Lekakis, Lazaros J.

Abstract Introduction: Axicabtagene ciloleucel (axi-cel) is an autologous anti-CD19 CAR T cell therapy approved by the US Food and Drug Administration for patients with relapsed or refractory large B cell lymphoma with ≥2 prior systemic therapies. Results from the primary analysis of ZUMA-1 demonstrated an objective response rate of 82%, with 54% complete responses (Neelapu & Locke et al. N Engl J Med. 2017). Grade ≥3 cytokine release syndrome and neurologic events occurred at 13% and 28%, respectively, and were generally reversible. Building on previous reports of CAR treatment-related tumor microenvironment (TME) changes (Galon et al. ASCO 2017. #3025), here, we examine associations between the pretreatment TME and clinical outcomes. Methods: Patients received axi-cel (target dose, 2.0 × 106 cells/kg) in phases 1 and 2 of ZUMA-1 (NCT02348216). Baseline tumor biopsy samples were analyzed by digital gene expression (NanoStringTM). Prespecified bioinformatics algorithm and cutoffs were applied to immune-mediated tumor regression genes (Immunosign®; Galon et al. Immunity. 2013), which included T cell-specific (effector T cell, Th1) genes, interferon pathway-related genes, chemokines, cytokines, and immune checkpoints. Expression analysis and scoring examined potential associations between TME features and response. A broader, hypothesis-generating analysis was performed using all PanCancer Immune Profiling Panel genes (770 genes) by NanoStringTM. Fisher's exact test and Wilcoxon signed rank test with multiple test correction by false discovery rate (Benjamini-Hochberg) were used. Results: Tumor samples from all immediate pre-treatment biopsy samples that passed quality control (6 nonresponders; 21 responders) were analyzed. Pretreatment TME Immunosign21 scores were elevated in responders vs nonresponders. Responses were seen in 18/20 patients (90%) with high and 3/7 patients (43%) with low Immunosign21 scores. Immune-related genes from the Immunosign21 or Pan Cancer profile that showed higher expression at baseline in responders included CTLA4, CD3γ, CD3ϵ, CD27, and ICOSL. Genes with lower expression in responders at baseline included MHC class II genes and cancer-testis antigens. Additional correlative analyses between TME characteristics and CAR T cell activity will be presented. Conclusions: Increased baseline expression of TME genes related to T cell activity, along with decreased expression of MHC class II and cancer testis antigens (CTAs), may be associated with a response to axi-cel. These findings should be validated in ongoing and subsequent studies. Citation Format: John M. Rossi, Jerome Galon, Sarah Turcan, Corinne Danan, Frederick L. Locke, Sattva S. Neelapu, David B. Miklos, Caron A. Jacobson, Lazaros J. Lekakis, Yi Lin, Armin Ghobadi, William Y. Go, Adrian Bot. Characteristics of the pretreatment tumor microenvironment may influence clinical response in patients with refractory large B cell lymphoma treated with axicabtagene ciloleucel (axi-cel) in the pivotal ZUMA-1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-016.

Abstract Introduction: Axicabtagene ciloleucel (axi-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy. ZUMA-1 is a multicenter registrational trial of axi-cel in patients with refractory, aggressive B-cell non-Hodgkin lymphoma. In a pre-specified interim analysis, ZUMA-1 met its primary endpoint with a 76% objective response rate and 47% complete response. The incidence of Grade 3 and higher (Gr 3+) cytokine release syndrome (CRS) and neurologic events (NE) was 13% and 29%, respectively, in 93 patients with 1 month follow-up (Neelapu ASH 2016). We present novel immune signatures of Gr 3+ CRS and NE by analyzing the axi-cel-related biomarker profile in association with clinical outcomes. Methods: In this interim analysis of 62 patients, 44 serum analytes pre- and post-axi-cel treatment were measured via ELISA at multiple timepoints during the first month. The number of CAR+ cells in blood was determined by qPCR. Kinetics and association of these markers with CRS and NE were analyzed. The treatment-related profile was defined by analytes with at least double an increase over baseline in at least 50% of patients. These analytes were selected and evaluated for association with Gr 3+ CRS or NE. Immune signatures were determined based on p-values applied to peak or cumulative levels of analytes and adjusted for multiplicity (stepdown method). Results: Out of 44 analytes measured, 12 demonstrated an increase by double over baseline in at least 50% of patients. This axi-cel-related biomarker profile includes immune proliferative/modulating cytokines, pro-inflammatory cytokines, markers of myeloid activation, and chemokines. Markers with the highest median-fold increase were IFNγ (44x), IL-10 (31x), IL-6 (26x), IL-15 (20x), and GRZB (17x). These peaked within 7-14 days and generally returned to baseline within 1 month post-treatment. Within this panel of 12 analytes elevated post-axi-cel treatment, markers associated with Gr 3+ CRS (p<0.05) were IL-10, IL-6, IL-2Rα, IL-8, MCP-1, IFNγ, IL-1Rα, and IP-10. Markers associated with Gr 3+ NE (p<0.05) were IL-6, IL-15, IL-8, and MCP-1. Peak levels of CAR T cells in blood, occurring within 14 days post-infusion, were associated with Gr 3+ NE (p=0.02) but not Gr 3+ CRS (p=0.6). A majority of patients with Gr 3+ NE had only Gr 0-2 CRS (16/22) while nearly 50% of patients with Gr 3+ CRS had Gr 0-2 NE (5/11). Conclusions: Biomarker and clinical evaluation suggests mechanistic differences underlying CRS and NE following axi-cel treatment. While Gr 3+ NE was associated with CAR T cell expansion, Gr 3+ CRS was instead associated with a broader array of serum markers, many linked to systemic myeloid activation. Further understanding of these immune signatures may provide insight into managing AEs associated with anti-CD19 CAR T cell therapy. Citation Format: Frederick L. Locke, John Rossi, Xiaodong Xue, Sattva S. Neelapu, Daniel H. Ryan, Armin Ghobadi, Lazaros J. Lekakis, David Miklos, Caron A. Jacobson, Ira Braunschweig, Olalekan Oluwole, Tanya Siddiqi, Yi Lin, John Timmerman, Patrick M. Reagan, Marika Sherman, Janice Nagatani, Xiao Zhang, Lynn Navale, William Y. Go, Jeff Wiezorek, Adrian Bot. Immune signatures of cytokine release syndrome and neurologic events in a multicenter registrational trial (ZUMA-1) in subjects with refractory diffuse large B cell lymphoma treated with axicabtagene ciloleucel (KTE-C19) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT020. doi:10.1158/1538-7445.AM2017-CT020

Abstract Introduction: Outcomes for pts with refractory aggressive NHL are poor with current therapies (Crump, ASCO 2016). Results from the interim analysis of (n=62) of ZUMA-1, the 1st multicenter trial of an anti-CD19 chimeric antigen receptor (CAR) T cell, axi-cel, in refractory aggressive NHL, showed an objective response rate (ORR) of 79% (complete response [CR] 52%; Blood 2016;128:LBA-6). Here we present results from the primary analysis of ZUMA-1. Methods: Pts received a target dose of 2 × 106 anti-CD19 CAR T cells/kg after lowdose conditioning with cy/flu. Eligible pts (≥18 y) had diffuse large B cell lymphoma (DLBCL), primary mediastinal B cell lymphoma (PMBCL) or transformed follicular lymphoma (TFL); an ECOG performance status (PS) 0-1; and refractory disease (progressive or stable disease as best response to last prior therapy, or relapsed ≤12 m of autologous stem cell transplant [ASCT]). The primary endpoint for this analysis was ORR in the combined DLBCL, PMBCL, and TFL population. Key secondary endpoints were duration of response (DOR), overall survival (OS), and frequency of adverse events (AEs). The primary analysis was triggered when 92 pts had at least 6 m of follow-up. Results: As of January 27, 2017, 111 pts from 22 institutions were enrolled; 101 pts (91%) received axi-cel. Median age was 58 y (range, 23-76), 67% male, 85% stage IIIIV, 47% IPI 3-4, 77% refractory to ≥2nd line of therapy, and 21% relapsed ≤12 m of ASCT. Axi-cel was successfully manufactured in 110/111 (99%) pts with an average turnaround time from apheresis to the clinical site of 17 d. With an ORR of 82% (n = 92; P<.0001) the study met the primary endpoint. The ORR in the mITT analysis set of 101 pts was 82% (CR 54%, PR 28%), and was consistent across key covariates including disease subtype, refractory status, stage, and IPI score. At a median follow up of 8.7 m, 44% of pts were in response and 39% were in CR. The median DOR was 8.2 m overall and not reached for pts who achieved a CR. Median OS was not reached; 80% of pts remained alive at 6 m. The most common Gr ≥3 treatmentemergent AEs were neutropenia (66%), leukopenia (44%), anemia (43%), febrile neutropenia (31%), and encephalopathy (21%). Gr ≥3 cytokine release syndrome (CRS) and neurologic events (NE) occurred in 13% and 28% of pts, respectively. All CRS and all NE resolved except 1 Gr 1 memory impairment. As previously reported, there were 3 Gr 5 AEs (3%). Peak and cumulative CAR T levels post-axi-cel were associated with durable responses. Conclusions: Axi-cel significantly improved ORR in patients with refractory aggressive NHL. The CR rate was 7-fold higher compared to historical controls (Crump, ASCO 2016) and nearly half the patients have an ongoing response. Axi-cel demonstrated significant clinical benefit with a manageable safety profile in pts lacking curative treatment options.[F.L.L. and S.S.N. contributed equally to this study.] Funding source: Kite Pharma and in part by funding from the Leukemia & Lymphoma Society (LLS) Therapy Acceleration Program treatment options. Citation Format: Frederick L. Locke, Sattva S. Neelapu, Nancy L. Bartlett, Lazaros J. Lekakis, David Miklos, Caron A. Jacobson, Ira Braunschweig, Olalekan Oluwole, Tanya Siddiqi, Yi Lin, John Timmerman, Jonathan W. Friedberg, Adrian Bot, John Rossi, Lynn Navale, Yizhou Jiang, Jeff Aycock, Meg Elias, Jeff Wiezorek, William Y. Go. Primary results from ZUMA-1: a pivotal trial of axicabtagene ciloleucel (axicel; KTE-C19) in patients with refractory aggressive non-Hodgkin lymphoma (NHL) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT019. doi:10.1158/1538-7445.AM2017-CT019