from November 2022 to July 2023. Patients who completed the Tec step-up dosing phase (first step-up, second step-up and first full doses) were divided into two cohorts based on prior TCRT exposure before treatment with Tec (prior TCRT exposure: cohort 1 and no prior TCRT exposure: cohort 2). Data collection included patient demographics, disease characteristics, prior LOT, and rates/grades of CRS and immune effector cell-associated neurotoxicity syndrome (ICANS). The Chi-square/Fisher exact test was used to compare differences in CRS rates between the two cohorts. Univariate and multivariate logistic regression analyses were performed to assess impact of prior TCRT exposure on CRS rates with Tec. The results were presented as odds ratios (ORs) with 95% confidence intervals (CIs). For cohort 1, the Mann-Whitney U-test was used to compare the median time elapsed from the last prior TCRT dose until the first Tec step-up dose between patients who developed CRS with Tec compared to those who did not. All statistical analyses were performed using SPSS software (version 29). Results: 50 patients (cohort 1: 25 and cohort 2: 25) were included in the final analysis. Baseline characteristics were comparable between the two cohorts except for prior LOT, where patients in cohort 1 represented a more heavily pretreated population (Table 1). The CRS rates were significantly lower in cohort 1 (40%, n=10) compared to cohort 2 (76%, n=19, p=0.02; Figure 1). CRS grades 1 and 2 occurred in 32% (n=8) and 8% (n=2) of patients in cohort 1 and 48% (n=12) and 28% (n=7) of patients in cohort 2, respectively (p=0.40). Among the CRS events, 60% (6/10) and 68% (13/19) occurred following the first Tec step-up dose in cohorts 1 and 2, respectively. In univariate logistic regression analysis, no prior exposure to a TCRT was associated with about a 5-fold increase in the incidence of CRS with Tec (OR= 4.8, 95% CI: 1.5-17.1.2, p=0.02). After adjusting for age, extramedullary disease (EMD) and elevated LDH levels, the impact of prior exposure to TCRT remained significant with an OR of 4.5 (95% CI: 1.3-18.6, p=0.01). In cohort 1 (prior TCRT exposure), the median time elapsed between the last TCRT dose and the first Tec step-up dose was 321.5 days (range: 50-808 days) in patients who developed CRS with Tec compared to 265 days (range: 41-1617 days) in those who did not (p=0.90). Conclusion: In our study, prior exposure to a TCRT was associated with a significantly lower incidence of CRS during the Tec step-up dosing phase, which may be suggestive of T-cell exhaustion. This observation will allow for optimization of CRS prophylactic strategies for RRMM patients receiving Tec treatment.

Phase 2 Study of Anakinra to Prevent CRS and Neurotoxicity after Treatment with Lisocabtagene Maraleucel: Planned Interim Analysis

BACKGROUND CD19 chimeric antigen receptor (CAR) T-cell therapies have transformed the treatment landscape for patients (pts) with relapsed/refractory B-cell malignancies, but they remain limited by significant toxicities: cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). While a more favorable toxicity profile had been reported with lisocabtagene maraleucel (liso-cel), based on our real-world experience CRS and ICANS are still observed in 70% and 30% of pts, respectively (Portuguese et al., ASH abstract #172978). Data from our group (Gazeau, TCT, 2023) and others (Strati, Blood, 2023; Park, Nat Med, 2023) suggested the recombinant interleukin-1 receptor antagonist anakinra may successfully prevent and treat CRS and ICANS. Thus, we conducted a phase 2 investigator-initiated clinical trial of anakinra to prevent CRS and ICANS after liso-cel (NCT04359784). We report here our planned interim analysis (n = 15). METHODS Adults ≥18 years of age with Karnofsky performance status ≥60% and B-cell non-Hodgkin lymphoma receiving liso-cel per the FDA label were eligible for this study. Anakinra was administered at 200 mg/day SC from day 0 through day +13 after liso-cel infusion, with the first dose administered approximately 2-4 hours prior to liso-cel infusion. CRS and ICANS severity were assessed per 2019 ASTCT criteria. The primary endpoint was the absence of any grade CRS assessed using the Bayesian optimal phase 2 design.The primary endpoint was not met if ≥6 of the first 15 pts developed any grade CRS. RESULTS Nineteen pts were screened for the study and 15 pts were enrolled. All 15 pts received liso-cel and all doses of SC anakinra. All pts were evaluable for toxicity assessment; 12 pts were evaluable for disease response assessment at day +28 (n = 3, no measurable disease prior to lymphodepletion [LD]). Pt and disease characteristics are shown in Table 1. Eleven pts (73%) had diffuse large B-cell lymphoma, 3 (20%) had active CNS involvement, and 5 (33%) had bulky disease (≥5 cm). Median pre-LD serum ferritin and C-reactive protein (CRP) were 153 ng/mL (IQR, 129-231) and 6.8 (IQR, 1.5-17.2), respectively. All 15 pts received anakinra as planned without dose adjustment or interruption. There were no injection-site reactions or AEs attributed to anakinra. Two pts developed infections during anakinra treatment and were both due to mild Clostridium difficile colitis requiring oral antibiotics. Eight pts (53%) developed any grade CRS, including 1 (7%) case of grade 3 CRS. Four pts (27%) developed any grade ICANS, including 3 (20%) with grade 3 (Figure 1). Median CRS onset and duration were 2 and 2.5 days, respectively, and median ICANS onset and duration were 6 and 9 days, respectively. Three pts (20%) required tocilizumab (range, 0-1 doses), 4 (50%) required dexamethasone (median total dose, 5 mg; range, 0-200 mg), and 1 (12%) required high-dose methylprednisolone. The best overall response rate (ORR) by Lugano criteria was 67% (complete response, n = 5 [42%]). Study pts were retrospectively compared to pts who received liso-cel per standard of care off trial without prophylactic anakinra at our center (n = 42). Despite higher median pre-LD CRP and IL-6 levels, the incidence of CRS was lower in anakinra-treated compared to anakinra-untreated pts (53% vs. 69%, respectively) with comparable median duration of CRS (2.5 vs. 3 days, respectively). The incidence and duration of ICANS were similar (27% vs. 28%; median 9 vs. 8 days, respectively), as was the incidence and duration of hospitalization (67% vs. 74%, median 9.5 vs. 10 days, respectively). Based on Locally Estimated Scatterplot Smoothing (LOESS) estimates, time from liso-cel infusion to CRP normalization was faster in patients receiving anakinra (9 days) compared to those receiving liso-cel alone (14 days). CONCLUSION Low-dose SC anakinra prophylaxis during liso-cel treatment was very well tolerated with preserved anti-tumor efficacy. While our primary endpoint was not reached at our planned interim analysis, we observed lower CRS rates and faster resolution of CRS in comparison to a real-world cohort of pts receiving liso-cel without prophylactic anakinra. To further enhance the preventative effects of anakinra, we plan to change the administration route from SC to intravenous, and to allow anakinra dose uptitration for the last 10 participants in the study.