Use Of IL-2 Research Articles

Abstract 4066: Generation of tumor targeted self-assembling split IL-12 subunits for the treatment of cancer

Abstract A major milestone in immuno-oncology was the development of immune checkpoint inhibitors, resulting in significant benefits for numerous patients. However, many patients are not responsive, become refractory, or cannot tolerate the treatment due to toxicity or side effects, demonstrating the need for additional immunotherapies. Cytokines are a class of promising immunomodulatory proteins being explored as therapeutics, but their success has been limited due to their rapid clearance or pleiotropic properties. Classically known as ‘signal 3’ of an endogenous immune response, IL-12p70 is a heterodimeric cytokine comprising p35 and p40 subunits. When administered exogenously, IL-12 is a potent stimulator of the immune system and can have profound anti-tumor activity; however, the clinical use of IL-12 has been limited due to poor systemic tolerability. Therefore, developing an immunotherapy that can be systemically administered and improve the therapeutic index could capitalize on the potential clinical benefit of IL-12. Mural Oncology has developed an innovative approach to mitigate the toxicity of IL-12 by splitting the heterodimer into inactive p35 and p40 monomers. The individual subunits are separately fused to two non-competitive antibody fragments targeting a highly expressed tumor-associated antigen. The goal of this approach is to conditionally activate IL-12 preferentially in the tumor microenvironment (TME). This is achieved by sequential administration of the targeted subunits, which will drive assembly and activity of the IL-12 heterodimer primarily at the tumor site, reducing systemic exposure and thereby potentially reducing associated toxicities. To engineer the split IL-12 subunits, a structure-based rational design approach was used to remove the natural intra-molecular disulfide bond and generate variants that maintained affinity between the p35 and p40 monomers. The engineered subunits were characterized using analytical methods and screened for the pair with the strongest affinity. Additionally, the candidate pair was assessed for receptor binding and functional activity on human T cells through phosphorylation of STAT4 and secretion of IFN-γ. Pharmacokinetics and pharmacodynamics were evaluated in mouse models with and without tumors demonstrating that dual targeting led to an increase in tumor retention, rapid clearance from circulation, and dose dependent release of IFN-γ. The results thus far demonstrate that the innovative approach of tumor targeted self-assembling split IL-12 has the potential to enhance the overall therapeutic potential of this cytokine. A development candidate will be identified and moved into clinical testing in cancer patients to enable us to fully understand if this design approach holds true in the clinical setting. Citation Format: Joshua Heiber, Pinar Gurel, Robert G. Newman, Kristiana Dreaden, Yanchun Zhao, Chunhua Wang, Su-Ping Pearson, Jean Chamoun. Generation of tumor targeted self-assembling split IL-12 subunits for the treatment of cancer [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 4066.

Risk of major adverse cardiovascular events and all-cause mortality among patients with psoriatic disease treated with tumor necrosis factor-α and interleukin-12/23 inhibitors: a nationwide population-based cohort study in Korea

Purpose Few studies have investigated the impact of biologics on the risk of major adverse cardiovascular events (MACEs) among Korean patients with psoriatic diseases. We compared the risk of MACEs and all-cause mortality among patients with psoriatic disease treated with tumor necrosis factor (TNF)-α and interleukin (IL)-12/23 inhibitors in Korea. Methods Patients with psoriatic disease prescribed with TNF-α and IL-12/23 inhibitors since 2016 were selected from the Korean National Health Insurance Service (NHIS) Database. Follow-up data for MACEs and all-cause mortality between 2016 and 2020 were collected. A total of 2886 individuals were included, including 1987 IL-12/23 inhibitor users and 899 TNF-α inhibitor users. Results Compared with IL-12/23 inhibitor users, TNF-α inhibitor users had a higher prevalence of dyslipidemia and a significantly higher risk of all-cause mortality but not MACE. After controlling for age, female TNF-α inhibitor users had a significantly increased risk of all-cause mortality. Meanwhile, after controlling for sex, TNF-α inhibitor users aged 60 years or older demonstrated a significantly elevated risk of all-cause mortality. In conclusion, No statistically significant difference in MACE risk was observed between patients who used TNF-α and IL-12/23 inhibitors. Nevertheless, the use of IL-12/23 inhibitors, especially among older and female patients, resulted in a lower overall mortality.

Abstract A006: Understanding the Potential of Human IL-12 and Chimeric IL-15 Combination for Cancer Immunotherapy

Abstract Autologous cell-based therapy is a preferred approach for Cancer immunotherapy. However, generating potent NK cells and antigen experienced T cells has been a challenge. To address this issue, we have developed a strategy of using the combination of IL-12 and IL-15 to activate CD4+ T cells, CD8+ T cells and NK cells. IL-12 and IL-15 possess distinct roles but both are potent inflammatory cytokines. IL-12 is a vital promoter of Th1 differentiation via activation of signal transducer and activator of transcription 4 (STAT4), while IL-15 is essential for developing innate immune response as well as contributing to the maintenance of memory CD8+ T cells. Substantial in vivo and in vitro data have been reported to support the role of IL-15 as a T cell growth factor. These activities of IL-12 and IL-15 make them ideal for combinatorial immunotherapy of cancer. However, the short half-life (~ 1hr) and poor bioavailability limits the therapeutic use of IL-15. To overcome these limitations, we have designed chimeric IL-15-IgG2 (Indian Patent Application No. 201721010096A) with an objective of augmenting the generation of memory T cells as well as reactivating them during the antigenic challenge. Our stable chimeric IL-15 has a half-life of >40 Hrs. In humans, IL-12 is needed for DCs to provoke rapid IFN-g production by NK cells, IL-15 seems essential for the NK cell proliferation. In the present study, we are testing the potential of chimeric IL-15 individually and in combination with native hIL-12 as an activator of CD4+ T cells, CD8+ T cells and NK cells. The combination of both cytokines shows potent release of IFN-g as well as activation of the T-cell subsets and NK cells. In our future studies we will use these pre-activated cells for adoptive transfer in cancer immunotherapy. Detailed findings will be reported during the conference. Citation Format: Priya Chandramohan Sharma, Digna Patel, Sarat K Dalai. Understanding the Potential of Human IL-12 and Chimeric IL-15 Combination for Cancer Immunotherapy [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 A006.

Trajectories of interleukin 10 and heart fatty acid-binding protein levels in traumatic brain injury patients with or without extracranial injuries.

Interleukin 10 (IL-10) and heart fatty acid-binding protein (H-FABP) have gained interest as diagnostic biomarkers of traumatic brain injury (TBI), but factors affecting their blood levels in patients with moderate-to-severe TBI are largely unknown. To investigate the trajectories of IL-10 and H-FABP between TBI patients with and without extracranial injuries (ECI); to investigate if there is a correlation between the levels of IL-10 and H-FABP with the levels of inflammation/infection markers C-reactive protein (CRP) and leukocytes; and to investigate if there is a correlation between the admission level of H-FABP with admission levels of cardiac injury markers, troponin (TnT), creatine kinase (CK), and creatine kinase MB isoenzyme mass (CK-MBm). The admission levels of IL-10, H-FABP, CRP, and leukocytes were measured within 24 h post-TBI and on days 1, 2, 3, and 7 after TBI. The admission levels of TnT, CK, and CK-MBm were measured within 24 h post-TBI. There was a significant difference in the concentration of H-FABP between TBI patients with and without ECI on day 0 (48.2 ± 20.5 and 12.4 ± 14.7 ng/ml, p = 0.02, respectively). There was no significant difference in the levels of IL-10 between these groups at any timepoints. There was a statistically significant positive correlation between IL-10 and CRP on days 2 (R = 0.43, p < 0.01) and 7 (R = 0.46, p = 0.03) after injury, and a negative correlation between H-FABP and CRP on day 0 (R = -0.45, p = 0.01). The levels of IL-10 or H-FABP did not correlate with leukocyte counts at any timepoint. The admission levels of H-FABP correlated with CK (R = 0.70, p < 0.001) and CK-MBm (R = 0.61, p < 0.001), but not with TnT. Inflammatory reactions during the early days after a TBI do not significantly confound the use of IL-10 and H-FABP as TBI biomarkers. Extracranial injuries and cardiac sources may influence the levels of H-FABP in patients with moderate-to-severe TBI.

Scavenger receptor a is a major homeostatic regulator that restrains drug-induced liver injury.

Drug-induced liver injury occurs frequently and can be life threatening. Although drug-induced liver injury is mainly caused by the direct drug cytotoxicity, increasing evidence suggests that the interplay between hepatocytes and immune cells can define this pathogenic process. Here, we interrogate the role of the pattern recognition scavenger receptor A (SRA) for regulating hepatic inflammation and drug-induced liver injury. Using acetaminophen (APAP) or halothane-induced liver injury models, we showed that SRA loss renders mice highly susceptible to drug hepatotoxicity, indicated by the increased mortality and liver pathology. Mechanistic studies revealed that APAP-induced liver injury exaggerated in the absence of SRA was associated with the decreased anti-inflammatory and prosurvival cytokine IL-10 concomitant with excessive hepatic inflammation. The similar correlation between SRA and IL-10 expression was also seen in human following APAP uptake. Bone marrow reconstitution and liposomal clodronate depletion studies established that the hepatoprotective activity of SRA mostly resized in the immune sentinel KCs. Furthermore, SRA-facilitated IL-10 production by KCs in response to injured hepatocytes mitigated activation of the Jun N-terminal kinase-mediated signaling pathway in hepatocytes. In addition, supplemental use of IL-10 with N -acetylcysteine, only approved treatment of APAP overdose, conferred mice improved protection from APAP-induced liver injury. We identify a novel hepatocyte-extrinsic pathway governed by the immune receptor SRA that maintains liver homeostasis upon drug insult. Giving that drug (ie, APAP) overdose is the leading cause of acute liver failure, targeting this hepatoprotective SRA-IL-10 axis may provide new opportunities to optimize the current management of drug-induced liver injury.

Biomarkers for differentiation of coronavirus disease 2019 or extracorporeal membrane oxygenation related inflammation and bacterial/fungal infections in critically ill patients: A prospective observational study.

Secondary infections in coronavirus disease 2019 (COVID-19) patients are difficult to distinguish from inflammation associated with COVID-19 and/or extracorporeal membrane oxygenation (ECMO). Therefore, highly specific and sensitive biomarkers are needed to identify patients in whom antimicrobial therapy can be safely withheld. In this prospective monocentric study, 66 COVID-19 patients admitted to the intensive care unit (ICU) for ECMO evaluation were included. A total of 46 (70%) patients with secondary infections were identified by using broad microbiological and virological panels and standardized diagnostic criteria. Various laboratory parameters including C-reactive protein (CRP), interleukin (IL)-6, procalcitonin (PCT), and IL-10 were determined at time of study inclusion. The best test performance for differentiating bacterial/fungal secondary infections and COVID-19 and/or ECMO associated inflammation was achieved by IL-10 (ROC-AUC 0.84) and a multivariant step-wise regression model including CRP, IL-6, PCT, and IL-10 (ROC-AUC 0.93). Data obtained in the present study highlights the use of IL-10 to differentiate secondary bacterial/fungal infections from COVID-19 and/or ECMO associated inflammation in severely ill COVID-19 patients.

Abstract 2863: Immunocytokines with target cell-restricted IL-15 activity for treatment of B cell malignancies

Abstract Antitumor antibodies like Rituximab and Trastuzumab activate the patient’s immune system to engage malignant cells. Despite the advances achieved by their introduction in cancer treatment, an urgent medical need remains to improve and optimize the efficacy of antibody therapy. This may be achievable using the cytokine IL-15 which induces proliferation and activation of both, NK cells and CD8 T cells, and enhances their cytolytic capacity. So far, short half-life, poor accumulation at the tumor site and severe toxicity upon systemic application due to unspecific immune activation prevent the broad use of IL-15 for treatment of cancer patients (Conlon et al, JCO 2015). IL-15 predominantly acts as part of an immunological synapse with IL-15Rα expressed on antigen-presenting cells, which present IL-15 in trans to IL-15Rβγ receptor expressing cytotoxic lymphocytes. We here report on the generation of so called “modified immunocytokines” (MICs) which consist of an Fc-optimized (SDIE modification) CD19 or CD20 antibody for targeting of (malignant) B cells fused to an IL-15 mutant with abolished binding to IL-15Rα termed MIC19 or MIC20. The abrogation of IL-15Rα binding by the IL-15 mutation enables substitution of the physiological trans-presentation by target binding of the antibody, allowing for target antigen-restricted stimulation of the IL-15Rβγ on NK cells and CD8 T cells. Analyses of activation and toxicity with MIC19 compared to a CD19 immunocytokine with an unmodified IL-15 (IC19) or immunocytokines with unrelated specificity as control confirmed target antigen-restricted function of the MIC proteins. Killing of autologous and allogeneic CD19+/CD20+ target cells was clearly superior as compared to the CD19-directed Fc optimized antibody (Tafasitamab) and Rituximab that bear no cytokine activity. Compared to antibody treatment, the MIC proteins induced a pronounced and long-lasting proliferation of effector cells and were effective to treat leukemia in a xenograft (Nalm-6) leukemia mouse model. Anti-leukemic activity was further confirmed in a murine NSG xenotransplantation model using patient ALL cells and human NK cells as effectors. In summary, MIC constructs consisting of an Fc-optimized antibody and mutated IL-15 with deficient IL-15Rα binding induce target cell restricted activation and proliferation of NK cells, resulting in efficient anti-leukemic activity. Our MICs thus combine the benefits of Fc-optimized antibodies and IL-15 activity and constitute a promising novel treatment modality for B cell malignancies with low side effects that allow the application of truly effective doses. Citation Format: Ilona Hagelstein, Latifa Zekri, Boris Klimovich, Martina S. Lutz, Carsten Greve, Stefanie Müller, Melanie Märklin, Bastian Schmied, Gundram Jung, Helmut R. Salih. Immunocytokines with target cell-restricted IL-15 activity for treatment of B cell malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2863.

Abstract P2-14-06: Durable responses with intratumoral electroporation of plasmid interleukin-12 plus pembrolizumab in patients with advanced triple-negative breast cancer: Cohort 1 update from KEYNOTE-890

Abstract BACKGROUND: Electroporated plasmid interleukin-12 (tavokinogene telseplasmid; TAVO-EP) delivered to accessible tumors by intratumoral injection induces sustained local expression of IL-12. IL-12 is a potent immunoregulatory cytokine that plays a key role in the crosstalk between innate (dendritic, macrophage, and natural killer) and adaptive (T and B) cells, promoting anti-tumor immune responses. TAVO-EP has been shown to induce activation of innate and adaptive tumor-infiltrating and peripheral immune cells, regression of treated and distant untreated lesions (abscopal effect), and expression of PD-L1 in patients with melanoma or triple-negative breast cancer (TNBC), without the systemic toxicity that limited therapeutic use of IL-12 historically. The combination of TAVO-EP and pembrolizumab has demonstrated durable responses in melanoma patients with immunologically “cold” tumors or with prior progression on anti-PD1 therapy. Anti-PD1 monotherapy has just over 5% overall response rate (ORR) in the second-line or later (2L+) treatment setting for advanced TNBC. New antibody-directed conjugate (ADC) chemotherapy has increased rates of responses compared with prior standard chemotherapy in 2L+ advanced TNBC; however, short duration of response (DOR), and toxicity are issues of concern. Therapies that can induce durable responses with limited toxicity are needed. METHODS: Cohort 1 of this Phase 2, open-label, multicenter study assessed the safety and efficacy of TAVO-EP in combination with pembrolizumab as 2L+ treatment for advanced TNBC. Eligible patients had at least 1 line of prior systemic therapy for advanced or metastatic disease, measurable disease by RECIST v1.1, and ≥1 lesion accessible for TAVO-EP treatment. Patients received pembrolizumab (200 mg IV) every 3 weeks and TAVO-EP (0.5 mg/mL at dose volume of ~1/4 lesion volume) on Days 1, 5, and 8 every 6 weeks. Tumor assessments were performed every 12 weeks. The primary endpoint was RECIST v.1.1 ORR by investigator review. Secondary endpoints included safety and tolerability, DOR, progression-free survival (PFS), immune-related RECIST (iRECIST) ORR and PFS, disease control rate, and overall survival (OS). ClinicalTrials.gov: NCT03567720. RESULTS: Between 01Nov2018 and 30Jan2020, 26 patients were enrolled and received at least one dose of study treatment (median follow up of 11.1 months). Patients had a median of 2 prior lines of systemic therapy for advanced disease (range 1-5). Among 23 patients evaluable for response, the ORR was 17.4% (4 with partial response [PR]). One responder with centrally confirmed PD-L1-negative disease and chest wall and bulky liver metastases had a sustained PR and an iRECIST complete response (CR). One responder had near complete regression of a large fungating chest wall skin lesion. The median DOR was 16.6 months. Median OS was 11.0 months (range 0.6-27.5+). The most common treatment-related adverse events (TRAEs) (all grades) were administration site pain and fatigue. Grade 3 TRAEs were reported in 6 patients (23%) including fatigue (11.5%); acute kidney injury, enterocolitis, and myocarditis (3.8% each). There were no Grade 4 or 5 TRAEs. CONCLUSIONS: The combination of TAVO-EP and pembrolizumab in pretreated patients with advanced TNBC resulted in durable RECIST v1.1 responses, including in PD-L1-negative disease, and was well tolerated. This novel immunotherapeutic regimen warrants further evaluation in 2L+ advanced TNBC. Cohort 2 exploring TAVO-EP + pembrolizumab + chemotherapy in frontline TNBC is currently enrolling. Citation Format: Melinda L. Telli, Irene Wapnir, Bianca Devitt, Katharine Cuff, Hatem Soliman, Shaveta Vinayak, David A. Canton, Christopher G. Twitty, Sunny Xie, Ying Lu, Donna Bannavong, Bridget O'Keeffe, Sandra Aung, Rohit Joshi. Durable responses with intratumoral electroporation of plasmid interleukin-12 plus pembrolizumab in patients with advanced triple-negative breast cancer: Cohort 1 update from KEYNOTE-890 [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-14-06.

Pirfenidone increases IL-10 and improves acute pancreatitis in multiple clinically relevant murine models.

Despite decades of research, there is no specific therapy for acute pancreatitis (AP). In the current study, we have evaluated the efficacy of pirfenidone, an antiinflammatory and antifibrotic agent that is approved by the FDA for treatment of idiopathic pulmonary fibrosis (IPF), in ameliorating local and systemic injury in AP. Our results suggest that treatment with pirfenidone in therapeutic settings (e.g., after initiation of injury), even when administered at the peak of injury, reduces severity of local and systemic injury and inflammation in multiple models of AP. In vitro evaluation suggests that pirfenidone decreases cytokine release from acini and macrophages and disrupts acinar-macrophage crosstalk. Therapeutic pirfenidone treatment increases IL-10 secretion from macrophages preceding changes in histology and modulates the immune phenotype of inflammatory cells with decreased levels of inflammatory cytokines. Antibody-mediated IL-10 depletion, use of IL-10–KO mice, and macrophage depletion experiments confirmed the role of IL-10 and macrophages in its mechanism of action, as pirfenidone was unable to reduce severity of AP in these scenarios. Since pirfenidone is FDA approved for IPF, a trial evaluating the efficacy of pirfenidone in patients with moderate to severe AP can be initiated expeditiously.

Mesenchymal stromal cells as carriers of IL-12 reduce primary and metastatic tumors of murine melanoma

Due to immunosuppressive properties and confirmed tropism towards cancer cells mesenchymal stromal cells (MSC) have been used in many trials. In our study we used these cells as carriers of IL-12 in the treatment of mice with primary and metastatic B16-F10 melanomas. IL-12 has confirmed anti-cancer activity, induces a strong immune response against cancer cells and acts as an anti-angiogenic agent. A major limitation of the use of IL-12 in therapy is its systemic toxicity. The aim of the work was to develop a system in which cytokine may be administered intravenously without toxic side effects. In this study MSC were used as carriers of the IL-12. We confirmed antitumor effectiveness of the cells secreting IL-12 (MSC/IL-12) in primary and metastatic murine melanoma models. We observed inhibition of tumor growth and a significant reduction in the number of metastases in mice after MSC/IL-12 administration. MSC/IL-12 decreased vascular density and increased the number of anticancer M1 macrophages and CD8+ cytotoxic T lymphocytes in tumors of treated mice. To summarize, we showed that MSC are an effective, safe carrier of IL-12 cytokine. Administered systemically they exert therapeutic properties of IL-12 cytokine without toxicity. Therapeutic effect may be a result of pleiotropic (proinflammatory and anti-angiogenic) properties of IL-12 released by modified MSC.

Irradiation Haematopoiesis Recovery Orchestrated by IL-12/IL-12Rβ1/TYK2/STAT3-Initiated Osteogenic Differentiation of Mouse Bone Marrow-Derived Mesenchymal Stem Cells.

PurposeRepairing the irradiation-induced osteogenic differentiation injury of bone marrow mesenchymal stem cells (BM-MSCs) is beneficial to recovering haematopoiesis injury in radiotherapy; however, its mechanism is elusive. Our study aimed to help meet the needs of understanding the effects of radiotherapy on BM-MSC osteogenic potential.Methods and MaterialsBalb/c mice and the BM-MSCs were used to evaluate the irradiation-induced osteogenic differentiation injury in vivo. The cellular and molecular characterization were applied to determine the mechanism for recovery of irradiation-derived haematopoiesis injuries.ResultsWe report a functional role of IL-12 in acute irradiation hematopoietic injury recovery and intend to dissect the possible mechanisms through BM-MSC, other than the direct effect of IL-12 on hematopoietic stem and progenitor cells (HSPCs). Specifically, we show that early use of IL-12 enhanced the osteogenic differentiation of BM-MSCs through IL-12Rβ1/TYK2/STAT3 signaling; furthermore, IL-12 induced osteogenesis facilitated bone formation and irradiation hematopoiesis recovery when transplanted BM-MSCs in the femur of Balb/c mice. For the mechanism of action, we found that IL-12 receptor beta 1 (IL-12Rβ1) expression of irradiated BM-MSCs was upregulated rapidly, coincidentally consistent with early use of IL-12 induced osteogenic differentiation enhancement. IL-12Rβ1 and tyrosine kinase 2 gene (Tyk2) silencing experiments and phosphotyrosine of signal transducer and activator of transcription 3 (p-STAT3) suppression experiments indicated the IL-12Rβ1/TYK2/STAT3 signaling was essential in IL-12-induced osteogenic differentiation enhancement of BM-MSCs.ConclusionThese findings suggested that IL-12 may exert BM-MSCs-based hematopoietic recovery by repairing osteogenic differentiation abilities damages through IL-12Rβ1/TYK2/STAT3 signaling pathway post-irradiation.

German S3-Guideline on the treatment of Psoriasis vulgaris, adapted from EuroGuiDerm - Part 2: Treatment monitoring and specific clinical or comorbid situations.

German S3-Guideline on the treatment of Psoriasis vulgaris, adapted from EuroGuiDerm - Part 2: Treatment monitoring and specific clinical or comorbid situations.

The risk of respiratory tract infections and interstitial lung disease with interleukin 12/23 and interleukin 23 antagonists in patients with autoimmune diseases: A systematic review and meta-analysis

BackgroundRespiratory tract infections (RTIs) and interstitial lung disease (ILD) secondary to interleukin (IL) 12/23 or IL-23 antagonists have been reported in autoimmune diseases.ObjectiveTo assess the risk of RTIs and noninfectious ILD with these drugs.MethodsWe conducted a systematic review and meta-analysis of randomized controlled trials. Risk of RTIs and noninfectious ILD was compared to placebo by Mantel-Haenszel risk difference. We divided RTIs into upper RTIs (URTI), viral URTIs, and lower RTIs (LRTIs) including infectious pneumonia. Noninfectious ILD included ILD, eosinophilic pneumonia, and pneumonitis.ResultsWe identified 54 randomized controlled trials including 10,907 patients with 6 IL-12/23 or IL-23 antagonists and 5175 patients with placebo. These drugs significantly increased the risk of RTIs (Mantel-Haenszel risk difference, 0.019; 95% confidence interval, 0.005-0.033; P = .007), which was attributed to URTIs, but not viral URTIs or LRTIs. There was no significant difference in infectious pneumonia and noninfectious ILD between 2 groups.LimitationsBecause of the rarity of infectious pneumonia and ILD, sensitivity analysis was required.ConclusionsThe use of IL-12/23 or IL-23 antagonists for autoimmune diseases increased the risk of URTIs, but not viral URTIs, LRTIs, and noninfectious ILD.

Potential use of IL-7 and IL-15 for ex vivo generation of LAK.

e15201 Background: A review of scientific literature has shown that IL-2 is most often used for the LAK generation, while the potential of other NK-stimulating interleukin cells remains poorly understood. In this study, we investigated the effect of IL-7 and IL-15 on ex vivo LAC generation. Methods: A fraction enriched in NK cells was isolated by magnetic cell sorting with the NK Cell Isolation Kit (#130-092-657, Miltenyi Biotec, Germany) from PBMC in 11 patients with stage II-III breast cancer without treatment. Cells were introduced into a 6-well 3x105 plate in RPMI medium (Gibco, USA) supplemented with 10% FBS (Gibco, USA). Cytokines 40 ng/ml were added to the wells in 6 variants: 1) IL-15; 2) IL-2; 3) IL-7; 4) IL-15+IL-7; 5) IL-15+IL-7+IL-2; 6) control without cytokines. Cells were cultured at 5.0% CO2 and 37°C. Cells were counted with a hemocytometer daily for 5 days and on days 8, 9 and 10 of cultivation. Results: The number of NK cells in control samples gradually decreased: by 2 times on day 5 and by 3 times on day 10. On day 5, the number of NK cells was 1.5 times higher than in the control when cultured with IL-2, and 1.4 times higher when cultured with IL-7+IL-15. After 9 days, a statistically significant increase in the number of cells, compared to the control sample, was observed with the addition of IL-2 (1.6 times); IL-15 and IL-7+IL-15 (1.5 times). On day 10, significant differences from the control were found in most samples: the number of cells was higher in samples cultured with IL-2 and IL-7+IL-15 (1.9 times) and with IL-15 and IL-2+IL-7+IL-15 (1.7 times). IL-7 alone led to a gradual decrease in the number of cells, and on days 8, 9 and 10 it was lower than in the control samples. Conclusions: In general, the introduction of cytokines into the samples enriched with NK cells contributed to the preservation of this subpopulation on days 5-10 of cultivation. However, the use of IL-7 and IL-15, both alone and in combination, did not lead to a significant increase in LAK compared to the use of IL-2.

Targeting the immunosuppressive tumor microenvironment: Synergistic effect of low-dose IL12 in combination with dual immune checkpoint inhibition in a preclinical model of ovarian cancer.

7 Background: Epithelial ovarian cancer (OC) is the most lethal gynecologic cancer with ~22,000 women diagnosed annually in the US. The impact of immune checkpoint inhibition (ICI) in the treatment of solid tumors has been significant. However, the response rates for OC are low ranging from 11-15%. It is critical to explore strategies to enhance the efficacy of ICI immunotherapy in OC. Targeting immunosuppressive factors and cells within the tumor microenvironment (TME) represents a feasible approach. The use of IL12 is attractive because induces potent antitumor activity by targeting myeloid cells and lymphocytes. However its clinical application has been hindered by its potential systemic toxicity. Here we explore the use of low dose intraperitoneal IL12 to enhance the antitumor activity of dual ICI in OC. Methods: Mice bearing ID8-VEGF tumors implanted intraperitoneally received either anti-PD1 alone or dual ICI treatment of anti-PD1 plus anti-CTLA4 with or without low dose IL12. Ascites accumulation was used as surrogate for tumor progression and determined by assessing weight increase. Blood and ascites were analyzed by flow cytometry for frequency of PMN-MDSC, M-MDSC, and activated T cells. Results: Low dose IL12 alone induced a significant delay in ascites accumulation when compared to untreated controls or mice treated with PD1 monotherapy or dual ICI. Addition of IL12 to dual ICI resulted in significant tumor regression and extended survival benefit compared to dual ICI alone. A synergistic effect of IL12 was not observed when combined with PD1 monotherapy. Antitumor responses associated with a marked decrease in the frequency of M-MDSC in blood and a decrease in both PMN- and M-MDSC in ascites. Decrease in MDSC associated with elevated levels of activated T cells. Conclusions: Low dose IL12 can induce regression of ID8-VEGF tumors. However, durable responses were only observed when IL12 was added to dual ICI. This suggests that IL12 can induce changes in the TME, particularly on MDSC, that can potentiate the antitumor activity of dual ICI. Our findings also suggest a crucial role of CTLA4 blockade perhaps via Treg targeting.

In the Absence of a TCR Signal IL-2/IL-12/18-Stimulated γδ T Cells Demonstrate Potent Anti-Tumoral Function Through Direct Killing and Senescence Induction in Cancer Cells.

Abundant IFN-γ secretion, potent cytotoxicity, and major histocompatibility complex-independent targeting of a large spectrum of tumors make γδ T cells attractive candidates for cancer immunotherapy. Upon tumor recognition through the T-cell receptor (TCR), NK-receptors, or NKG2D, γδ T cells generate the pro-inflammatory cytokines TNF-α and IFN-γ, or granzymes and perforin that mediate cellular apoptosis. Despite these favorable potentials, most clinical trials testing the adoptive transfer of pharmacologically TCR-targeted and expanded γδ T cells resulted in a limited response. Recently, the TCR-independent activation of γδ T cells was identified. However, the modulation of γδ T cell’s effector functions solely by cytokines remains to be elucidated. In the present study, we systematically analyzed the impact of IL-2, IL-12, and IL-18 in parallel with TCR stimulation on proliferation, cytokine production, and anti-tumor activity of γδ T cells. Our results demonstrate that IL-12 and IL-18, when combined, constitute the most potent stimulus to enhance anti-tumor activity and induce proliferation and IFN-γ production by γδ T cells in the absence of TCR signaling. Intriguingly, stimulation with IL-12 and IL-18 without TCR stimulus induces a comparable degree of anti-tumor activity in γδ T cells to TCR crosslinking by killing tumor cells and driving cancer cells into senescence. These findings approve the use of IL-12/IL-18-stimulated γδ T cells for adoptive cell therapy to boost anti-tumor activity by γδ T cells.

The Synergistic Use of IL-15 and IL-21 for the Generation of NK Cells From CD3/CD19-Depleted Grafts Improves Their ex vivo Expansion and Cytotoxic Potential Against Neuroblastoma: Perspective for Optimized Immunotherapy Post Haploidentical Stem Cell Transplantation.

Neuroblastoma (NB) is the most common solid extracranial tumor in childhood. Despite therapeutic progress, prognosis in high-risk NB is poor and innovative therapies are urgently needed. Therefore, we addressed the potential cytotoxic capacity of interleukin (IL)-activated natural killer (NK) cells compared to cytokine-induced killer (CIK) cells for the treatment of NB. NK cells were isolated from peripheral blood mononuclear cells (PBMCs) by indirect CD56-enrichment or CD3/CD19-depletion and expanded with different cytokine combinations, such as IL-2, IL-15, and/or IL-21 under feeder-cell free conditions. CIK cells were generated from PBMCs by ex vivo stimulation with interferon-γ, IL-2, OKT-3, and IL-15. Comparative analysis of expansion rate, purity, phenotype and cytotoxicity was performed. CD56-enriched NK cells showed a median expansion rate of 4.3-fold with up to 99% NK cell content. The cell product after CD3/CD19-depletion consisted of a median 43.5% NK cells that expanded significantly faster reaching also 99% of NK cell purity. After 10–12 days of expansion, both NK cell preparations showed a significantly higher median cytotoxic capacity against NB cells relative to CIK cells. Remarkably, these NK cells were also capable of efficiently killing NB spheroidal 3D culture in long-term cytotoxicity assays. Further optimization using a novel NK cell culture medium and a prolonged culturing procedure after CD3/CD19-depletion for up to 15 days enhanced the expansion rate up to 24.4-fold by maintaining the cytotoxic potential. Addition of an IL-21 boost prior to harvesting significantly increased the cytotoxicity. The final cell product consisted for the major part of CD16−, NCR-expressing, poly-functional NK cells with regard to cytokine production, CD107a degranulation and antitumor capacity. In summary, our study revealed that NK cells have a significantly higher cytotoxic potential to combat NB than CIK cell products, especially following the synergistic use of IL-15 and IL-21 for NK cell activation. Therefore, the use of IL-15+IL-21 expanded NK cells generated from CD3/CD19-depleted apheresis products seems to be highly promising as an immunotherapy in combination with haploidentical stem cell transplantation (SCT) for high-risk NB patients.

P2.04-56 Improved Survival of NSCLC Filipino Patients Given Autologous Dendritic Cell Vaccine: Case Series with CTC Upgrade and IL15

Lung cancer remains to be a major malignancy among Filipinos with a fatality rate of 19.2 for every 100,000 in 2018. The Molecular Diagnostics and Cellular Therapeutics Laboratory of the Lung Center of the Philippines has developed a complimentary therapy using autologous dendritic cell vaccine for lung adenocarcinoma, the preliminary result of which was reported in this Conference in 2013. From then onwards, a number of modifications has been incorporated in the protocol as part of the continuing research and development program of the Center. Herein, reported is the comparative performance of the vaccination protocol in the period 2009-2013 and 2014-2018 and the modifications introduced that accounted for the improved survival. Chart data of sixteen lung adenocarcinoma patients in 2009-2013 and five patients in 2014-2018 who have undergone the immune cell therapy as part of their treatment regimen, were retrieved and compared in terms of their survival in 3, 6 and 9 month timepoints. Protocol for immune cell therapy in the same period were also retrieved and compared. The patients have executed corresponding informed consent and their therapy has undergone ethics review and approval of the Stem Cell Ethics Committee of the Center. Patients in 2009-2013 included 1 stage1, 1 stage 2, 6 stage 3 and 8 stage 4, while patients in 2014-2018 included 1 stage 1 and 4 stage 4. For stage 1, there was a 100% survival in the 3, 6 and 9 month timepoints in both periods. For stage 4 there was a 87.5%, 50% and 12.5% survival respectively in the 3, 6 and 9 month timepoints for the 2009-2013 period while a 100%, 75% and75% survival for 2014-2018 period. Protocol evaluation showed an increase in circulating tumor gene targets used for peptide priming (i.e. from 15 to 22 targets) and the use of IL15. The additional targets included were: BRACHURY, CD133, hTERT, p53, NRAS, S100A14, and CA125 Although preliminary, the additional targets and the use of IL15 could be attributed to the improved survival rate of patients, especially for stage 4 patients.

First-in-human trial of rhIL-15 and haploidentical natural killer cell therapy for advanced acute myeloid leukemia

AbstractIn vivo expansion of haploidentical natural killer (NK) cell infusions with interleukin-2 (IL-2) can induce remission of refractory acute myeloid leukemia, but efficacy may be hampered by concurrent stimulation of host regulatory T cells. To overcome this limitation, we substituted the NK homeostatic factor IL-15 in 2 phase 1/2 trials. Forty-two patients received either intravenous (IV) (NCT01385423) or subcutaneous (SC) (NCT02395822) recombinant human IL-15 (rhIL-15) after lymphodepleting chemotherapy and haploidentical NK cells. Escalating doses of rhIL-15 (0.3-1.0 μg/kg) were given on 12 consecutive days in a phase 1 trial. Of 26 patients, 36% had robust in vivo NK-cell expansion at day 14, and 32% achieved complete remission. Hypothesizing that SC dosing of rhIL-15 would be safer and better tolerated, 16 patients received 10 once per day doses of SC rhIL-15 at 2.0 μg/kg on a phase 2 trial. NK-cell expansion at day 14 was seen in 27% of the patients, and 40% achieved remission. rhIL-15 induced better rates of in vivo NK-cell expansion and remission compared with previous trials with IL-2, but it was associated with previously unreported cytokine release syndrome (CRS) after SC but not IV dosing. CRS was observed in 56% of patients given SC rhIL-15 (with concurrent neurologic toxicity in 5 of 9 patients) and was responsive to steroids and tocilizumab. SC administration was associated with slower pharmacokinetic clearance and higher levels of IL-6 than IV dosing. These novel trials testing the use of IL-15 to potentiate cell therapy suggest that dosing schedules based on pharmacokinetics and pharmacodynamics will preserve the therapeutic benefits of IL-15 and minimize CRS. These trials were registered at www.clinicaltrials.gov as #NCT01385423 and #NCT02395822.

Safety and efficacy of Tet-regulated IL-12 expression in cancer-specific T cells

ABSTRACTWe explored whether engineering of T cell specificity and effector function improves immunotherapy of solid tumors. Although IL-12 can enhance cancer immunity, a strategy of safe IL-12 delivery without toxicity is currently lacking. We engineered T cells to express IL-12 controlled by the NFAT promoter responsive to TCR stimulation, or by the Tet-On promoter responsive to doxycycline. In vivo, NFAT-engineered T cells caused lethal toxicity, while Tet-engineered T cells were safe in the absence of doxycycline. Combining gene transfer of the melanoma-specific TRP2-TCR with Tet-IL-12 engineering revealed that temporal induction of IL-12 was essential to inhibit the growth of B16F10 melanoma tumors. Induced IL-12 increased the number of tumor-infiltrating T cells and also prevented the down-modulation of the TRP2-TCR and the associated up-regulation of the PD1 marker that was observed in the absence of IL-12. In addition, temporal induction of IL-12 expression also increased the number of plasmacytoid DC in the tumor micro-environment. We show that repeated induction of IL-12 can be used to enhance control of tumor growth without encountering systemic toxicity. The observation that TCR engineering combined with Tet-regulated IL-12 expression can achieve tumor immunity without the side effects that are usually associated with the in vivo use of IL-12 warrants translation of this concept into the clinic.