Tumor infiltration and cytokine biomarkers of prostate stem cell antigen (PSCA)-directed GOCAR-T cells in patients with advanced pancreatic tumors.

2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 734-734
Author(s):  
Joanne Shaw ◽  
Brandon Ballard ◽  
Xiaohui Yi ◽  
Aditya Malankar ◽  
Matthew R. Collinson-Pautz ◽  
...  

734 Background: PSCA is a cell surface protein overexpressed in approximately 60% of pancreatic cancers. BPX-601 is an autologous GOCAR-T cell therapy engineered to express a PSCA-CD3ζ CAR and the MyD88/CD40 (iMC) costimulatory domain activated by rimiducid (Rim), designed to boost CAR-T performance in solid tumors. The safety and activity of BPX-601 activated with Rim in PSCA+ metastatic pancreatic cancer is being assessed in a Phase 1/2 clinical trial, BP-012 (NCT02744287). Methods: Phase 1 of BP-012 is a 3+3 dose escalation of BPX-601 (1.25-5 x106/kg) administered on Day 0 with a single, fixed-dose of Rim (0.4 mg/kg) on Day 7 in subjects with previously treated PSCA+ metastatic pancreatic cancer. All 5 subjects in cohort 5B received Flu/Cy lymphodepletion followed by BPX-601 (5 x106/kg) and Rim. BPX-601 kinetics, PBMC phenotype, and serum cytokines were assayed by qPCR, flow cytometry, and cytokine multiplex, respectively. Baseline and on-treatment biopsies were evaluated by RNAscope in situ hybridization. Results: BPX-601 cells expanded in all subjects and persisted up to 9 months (median 42 days). Transient reduction in BPX-601 vector copy number and total T cell count concurrent with Rim infusion, supports margination of activated BPX-601 cells. Increased serum cytokines, such as IFN-γ and GM-CSF, were observed following BPX-601 infusion with further elevation after Rim activation. All subjects with evaluable on-treatment biopsies had infiltration of BPX-601 cells (n = 3) proximal to tumor cells 7-15 days after Rim, but not in an end of treatment biopsy > 200 days after Rim (n = 1). Stratification by best response (RECIST 1.1) revealed stable disease in 3 subjects and progressive disease in 2 subjects was potentially associated with distinct cytokine signatures. Conclusions: BPX-601 GOCAR-T cells expand and persist in patients with PSCA+ metastatic pancreatic cancer and infiltrate metastatic lesions. A peripheral cytokine signature was observed following BPX-601 infusion. Select cytokines were enhanced after GOCAR-T cell activation and may correlate with clinical response. A cohort of subjects exploring serial administration of Rim is open for enrollment. Clinical trial information: NCT02744287.

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A663-A663
Author(s):  
Keegan Cooke ◽  
Juan Estrada ◽  
Jinghui Zhan ◽  
Jonathan Werner ◽  
Fei Lee ◽  
...  

BackgroundNeuroendocrine tumors (NET), including small cell lung cancer (SCLC), have poor prognosis and limited therapeutic options. AMG 757 is an HLE BiTE® immune therapy designed to redirect T cell cytotoxicity to NET cells by binding to Delta-like ligand 3 (DLL3) expressed on the tumor cell surface and CD3 on T cells.MethodsWe evaluated activity of AMG 757 in NET cells in vitro and in mouse models of neuroendocrine cancer in vivo. In vitro, co-cultures of NET cells and human T cells were treated with AMG 757 in a concentration range and T cell activation, cytokine production, and tumor cell killing were assessed. In vivo, AMG 757 antitumor efficacy was evaluated in xenograft NET and in orthotopic models designed to mimic primary and metastatic SCLC lesions. NSG mice bearing established NET were administered human T cells and then treated once weekly with AMG 757 or control HLE BiTE molecule; tumor growth inhibition was assessed. Pharmacodynamic effects of AMG 757 in tumors were also evaluated in SCLC models following a single administration of human T cells and AMG 757 or control HLE BiTE molecule.ResultsAMG 757 induced T cell activation, cytokine production, and potent T cell redirected killing of DLL3-expressing SCLC, neuroendocrine prostate cancer, and other DLL3-expressing NET cell lines in vitro. AMG 757-mediated redirected lysis was specific for DLL3-expressing cells. In patient-derived xenograft and orthotopic models of SCLC, single-dose AMG 757 effectively engaged human T cells administered systemically, leading to a significant increase in the number of human CD4+ and CD8+ T cells in primary and metastatic tumor lesions. Weekly administration of AMG 757 induced significant tumor growth inhibition of SCLC (figure 1) and other NET, including complete regression of established tumors and clearance of metastatic lesions. These findings warranted evaluation of AMG 757 (NCT03319940); the phase 1 study includes dose exploration (monotherapy and in combination with pembrolizumab) and dose expansion (monotherapy) in patients with SCLC (figure 2). A study of AMG 757 in patients with neuroendocrine prostate cancer is under development based on emerging data from the ongoing phase 1 study.Abstract 627 Figure 1AMG 757 Significantly reduced tumor growth in orthotopic SCLC mouse modelsAbstract 627 Figure 2AMG 757 Phase 1 study designConclusionsAMG 757 engages and activates T cells to kill DLL3-expressing SCLC and other NET cells in vitro and induces significant antitumor activity against established xenograft tumors in mouse models. These preclinical data support evaluation of AMG 757 in clinical studies of patients with NET.Ethics ApprovalAll in vivo work was conducted under IACUC-approved protocol #2009-00046.


Blood ◽  
2020 ◽  
Vol 135 (15) ◽  
pp. 1232-1243 ◽  
Author(s):  
Kodandaram Pillarisetti ◽  
Suzanne Edavettal ◽  
Mark Mendonça ◽  
Yingzhe Li ◽  
Mark Tornetta ◽  
...  

Abstract T-cell–mediated approaches have shown promise in myeloma treatment. However, there are currently a limited number of specific myeloma antigens that can be targeted, and multiple myeloma (MM) remains an incurable disease. G-protein–coupled receptor class 5 member D (GPRC5D) is expressed in MM and smoldering MM patient plasma cells. Here, we demonstrate that GPRC5D protein is present on the surface of MM cells and describe JNJ-64407564, a GPRC5DxCD3 bispecific antibody that recruits CD3+ T cells to GPRC5D+ MM cells and induces killing of GPRC5D+ cells. In vitro, JNJ-64407564 induced specific cytotoxicity of GPRC5D+ cells with concomitant T-cell activation and also killed plasma cells in MM patient samples ex vivo. JNJ-64407564 can recruit T cells and induce tumor regression in GPRC5D+ MM murine models, which coincide with T-cell infiltration at the tumor site. This antibody is also able to induce cytotoxicity of patient primary MM cells from bone marrow, which is the natural site of this disease. GPRC5D is a promising surface antigen for MM immunotherapy, and JNJ-64407564 is currently being evaluated in a phase 1 clinical trial in patients with relapsed or refractory MM (NCT03399799).


2017 ◽  
Vol 35 (7_suppl) ◽  
pp. 168-168 ◽  
Author(s):  
Douglas G. McNeel ◽  
Jens C. Eickhoff ◽  
Robert Jeraj ◽  
Mary Jane Staab ◽  
Jane Straus ◽  
...  

168 Background: We have previously investigated a DNA vaccine encoding prostatic acid phosphatase (PAP, pTVG-HP) in patients with PSA-recurrent prostate cancer, and have demonstrated that this can be safely administered over many months and can elicit PAP-specific T cells. A phase 2 trial is currently underway. In preclinical models, we have found that blockade of regulatory receptors, including PD-1, at the time of T cell activation with vaccination produced anti-tumor responses in vivo. Similarly, we have recently found that patients with prostate cancer previously immunized with a DNA vaccine develop PD-1-regulated T cells. These findings suggested that combined PD-1 blockade with vaccination should elicit superior anti-tumor responses in patients with prostate cancer. Methods: A clinical trial was designed to evaluate the immunological and clinical efficacy of pTVG-HP when delivered in combination or in sequence with pembrolizumab, in patients with mCRPC. Serial biopsies, blood draws, and exploratory FLT PET/CT imaging are being conducted for correlative analyses. Results: While trial accrual continues, 1 of 14 subjects has experienced a grade 3 adverse event. There have been no grade 4 events. Several patients treated with the combination have experienced serum PSA declines, and several have experienced decreases in tumor volume by radiographic imaging at 12 weeks, including one partial response. Expansion of PAP-specific Th1-biased T cells has been detected in peripheral blood samples. Exploratory FLT PET/CT imaging has demonstrated proliferative responses in metastatic lesions and in vaccine-draining lymph nodes. Evaluation of biopsy specimens for recruitment of antigen-specific T cells is currently underway. Conclusions: PD-1 pathway inhibitors have demonstrated little clinical activity to date when used as single agents for treating prostate cancer. Our findings suggest that combining this blockade with tumor-targeted T-cell activation by a DNA vaccine is safe and can augment tumor-specific T cells, detectable within the peripheral blood and by imaging, and result in objective anti-tumor changes. Clinical trial information: NCT02499835.


2019 ◽  
Vol 37 (7_suppl) ◽  
pp. 301-301 ◽  
Author(s):  
Julie Bailis ◽  
Petra Deegen ◽  
Oliver Thomas ◽  
Pamela Bogner ◽  
Joachim Wahl ◽  
...  

301 Background: mCRPC is a disease of high unmet medical need, especially for patients who fail novel hormonal therapies and chemotherapy. BiTE molecules provide an off the shelf therapy that activates a patient’s own immune system and redirects T cells to kill tumor cells. The BiTE mechanism of action is distinct from other immunotherapies and may unlock immune response in mCRPC. PSMA is a compelling BiTE target that is highly expressed on PCa compared to normal tissue and has increased expression in mCRPC. Methods: AMG 160 is a fully human, half-life extended (HLE) BiTE that targets PSMA on tumor cells and CD3 on T cells. AMG 160 comprises two tandem single chain variable fragments fused to an Fc domain. Results: AMG 160 binds human and non-human primate (NHP) PSMA and CD3, leading to T cell activation and proliferation and cytokine production. AMG 160 redirects T cells to kill PSMA-positive cancer cell lines in vitro, including those with low PSMA levels or androgen-independent signaling. Weekly dosing of AMG 160 induces significant antitumor activity in established PCa xenograft model. The pharmacokinetics (PK) and pharmacodynamics of AMG 160 were tested in NHP. AMG 160 treatment led to BiTE target engagement in vivo, including transient T cell activation and cytokine release in blood, and mixed cellular infiltrates in multiple organs known to express PSMA. AMG 160 treatment was well tolerated. Cytokine release associated with the first dose could be attenuated using a step dose regimen. The half-life of AMG 160 in NHP was about one week. Based on allometric scaling, the PK profile of AMG 160 may be projected to enable dosing every other week in humans. Conclusions: AMG 160 is a potent HLE BiTE with specificity for PSMA-positive tumor cells. A Phase 1 study is planned to evaluate the safety and efficacy of AMG 160 in patients with mCRPC.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 3101-3101
Author(s):  
Alexander Starodub ◽  
Sarina Anne Piha-Paul ◽  
Raghad Karim ◽  
Curtis Ruegg ◽  
Victoria Smith ◽  
...  

3101 Background: Overcoming the immune-suppressive tumor environment induced by myeloid-derived suppressor cells (MDSC) is a major challenge in immune therapy. CD33 signaling in immature myeloid cells promotes expansion of MDSC and production of immune-suppressive factors. AMV564 is a bivalent, bispecific T-cell engager that binds CD3 and CD33. Preferential binding of AMV564 to areas of high CD33 density enables selective targeting of MDSC. Ex vivo data (Cheng 2017; Blood;130:51) and an ongoing clinical trial in acute myeloid leukemia (NCT03144245) demonstrate the ability of AMV564 to deplete MDSC while sparing monocytes and neutrophils. Methods: In this 3+3 dose escalation study, patients with advanced solid tumors receive AMV564 once daily via subcutaneous (SC) injection for 2 out of 3 wks per cycle, alone or in combination with pembrolizumab (200 mg every 3 wks). Key objectives are to evaluate AMV564 safety, identify a maximum tolerated or recommended phase 2 dose, and evaluate PK, immunophenotype of myeloid and T cell compartments, and preliminary efficacy. Results: Eleven patients have been enrolled: 8 monotherapy (3 at 15 mcg/d, 5 at 50 mcg/d) and 3 combination (5 mcg/d). Tumor types include ovarian (n = 2), small bowel, gastroesophageal junction, endometrial, rectal, penile, urothelial, squamous cell carcinoma (skin), appendiceal, and non-small cell lung. AMV564 was associated with grade (G) 1-2 injection site reactions and G1-2 fevers, which were manageable with acetaminophen and diphenhydramine, as well as G2 weight gain and G3 anemia. No dose-liming toxicity has been observed in any cohort. Three monotherapy patients (15 mcg/d) were evaluable for efficacy with ≥1 on-treatment scan; 2 had SD and 1 PD per RECIST 1.1 criteria. T cell activation, as shown by redistribution from the periphery (margination), was apparent in the first week of dosing for most patients. Compensatory myelopoiesis led to initial expansion of MDSC which were then depleted by AMV564. Increased cytotoxic T cell activation and T-helper (Th) 1 response was evidenced by increased T-bet positive CD4 and CD8 cells and controlled or decreased regulatory T cells. In some patients, effector memory CD8 cell populations (Tem and Temra) were expanded. Conclusions: AMV564 is safe and tolerable when administered SC at doses of 15 mcg/d alone and 5 mcg/d in combination with pembrolizumab. AMV564 depleted MDSC populations and altered T cell profiles consistent with activation of cytotoxic T cells and a Th1 response. Clinical trial information: NCT04128423 .


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1455-1455 ◽  
Author(s):  
Peter Westervelt ◽  
Gail J. Roboz ◽  
Jorge E. Cortes ◽  
Hagop M. Kantarjian ◽  
Sangmin Lee ◽  
...  

Abstract Background: AMV564 is a novel bivalent, bispecific (2x2) CD33/CD3 targeted immunotherapy that binds both CD33 and the invariant CD3ε on T-cell receptors with strong avidity, thus creating an immune synapse between CD33-expressing cells and T cells, initiating T-cell directed lysis of CD33 expressing cells, and inducing expansion, differentiation and proliferation of T cells. By design, AMV564 has reduced clearance and therefore has a longer half-life (t1/2) than monovalent, bispecific T-cell engagers. In preclinical investigations using both leukemic cell lines and primary cells from AML patients, AMV564 eliminated myeloid blasts with picomolar potency and broad activity independent of cytogenetic or molecular abnormalities, CD33 expression level, and disease stage, with no nonspecific activation of T cells (Reusch U et al. Clin Cancer Res 2016;22:5829-38). Methods: This is an ongoing Phase 1 study with a 3+3 dose-escalation design (NCT03144245). The primary objectives of this study are to characterize the safety, tolerability, and preliminary anti-leukemic activity of AMV564. Evaluation of pharmacokinetics (PK), cytokine changes, and immunophenotyping are secondary objectives. Key inclusion/exclusion criteria are: adults with relapsed and/or refractory AML after 1-2 prior induction regimens (with a standard anthracycline-based regimen or hypomethylating agent) and no more than 2 prior salvage regimens. AMV564 is administered by continuous intravenous infusion (CIV) for 14 consecutive days for up to 2 induction cycles. AMV564 and cytokine (IL2, IL4, IL6, IL8, IL10, TNF-α, and IFN-γ) concentrations were measured by validated immunoassays. T-cell activation was measured using flow cytometry to quantify T cells expressing CD25, CD38, CD69, or HLA-DR. Results: To date, 19 patients (10 male/9 female) with a median age of 72 years (range 24-84) have been enrolled in 6 dosing cohorts: 0.5, 1.5, 5.0, 15, 50, and 100 mcg/day. Thirteen patients (68%) had secondary AML and/or adverse cytogenetics, including 6 patients (32%) with a p53 mutation. Fifteen patients (79%) had received at least 1 prior salvage regimen and 11 (58%) had received prior intensive chemotherapy, including 6 patients (32%) who had received a high-dose (≥ 1 gm/m2) cytarabine-based regimen. Overall, 18 patients were evaluable for toxicity and response. No dose-limiting toxicity or treatment-related grade ≥ 3 adverse events (AE) were reported. Grade 2 CRS was observed in 1 patient (treated at 50 mcg/day) without a lead-in dose and was managed with drug interruption and 1 dose of tocilizumab. The patient was able to resume dosing and completed the full 14-day scheduled therapy without recurrence of CRS. Subsequent patients treated at 50 mcg/day and above were given a 15 mcg/day lead-in dose for 3 days followed by 11 days at the assigned dose level. The most common grade ≥ 3 treatment-emergent AE has been febrile neutropenia, reported in 39% (7/18) of patients and all considered unrelated to study drug. No patient has died within 30 days of treatment initiation. AMV564 PK was linear with a terminal t1/2 of 2-3 days. Plasma concentrations increased gradually, with times to steady-state concentration of 3-7 days. Marked increases in IL6 (peak concentration, 1.1 ng/mL), IL8 (1.5 ng/mL), and IL10 (0.3 ng/mL) cytokines were observed and increased numbers of activated T-cells were detected post-treatment. Reductions in bone marrow blasts, ranging from 13% to 91%, were observed in 12 of 18 evaluable patients including a partial response after cycle 1 in 1 patient at the 100 mcg/day dose level. Conclusions: AMV564 is well-tolerated and demonstrates anti-leukemic activity through T-cell engagement. AMV564 has a unique PK profile with a gradual increase in drug concentration and thus the potential for controlled T-cell activation. Disclosures Roboz: Daiichi Sankyo: Consultancy; Argenx: Consultancy; Sandoz: Consultancy; Aphivena Therapeutics: Consultancy; Cellectis: Research Funding; Argenx: Consultancy; Eisai: Consultancy; Celgene Corporation: Consultancy; Roche/Genentech: Consultancy; Jazz Pharmaceuticals: Consultancy; Otsuka: Consultancy; Roche/Genentech: Consultancy; Jazz Pharmaceuticals: Consultancy; Otsuka: Consultancy; AbbVie: Consultancy; Astex Pharmaceuticals: Consultancy; Celgene Corporation: Consultancy; Janssen Pharmaceuticals: Consultancy; AbbVie: Consultancy; Astex Pharmaceuticals: Consultancy; Bayer: Consultancy; Novartis: Consultancy; Sandoz: Consultancy; Novartis: Consultancy; Celltrion: Consultancy; Aphivena Therapeutics: Consultancy; Pfizer: Consultancy; Cellectis: Research Funding; Eisai: Consultancy; Orsenix: Consultancy; Celltrion: Consultancy; Bayer: Consultancy; Pfizer: Consultancy; Janssen Pharmaceuticals: Consultancy; Daiichi Sankyo: Consultancy; Orsenix: Consultancy. Cortes:Novartis: Consultancy, Research Funding; Astellas Pharma: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Arog: Research Funding. Lee:AstraZeneca: Consultancy; Clinipace: Consultancy; Karyopharm Therapeutics Inc: Consultancy; LAM Therapeutics: Research Funding; Amgen: Consultancy. Rettig:Amphivena Therapeutics: Research Funding; Novimmune: Research Funding. Han:Amphivena Therapeutics, Inc: Employment. Guenot:Amphivena Therapeutics, Inc: Employment. Feldman:Amphivena Therapeutics, Inc: Employment.


2016 ◽  
Vol 34 (4_suppl) ◽  
pp. 452-452 ◽  
Author(s):  
Nathan Bahary ◽  
Ignacio Garrido-Laguna ◽  
Andrea Wang-Gillam ◽  
Asha Nyak-Kapoor ◽  
Eugene Kennedy ◽  
...  

452 Background: IDO is a tryptophan-catabolizing enzyme that plays a key role in the normal regulation of peripheral immune tolerance. Tumors also employ this mechanism to induce a state of immunosuppression. In cancer, IDO mediates an acquired immune tolerance towards tumors, allowing evasion of immune mediated destruction. Indoximod is a broad IDO pathway inhibitor, as it has been shown to potentially interfere with multiple targets within the IDO pathway. Pre-clinical models have demonstrated synergy between indoximod and chemotherapy. The combination of gemcitabine (Gem) and nab-paclitaxel (Nab) is a current SOC for first line treatment of metastatic pancreas cancer. This trial is designed to determine the potential for benefit of combination therapy with indoximod and Gem / Nab for to patients with metastatic pancreatic cancer. Methods: Indoximod was escalated (600mg/1000mg/1200mg PO twice daily continuous dosing) in combination with Gem / Nab (1000mg/m2 / 125mg/m2 q week x 3 per 4 week cycle) in a 3+3 design. Patients were first line metastatic pancreatic cancer or minimum 6 months from adjuvant chemo and / or radiation following previous resection. Treatment continues until progression or toxicity. Primary endpoints for Phase 1 include safety, toxicity, and determination of a Phase 2 dose. The prospective collection of tumor samples for exploration of biomarkers is built into the trial. Results: 15 patients were required to successfully dose escalate the Phase 1 study to 1200 mg twice daily. Two patients were replaced in the lowest dose cohort after rapid deterioration due to underlying disease during the regimen limiting toxicity (RLT) window. One RLT was observed during the study (ascites Grade 3) at the highest dose cohort. The most common AE’s (all Grade 1 or 2) occurring in ≥ 4 subjects, regardless of attribution, were nausea, fatigue, peripheral edema, peripheral neuropathy, alopecia. Conclusions: Indoximod and Gem / Nab were well tolerated in a clinical trial setting. The Phase 2 dose was set at 1200 mg twice daily and Phase 2 enrollment (target 80 patients) is ongoing. Updated results will be presented. Clinical trial information: NCT02077881.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2057-2057
Author(s):  
Louis B. Nabors ◽  
Lawrence S. Lamb ◽  
Melissa Jo Beelen ◽  
Thriumaine Pillay ◽  
Mariska ter Haak ◽  
...  

2057 Background: Temozolomide (TMZ) transiently upregulates NKG2D ligands targeted by innate immune effector cells. Lymphodepletion impairs this immune response, however, genetic modification of ex vivo expanded γδ T cells with an MGMT-expressing lentivector confers resistance to TMZ, allowing concurrent chemotherapy and γδ T cell infusion, thereby targeting the tumor when NKG2DL are maximally expressed. This Drug Resistant Immunotherapy (DRI) is currently being evaluated in a Phase 1 first in human study (NCT04165941) and interim safety and biologic correlative analysis are detailed here for the first dosing cohort. Methods: Adults with newly diagnosed, untreated glioblastoma (GBM), adequate organ function, and a KPS≥70% will be enrolled. Subjects undergo subtotal resection and placement of a Rickham reservoir followed 3-4 weeks by apheresis from which γδ T cells are expanded, transduced with an MGMT-expressing lentivector, harvested, and cryopreserved. Standard of care induction TMZ/radiation therapy is initiated followed by 6 cycles of maintenance TMZ. Intravenous TMZ (150mg/m2) and intracranial dosing of 1 x 107 γδ T cells occur on day 1 of each maintenance cycle. Daily oral TMZ 150mg/m2 follows for Days 2-5. Dose level 1 (DL1) subjects receive 1 fixed dose of γδ T cells and DL2 receive 3 doses administered on Day 1 of each of first 3 cycles of TMZ dependent on absence of dose limiting toxicity. Primary endpoint is safety; secondary endpoints include progression free and overall survival. Immunologic and genomic correlative analyses are being conducted at specific time points from peripheral blood and cerebral spinal fluid collected from the Rickham. Results: Six subjects (4 females, 2 males) have been enrolled in DL1. All subjects were IDH1-WT with 5 subjects MGMT unmethylated and 1 methylated. Of these, 1 generated inadequate gd T cells and 2 withdrew consent prior to DRI treatment. For the 3 that received DRI, treatment-related adverse events with maximum CTCAE Grade 3 occurred in 1 subject; UTI, dehydration, and thrombocytopenia. The most common Grade 1/2 events included: fever, leukopenia, nausea, and vomiting which were attributable to TMZ or radiotherapy. Circulating T cells remained below normal range throughout maintenance phase in 2/3 subjects. NK and gd T cell numbers remained within low normal range for 3/3 and 2/3 subjects, respectively. Serum Th1 (IFNg, IL-2, TNFa) and Th2 (IL4, IL5, IL-10) cytokines were within clinical range although TNFa remained elevated from the gdT cell infusion through day +30 in 2 subjects. Conclusions: Administration of MGMT-gene modified gdT cells and TMZ as DRI is feasible in lymphodepleted subjects during TMZ maintenance phase and sufficiently safe to warrant further investigation at additional doses. Clinical trial information: NCT04165941.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A417-A417
Author(s):  
Elizabeth Martinez ◽  
Jason Faris ◽  
Reinhard Von Roemeling ◽  
Steven Angelides ◽  
Melissa Johnson

BackgroundVISTA (V-domain Ig suppressor of T cell activation) is a key negative immune checkpoint regulator, locking T cells in a quiescent state, unlike PD1 and CTLA4, which are expressed on activated T cells. Preclinically, VISTA monoclonal antibody treatment increased the number of tumor-specific T cells in the periphery, and enhanced the infiltration, proliferation and effector function of tumor-reactive T cells within the tumor microenvironment (TME). VISTA blockade alters the suppressive feature of the TME by decreasing the presence of monocytic myeloid-derived suppressor cells and increasing the presence of activated dendritic cells (DCs) within the TME leading to enhanced T cell mediated immunity. VISTA monoclonal antibody administration as a monotherapy has been shown to suppress the growth of both transplantable and inducible melanoma in preclinical models. CI-8993 is a first-in-class, fully human immunoglobulin (Ig) G1κ monoclonal antibody (mAb) against the VISTA ligand. Prior human clinical evaluation of CI-8993 demonstrated target-related clinical findings and pharmacodynamic activity at 0.15 mg/kg.MethodsThis phase 1 study is being conducted in the USA (NCT04475523) and is designed as a 3+3 dose escalation study beginning at 0.15 mg/kg. Patients with solid tumor malignancy (non-lymphoma) that is metastatic or unresectable and considered relapsed and/or refractory to prior therapy will be included, excluding prior CAR-T therapy or allogenic transplant. Patients will be treated with an initial step-dose of CI-8993 by IV infusion, followed by every 2 weeks of a full dose, until disease progression or toxicity. Efficacy, pharmacokinetics, pharmacodynamic and safety endpoints will be monitored and reported.ResultsN/AConclusionsN/AEthics ApprovalThe study was approved by Dartmouth-Hitchcock, Norris Cotton Cancer Center Ethics Board, approval number IRB00012031The study was approved Sarah Cannon Caner Research Institute, approval number IORG0000689


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4373-4373
Author(s):  
Valentina Ferrari ◽  
Tiffany N Tanaka ◽  
Alison Tarke ◽  
Hanna Fields ◽  
Luca Ferrari ◽  
...  

Abstract Background: There are few therapeutic options for higher risk patients with myelodysplastic syndrome (MDS) who fail standard therapy, and their 2-year survival rate is approximately 15%. Here we report on a recently initiated collaborative (industry-academia) first-in-human phase 1 clinical trial to assess the safety and tolerability of a novel form of adoptive T cell immunotherapy for such patients that targets patient and disease-specific, mutation-derived neoantigens. This experimental therapy is based on the concept that a) cancer is caused by somatic mutations that may generate novel immunogenic proteins (ie, neopeptides and possible neoantigens), b) that the adaptive immune system can be trained ex vivo to recognize neopeptides as neoantigens and c) that infusion of culture-expanded, neoantigen-immunized autologous T cells may be safe and therapeutically effective. Methods: This is an open-label, phase 1, 3+3 dose escalation trial with 3 cell doses (0.3, 1, and 3.0 × 107nucleated cells/kg) in cohorts of 3 patients each (see www.clinicaltrials.gov, NCT-03258359). Eligible subjects are 18 years of age or older and will have Intermediate, High, or Very High risk MDS by the revised International Prognostic Scoring System, with at least one cytopenia, and will have failed or relapsed after 6 cycles of standard hypomethylating therapy or declined such therapy, an ECOG status 0-2, and adequate organ function. Each patient's MDS-related mutations are identified and autologous T cells are immunized ex vivo with peptides corresponding to the mutated protein(s), then expanded and suitability-tested for experimental infusion (referred to as PACTN). Importantly, the T cells must demonstrate neoantigen specificity and must kill autologous MDS stem-progenitor cells prior to qualification for infusion. Each eligible subject receives a single infusion of autologous PACTN followed by intensive monitoring for adverse events (AEs) for 4 weeks and periodic monitoring for 1 year. The primary study end-point (EP) is assessment of dose-limiting toxicity (DLT) and maximum tolerated PACTN dose (MTD). Secondary EPs include disease response 1 month after PACTN infusion, overall and progression-free survival at 6 and 12 months, and assessment of the peak abundance and persistence of the infused T cells in peripheral blood. Exploratory EPs include an assessment of the effect of PACTN infusion on the allele frequencies of the targeted and non-targeted MDS mutations in blood and marrow leukocytes. Results: At this time, two subjects have been infused with PACTN in the first dose cohort. Neither subject had an infusion reaction, severe AE, or DLT after follow-up for 2-3 months, nor has a disease response occurred in these subjects. Of interest, the infused PACTN product in the first subject showed 59% clonal dominance by a single T cell receptor (TCR) clone that was present at only 0.002% in patient's blood prior to T cell immunization with neoantigen related peptides. Multiple additional expanded TCR clones were also identified in the infused PACTN product. The presence of a dominant TCR clone in the PACTN product enabled the assessment of the in vivo abundance and persistence of the clone after PACTN infusion. The dominant clone expanded between day 1 and day+4 after PACTN infusion to a peak frequency of 0.13%, representing a 64-fold expansion of this TCR compared with the pre-infusion sample of blood leukocytes, then decreased to 0.09% by day +8. The clone was also demonstrated in bone marrow on day +15 at a frequency of 0.03%, representing a 20-fold expansion of this TCR clone compared with the pre-infusion marrow sample. Similar studies on the second subject are in progress, and will be continued in future subjects as the clinical trial continues. Finally, our studies show that it has been possible to effectively immunize autologous T cells to patient-specific neoantigens in all patients studied with MDS (n=4) and also all patients with AML (n=3) studied to date. Conclusion: The early results of this clinical trial support the feasibility and safety of this novel approach to adoptive T cell mediated immunotherapy for patients with higher-risk MDS and encourages continuation of the trial in the higher dose level cohorts. Disclosures Ferrari: Persimmune, Inc.: Employment. Tarke:Persimmune, Inc.: Employment. Fields:Persimmune, Inc.: Employment. Ferrari:Persimmune, Inc.: Employment. Ni:Persimmune, Inc.: Employment. Ferrari:Persimmune, Inc.: Employment. Warner:Persimmune, Inc.: Employment. Jochelson:PersImmune, Inc.: Consultancy. Bejar:Celgene: Consultancy, Honoraria; AbbVie/Genentech: Consultancy, Honoraria; Takeda: Research Funding; Genoptix: Consultancy; Modus Outcomes: Consultancy; Foundation Medicine: Consultancy; Astex/Otsuka: Consultancy, Honoraria. Vitiello:Persimmune, Inc.: Employment. Lane:PersImmune, Inc.: Employment.


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