Risk Of Cytokine Release Syndrome Research Articles

Screening Analysis of Predictive Markers for Cytokine Release Syndrome Risk in CAR-T Cell Therapy

Background: Chimeric Antigen Receptor (CAR)-T cell therapy has emerged as a highly effective treatment for hematological tumors. However, the associated adverse reaction, Cytokine Release Syndrome (CRS), poses a significant challenge. While numerous studies have investigated CRS biomarkers during CAR-T cell therapy, the ability to predict CRS risk prior to treatment initiation remains a crucial yet underexplored aspect. Objective: The primary purpose of this study was to address the issue of limited data, explore an alternative approach using public data to identify predictive markers for CRS risk assessment from RNA-Seq in pre-treatment patients data, and comprehend the inducible mechanisms underlying CRS. Methods: We integrated information from two public databases, the FDA Adverse Event Reporting System (FAERS) for adverse reaction reports of CAR-T cell therapy and the Cancer Genome Atlas (TCGA) for RNA-Seq data on corresponding hematological tumors. Candidate genes were screened by correlation analysis between Reported Odds Ratio (ROR) values and RNA-Seq gene expression levels, and then core factors were identified through stepwise analysis of pathway enrichment, cluster analysis, and protein interactions. Results: Our analysis highlighted the correlation between CRS risk and pre-treatment T cell activation/ proliferation, identifying key genes (IFN-γ, IL1β, IL2, IL6, and IL10) as significant CRS indicators. Conclusion: This study offers a unique perspective on predicting CRS risk before CAR-T cell therapy, circumventing the challenges of scarce clinical data by leveraging analysis of public databases. It elucidates the crucial role of T cell activation/proliferation dynamics in CRS. The analytical methods and identified markers provide a reference for the research and clinical application of CAR-T cell therapy.

A phase 1/2 study of ubamatamab (REGN4018), a MUC16×CD3 bispecific antibody, administered alone or in combination with cemiplimab (anti–PD-1) in patients with recurrent ovarian cancer or MUC16+ endometrial cancer.

TPS5632 Background: Mucin 16 (MUC16) is a cell surface glycoprotein that is overexpressed in ovarian cancer (OC) and endometrial cancer (EC). Ubamatamab is a MUC16 × cluster of differentiation 3 (MUC16×CD3) bispecific antibody that bridges MUC16 on tumor cells and CD3 on T cells to promote T-cell–mediated cytotoxicity. Cemiplimab, a monoclonal antibody targeting the programmed cell death-1 (PD-1) receptor, enhanced MUC16×CD3 activity in preclinical models. In Phase 1 of this first-in-human study (NCT03564340), ubamatamab alone and in combination with cemiplimab demonstrated an acceptable safety profile, durable clinical activity across a range of doses, and linear pharmacokinetics (PK) in patients (pts) with recurrent OC (Liu et al. IGCS 2023. Plenary 03). Phase 2 will assess the efficacy of ubamatamab alone and in combination with cemiplimab in pts with recurrent OC. Ubamatamab will also be evaluated for recurrent advanced or metastatic EC that is MUC16+. Methods: For individuals with recurrent OC, elevated serum cancer antigen (CA)-125 ≥2× the upper limit of normal, and up to four prior lines of cytotoxic therapy, weekly dosing of ubamatamab alone or in combination with cemiplimab will be evaluated in monotherapy and combination therapy expansion cohorts. A Phase 2 cohort will also be randomized 1:1:1 to receive ubamatamab 250 mg IV Q3W or 800 mg IV Q3W or ubamatamab 250 mg IV Q3W + cemiplimab 350 mg IV Q3W. For the EC cohort (≥25% of tumor cells MUC16+, as assessed by immunohistochemistry [IHC]) pts with advanced or metastatic EC that has progressed or is recurrent after prior anti–PD-1 therapy and prior platinum-based chemotherapy will be enrolled. The initial EC cohort will receive ubamatamab 250 mg IV Q3W. Based upon observed safety and activity, additional cohorts may be enrolled to receive ubamatamab 800 mg IV Q3W and/or ubamatamab 250 mg IV Q3W + cemiplimab 350 mg IV Q3W. To limit the risk of cytokine release syndrome, all pts will receive ubamatamab once-weekly step-up dosing prior to addition of cemiplimab and/or Q3W dosing. Expansion cohorts will use a Simon 2-stage study design, with an interim analysis after the first 20 pts. Any treatment arm with ≥3 objective responses may be expanded to 50 pts. In Phase 2, the primary endpoint will be the objective response rate for each arm (RECIST v1.1). Secondary endpoints include duration of response and progression-free survival, safety, PK, and change from baseline in quality of life. Exploratory objectives include clinical correlation with serum CA-125, MUC16 IHC, and immune markers. The study is currently enrolling to these OC and EC expansion cohorts. Clinical trial information: NCT03564340 .

Ambulatory teclistamab administration in patients with relapsed/refractory multiple myeloma.

11146 Background: Teclistamab (Tec) is the first B-Cell Maturation antigen (BCMA)xCD3 bispecific antibody FDA approved for the treatment of relapsed or refractory multiple myeloma (RRMM) in patients who have received ≥4 prior lines of therapy. The phase 1-2 MajesTec-1 study raised concerns for cytokine release syndrome (CRS)/immune effector cell-associated neurotoxicity syndrome (ICANS). 48-hour inpatient observation is recommended for step-up dosing, which imposes financial and logistical burdens. We report our institutional experience with ambulatory Tec administration. Methods: Our inpatient/outpatient (IPOP) hybrid nursing unit is staffed with specialized nurses, advanced practice providers, and attending physicians. Our patients treated in IPOP must live within 1 hour of the hospital and have a 24-hour caregiver. Patients were treated with the recommended step-up dosing schedule. CRS grading and ICE scoring were performed daily. Both CRS and ICANS were graded according to the ASTCT grading systems. We collected toxicities until the second full treatment dose, at which point hospitalization is no longer recommended. Results: In total, 25 patients were treated with Tec between January 2023 to December 2023. The median age was 70 years old (range 59-89), with a median of 6 prior lines of therapy. One patient was dialysis dependent prior to starting Tec. All patients were triple class refractory. Thirteen patients (52%) received prior bone marrow transplant. One (4%) patient received prior anti-BCMA CAR-T therapy. Seventeen patients (68%) required admission during the Tec ramp-up period. CRS was observed in 15 (60 %) patients, all of which were grade I/II events. Fourteen of these patients were hospitalized for CRS. They were admitted for median number of 2 hospital days (range 1-6). Tocilizumab was administered for Grade 2 CRS in 3 patients (12%). ICANS was reported in 4 (16%) patients. Two of those patients developed Grade 2 ICANS which completely resolved with dexamethasone. The median number of admitted hospital days for these patients was 3 days (range 2-49). Neutropenia with ANC < 500 was seen in only 1 (4%) patient. Grade 3/4 infections were seen in 3 (12%) patients during the ramp-up period. Conclusions: Tec administration through an inpatient/outpatient hybrid model is safe and feasible. CRS was common but low grade and short lived. ICANS was observed, but remained low grade and may be attributable to our older patient population. As our center gained experience with the Tec management, we noticed lower rates of admission for low grade CRS. Lower incidences of infections and neutropenia demonstrate that these complications emerge in the months after starting therapy. Future studies will help identify patients who are higher risk for CRS and ICANS during ramp-up treatment and may pave the way for prophylactic interventions and outpatient administration.

Blinatumomab-induced macrophage activating syndrome (MAS) in adult with B-cell acute lymphoblastic leukemia (B-ALL)

Blinatumomab as a single agent has demonstrated superiority over salvage chemotherapy in patients with relapsed and refractory B-cell acute lymphoblastic leukemia (B-ALL), with manageable safety and efficacy. Though known to have anticipated drug toxicities including cytokine release syndrome (CRS) and neurotoxicity, there is only one prior report of macrophage activating syndrome (MAS) due to blinatumomab. Case Presentation: We report the first case of blinatumomab-induced MAS in an adult. The patient presented with fever, cough, and weakness on the second cycle of blinatumomab. Complete blood count was notable for severe leukopenia, with comprehensive metabolic panel notable for elevated alkaline phosphatase, AST, ALT, LDH, and hyperferritinemia consistent with MAS. The patient was already in MRD-negative remission at presentation with MAS. She responded rapidly to withholding the drug and administration of both tocilizumab and dexamethasone. She was able to restart therapy with blinatumomab dosed at 9 mcg/day with no recurrence of symptoms. Though MAS is not an expected association with blinatumomab, the risk for CRS is. Secondary MAS in this case likely shares a mechanism with other hyperinflammatory conditions. Management includes holding the offending agent, like blinatumomab, and administering tocilizumab and dexamethasone. Future research will be needed to predict which patients are at highest risk to develop MAS after similar T-cell therapies.

Predictive model for the risk of cytokine release syndrome with glofitamab treatment for diffuse large B-cell lymphoma

Predictive model for the risk of cytokine release syndrome with glofitamab treatment for diffuse large B-cell lymphoma

Outpatient administration of CAR T-cell therapy: a focused review with recommendations for implementation in community based centers.

Chimeric Antigen Receptor T-cell (CAR-T) therapy has transformed the treatment landscape for hematological malignancies, showing high efficacy in patients with relapsed or refractory (R/R) disease and otherwise poor prognosis in the pre-CAR-T era. These therapies have been usually administered in the inpatient setting due to the risk of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). However, there is a growing interest in the transition to outpatient administration due to multiple reasons. We review available evidence regarding safety and feasibility of outpatient administration of CD19 targeted and BCMA targeted CAR T-cell therapy with an emphasis on the implementation of outpatient CAR-T programs in community-based centers.

Development of a chimeric cytokine receptor that captures IL-6 and enhances the antitumor response of CAR-T cells

The efficacy of chimeric antigen receptor (CAR)-engineered Tcell therapy is suboptimal in most cancers, necessitating further improvement in their therapeutic actions. However, enhancing antitumor Tcell response inevitably confers an increased risk of cytokine release syndrome associated with monocyte-derived interleukin-6 (IL-6). Thus, an approach to simultaneously enhance therapeutic efficacy and safety is warranted. Here, we develop a chimeric cytokine receptor composed of the extracellular domains of GP130 and IL6RA linked to the transmembrane and cytoplasmic domain of IL-7R mutant that constitutively activates the JAK-STAT pathway (G6/7R or G6/7R-M452L). CAR-T cells with G6/7R efficiently absorb and degrade monocyte-derived IL-6 invitro. The G6/7R-expressing CAR-T cells show superior expansion and persistence invivo, resulting in durable antitumor response in both liquid and solid tumor mouse models. Our strategy can be widely applicable to CAR-T cell therapy to enhance its efficacy and safety, irrespective of the target antigen.

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.

Abstract CT243: Primary analysis of the Phase 2 ELM-2 study: Odronextamab in patients (pts) with relapsed/refractory follicular lymphoma (R/R FL)

Abstract Background: R/R FL is an incurable disease and outcomes worsen with successive relapses. A high unmet need remains for therapies that improve tumor control and extend survival after relapse. Odronextamab, an off-the-shelf CD20×CD3 bispecific antibody, demonstrated compelling efficacy, generally manageable safety, and maintenance of pt-reported overall quality of life scores from baseline in an interim analysis of the ELM-2 study (NCT03888105) in heavily pretreated pts with R/R FL (Villasboas et al. ASH 2023). Here, for the first time, we present the primary analysis of R/R FL in ELM-2. Methods: IV odronextamab was administered in 21-day cycles (C) until disease progression/unacceptable toxicity. Steroid prophylaxis and step-up dosing (0.7/4/20 mg) were used in C1 to mitigate the risk of cytokine release syndrome (CRS), followed by 80 mg on Days (D) 1, 8, and 15 of C2-4. Maintenance dosing continued at 160 mg Q2W, or Q4W if complete response (CR) was durable for 9 months (mo). Primary endpoint was objective response rate (ORR) per Lugano criteria by independent central review (ICR). Secondary endpoints included CR rate, duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Primary analysis was performed when 128 pts had ≥52 weeks’ follow-up. Results: At data cutoff (Oct 20, 2023), 128 pts with FL Grade (Gr) 1-3a were evaluable for efficacy and safety: median age 61 yrs (range 22-84); FLIPI risk score 3-5 57.8%; POD24 49.2%; median 3 prior lines of therapy (2-13); 71.9% refractory to last treatment (Tx); 74.2% refractory to an anti-CD20 antibody. The median no. of Tx cycles was 19.4 (0.1-95.9); 95.3% and 85.2% of pts completed C1 and C4, respectively.Median efficacy follow-up was 20.1 mo; ORR was 80.5% and CR rate was 73.4% confirmed by ICR. Responses were durable (median DOR 22.6 mo; median DOCR 25.1 mo). Median PFS was 20.7 mo and 24-mo PFS was 46.1%. Median OS was not reached and 24-mo OS was 70.1%.The odronextamab safety profile was generally manageable and consistent with previous reports. Tx-emergent adverse events (AEs) occurred in all pts (Gr ≥3 85.9%); 15.6% had AEs leading to Tx discontinuation. With 0.7/4/20 mg step up (n=60), CRS events were mostly low grade (Gr 1 45.0%; Gr 2 10.0%; Gr 3 in 1 pt), occurred mostly in C1, and resolved in a median of 2 days; ICANS was reported in 1 pt (Gr 2). Infection rates were consistent with heavily pretreated, immunosuppressed pts (Leonard et al. JCO 2019; Hayne et al. BBMT 2020), occurring in 79.7% (102/128) of pts (Gr 4/5 14.0%; COVID-19 36.7% [Gr 5 6.3%]).Conclusion: Odronextamab demonstrated deep and durable responses in heavily pretreated pts with R/R FL; 91% of responders achieved CR, correlating with favorable PFS and OS at 24 mo. Odronextamab had a generally manageable safety profile and a low incidence of Gr 3 CRS/ICANS. Odronextamab could offer an important off-the-shelf Tx option for pts with heavily pretreated R/R FL. Citation Format: Geoffrey Chong, Michal Taszner, Silvana Novelli, Seok-Goo Cho, Jose C. Villasboas, Ana Jiménez Ubieto, Benoît Tessoulin, Michelle Poon, David Tucker, Jan Walewski, Yuqin Song, Emmanuel Bachy, Stephanie Guidez, Aranzazu Alonso, Deepa Jagadeesh, Stefano Luminari, Laura Magnano Mayer, Elżbieta Iskierka-Jażdżewska, Monica Tani, Jingxian Cai, Amulya Uppala, Saleem Shariff, Jurriaan Brouwer-Visser, Aafia Chaudhry, Hesham Mohamed, Srikanth Ambati, Tae Min Kim. Primary analysis of the Phase 2 ELM-2 study: Odronextamab in patients (pts) with relapsed/refractory follicular lymphoma (R/R FL) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT243.

Abstract CT068: Interim results of the ongoing phase 1-2 clinical trial of KVA12123, an engineered IgG1 targeting VISTA, as monotherapy and in combination with pembrolizumab in patients with advanced solid tumors

Abstract V-domain Ig Suppressor of T-cell Activation (VISTA), a promising immuno-oncology target, is primarily expressed by immunosuppressive myeloid cells that infiltrate solid tumors. VISTA may contribute to resistance to anti-PD-(L)1 and anti-CTLA-4 therapies and correlates with a poor prognosis. KVA12123 is a human IgG1 monoclonal antibody that specifically binds to VISTA at neutral and acidic pHs. It was designed to improve pharmacokinetic (PK) characteristics as well as reduce the risk of cytokine release syndrome (CRS). KVA12123 exhibited strong anti-tumor activity alone and in combination with anti-PD1 in preclinical studies. It demonstrated an excellent safety profile in non-human primates. The VISTA-101 clinical trial is a first-in-human, Phase 1/2, multicenter, open-label, safety, PK and pharmacodynamic (PD) evaluation of KVA12123, both as monotherapy and in combination with pembrolizumab, in adult patients with advanced solid tumors (NCT05708950). METHODS: The phase 1 of VISTA-101 is an accelerated Bayesian Optimal Interval Design consisting of two arms: Part A) KVA12123 monotherapy dose escalation from 3 mg to 1000 mg including 6 cohorts and Part B) KVA12123 dose escalation from 30 mg to 1000 mg in combination with 400 mg fixed dosing of pembrolizumab including 4 cohorts. The primary objectives are safety, tolerability and to define a recommended phase 2 dose. Safety, PK and receptor occupancy data were considered during dose escalation. VISTA-101 is also assessing PD and predictive biomarkers of response. Patient tumor response is evaluated by iRECIST. RESULTS: Forty-two patients have been enrolled in the dose escalation monotherapy arm of the study. KVA12123 was administered at doses ranging from 3 to 1000 mg every 2 weeks over a 6-week cycle. KVA12123 was well tolerated at all dose levels and no DLTs were observed. The most frequently observed adverse events were grade 1 or 2 transient infusion-related reactions. No evidence of CRS-associated cytokines were detected. PK analysis demonstrated greater than dose-proportional exposure consistent with target-mediated metabolism. A VISTA receptor occupancy assay demonstrated full target engagement at doses of 30 mg and above. PD analysis indicated a dose-dependent induction of pro-inflammatory myeloid derived cytokines and chemokines involved in immune cell activation and recruitment to the tumor microenvironment including CCL2, CCL3, CCL4 and CXCL10. Increases in nonclassical monocytes, NK cells, CD4+ and CD8+ T cells were also demonstrated, consistent with observations made in preclinical models and indicative of VISTA target engagement. Patient tumor response evaluations in the monotherapy arm will be reported. The study continues to evaluate KVA12123 both as a monotherapy and in combination with pembrolizumab to define the recommended phase 2 dose. Citation Format: Evan Y. Yu, Jason Henry, Manish R. Patel, Paul Swiecicki, Ida Micaily, Benjamin Garmezy, Kalyan Banda, Vinny Hayreh, Kurt Lustig, Yulia Ovechkina, Shawn P. Iadonato, Thierry Guillaudeux, Lee Rosen. Interim results of the ongoing phase 1-2 clinical trial of KVA12123, an engineered IgG1 targeting VISTA, as monotherapy and in combination with pembrolizumab in patients with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT068.

Meta-DHGNN: method for CRS-related cytokines analysis in CAR-T therapy based on meta-learning directed heterogeneous graph neural network.

Chimeric antigen receptor T-cell (CAR-T) immunotherapy, a novel approach for treating blood cancer, is associated with the production of cytokine release syndrome (CRS), which poses significant safety concerns for patients. Currently, there is limited knowledge regarding CRS-related cytokines and the intricate relationship between cytokines and cells. Therefore, it is imperative to explore a reliable and efficient computational method to identify cytokines associated with CRS. In this study, we propose Meta-DHGNN, a directed and heterogeneous graph neural network analysis method based on meta-learning. The proposed method integrates both directed and heterogeneous algorithms, while the meta-learning module effectively addresses the issue of limited data availability. This approach enables comprehensive analysis of the cytokine network and accurate prediction of CRS-related cytokines. Firstly, to tackle the challenge posed by small datasets, a pre-training phase is conducted using the meta-learning module. Consequently, the directed algorithm constructs an adjacency matrix that accurately captures potential relationships in a more realistic manner. Ultimately, the heterogeneous algorithm employs meta-photographs and multi-head attention mechanisms to enhance the realism and accuracy of predicting cytokine information associated with positive labels. Our experimental verification on the dataset demonstrates that Meta-DHGNN achieves favorable outcomes. Furthermore, based on the predicted results, we have explored the multifaceted formation mechanism of CRS in CAR-T therapy from various perspectives and identified several cytokines, such as IFNG (IFN-γ), IFNA1, IFNB1, IFNA13, IFNA2, IFNAR1, IFNAR2, IFNGR1 and IFNGR2 that have been relatively overlooked in previous studies but potentially play pivotal roles. The significance of Meta-DHGNN lies in its ability to analyze directed and heterogeneous networks in biology effectively while also facilitating CRS risk prediction in CAR-T therapy.

Abstract 6713: TICTE, A trispecific T-cell engager with immune checkpoint modulation for solid tumors

Abstract Background: Bispecific T-cell engager (BiTE) is a targeted cancer immunotherapy which bridges T-cells to cancer cells, leading to activation of T-cells and killing cancer cells. While BiTEs have shown promising therapeutic efficacy in the treatment of hematological malignancies, therapeutic benefit of T-cell engagers are still in exploration for the treatment of solid tumors. Upregulation of immune checkpoints presents one of the major resistant mechanisms of the BiTE therapy. Here, we report a Trispecific Immune Check-point T-Cell Engager (TICTE) platform that targets both CD3 and PD-L1 simultaneously, which activates the T-cells as well as modulates the immune checkpoint blockade through the PD/PD-L1 axis, respectively. Our in vitro and in vivo studies demonstrate that the TICTEs induce dramatic and superior antitumor activity compared to its counterpart BiTE alone and the BiTE with anti-PD-L1 combination. These studies suggest that the TICTE (CD3xTAAxPD-L1), a single-agent with dual function of T-cell activation and immune checkpoint modulation, may provide an efficacious therapy to patients with solid tumors. Methods: Various TICTEs and BiTEs formats using the human IgG like architecture in three different TAA examples were generated. Their biophysical and biological activities were characterized. The cell binding activity and antigen density of cell lines were determined using flow cytometry. TDCC activity was measured using xCELLigence RTCA eSight system. In vitro efficacy was evaluated with multiple cancer cell lines and toxicity was evaluated with normal cell lines. The humanized xenograft models were utilized to investigate the TICTEs efficacy in vivo. Results: All TICTEs adopted their intended forms and showed robust biophysical properties. The TICTEs demonstrated the blockade activity of PD1/PD-L1 axis, as well preferentially targeted tumor cells expressed both TAAs and PD-L1. Large therapeutic windows were observed in three TAA (cMET, Her2 and Trop2) TICTEs. TICTEs showed a superior efficacy compared to counterpart BiTEs and combination of BiTE with a PD-L1 inhibitor in vitro and in vivo. Low cytokine release was observed compared to combination of BiTEs with a PD-L1 inhibitor, signifying the reduced risk of cytokine release syndrome (CRS) often associated with BiTE therapy. Conclusion: A single agent of the TICTE platform with unique biological property, superior efficacy and low cytokine release could represent an alternative combination immunotherapy for solid tumors. Citation Format: Xiufeng Wu, Xiaoshan Min, Yinan Wu, Lin Liu, Jing Zhou, Silvia Hudson, Shih-ping Chen, Jennifer Li, Will Draper, Subhadra Dash, Shidong Ma, Hang Chen, Zhulun Wang. TICTE, A trispecific T-cell engager with immune checkpoint modulation for solid tumors [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 6713.

Abstract 6343: AnTenGagerTM, a novel “2+1” T cell engager platform, enables conditional T cell activation with reduced risk of CRS

Abstract Background: CD3+ T cell engaging bispecific antibodies (TCE) redirect T cells to attack targeted tumor cells by simultaneously binding TAA on cancer cells and CD3 complex on a T cell to form a TCR-independent immune synapse. Multiple TCEs have demonstrated promising therapeutic efficacy in the treatment of hematological malignancies. In contrast, suboptimal efficacy in the treatment of solid tumors and the risk of inducing cytokine release syndrome (CRS) continue to be major challenges. Several factors, such as format, affinity, and valency of the antibody, TAA copy number, and antigen size and epitope, can impact the therapeutic efficacy and safety of a TCE. In this study, we developed a novel “2+1” TCE platform, AnTenGagerTM, which enables conditional T cell binding and activation upon TAA-crosslinking, potent anti-tumor activity, and reduced risk of CRS. Methods: Humanized CD3 antibodies were derived from mouse hybridoma, followed by affinity optimization utilizing Computer Aided Drug Design. The Fab-scFv-Fab format was used as the backbone structure of AnTenGagers. The anti-CD3 scFv sequences and the length of peptide linkers between VH/VL, scFv/CH1, and scFv/CH2 were screened and compared in different preclinical assays. LALA mutations (L234A, L235A) were introduced to abolish the Fc receptor binding capability. In a series of in vitro and/or in vivo models, the efficacy, safety and developability of AnTenGagers targeting multiple TAAs, such as Her2, GD2, CDH6, LILRB4, FLT3 and GPRC5D, were evaluated. Results: A library of humanized parental CD3 antibodies with a broad spectrum of affinities were generated, some of which cross react with monkey CD3. AnTenGagers exhibited limited binding to CD3-positive cells before TAA-crosslinking, suggesting a reduced risk of CRS that is caused by systemic CD3+T cell activation. Four CD3 sequences with varying affinities were utilized to construct AnTenGagers with identical TAA-targeting arm. Compared to clinical benchmarks targeting the same TAA, all AnTenGagers demonstrated substantially lower binding capacity to CD3+ cells in the absence of TAA-crosslinking, while inducing increased cytotoxicity against target-positive tumor cells. In addition, they induced significantly less ex-vivo cytokine release by human PBMC than benchmarks. Notably, all AnTenGagers demonstrated enhanced in vivo efficacy compared to the benchmark, exhibiting complete response (CR) in PBMC humanized MM1S mouse CDX model while the serum concentration of proinflammatory cytokines was substantially lower in groups treated with AnTenGagers. AnTenGagers also demonstrated good developability with high expression yield, good thermostability and high stability under different stress conditions. Conclusions: These results suggested that AnTenGagerTM is a promising platform for developing the next generation of TCEs with enhanced efficacy and safety. Citation Format: Bing Hou, Hui Yuwen, Tengteng Li, Yijing Ren, Ao Sun, Zaoshun Hu, Jay Mei, Bo Shan. AnTenGagerTM, a novel “2+1” T cell engager platform, enables conditional T cell activation with reduced risk of CRS [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 6343.

Abstract 2372: ATG-102, a novel LILRB4 x CD3 T cell engager, targeting two nonoverlapping epitopes of LILRB4, for the treatment of monocytic AML

Abstract Background: Acute myeloid leukemia (AML) is the most common acute leukemia in adults, and the treatment of AML, especially monocytic AML subtypes still has a poor outcome. T cell engagers (TCE) have been well used for the treatment of hematological malignancies, such as B cell leukemia and multiple myeloma. However, lack of ideal target antigens that only express on AML and leukemic stem cells (LSCs) but not on normal hematopoietic stem cells (HSCs) hampers the development of TCE therapy for AML. Leukocyte immunoglobulin-like receptor B4 (LILRB4), an inhibitory receptor belonging to the LILR family, is highly and restrictedly expressed on monocytic M4/M5 AML subtypes and LSCs, but not on normal HSCs which makes it an ideal target for TCE. Here we report a novel LILRB4 x CD3 bispecific T cell engager based on AnTenGagerTM platform, ATG-102. It targets two distinct epitopes of LILRB4, inducing potent T cell-dependent cellular cytotoxicity (TDCC) with low CRS, resulting in a potent anti-tumor efficacy in vitro and in vivo. Method: ATG-102 was constructed by introducing a high affinity anti-CD3 single chain fragment variable (scFv) to the hinge region of one of the heavy chains of a LILRB4 monoclonal antibody. A scFv targeting another epitope of LILRB4 was connected to the C terminal of the same heavy chain by GSSS linker, enabling a trivalent, dual epitope recognition of LILRB4. ATG-102 was evaluated in a series of preclinical studies for binding epitope and affinity, T cell activation, T cell dependent cytotoxicity (TDCC), and cytokine release. The in vivo antitumor efficacy of ATG-102 was evaluated in a humanized PBMCs and THP-1-luciferase cells engrafted NCG mice model. Results: ATG-102 binds to LILRB4 positive cells with a single-digit nM affinity. It binds to two distinct and nonoverlapping epitopes of LILRB4. ATG-102 showed limited binding capability to CD3+ cells before LILRB4 crosslinking. However, with the presence of LILRB4 positive THP-1 cell, ATG-102 strongly activated primary T cells, upregulating early and later markers of T cell activation, CD69 and CD25, respectively. ATG-102 induced strong TDCC against LILRB4-high expressing THP-1 cells, and it induced more potent TDCC against LILRB4-low expressing MOLM-13 cells than a benchmark antibody. While compared with benchmark, ATG-102 induced significantly lower release of IL-6, which is one of the major cytokines involved in cytokine release syndrome (CRS). In addition, ATG-102 demonstrated more potent in vivo anti-tumor efficacy compared with the benchmark antibody at 1 mg/kg and 0.1 mg/kg dose level in PBMC-humanized NCG mice bearing THP-1-luciferase cells. Conclusion: ATG-102 demonstrates trivalent, dual epitope recognition of LILRB4, conditionally redirects and activates T cells to recognize and kill monocytic AML cells. It demonstrates potent in vitro and in vivo anti-tumor efficacy with low risk of CRS. Citation Format: Ao Sun, Mengshi Gao, Rong Guo, Huiling Liu, Zaoshun Hu, Enlin Zheng, Hui Yuwen, Peng Chen, Jay Mei, Bo Shan, Bing Hou. ATG-102, a novel LILRB4 x CD3 T cell engager, targeting two nonoverlapping epitopes of LILRB4, for the treatment of monocytic AML [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 2372.

Impact of Treatment Modality and Route of Administration on Cytokine Release Syndrome in Relapsed or Refractory Multiple Myeloma: A Meta-Analysis.

B-cell maturation antigen (BCMA)-targeting immunotherapies (e.g., chimeric antigen receptor T cells (CAR-T) and bispecific antibodies (BsAbs)) have achieved remarkable clinical responses in patients with relapsed and/or refractory multiple myeloma (RRMM). Their use is accompanied by exaggerated immune responses related to T-cell activation and cytokine elevations leading to cytokine release syndrome (CRS) in some patients, which can be potentially life-threatening. However, systematic evaluation of the risk of CRS with BCMA-targeting BsAb and CAR-T therapies, and comparisons across different routes of BsAb administration (intravenous (i.v.) vs. subcutaneous (s.c.)) have not previously been conducted. This study utilized a meta-analysis approach to compare the CRS profile in BCMA-targeting CAR-T vs. BsAb immunotherapies administered either i.v. or s.c. in patients with RRMM. A total of 36 studies including 1,560 patients with RRMM treated with BCMA-targeting CAR-T and BsAb therapies were included in the analysis. The current analysis suggests that compared with BsAbs, CAR-T therapies were associated with higher CRS incidences (88% vs. 59%), higher rates of grade ≥ 3 CRS (7% vs. 2%), longer CRS duration (5 vs. 2 days), and more prevalent tocilizumab use (44% vs. 25%). The proportion of CRS grade ≥ 3 may also be lower (0% vs. 4%) for BsAb therapies administered via the s.c. (3 studies, n = 311) vs. i.v. (5 studies, n = 338) route. This meta-analysis suggests that different types of BCMA-targeting immunotherapies and administration routes could result in a range of CRS incidence and severity that should be considered while evaluating the benefit-risk profiles of these therapies.

Glofitamab (Columvi)


 CADTH recommends that Columvi be reimbursed by public drug plans for the treatment of adult patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) not otherwise specified, DLBCL arising from follicular lymphoma (trFL), or primary mediastinal B-cell lymphoma (PMBCL), who have received 2 or more lines of systemic therapy and are ineligible to receive or cannot receive CAR-T cell therapy or have previously received CAR-T cell therapy if certain conditions are met.
 Columvi should only be covered to treat adult patients who have DLBCL not otherwise specified, trFL, or PMBCL that has come back or that did not respond to 2 or more previous treatments for their cancer, and who have also previously received CAR-T cell therapy, declined CAR-T cell therapy, or cannot receive CAR-T cell therapy.
 Columvi should only be reimbursed for a maximum of 12 treatment cycles, after a single dose of obinutuzumab to reduce the risk of cytokine release syndrome (CRS) and should not be given in combination with other anticancer drugs. Reimbursement of Columvi should be discontinued if a patient’s cancer grows or spreads or if treatment is unacceptably toxic to the patient. Columvi should only be reimbursed when prescribed by specialists with experience managing DLBCL, and if its cost is reduced.

Cellular dynamics following CAR T cell therapy are associated with response and toxicity in relapsed/refractory myeloma

B-cell maturation antigen (BCMA)-targeting chimeric antigen receptor (CAR) T cells revolutionized the treatment of relapsed/refractory multiple myeloma (RRMM). However, data on cellular (CAR) T cell dynamics and the association with response, resistance or the occurrence of cytokine release syndrome (CRS) are limited. Therefore, we performed a comprehensive flow cytometry analysis of 27 RRMM patients treated with Idecabtagene vicleucel (Ide-cel) to assess the expansion capacity, persistence and effects on bystander cells of BCMA-targeting CAR T cells. Additionally, we addressed side effects, like cytokine release syndrome (CRS) and cytopenia. Our results show that in vivo expansion of CD8+ CAR T cells is correlated to response, however persistence is not essential for durable remission in RRMM patients. In addition, our data provide evidence, that an increased fraction of CD8+ T cells at day of leukapheresis in combination with successful lymphodepletion positively influence the outcome. We show that patients at risk for higher-grade CRS can be identified already prior to lymphodepletion. Our extensive characterization contributes to a better understanding of the dynamics and effects of BCMA-targeting CAR T cells, in order to predict the response of individual patients as well as side effects, which can be counteracted at an early stage or even prevented.

Abstract A036: Development of a stirred-tank bioreactor scale-up approach to allogeneic natural killer cell culture

Abstract Natural killer (NK) cells are innate lymphocytes that play a critical role in the immune response, as they recognize and eliminate virus-infected, cancerous, and other abnormal cells in an antigen-independent manner. This unique method of recognition makes NK cells an attractive target for utilization as an immunotherapy, as studies have demonstrated they reduce both the induction of graft-versus-host disease and the risk of cytokine release syndrome compared to T-cell based therapies. Additionally, these advantages over canonical T-cell therapies make NK therapies attractive candidates for allogeneic, as opposed to autologous, products. Given their cost-effective scale-up potential, developing a stirred-tank bioreactor (STR)-based NK cell expansion platform to achieve clinical-level expansion is of significant interest, as it would reduce the cost of producing such therapies and improve patient accessibility. To test ideal culture conditions for STR expansion, NK cells were first isolated from healthy donor Leukopaks prior to cryopreservation. Frozen, isolated NK cells were then thawed, co-cultured with varying ratios of irradiated K562 cells and supplemental cytokines from Cytiva in a 6-well G-Rex or DASbox® STR. Finally, cells were harvested for downstream analytics, including identity and functional characterization by flow cytometry and potency assays. A fold expansion of greater than 100 was achieved once the ratio of irradiated K562 to NK cells was optimized. One of the primary challenges encountered was donor-to-donor variation, not only with respect to proliferative capacity, but NK functional phenotype and activity as well. Therefore, a small-scale donor screen was conducted and donors with similar proliferative and functional capabilities were selected for large-scale expansion. Future work will focus on optimizing NK cell transduction to enable genetic customization and scaling-up to a clinically-relevant STR. The successful small-scale NK expansion in an STR demonstrated here lays the groundwork for an expansion platform that enables the manufacturing of various NK-based therapeutics at clinical scale. Citation Format: Mathura Yogalingam, Rebecca Jagroop, Alireza Khalajzadeh, Thergiory Irrazabal, Melissa Perea, Pooja Pushparaj, Roxana Roshankhah, Paul Bowles, Michael Le. Development of a stirred-tank bioreactor scale-up approach to allogeneic natural killer cell culture [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2023 Oct 1-4; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Immunol Res 2023;11(12 Suppl):Abstract nr A036.

Preclinical Characterization of the Anti-Leukemia Activity of the CD33/CD16/NKG2D Immune Modulating TriNKET ® BMS-986357 (CC-96191)

CD33 is widely expressed by myeloid cells and is a validated drug target in acute myeloid leukemia (AML), as shown by the benefit of some patients from the CD33 antibody-drug conjugate gemtuzumab ozogamicin (GO). However, GO is often ineffective and toxic, prompting interest in more potent CD33-directed therapies. Success of T cell-engaging bispecific antibodies in lymphoid malignancies has raised enthusiasm for similar agents targeting CD33, but toxicities from activated T cells cause significant challenges for their use and provide a strong rationale to explore drugs engaging natural killer (NK) cells. Here, we investigated BMS-986357, a TriNKET ® that activates NK cells via CD16 and NKG2D receptors while targeting CD33. This format was chosen because simultaneous engagement of multiple activating NK cell receptors yields greater cytotoxic activity against neoplastic cells than engagement via a single activating receptor. Surface plasmon resonance analyses showed BMS-986357 simultaneously binds CD33, NKG2D, and CD16a, and co-engagement of NKG2D and CD16a increases the avidity. In the presence of primary human NK cells from healthy donors or a human NK cell line, the TriNKET ® demonstrated broad cytolytic anti-leukemia activity in a strictly CD33-dependent manner using a panel of CD33-expressing or CD33-deficient/deleted acute leukemia cells. Consistent with this, removing the CD33 binding domain rendered BMS-986357 ineffective against CD33+ AML cells. Drug-induced cytotoxicity was greater with BMS-986357 than with monoclonal CD33 antibodies, including lintuzumab and an afucosylated antibody with enhanced NK function, demonstrating the benefit of the TriNKET ® format. Compared to BMS-986357, substantially less cytotoxicity was observed with an Fc-mutant variant of BMS-986357 that abrogates binding to CD16a or an NKG2D dead-arm TriNKET ®, and cytolytic effects were reduced with a CD16-deficient NK cell line vs. a CD16-expressing subline, indicating maximal efficacy of BMS-986357 required co-engagement of CD16a and NKG2D. Using sublines of OCI-AML3 and KG-1 cells (both cell lines with low endogenous CD33 expression) to overexpress wild-type CD33 at increasing levels, we found low abundance of CD33 curtailed BMS-986357-induced cytotoxicity. Flow cytometric binding studies identified BMS-986357 to recognize the membrane-distal V-set domain of CD33. Unlike GO, BMS-986357-mediated cytolysis was not affected by over-expression of ABC transporter proteins by AML cells. The potency but not maximal activity of BMS-986357 was reduced by super-physiologic concentrations of soluble CD33; in contrast, the soluble form of the NKG2D ligand MICA did not impact TriNKET ® activity. In the presence of CD33+ AML cells, BMS-986357 activated NK cells but not T cells from healthy donor peripheral blood mononuclear cells and produced similar levels of maximum cytolysis as a CD33/CD3 bispecific antibody. Despite this, BMS-986357 elicited 10 to >100-fold lower soluble cytokine levels including IFN-γ, TNF, IL-6, and GM-CSF than a CD33/CD3 bispecific antibody, suggesting BMS-986357 has the potential for CD33/CD3 bispecific-like efficacy without the associated risk of cytokine release syndrome. Finally, in bone marrow specimens from patients with AML, BMS-986357 killed AML cells but not normal monocytes, suggesting selectivity of drug-induced cytotoxicity toward neoplastic cells, consistent with the notion NK cells are capable to differentiate between healthy and leukemic CD33+ cells. This selectivity suggests BMS-986357 may produce less myelosuppressive toxicity than what has been observed with CD33 targeting antibody-drug conjugates. In summary, our findings demonstrate that BMS-986357 TriNKET ® has potent CD33-dependent cytolytic activity in vitro against human AML cells, supporting the drug's exploration in early phase clinical trials. One such trial (NCT04789655) has opened accrual for adults with relapsed/refractory AML.

Clinical Factors Associated with Cytokine Release Syndrome and Dosing Recommendations for Restarting Elranatamab Following an Interruption

BACKGROUND In the MagnetisMM-3 (NCT04649359) study, elranatamab (ELRA) administered at a dose of 76 mg once-weekly (QW) with 2 step-up priming doses of 12 mg on day 1 and 32 mg on day 4 had a manageable safety profile, with 56.3% of patients developing cytokine release syndrome (CRS) and 98.8% of events occurring with the first 3 doses. Here, we report clinical factors associated with CRS and dosing recommendations for restarting treatment after dose interruptions in patients with relapsed or refractory multiple myeloma (RRMM) undergoing treatment with ELRA. METHODS Eligible patients received ELRA subcutaneously in step-up priming doses of 12 and 32 mg on days 1 and 4 of cycle 1, respectively, followed by 76 mg of ELRA QW. CRS events were graded according to the criteria of the American Society for Transplantation and Cellular Therapy and managed according to published guidelines. Multivariable analyses were performed to identify clinical factors associated with CRS. Baseline factors (extramedullary disease by BICR, prior antibody-drug conjugate, prior CAR-T, number of prior lines of therapy [≤5, >5], sex, and age [continuous variable]) were included in the model for CRS after the initial dose, and only post-baseline factors (time to previous CRS and time to initial tocilizumab use) were included in the model for CRS after the second dose. A previously described population pharmacokinetic (PK) model was used to simulate different interruption scenarios and determine how long it takes for ELRA exposure to drop below the threshold associated with CRS events (Hibma J, et al. Poster presented at PAGE 31 2023 [abstract 10648]). The data used to develop this model was collected from the following open-label elranatamab trials: MagnetisMM-1 (NCT03269136; phase 1), MagnetisMM-2 (NCT04798586; phase 1), MagnetisMM-3 (NCT04649359; phase 2), and MagnetisMM-9 (NCT05014412; phase 1/2). Of 183 patients who were treated in MagnetisMM-3 with the 2 step-up priming dosing, 106 patients (57.9%) experienced CRS, 43.7% grade 1, 13.7% grade 2, and 0.5% grade 3. Tocilizumab was used to manage CRS. Of the 130 CRS events, 37 (28.5%; 20 grade 1 and 17 grade ≥2) were treated with tocilizumab, and 93 (71.5%; 82 grade 1 and 11 grade ≥2) were not. After the initial elranatamab dose, 79/183 patients had CRS. The presence of extramedullary disease was predictive of a decreased risk of CRS after the initial dose. Of the 180 who received a second elranatamab dose, 35 had CRS afterwards. In a multivariable model also adjusting for CRS after the initial dose, prior tocilizumab use was predictive of a decreased risk of CRS after the second dose. After receiving doses of 76 mg of ELRA, 16 instances of dose delays lasting >6 to ≤12 weeks were observed. In most of these instances (11/16; 68.8%), patients did not repeat the 32-mg step-up dose. In 5 instances, patients restarted treatment with 32 mg of ELRA. No patients experienced CRS after retreatment. For the 4 instances of dose delays lasting >12 weeks after a 76-mg dose, patients repeated the 32-mg step-up dose in 2 instances, and patients received >32 mg ELRA after the interruption in the other 2 instances, with none experiencing CRS after retreatment. With dose delays of 6-12 weeks, ELRA exposure decreases below the C max after a 32-mg dose but not less than that for the 12-mg dose. With dose delays >12 weeks, ELRA exposure decreases below the C max after a 12-mg dose. To minimize the risk of CRS events after dose interruptions, clinical and PK data and modeling were used to develop recommendations for restarting therapy (Figure). CONCLUSIONS Extramedullary disease and use of tocilizumab were associated with a decreased risk of CRS. Based on clinical and PK data and modeling, it is recommended that patients receiving 76 mg ELRA who then experience dose delays lasting 6-12 or >12 weeks should restart treatment at doses of 32 or 12 mg, respectively.