535 A phase I/II study of REGN7075 (EGFRxCD28 costimulatory bispecific antibody) in combination with cemiplimab (anti–PD-1) in patients with advanced solid tumors

BackgroundT-cell redirecting bispecific antibodies (bsAbs) are therapeutics that recognize two distinct antigens: a tumor-associated antigen on tumor cells to promote recruitment of T-cells to the tumor, and a receptor on T-cells to potentiate anti-tumor activity. REGN7075 is a human immunoglobulin G4-based costimulatory bsAb designed to bridge epidermal growth factor receptor (EGFR) positive tumor cells with CD28 positive T-cells and to provide amplified T-cell receptor-CD3 complex-mediated T-cell activation within the tumor, through the activation of CD28 co-stimulation. In genetically humanized immunocompetent mouse models, REGN7075 in combination with anti–PD-1 (antibody directed against programmed cell death-1 receptor) improved anti-tumor activity compared with either single agent alone.1MethodsThis is an open label, Phase I/II, first-in-human study evaluating the safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity of REGN7075 (EGFRxCD28) alone and in combination with cemiplimab in patients with advanced solid tumors (NCT04626635). Patients must have a protocol-defined advanced solid tumor, be ≥18 years of age (≥20 years in Japan), have an Eastern Cooperative Oncology Group performance status of 0 or 1, and be naïve to anti–PD-1/anti–PD-ligand(L)1.This study includes dose escalation (a 4+3 design modified from 3+3; Part 1) and expansion phases (Part 2). In Part 1, patients will receive a lead-in of REGN7075 monotherapy for 3 weeks followed by combination therapy with cemiplimab 350 mg every 3 weeks. Study therapies are administered until disease progression, intolerable adverse events, withdrawal of consent, or other stopping criterion is met. Once a recommended Phase 2 dose is determined in Part 1, four tumor-specific expansion cohorts will be opened: non-small cell lung cancer (PD-L1 ≥50%), triple-negative breast cancer, colorectal cancer (microsatellite stable), and cutaneous squamous cell carcinoma. Primary endpoints are safety and tolerability of REGN7075 alone or in combination with cemiplimab for Part 1, and objective response rate per Response Evaluation Criteria in Solid Tumors version 1.1 for Part 2. This study is currently open to enrollment.Trial RegistrationClinicalTrials.gov identifier NCT04626635.ReferencesWaite JC, Wang B, Haber L, et al. Tumor-targeted CD28 bispecific antibodies enhance the antitumor efficacy of PD-1 immunotherapy. Sci Transl Med 2020;12:2325.Ethics ApprovalThis study was conducted in accordance with the principles of the Declaration of Helsinki and the International Conference on Harmonization Good Clinical Practice guidelines. The study protocol and all amendments were approved by the institutional review board/ethics committee at each participating study site.ConsentAll patients provided written informed consent.

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412 First-in-human phase I/IIa trial to evaluate the safety and initial clinical activity of DuoBody®-PD-L1×4–1BB (GEN1046) in patients with advanced solid tumors

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0412 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A437-A437

Author(s):

Elena Garralda ◽

Ravit Geva ◽

Eytan Ben-Ami ◽

Corinne Maurice-Dror ◽

Emiliano Calvo ◽

...

Keyword(s):

T Cells ◽

Informed Consent ◽

Antitumor Activity ◽

Phase I ◽

Solid Tumors ◽

Therapeutic Window ◽

Clinical Activity ◽

Advanced Solid Tumors ◽

Link Type ◽

Dose Levels

BackgroundAgonistic 4-1BB monoclonal antibodies were preclinically validated as promising cancer immunotherapies, both as monotherapy and as potentiators of the activity of PD-(L)1–blocking agents. However, toxicity and a narrow therapeutic window have hampered their clinical development. DuoBody-PD-L1×4-1BB, a first-in-class, bispecific, next-generation checkpoint immunotherapy, was designed to overcome these limitations by activating T cells through conditional 4-1BB costimulation, while simultaneously blocking the PD-L1 axis. We present preliminary data from the ongoing, first-in-human, open-label, phase I/IIa trial of DuoBody-PD-L1×4-1BB in advanced solid tumors (NCT03917381).MethodsDuring dose escalation, patients with metastatic or unresectable solid tumors not eligible for standard therapy received flat-dose DuoBody-PD-L1×4-1BB (25–1200 mg) intravenously every 3 weeks until disease progression or unacceptable toxicity. Primary endpoints were dose-limiting toxicities (DLTs) and adverse events (AEs). Secondary endpoints included pharmacokinetic parameters and antitumor activity (RECIST 1.1). Pharmacodynamic biomarkers and antitumor activity (iRECIST) were assessed as exploratory endpoints.ResultsAs of June 22, 2020, 61 patients were enrolled (median age: 59 years). The most common cancer types were colorectal (19.7%), ovarian (14.8%), pancreatic (9.8%), and NSCLC (9.8%). Patients had previously received a median (range) of 3 (1–11) treatments; 44.2% had prior anti-PD-(L)1 immunotherapy. Patients received a median (range) of 4 (1–15) treatment cycles; Cmax was observed shortly after the end of infusion (mean T½: 2.3–10.3 days). Maximum tolerated dose was not reached; 6 patients experienced DLTs. The most common (=10%) treatment-related AEs (all grades; grades 3–4) were transaminase elevation (24.6%; 9.8%), hypothyroidism (16.4%; 1.6%), and fatigue (13.1%; 1.6%). Treatment-related grade-3 transaminase elevations decreased upon corticosteroid administration; no treatment-related bilirubin increases or grade-4 transaminase elevations occurred. Disease control, including stable disease at first assessment and partial responses in triple-negative breast cancer, ovarian cancer, and immune checkpoint inhibitor (ICI)–pretreated NSCLC, occurred in 40/61 patients (65.6%). Pharmacologic activity, as measured by modulation of adaptive immunity mediators, was observed across a broad range of dose levels. Peripheral proliferating (Ki67+) CD8+ effector memory T cells and serum interferon-gamma levels showed maximum induction relative to baseline (p=0.01) 8 days following treatment.ConclusionsDuoBody-PD-L1×4-1BB demonstrated biologic activity and a manageable safety profile. Encouraging early clinical activity across different dose levels was observed in a heavily pretreated population with advanced solid tumors, including those resistant to prior immunotherapy or typically less sensitive to ICIs. Expansion cohorts of patients for whom DuoBody-PD-L1×4-1BB treatment could be relevant and biologically sound have started enrollment. Updated data will be presented.AcknowledgementsThe authors thank Manish Gupta, Lei Pang, and Thomas Breuer at Genmab A/S; Alice Bexon, Alexander Muik, and Friederike Gieseke at BioNTech SE; and Zuzana Jirakova (formerly at BioNTech SE) for their valuable contributions. This trial was funded by Genmab A/S and BioNTech SE.Trial RegistrationClinicalTrials. gov; trial number: NCT03917381Ethics ApprovalThis trial is undertaken following full approval of the final protocol, amendments, informed consent form, applicable recruiting materials, and subject compensation programs by the Independent Ethics Committee/Institutional Review Board.ConsentWritten informed consent, in accordance with principles that originated in the Declaration of Helsinki 2013, current ICH guidelines including ICH-GCP E6(R2), applicable regulatory requirements, and sponsor policy, was provided by the patients.

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Safety of BI 754111, an anti-LAG-3 monoclonal antibody (mAb), in combination with BI 754091, an anti-PD-1 mAb, in patients with advanced solid tumors.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.15_suppl.3063 ◽

2020 ◽

Vol 38 (15_suppl) ◽

pp. 3063-3063

Author(s):

Melissa Lynne Johnson ◽

Manish R. Patel ◽

Mohamad Cherry ◽

Yoon-Koo Kang ◽

Kensei Yamaguchi ◽

...

Keyword(s):

T Cell ◽

Phase I ◽

Solid Tumors ◽

Phase Ii ◽

Group Performance ◽

Eastern Cooperative Oncology Group ◽

T Cell Response ◽

Fixed Dose ◽

Advanced Solid Tumors ◽

Median Treatment

3063 Background: LAG-3, an immune checkpoint receptor involved in T-cell regulation, is frequently co-expressed with PD-1. LAG-3 and PD-1 signaling contributes to immune cell exhaustion and reduces the immune response to tumor cells. Dual inhibition of PD-1 and LAG-3 may reactivate the T-cell response better than blockade of either individual pathway. Here, we report combined safety data from 4 trials investigating BI 754111, an anti-LAG-3 mAb, in combination with BI 754091, an anti-PD-1 mAb, in patients with advanced solid tumors. Methods: Data from 2 phase I dose-escalation/expansion trials, 1 phase I imaging trial, and 1 phase II trial were included. Eligible patients had advanced and/or metastatic solid tumors with measurable disease and an Eastern Cooperative Oncology Group performance status ≤1. Patients received BI 754111 (intravenously [iv], 4–800 mg) in combination with BI 754091 (iv, 240 mg fixed dose) every 3 weeks (q3w). Patients remained on treatment until progressive disease or unacceptable toxicity. In each trial, safety was assessed by incidence and severity of adverse events (AEs), and graded according to Common Terminology Criteria for AEs, version 5. Results: Overall, 321 patients were treated with BI 754111 in combination with BI 754091 (200 [62%] male; median age, 63 years [range 18–88]). Median treatment exposure was 85 days (range 9–625). Of these patients, 282 (87.9%) had any AE (G≥3 in 99 [30.8%]). 285 patients received the 600 mg recommended phase II dose of BI 754111 plus BI 754091 240 mg q3w. Median treatment exposure in these patients was 74 days (range, 8–590). The table shows the 3 most common AEs and 4 most common immune-related AEs, and their frequency. 21 (7.4%) patients had AEs leading to study drug discontinuation, most commonly infusion-related reactions (IRRs) in 6 (2.1%) patients. Serious AEs (all-cause) occurred in 77 patients (27.0%), most commonly pleural effusion in 6 (2.1%) and deep vein thrombosis in 4 (1.4%) patients. 2 patients (0.7%) experienced an AE resulting in death (cardiac tamponade and acute kidney injury, both related to underlying diseases). Conclusions: The combination of BI 754111 and BI 754091 had a manageable safety profile, similar to other checkpoint inhibitors. Clinical trial information: NCT03156114, NCT03433898, NCT03697304, NCT03780725 . [Table: see text]

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Combination of T-Cell Bispecific Antibodies With PD-L1 Checkpoint Inhibition Elicits Superior Anti-Tumor Activity

Frontiers in Oncology ◽

10.3389/fonc.2020.575737 ◽

2020 ◽

Vol 10 ◽

Author(s):

Johannes Sam ◽

Sara Colombetti ◽

Tanja Fauti ◽

Andreas Roller ◽

Marlene Biehl ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Tumor Cells ◽

Resistance Mechanisms ◽

Bispecific Antibodies ◽

Great Promise ◽

Tumor Escape ◽

Blocking Antibody ◽

Adaptive Resistance ◽

Anti Tumor Activity

T-cell Bispeciﬁc Antibodies (TCBs) elicit anti-tumor responses by cross-linking T-cells to tumor cells and mediate polyclonal T-cell expansion that is independent of T-cell receptor specificity. TCBs thus offer great promise for patients who lack antigen-speciﬁc T-cells or have non-inflamed tumors, which are parameters known to limit the response of checkpoint inhibitors. The current study deepens the understanding of TCB mode of action and elaborates on one of the adaptive resistance mechanisms following its treatment in vivo in humanized mice and syngeneic pre-clinical tumor models. Single-agent TCB treatment reduced tumor growth compared with controls and led to a 2–10-fold increase in tumor-infiltrating T-cells, regardless of the baseline tumor immune cell infiltration. TCB treatment strongly induced the secretion of CXCL10 and increased the frequency of intra-tumor CXCR3+ T-cells pointing to the potential role of the CXCL10-CXCR3 pathway as one of the mechanisms for T-cell recruitment to tumors upon TCB treatment. Tumor-infiltrating T-cells displayed a highly activated and proliferating phenotype, resulting in the generation of a highly inflamed tumor microenvironment. A molecular signature of TCB treatment was determined (CD8, PD-1, MIP-a, CXCL10, CXCL13) to identify parameters that most robustly characterize TCB activity. Parallel to T-cell activation, TCB treatment also led to a clear upregulation of PD-1 on T-cells and PD-L1 on tumor cells and T-cells. Combining TCB treatment with anti-PD-L1 blocking antibody improved anti-tumor efficacy compared to either agent given as monotherapy, increasing the frequency of intra-tumoral T-cells. Together, the data of the current study expand our knowledge of the molecular and cellular features associated with TCB activity and provide evidence that the PD-1/PD-L1 axis is one of the adaptive resistance mechanisms associated with TCB activity. This mechanism can be managed by the combination of TCB with anti-PD-L1 blocking antibody translating into more efficacious anti-tumor activity and prolonged control of the tumor outgrowth. The elucidation of additional resistance mechanisms beyond the PD-1/PD-L1 axis will constitute an important milestone for our understanding of factors determining tumor escape and deepening of TCB anti-tumor responses in both solid tumors and hematological disorders.

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872 PD1 x TGFbR2 and CD5 x TGFbR2 bispecifics selectively block TGFbR2 on target-positive T cells, promote T cell activation, and elicit an anti-tumor response in solid tumors

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.872 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A913-A913

Author(s):

Gregory Moore ◽

Suzanne Schubbert ◽

Christine Bonzon ◽

Kendra Avery ◽

Rumana Rashid ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Solid Tumors ◽

T Cell Activation ◽

Tumor Response ◽

Bispecific Antibodies ◽

Nsg Mice ◽

Anti Tumor Activity

BackgroundTGFbeta production by solid tumors and their microenvironment is a major mechanism used by tumors to avoid immunosurveillance. Blockade of TGFbeta has been shown to promote an anti-tumor response; however, systemic blockade of TGFbeta has also been associated with toxicity. We hypothesized that a T cell-targeted TGFbR2 bispecific antibody could selectively block the suppressive activity of TGFbeta on T cells and enhance their anti-tumor activity while avoiding toxicity associated with systemic blockade.MethodsWe engineered bispecific antibodies that simultaneously engage PD1 (activated) or CD5 (pan T) and block TGFbR2 using Xencor’s XmAb® platform. The anti-TGFbR2 arm was tuned for optimal activity by introducing affinity-modulating amino acid substitutions. The activity of TGFbR2 bispecifics was evaluated in vitro using a signaling assay to measure phosphorylated SMAD (pSMAD) by flow cytometry with exogenous TGFbeta in unactivated and activated PBMC. In vivo activity was evaluated by monitoring the engraftment of human PBMC in NSG mice (huPBMC-NSG). Anti-tumor activity was assessed in huPBMC-NSG mice engrafted with established human cancer cell lines.ResultsTGFbR2 bispecifics were confirmed to bind PD1 or CD5 and block binding of TGFbeta to TGFbR2. In vitro, we found that T cells from serum-deprived PBMC exhibited robust induction of pSMAD in response to TGFbeta, and TGFbR2 bispecifics selectively inhibited pSMAD induction in target-positive T cells as demonstrated by over a 100-fold potency increase compared to an untargeted anti-TGFbR2 control. Additionally, we saw an enhancement of potency when evaluating activity in target-high T cells versus target-low or -negative immune cells. Intriguingly, CD5-targeted TGFbR2 bispecifics allowed for the targeting of a broader population of T cells compared to PD1-targeting while still conferring potent selectivity against target-negative cells. In vivo, treatment of huPBMC-NSG mice with TGFbR2 bispecifics promoted superior T cell engraftment. Furthermore, TGFbR2 bispecific treatment of huPBMC-NSG mice containing established MDA-MB-231 triple-negative breast cancer tumors promoted an anti-tumor response that was augmented with PD1 blockade.ConclusionsPD1 x TGFbR2 and CD5 x TGFbR2 bispecific antibodies were engineered to selectively block TGFbR2 on target-positive T cells and evaluated in vitro and in vivo. These observations are compelling and suggest that development of these bispecifics is warranted for the treatment of human malignancies.

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697 Tumor-targeted CD28 costimulatory bispecific antibodies enhance T cell activation in solid tumors

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0697 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A739-A739

Author(s):

Michael Hedvat ◽

Veronica Zeng ◽

Juan Diaz ◽

Christine Bonzon ◽

Kendra Avery ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Solid Tumors ◽

Cancer Cell ◽

T Cell Activation ◽

Cell Activation ◽

Bispecific Antibodies ◽

Anti Tumor Activity

BackgroundT cells in the tumor micro-environment require TCR/MHC engagement and co-stimulatory receptor engagement to achieve complete activation. Solid tumors often lack expression of CD28 ligands, so we hypothesized that activation of CD28 signaling could be beneficial in solid tumors. We designed tumor-associated-antigen (TAA) x CD28 bispecific antibodies that conditionally costimulate CD28 only in the presence of TAA and TCR engagement. Clinical application of this class of antibodies has potential to enhance activity of either anti-PD(L)1 antibodies or TAA x CD3 T cell engagers.MethodsWe designed a stability and affinity optimized anti-CD28 antibody that can be paired with TAA of choice to engage CD28 monovalently using Xencor’s XmAb 2+1 and 1+1 platforms. In vitro T cell activation with these bispecifics was measured by T cell proliferation, cytokine production, and cytotoxicity, in co-cultures of human cancer cell lines mixed with primary human CD3-stimulated T cells. In vitro activity was validated in a CMV recall assay measuring CMV+ T cell proliferation of CMV+ PBMC co-cultured with cancer cell lines ectopically treated with pp65-derived NLV-peptide. In vivo anti-tumor and T cell proliferative activity of B7H3 x CD28 bispecific antibodies were determined in tumor-bearing huPBMC-NSG mice treated simultaneously with TAA x CD3 bispecific antibody. In vivo activity of PDL1 x CD28 antibodies was determined with hCD28 KI mice inoculated with MC38 tumors expressing hPDL1-antigen. Finally, safety and tolerability of B7H3 x CD28 and PDL1 x CD28 was determined in cynomolgus monkeys.ResultsB7H3 x CD28 and PDL1 x CD28 antibodies enhanced T cell degranulation, cytokine secretion, and cancer cell cytotoxicity in concert with CD3 stimulation only in the presence of target antigen. B7H3 x CD28, alone or in combination with anti-PD1 antibody, enhanced proliferation of CMV+ T cells recognizing cancer cells loaded with pp65-derived NLV peptide. PDL1 x CD28 also enhanced CMV+ cell expansion but did not synergize with anti-PD1 antibody treatment. B7H3 x CD28 significantly enhanced in vivo anti-tumor activity of TAA x CD3 antibodies while also promoting greater T cell expansion. In hCD28 mice inoculated with MC38 tumors expressing hPDL1, PDL1 x CD28 antibody inhibited tumor growth greater than an anti-PDL1 antibody alone. B7H3 x CD28 and PDL1 x CD28 were well tolerated in cynomolgus monkeys.ConclusionsB7H3 x CD28 and PDL1 x CD28 bispecific antibodies show promising anti-tumor activity and warrant further development.

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P09.05 Plasma CD27, a surrogate of intratumoral CD27-CD70 interaction, correlates with immunotherapy resistance in renal cancer

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-itoc8.55 ◽

2021 ◽

Vol 9 (Suppl 1) ◽

pp. A30.1-A30

Author(s):

N Benhamouda ◽

I Sam ◽

N Epaillard ◽

A Gey ◽

A Saldmann ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Tumor Microenvironment ◽

Single Cell ◽

Solid Tumors ◽

Tumor Cells ◽

Principal Investigator ◽

Cell Phenotype ◽

Metastatic Rcc ◽

Research Grant

BackgroundCD70, a costimulatory molecule on antigen presenting cells, is known to activate CD27-expressing T cells. CD27-CD70 interaction leads to the release of soluble CD27 (sCD27). However, persistent interaction of CD27 and CD70 such as in chronic infection may exhaust the T cell pool and promote apoptosis. Surprisingly, our analysis based on TCGA database show that clear cell renal cell carcinoma (ccRCC) expresses the highest levels of CD70 among all solid tumors. Despite the important clinical efficacy of immunotherapy by anti-PD-1 in RCC patients, the overall response to anti-PD1 remains modest. The relationship between the CD27-CD70 interaction in the RCC and the response to immunotherapy is still unclear.Materials and MethodsTo study the CD27 and CD70 expression in the tumor microenvironment (TME), FFPE tumor tissues from 25 RCC patients were analysed using multiplex in situ immunofluorescence. 10 fresh RCC tumor samples were collected to analyse the phenotype of CD27+ T cells by flow cytometry and 4 samples were proceeded for single-cell RNA-seq analysis. A cohort of metastatic RCC patients (n = 35) treated by anti-PD-1 were enrolled for the measurement of plasma sCD27 by ELISA and the survival analysis is also realized.ResultsIn the TME, we demonstrated that CD27+ T cells interact with CD70-expressing tumor cells. In fresh tumors from RCC patients, CD27+ T cells express higher levels of cleaved caspase 3 (a classical marker of apoptosis) than CD27- T cells. We confirmed the apoptotic signature (BAX, FASLG, BCL2L11, CYCS, FBXO32, LGALS1, PIK3R1, TERF1, TXNIP, CDKN2A) of CD27+ T cells by single-cell RNAseq analysis. CD27+T cells also had a tissue resident memory T cell phenotype with enriched gene expression of ITGAE, PRDM1, RBPJ and ZNF683. Moreover, CD27+T cells display an exhaustion phenotype with the expression of multiple inhibitory receptors gene signature (PDCD1, CTLA4, HAVCR2, LAG3, etc). Besides, intratumoral CD27-CD70 interaction significantly correlates with plasma sCD27 concentration in RCC (p = 0.0017). In metastatic RCC patients treated with anti-PD-1, higher levels of sCD27 predict poor overall survival (p = 0.037), while it did not correlate with inflammatory markers or clinical prognostic criteria.ConclusionsIn conclusion, we demonstrated that sCD27, a surrogate of T cell dysfunction in tumors likely induced by persistent interactions of CD27+T cells and CD70-expressing tumor cells, is a predictive biomarker of resistance to immunotherapy in mRCC. To our knowledge, this is the first report showing that a peripheral blood biomarker may reflect certain aspects of the tumor-host interaction in the tumor microenvironment. Given the frequent expression of CD70 and CD27 in solid tumors, our findings may be further extended to other types of tumors. CD70-CD27 interaction could thus be considered as a mechanism of tumor escape, but also a novel therapeutic target in cancers.Disclosure InformationN. Benhamouda: None. I. Sam: None. N. Epaillard: None. A. Gey: None. A. Saldmann: None. J. Pineau: None. M. Hasan: None. V. Verkarre: None. V. Libri: None. S. Mella: None. C. Granier: None. C. Broudin: None. P. Ravel: None. B. Jabla: None. N. Chaput: None. L. Albiges: None. Y. Vano: None. O. Adotevi: None. S. Oudard: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Modest; SIRIC CARPEM, FONCER. E. Tartour: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Modest; Fondation ARC, INCA PLBio, Labex Immuno-Oncology, SIRIC CARPEM, FONCER, IDEX université de Paris, Inserm Transfert.

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121 ICAM-1-specific affinity tuned CAR T cells expressing SSTR2 for real-time imaging

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.121 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A130-A130

Author(s):

Jingmei Hsu ◽

Eric von Hofe ◽

Michael Hsu ◽

Koen Van Besien ◽

Thomas Fahey ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Phase I ◽

Tumor Cells ◽

Somatostatin Receptor ◽

Laboratory Animals ◽

Therapeutic Window ◽

Car T Cells ◽

Car T

BackgroundThe use of CAR T cells for solid tumors has a number of challenges, such as lack of tumor-specific targets, CAR T cell exhaustion, and the immunosuppressive tumor microenvironment. To address these challenges, AffyImmune has developed technologies to affinity tune and track CAR T cells in patients. The targeting moiety is affinity tuned to preferentially bind to tumor cells overexpressing the target while leaving normal cells with low basal levels untouched, thereby increasing the therapeutic window and allowing for more physiological T cell killing. The CAR T cells are designed to express SSTR2 (somatostatin receptor 2), which allows for the tracking of CAR T cells in vivo via PET/CT scan using FDA-approved DOTATATE.MethodsAIC100 was generated by affinity tuning the I-domain of LFA-1, the physiological ligand to ICAM-1. Various mutants with 106-fold difference in affinity were evaluated for affinity. This allowed structure activity relationships to be conducted using CAR T cells expressing the various affinity mutants against targets with varying antigen densities. The variant with micromolar affinity was clearly the most effective in non-clinical animal models. AIC100 is currently being evaluated to assess safety, CAR T expansion, tumor localization, and preliminary activity in patients with advanced thyroid cancer in a phase I study (NCT04420754). Our study uses a modified toxicity probability interval design with three dosage groups of 10 x 106, 100 x 106, and 500 x 106 cells.ResultsPreclinical studies demonstrated greater in vivo anti-tumor activity and safety with lower affinity CAR T cells. A single dose of AIC100 resulted in tumor elimination and significantly improved survival of animals. AIC100 activity was confirmed in other high ICAM-1 tumor models including breast, gastric, and multiple myeloma. In a Phase I patient given 10-million CAR T cells, near synchronous imaging of FDG and DOTATATE revealed preliminary evidence of transient CAR T expansion and tumor reduction at multiple tumor lesions, with the peak of CAR T density coinciding with the spike in CAR T numbers in blood.ConclusionsWe have developed affinity tuned CAR T cells designed to selectively target ICAM-1 overexpressing tumor cells and to spatiotemporally image CAR T cells. Near-synchronous FDG and DOTATATE scans will enhance patient safety by early detection of off-tumor CAR T activity and validation of tumor response. We anticipate that our ‘tune and track’ technology will be widely applicable to developing potent yet safe CAR T cells against hard-to-treat solid cancers.Trial RegistrationNCT04420754Ethics ApprovalIRB number19-12021154IACUC (animal welfare): All animal experiments were performed in accordance with the National Institute of Health’s Guide for the Care and Use of Laboratory Animals. Animal handling protocols were approved by the Institutional Laboratory Animal Use and Care Committee of Weill Cornell Medicine (Permit Number: 2012–0063).

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368 Consistent pattern of immune activation induced by oncolytic adenovirus ONCOS-102 across diverse types of solid tumors

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.368 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A396-A396

Author(s):

Lukasz Kuryk ◽

Anne-Sophie Moller ◽

Sandeep Kumar ◽

Alexander Shoushtari ◽

Luis Paz Ares ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Solid Tumors ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Clinical Importance ◽

Oncolytic Adenovirus ◽

Link Type ◽

Tumor Types

BackgroundSolid tumors exhibit highly variable compositions of immune infiltrates. Therapeutic compounds driving uniform remodeling of tumor microenvironment (TME) across tumor types may improve the efficacy of cancer immunotherapy. ONCOS-102, a granulocyte-macrophage colony stimulating factor (GM-CSF)-expressing oncolytic adenovirus (Ad5/3-D24-GMCSF), was tested for its safety, therapeutic efficacy and capacity to remodel TME in recently completed phase I/II clinical studies in anti-PD-1 refractory melanoma (NCT03003676) and malignant pleural mesothelioma (MPM) (NCT02879669).MethodsBiopsies were obtained from tumor lesions of patients treated with intra-tumoral injections of ONCOS-102 in combination with chemotherapy or pembrolizumab for MPM and melanoma, respectively. Tumor immune infiltrates were analyzed by immunohistology using several antibody panels. On-treatment biopsies were compared to paired baseline samples as wells as to samples from control patients treated with chemotherapy alone in the case of MPM. Gene expression data obtained by next generation RNA sequencing were used to complement the immunohistology analysis and all results were correlated to clinical outcomes.ResultsComparative TME analysis of anti-PD-1 refractory melanoma and MPM tumors revealed noticeably lower baseline T-cell infiltration in mesothelioma. Thus, fractions of CD8+ T-cells were significantly below 10% in 80% of MPM biopsies while approaching or exceeding this level in 60% of melanoma baseline samples. Comparison of tumor biopsies obtained at baseline or on-treatment, demonstrated increased infiltration by both CD4+ and CD8+ T-cells in large proportions of melanoma (CD4+: 13/20 (65%); CD8+: 16/19 (84%) and MPM (CD4+: 10/15 (67%); CD8+: 9/15 (60%) tumor lesions in response to ONCOS-102. Frequencies of cytotoxic T-cells with high granzyme-B expression also increased in response to the treatment in both tumor types, in particular when assessed as percentage of total CD8+ T-cells. Other observed changes induced by ONCOS-102 in samples taken from CR, PR and SD patients with MPM or melanoma included increased CD8/Treg ratio and modulation of PD-L1 expression. Biological and clinical importance of these findings was further supported by correlation between modulation of several subsets of genes related to the process of T-cell activation, such as cytotoxic granule components and co-stimulatory molecules, and clinical response to ONCOS-102 in melanoma and both tumor response and overall survival in MPM patients.ConclusionsONCOS-102 drives pro-inflammatory modulation of immune TME across tumor types of different origins, anatomical locations and immunological baseline characteristics. Our data support potential of ONCOS-102 to serve as a potent immune sensitizing agent in combination therapies with various classes of immunomodulatory compounds and chemotherapy.

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Double Strike Approach for Tumor Attack: Engineering T Cells Using a CD40L:CD28 Chimeric Co-Stimulatory Switch Protein for Enhanced Tumor Targeting in Adoptive Cell Therapy

Frontiers in Immunology ◽

10.3389/fimmu.2021.750478 ◽

2021 ◽

Vol 12 ◽

Author(s):

Luis Felipe Olguín-Contreras ◽

Anna N. Mendler ◽

Grzegorz Popowicz ◽

Bin Hu ◽

Elfriede Noessner

Keyword(s):

T Cells ◽

T Cell ◽

Solid Tumors ◽

Tumor Cells ◽

T Cell Activation ◽

Intracellular Signaling ◽

Adoptive Cell Therapy ◽

Tumor Rejection ◽

Target Cells ◽

Type I

Activation of co-stimulatory pathways in cytotoxic T lymphocytes expressing chimeric antigen receptors (CARs) have proven to boost effector activity, tumor rejection and long-term T cell persistence. When using antigen-specific T cell receptors (TCR) instead of CARs, the lack of co-stimulatory signals hampers robust antitumoral response, hence limiting clinical efficacy. In solid tumors, tumor stroma poses an additional hurdle through hindrance of infiltration and active inhibition. Our project aimed at generating chimeric co-stimulatory switch proteins (CSP) consisting of intracellular co-stimulatory domains (ICD) fused to extracellular protein domains (ECD) for which ligands are expressed in solid tumors. The ECD of CD40L was selected for combination with the ICD from the CD28 protein. With this approach, it was expected to not only provide co-stimulation and strengthen the TCR signaling, but also, through the CD40L ECD, facilitate the activation of tumor-resident antigen-presenting cells (APCs), modulate activation of tumor endothelium and induce TCR-MHC independent apoptotic effect on tumor cells. Since CD28 and CD40L belong to different classes of transmembrane proteins (type I and type II, respectively), creating a chimeric protein presented a structural and functional challenge. We present solutions to this challenge describing different CSP formats that were successfully expressed in human T cells along with an antigen-specific TCR. The level of surface expression of the CSPs depended on their distinct design and the state of T cell activation. In particular, CSPs were upregulated by TCR stimulation and downregulated following interaction with CD40 on target cells. Ligation of the CSP in the context of TCR-stimulation modulated intracellular signaling cascades and led to improved TCR-induced cytokine secretion and cytotoxicity. Moreover, the CD40L ECD exhibited activity as evidenced by effective maturation and activation of B cells and DCs. CD40L:CD28 CSPs are a new type of switch proteins designed to exert dual beneficial antitumor effect by acting directly on the gene-modified T cells and simultaneously on tumor cells and tumor-supporting cells of the TME. The observed effects suggest that they constitute a promising tool to be included in the engineering process of T cells to endow them with complementary features for improved performance in the tumor milieu.

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Long term results from a phase 1 trial of GEN-009, a personalized neoantigen vaccine, combined with PD-1 inhibition in advanced solid tumors.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.2613 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. 2613-2613

Author(s):

Maura L. Gillison ◽

Mark M. Awad ◽

Przemyslaw Twardowski ◽

Ammar Sukari ◽

Melissa Lynne Johnson ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Immune Responses ◽

Solid Tumors ◽

Salvage Therapy ◽

Ex Vivo ◽

T Cell Responses ◽

Long Term Results ◽

Advanced Solid Tumors ◽

Cell Responses

2613 Background: GEN-009 is an adjuvanted personalized cancer vaccine containing up to 20 neoantigens selected by ATLAS, an ex vivo bioassay screening autologous T cells for immune responses against both neoantigens as well as Inhibigens. Inhibigen-specific T cells suppress immunity and have been shown to accelerate tumor progression in mice and are avoided in GEN-009. In cohort A, all patients immunized in the adjuvant setting with GEN-009 monotherapy developed immune responses. Nearly all (99%) of selected peptides were immunogenic: ex vivo CD4+ and CD8+ fluorospot responses specific for 51% and 41% of immunized peptides, respectively. Seven of 8 patients continue without progression with a median follow up of 18 months. Methods: GEN-009 is being evaluated in patients (pts) with advanced cancer who received standard-of-care (SOC) PD-1 inhibitor as monotherapy or in combination therapy during vaccine manufacturing. Five vaccine doses were administered over 24 weeks in combination with a PD-1 CPI. Patients who progressed prior to vaccination received alternative salvage therapy followed by GEN-009 in combination. Peripheral T cell responses were measured by fluorospot assays in ex vivo and in vitro stimulation. Results: 15 pts received GEN-009 in combination with a PD-1 inhibitor; 1 patient received GEN-009 monotherapy. Median number of neoantigens per vaccine was 14 (5-18). GEN-009-related adverse events were limited to vaccine injection site reactions and mild myalgias or fatigue. Longitudinal evaluation of ex vivo T cell responses revealed that sequential vaccination with GEN-009 had an overall additive effect on the robustness of IFNγ secretion and responses were persistent for at least 6 months in some patients. Epitope spread was detected in CPI sensitive patients, but not in CPI refractory patients receiving salvage therapy. Three patients who responded to PD-1 inhibition followed by disease stabilization then demonstrated further reduction after GEN-009 vaccination that could represent vaccine effect. Eight of 9 CPI responsive patients are progression-free from 3 to 10 months after first vaccine dose. Four of 7 CPI refractory patients have experienced unexpected prolonged stable disease after vaccination of up to 8 months after vaccination. 2 of 2 patients with available samples lost all evidence of circulating tumor DNA including non-targeted neoantigens. Conclusions: Vaccination with GEN-009 in combination with anti-PD-1 CPI in patients with advanced solid tumors shows little additive toxicity. Preliminary data demonstrate induction of broad neoantigen-specific immune responses and epitope spreading in the presence of PD-1 CPI. Broad immunity against tumor specific targets and encouraging patient outcomes support further study. Clinical trial information: NCT03633110.

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