The efficacy and safety of short-term and low-dose IL-2 combined with tocilizumab to treat rheumatoid arthritis.

Background: Immunotherapy targeting factors related to immune imbalance has been widely employed for RA treatment. This study aimed to evaluate the efficacy and safety of low-dose interleukin (IL)-2 combined with tocilizumab (TCZ), a biologics targeting IL-6, in RA patients. Methods: Fifty adults with active RA who met the criteria with complete clinical data were recruited, and divided into three groups: control group (n=15), IL-2 group (n=26), and IL-2+TCZ group (n=9). In addition to basic treatment, participants in the IL-2 group received IL-2 (0.5 MIU/day), while participants in the IL-2+TCZ group received IL-2 (0.5 MIU/day) along with one dose of TCZ (8 mg/kg, maximum dose: 800 mg). All subjects underwent condition assessment, laboratory indicators and safety indicators detection, and records before treatment and one week after treatment. Results: Compared with the baseline, all three groups showed significant improvement in disease conditions, as evidenced by significantly reduced disease activity indicators. The low-dose IL-2 and combination treatment groups demonstrated a violent proliferation of Tregs, while the absolute number of Th1, Th2, and Th17 cells in the latter group showed a decreasing trend. The decrease in the Th17/Treg ratio was more pronounced in the IL-2+TCZ groups. No significant adverse reactions were observed in any of the patients. Conclusion: Exogenous low doses of IL-2 combined TCZ were found to be safe and effective in reducing effector T cells and appropriately increasing Treg levels in RA patients with high effector T cell levels. This approach helps regulate immune homeostasis and contributes to the prevention of disease deterioration. Clinical trial registration: https://www.chictr.org.cn/showprojEN.html?proj=13909, identifier ChiCTR-INR-16009546.

IL-2-free tumor-infiltrating lymphocyte therapy with PD-1 blockade demonstrates potent efficacy in advanced gynecologic cancer.

BACKGROUND: Tumor-infiltrating lymphocyte (TIL) therapy has been restricted by intensive lymphodepletion and high-dose intravenous interleukin-2 (IL-2) administration. To address these limitations, we conducted preclinical and clinical studies to evaluate the safety, antitumor activity, and pharmacokinetics of an innovative modified regimen in patients with advanced gynecologic cancer. METHODS: Patient-derived xenografts (PDX) were established from a local recurrent cervical cancer patient. TILs were expanded ex vivo from minced tumors without feeder cells in the modified TIL therapy regimen. Patients underwent low-dose cyclophosphamide lymphodepletion followed by TIL infusion without intravenous IL-2. The primary endpoint was safety; the secondary endpoints included objective response rate, duration of response, and T cell persistence. RESULTS: In matched patient-derived xenografts (PDX) models, homologous TILs efficiently reduced tumor size (p < 0.0001) and underwent IL-2 absence in vivo. In the clinical section, all enrolled patients received TIL infusion using a modified TIL therapy regimen successfully with a manageable safety profile. Five (36%, 95% CI 16.3-61.2) out of 14 evaluable patients experienced objective responses, and three complete responses were ongoing at 19.5, 15.4, and 5.2 months, respectively. Responders had longer overall survival (OS) than non-responders (p = 0.036). Infused TILs showed continuous proliferation and long-term persistence in all patients and showed greater proliferation in responders which was indicated by the Morisita overlap index (MOI) of TCR clonotypes between infused TILs and peripheral T cells on day 14 (p = 0.004) and day 30 (p = 0.004). Higher alteration of the CD8+/CD4+ ratio on day 14 indicated a longer OS (p = 0.010). CONCLUSIONS: Our modified TIL therapy regimen demonstrated manageable safety, and TILs could survive and proliferate without IL-2 intravenous administration, showing potent efficacy in patients with advanced gynecologic cancer. TRIAL REGISTRATION: NCT04766320, Jan 04, 2021.

Phase 1 first-in-human dose-escalation study of ANV419 in patients with relapsed/refractory advanced solid tumors.

Patients with advanced cancer, previously treated with immune checkpoint blockade therapy, may retain residual treatment when undergoing the initial infusion of experimental monotherapy in phase 1 clinical trials. ANV419, an antibody-cytokine fusion protein, combines interleukin-2 (IL-2) with an anti-IL-2 monoclonal antibody, aiming to stimulate the expansion of CD8 T and natural killer lymphocytes while restricting regulatory T lymphocytes. In the recent publication of the phase 1 dose escalation study of ANV419, a notable gap exists in detailed information regarding patients' prior antitumoral treatments, specifically programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) targeted monoclonal antibodies. Some patients likely retained residual anti-PD-1/PD-L1 monoclonal antibodies, potentially influencing the outcomes of ANV419. In a separate clinical cohort, we retrospectively measured the residual concentration of nivolumab and pembrolizumab, revealing persistent serum concentrations of anti-PD-1/PD-L1 antibodies even months after treatment cessation. This underscores the importance of comprehensively documenting prior immunotherapy details in clinical trials. Such information is crucial for understanding potential interactions that may impact both immunological and clinical effects.

Mathematical model for IL-2-based cancer immunotherapy.

A basic mathematical model for IL-2-based cancer immunotherapy is proposed and studied. Our analysis shows that the outcome of therapy is mainly determined by three parameters, the relative death rate of CD4+ T cells, the relative death rate of CD8+ T cells, and the dose of IL-2 treatment. Minimal equilibrium tumor size can be reached with a large dose of IL-2 in the case that CD4+ T cells die out. However, in cases where CD4+ and CD8+ T cells persist, the final tumor size is independent of the IL-2 dose and is given by the relative death rate of CD4+ T cells. Two groups of in silico clinical trials show some short-term behaviors of IL-2 treatment. IL-2 administration can slow the proliferation of CD4+ T cells, while high doses for a short period of time over several days transiently increase the population of CD8+ T cells during treatment before it recedes to its equilibrium. IL-2 administration for a short period of time over many days suppresses the tumor population for a longer time before approaching its steady-state levels. This implies that intermittent administration of IL-2 may be a good strategy for controlling tumor size.

[Effect of Low-Dose Recombinant Interleukin-2 Therapy on Immunocyte Subsets in Children with Solid Tumor].

OBJECTIVE: To evaluate the effect of low-dose recombinant interleukin-2 (rIL-2) therapy on immunocyte subsets and its side effects in children with solid tumor. METHODS: A total of 22 children (11 males and 11 females) with solid tumor in our department from December 2012 to November 2017 were selected, with a median age of 9 (3-16) years old when starting IL-2 therapy. ALL surgeries and chemotherapy of children had been completed before low-dose rIL-2 therapy, and 17 cases achieved complete remission (CR) and 5 cases achieved partial remission (PR). A low-dose rIL-2 therapy was given 1 month after chemotherapy for 1 year: 4×105 IU/(m2·d), s.c. for every other day, 3 times per week. The immunocyte subsets were detected every 3 months until the end of treatment, meanwhile, disease condition and therapy-related side effects were followed up. RESULTS: After low-dose rIL-2 therapy in 22 children, the absolute values of CD3+ T cells, CD3-CD56+ natural killer cells, CD3+CD4+ helper T cells (Th) and CD3+CD8+ cytotoxic T cells were up-regulated remarkably, as well as Th/suppressor T cells (all P < 0.05). While, there were no significant differences in absolute value and proportion of CD4+CD25+CD127- Treg cells during therapy. Among the 17 children who achieved CR before rIL-2 therapy, 14 cases continued to maintain CR after therapy, while 3 cases relapsed, and with 2 died after treatment abandonment. The 5 children who achieved PR before low-dose rIL-2 therapy were evaluated CR by PET/CT scan after treatment. In the early stage of low-dose rIL-2 therapy, 1 child developed skin rashes at the injection sites, and 2 children ran a slight to mild transient fever. Their symptoms disappeared without any organ damage after symptomatic treatment. CONCLUSION: Low-dose rIL-2 therapy has good drug tolerance, and changes the distribution of anti-tumor immune-cell subgroup in peripheral blood of children with solid tumor remarkably without up-regulation of absolute value and ratio of Treg cells.

Tumor-Targeted Delivery of IL-2 by Fusing with a pH Low Insertion Peptide for Antitumor Immunotherapy.

As a pleiotropic cytokine, interleukin-2 (IL-2) can effectively regulate lymphocyte proliferation, survival, and active antitumor immune responses in tumor microenvironments. Although the ability of IL-2 to boost immune responses was reported in cancer patients, its short circulating half-life and high toxicity hinder its broad and continual clinical application. Herein, we developed a novel tumor target agent by fusing pH low insertion peptides (pHLIP) with IL-2, forming the fusion protein pHLIP-IL2. Based on the low pH insertion property of pHLIP, the pHLIP-IL2 fusion protein could be selectively delivered to the acidic tumor microenvironments and then promote the proliferation of killer immune cells to elicit tumor regression. We found that pHLIP-IL2 fusion proteins can be significantly enriched in tumor tissues and can effectively reduce tumor size in diverse tumor models, including breast cancer and melanoma, without apparent adverse effects. These data suggest that the pHLIP-IL2 fusion protein may be a promising solution for the continual and extensive application of IL-2, and pHLIP-IL2 is a potential and valuable therapeutic drug for cancer patients with antitumor immunotherapy.

Co-administration of chicken IL-2 alleviates clinical signs and replication of the ILTV chicken embryo origin vaccine by pre-activating natural killer cells and cytotoxic T lymphocytes.

IMPORTANCE: Chickens immunized with the infectious laryngotracheitis chicken embryo origin (CEO) vaccine (Medivac, PT Medion Farma Jaya) experience adverse reactions, hindering its safety and effective use in poultry flocks. To improve the effect of the vaccine, we sought to find a strategy to alleviate the respiratory reactions associated with the vaccine. Here, we confirmed that co-administering the CEO vaccine with chIL-2 by oral delivery led to significant alleviation of the vaccine reactions in chickens after immunization. Furthermore, we found that the co-administration of chIL-2 with the CEO vaccine reduced the clinical signs of the CEO vaccine while enhancing natural killer cells and cytotoxic T lymphocyte response to decrease viral loads in their tissues, particularly in the trachea and conjunctiva. Importantly, we demonstrated that the chIL-2 treatment can ameliorate the replication of the CEO vaccine without compromising its effectiveness. This study provides new insights into further applications of chIL-2 and a promising strategy for alleviating the adverse reaction of vaccines.

Real-world experience with low-dose IL-2 for children and young adults with refractory chronic graft-versus-host disease.

The majority of patients with chronic graft-versus-host disease (cGVHD) are steroid refractory (SR), creating a need for safe and effective therapies. Subcutaneous low-dose interleukin-2 (LD IL-2), which preferentially expands CD4+ regulatory T cells (Tregs), has been evaluated in 5 clinical trials at our center with partial responses (PR) in ∼50% of adults and 82% of children by week 8. We now report additional real-world experience with LD IL-2 in 15 children and young adults. We conducted a retrospective chart review of patients with SR-cGVHD at our center who received LD IL-2 from August 2016 to July 2022 not on a research trial. The median age at start of LD IL-2 was 10.4 years (range, 1.2-23.2 years) at a median of 234 days from cGVHD diagnosis (range, 11-542 days). Patients had a median of 2.5 (range, 1-3) active organs at LD IL-2 start and received a median of 3 (range, 1-5) prior therapies. The median duration of LD IL-2 therapy was 462 days (range, 8-1489 days). Most patients received 1 × 106 IU/m2 per day. There were no serious adverse effects. The overall response rate in 13 patients who received >4 weeks of therapy was 85% (complete response, n = 5; PR, n = 6) with responses in diverse organs. Most patients significantly weaned corticosteroids. Tregs preferentially expanded with a median peak fold increase of 2.8 in the ratio of Tregs to CD4+ conventional T cells (range, 2.0-19.8) by 8 weeks on therapy. LD IL-2 is a well-tolerated, steroid-sparing agent with a high response rate in children and young adults with SR-cGVHD.

Low-dose interleukin-2 promotes immune regulation in face transplantation: A pilot study.

Face transplantation is a life-changing procedure for patients with severe composite facial defects. However, it is hampered by high acute rejection rates due to the immunogenicity of skin allograft and toxicity linked to high doses of immunosuppression. To reduce immunosuppression-associated complications, we, for the first time in face transplant recipients, used low-dose interleukin 2 (IL-2) therapy to expand regulatory T cells (Tregs) in vivo and to enhance immune modulation, under close immunological monitoring of peripheral blood and skin allograft. Low-dose IL-2 achieved a sustained expansion (∼4-fold to 5-fold) of circulating Tregs and a reduction (∼3.5-fold) of B cells. Post-IL-2 Tregs exhibited greater suppressive function, characterized by higher expression of TIM-3 and LAG3co-inhibitory molecules. In the skin allograft, Tregs increased after low-dose IL-2 therapy. IL-2 induced a distinct molecular signature in the allograft with reduced cytotoxicity-associated genes (granzyme B and perforin). Two complications were observed during the trial: one rejection event and an episode of autoimmune hemolytic anemia. In summary, this initial experience demonstrated that low-dose IL-2 therapy was not only able to promote immune regulation in face transplant recipients but also highlighted challenges related to its narrow therapeutic window. More specific targeted Treg expansion strategies are needed to translate this approach to the clinic.

Low-dose interleukin-2 treatment increases the proportion of regulatory T cells in patients with rheumatic diseases: A meta-analysis.

BACKGROUND: It is now accepted that immune tolerance disorders caused by inadequate Treg cell function or number are important factors in the development and progression of rheumatic diseases. There is increasing evidence that ld IL-2 treatment increases the proportion of Treg cells in patients' peripheral blood, but this conclusion is still controversial. Here, we performed a meta-analysis of reports documenting the proportion of Treg cells and the rate of adverse events in patients with rheumatic disease before and after the administration of ld IL-2 to better understand its effect and safety on Treg cells in the field of rheumatic diseases. METHODS: We systematically searched PubMed, Embase, Scopus, Cochrane Library, and Web of science databases up to 15th November 2022 and identified studies that reported the proportion of peripheral blood Treg cells before and after ld IL-2 treatment in patients with rheumatic disease. Random-effects model was used to perform a meta-analysis of Treg cell proportions before and after ld IL-2 administration, and a meta-regression analysis was performed to explore heterogeneity. Inconsistency was evaluated using the I-squared index (I2), and publication bias was assessed by examining funnel plot asymmetry using the Egger tests. RESULTS: Eighteen studies involving 1608 patients were included in the meta-analysis. The proportion of Treg cells in peripheral blood of these patients increased significantly after receiving ld IL-2 treatment [1.07 (95% CI 0.86,1.27), p < 0.001, I2 = 67.3%]. Next, Meta-regression was performed for 5 variables including publish year, disease type, trail type and dosage and duration of the medication. The results suggest that these variables do not lead to high heterogeneity. (p = 0.698, 0.267, 0.502, 0.843, 0.560, respectively). And finally, statistical analysis showed no difference in adverse reactions between ld IL-2 group and control group in treatment [1.06 (95% CI 0.86,1.31), p = 0.586, I2 = 53.8%], which is unreliable because the data is so small. CONCLUSIONS: Ld IL-2 does increase the proportion of peripheral blood Treg cells in patients with rheumatism, and single and cumulative doses must be considered when using ld IL-2. In addition, more studies on the safety of ld IL-2 are urgently needed.

A (Controlled) Spill of IL2 for Localized Treatment of Mesothelioma.

A microencapsulated, cell-based IL2 cytokine factory was recently developed, and the safety and efficacy of this platform in a mouse model of mesothelioma were demonstrated. This platform has the potential to overcome current challenges in the delivery of therapeutic cytokines for cancer immunotherapy. See related article by Nash et al., p. 5121.

Activation of Adaptive and Innate Immune Cells via Localized IL2 Cytokine Factories Eradicates Mesothelioma Tumors.

PURPOSE: IL2 immunotherapy has the potential to elicit immune-mediated tumor lysis via activation of effector immune cells, but clinical utility is limited due to pharmacokinetic challenges as well as vascular leak syndrome and other life-threatening toxicities experienced by patients. We developed a safe and clinically translatable localized IL2 delivery system to boost the potency of therapy while minimizing systemic cytokine exposure. EXPERIMENTAL DESIGN: We evaluated the therapeutic efficacy of IL2 cytokine factories in a mouse model of malignant mesothelioma. Changes in immune populations were analyzed using time-of-flight mass cytometry (CyTOF), and the safety and translatability of the platform were evaluated using complete blood counts and serum chemistry analysis. RESULTS: IL2 cytokine factories enabled 150× higher IL2 concentrations in the local compartment with limited leakage into the systemic circulation. AB1 tumor burden was reduced by 80% after 1 week of monotherapy treatment, and 7 of 7 of animals exhibited tumor eradication without recurrence when IL2 cytokine factories were combined with anti-programmed cell death protein 1 (aPD1). Furthermore, CyTOF analysis showed an increase in CD69+CD44+ and CD69-CD44+CD62L- T cells, reduction of CD86-PD-L1- M2-like macrophages, and a corresponding increase in CD86+PD-L1+ M1-like macrophages and MHC-II+ dendritic cells after treatment. Finally, blood chemistry ranges in rodents demonstrated the safety of cytokine factory treatment and reinforced its potential for clinical use. CONCLUSIONS: IL2 cytokine factories led to the eradication of aggressive mouse malignant mesothelioma tumors and protection from tumor recurrence, and increased the therapeutic efficacy of aPD1 checkpoint therapy. This study provides support for the clinical evaluation of this IL2-based delivery system. See related commentary by Palanki et al., p. 5010.

PIVOT-12: a phase III study of adjuvant bempegaldesleukin plus nivolumab in resected stage III/IV melanoma at high risk for recurrence.

Bempegaldesleukin (BEMPEG: NKTR-214) is an immunostimulatory IL-2 cytokine prodrug engineered to deliver a controlled, sustained and preferential IL-2 pathway signal. Nivolumab (NIVO), a PD-1 inhibitor, has been shown to prolong survival in patients with advanced melanoma and recurrence-free survival in the adjuvant setting. PIVOT-02 showed that BEMPEG plus NIVO was well-tolerated and demonstrated clinical activity as first-line therapy in metastatic melanoma. PIVOT-12 is a randomized, phase III, global, multicenter, open-label study comparing adjuvant therapy with BEMPEG plus NIVO versus NIVO alone in adult and adolescent patients with completely resected cutaneous stage III/IV melanoma at high risk of recurrence. The primary objective is to compare the efficacy, as measured by recurrence-free survival, of BEMPEG plus NIVO versus NIVO.

Following surgery, patients with advanced melanoma may require further treatment to reduce the likelihood of disease recurrence. Nivolumab (NIVO), a checkpoint inhibitor, reduces the risk of melanoma recurrence by enhancing the ability of the immune system to fight disease. Despite the availability of NIVO and other therapies, many patients with melanoma still experience disease recurrence after surgery. This article presents information on a clinical trial named PIVOT-12, which aims to assess the effectiveness of a new investigational drug called bempegaldesleukin that modifies the immune system and is given with NIVO to patients with stage III/IV melanoma following surgery. The main end point being measured is recurrence-free survival, which measures the time between a patient starting the study and the date of disease recurrence. Clinical Trial Registration: NCT04410445 (ClinicalTrials.gov).

Regulatory T-Cell Response to Low-Dose Interleukin-2 in Ischemic Heart Disease.

Regulatory T-Cell Response to Low-Dose Interleukin-2 in Ischemic Heart Disease This phase 1b/2a, randomized, double-blind, placebo-controlled, dose-escalation trial tested low-dose subcutaneous aldesleukin (recombinant IL-2) in patients with ischemic heart disease. Low-dose IL-2 expanded Tregs, without adverse events of major concern. Single-cell RNA-sequencing of circulating immune cells was used to provide mechanistic assessment of the treatment's effects.

Restoration of HBV-specific CD8+ T-cell responses by sequential low-dose IL-2 treatment in non-responder patients after IFN-α therapy.

Patients with chronic hepatitis B (CHB) undergoing interferon (IFN)-α-based therapies often exhibit a poor HBeAg serological response. Thus, there is an unmet need for new therapies aimed at CHB. This study comprised two clinical trials, including 130 CHB patients, who were treatment-naïve; in the first, 92 patients were systematically analyzed ex vivo for interleukin-2 receptor (IL-2R) expression and inhibitory molecules expression after receiving Peg-IFN-α-2b therapy. In our second clinical trial, 38 non-responder patients, in whom IFN-α therapy had failed, were treated with or without low-dose IL-2 for 24 weeks. We then examined the hepatitis B virus (HBV)-specific CD8+ T-cell response and the clinical outcome, in these patients. Although the majority of the participants undergoing Peg-IFN-α-2b therapy were non-responders, we observed a decrease in CD25 expression on their CD4+ T cells, suggesting that IFN-α therapy may provide a rationale for sequential IL-2 treatment without increasing regulatory T cells (Tregs). Following sequential therapy with IL-2, we demonstrated that the non-responders experienced a decrease in the numbers of Tregs and programmed cell death protein 1 (PD-1) expression. In addition, sequential IL-2 administration rescued effective immune function, involving signal transducer and activator of transcription 1 (STAT1) activation. Importantly, IL-2 therapy significantly increased the frequency and function of HBV-specific CD8+ T cells, which translated into improved clinical outcomes, including HBeAg seroconversion, among the non-responder CHB patients. Our findings suggest that sequential IL-2 therapy shows efficacy in rescuing immune function in non-responder patients with refractory CHB.

Radiotherapy and High-Dose Interleukin-2: Clinical and Immunological Results of a Proof of Principle Study in Metastatic Melanoma and Renal Cell Carcinoma.

High-dose interleukin-2 (HD IL-2) has curative potential in metastatic melanoma (MM) and renal cell carcinoma (RCC). Radiotherapy (RT) kills cancer cells and induces immunomodulatory effects. Prospective trials exploring clinical and immunological properties of combined RT/HD IL-2 are still needed. We designed a phase II, single-arm clinical trial for patients with MM and RCC. The treatment schedule consisted of 3 daily doses of 6-12 Gy of RT to 1-5 non-index metastatic fields, before IL-2 at the first and third treatment cycle. HD IL-2 was administered by continuous infusion for 72 hours and repeated every 3 weeks for up to 4 cycles, thereafter every 4 weeks for a maximum of 2 cycles. The primary endpoint was the immunological efficacy of the combined RT/HD IL-2 treatment (assessed by IFN-γ ELISPOT). Nineteen out of 22 patients were evaluable for immunological and clinical response. Partial response occurred in 3 (15.7%) patients and stable disease was observed in 7 (36.8%). The disease control rate was 52.6% after a median follow up of 39.2 months. According to Common Terminology Criteria for Adverse Events 4.0 (CTCAE 4.0), the majority of toxicities were grade 1-2. Immunological responses were frequent and detected in 16 (84.2%) patients. Increased levels of IL-8 and IL-10 in melanoma, circulating effector memory CD4+ and intratumoral CD8+ T cells in both tumor types were detected after therapy. Overall the treatment was well tolerated and immunologically active. Immunomonitoring and correlative data on tumor and peripheral blood cell subsets suggest that this combination treatment could be a promising strategy for patients progressing after standard treatments.

Pharmacokinetics and Pharmacodynamic Effects of Nemvaleukin Alfa, a Selective Agonist of the Intermediate-Affinity IL-2 Receptor, in Cynomolgus Monkeys.

Nemvaleukin alfa (nemvaleukin, ALKS 4230) is a novel cytokine created by the fusion of circularly permuted interleukin-2 (IL-2) to the IL-2Rα subunit of the IL-2 receptor (IL-2R) complex that confers selectivity for the intermediate-affinity IL-2R expressed on CD8+ T cells and natural killer (NK) cells. The pharmacokinetics and selective pharmacodynamic properties of nemvaleukin have been demonstrated using in vitro and in vivo mouse models. The pharmacokinetic/pharmacodynamic effects of nemvaleukin on immune cell subtypes were evaluated in cynomolgus monkeys after intravenous and subcutaneous administration to inform dose selection and predict pharmacodynamic effects in humans. Male drug-naïve cynomolgus monkeys (N = 15) were administered either single-dose (0.3 mg/kg i.v.; 0.3 mg/kg or 1.0 mg/kg s.c.) or repeated doses (0.1 mg/kg i.v. on days 1-5 or 0.5 mg/kg s.c. on days 1 and 4) of nemvaleukin. Serial blood samples were collected for pharmacokinetic assessment, immunophenotyping by flow cytometry, and profiling of serum cytokines. Repeat-dose subcutaneous administration of nemvaleukin with less frequent dosing resulted in total systemic exposure and trough serum concentrations comparable to those seen with intravenous administration, with lower peak serum concentrations. Transient elevation of interferon-γ and IL-6 peaked at 2 and 8 hours after intravenous and subcutaneous administration, respectively. Selective expansion of immunoprotective central memory, effector memory, terminal effector CD8+ T cells, and CD56+ NK cells, and minimal expansion of immunosuppressive CD4+CD25+FoxP3+ regulatory T cells was observed after both intravenous and subcutaneous administration. These data support the ongoing clinical evaluation of intravenous and subcutaneous nemvaleukin. SIGNIFICANCE STATEMENT: Administration of the novel interleukin-2 receptor agonist nemvaleukin alfa to cynomolgus monkeys resulted in selective expansion of immune effector cells, including CD8+ T and natural killer cells with minimal effects on immunosuppressive CD4+ regulatory T cells, confirming the design of nemvaleukin and highlighting its potential as a cancer immunotherapy. Subcutaneous administration of nemvaleukin achieved systemic exposure and immunostimulatory effects similar to those observed after more frequent intravenous dosing and may represent a practical alternative in a clinical setting.

Interleukin 2 Ameliorates Autoimmune Neuroinflammation by Modulating the Balance of T Helper 17 Cells and Regulatory T Cells in Mouse.

OBJECTIVE: Multiple sclerosis (MS) is a progressive autoimmune-mediated inflammation of the central nervous system (CNS), and experimental autoimmune encephalomyelitis (EAE) is a suitable model to study the pathogenesis of MS. IL-2 has been considered as both a T cell growth factor and an anti-inflammatory cytokine. In the present study, we investigated the effects of a low dose IL-2 treatment on mouse EAE therapy. METHOD: The expression of IL-2 and IL-2 receptor were predicted using public microarray data and verified by real-time PCR and ELISA in mouse EAE model. Mice were injected with Myelin Oligodendrocyte Glycoprotein (35-55)(MOG35-55) subcutaneously to induce EAE model. IL-2 treatment was initiated during 5 consecutive days from day 15 post MOG35-55 immunization. Flow cytometry was applied to investigate the proportions of Th17 and Treg cells. ELISA was used to detect the concentrations of IL-17a, IFNr, IL-10 and TGFb. RESULTS: In this study, we showed that the IL-2 treatment ameliorates the clinical severity of EAE. Flow cytometry results indicated that the therapeutic effect was related to a reduction of Th17 cells and an expansion of Treg cells in the EAE spinal cord. In vitro experiments also confirmed the anti-inflammatory effect of IL-2 in EAE-reactivated T cells. CONCLUSION: Low-dose IL-2 is a potential therapeutic strategy for EAE and MS.

The effect of low-dose IL-2 and Treg adoptive cell therapy in patients with type 1 diabetes.

BACKGROUNDA previous phase I study showed that the infusion of autologous Tregs expanded ex vivo into patients with recent-onset type 1 diabetes (T1D) had an excellent safety profile. However, the majority of the infused Tregs were undetectable in the peripheral blood 3 months postinfusion (Treg-T1D trial). Therefore, we conducted a phase I study (TILT trial) combining polyclonal Tregs and low-dose IL-2, shown to enhance Treg survival and expansion, and assessed the impact over time on Treg populations and other immune cells.METHODSPatients with T1D were treated with a single infusion of autologous polyclonal Tregs followed by one or two 5-day courses of recombinant human low-dose IL-2 (ld-IL-2). Flow cytometry, cytometry by time of flight, and 10x Genomics single-cell RNA-Seq were used to follow the distinct immune cell populations' phenotypes over time.RESULTSMultiparametric analysis revealed that the combination therapy led to an increase in the number of infused and endogenous Tregs but also resulted in a substantial increase from baseline in a subset of activated NK, mucosal associated invariant T, and clonal CD8+ T cell populations.CONCLUSIONThese data support the hypothesis that ld-IL-2 expands exogenously administered Tregs but also can expand cytotoxic cells. These results have important implications for the use of a combination of ld-IL-2 and Tregs for the treatment of autoimmune diseases with preexisting active immunity.TRIAL REGISTRATIONClinicalTrials.gov NCT01210664 (Treg-T1D trial), NCT02772679 (TILT trial).FUNDINGSean N. Parker Autoimmune Research Laboratory Fund, National Center for Research Resources.

Ultra-Low Dose Cytokines in Rheumatoid Arthritis, Three Birds with One Stone as the Rationale of the 2LARTH® Micro-Immunotherapy Treatment.

Tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) are two cytokines involved in the perpetuation of the chronic inflammation state characterizing rheumatoid arthritis (RA). Significant advances in the treatment of this pathology have been made over the past ten years, partially through the development of anti-TNF and anti-IL-1 therapies. However, major side effects still persist and new alternative therapies should be considered. The formulation of the micro-immunotherapy medicine (MIM) 2LARTH® uses ultra-low doses (ULD) of TNF-α, IL-1ß, and IL-2, in association with other immune factors, to gently restore the body's homeostasis. The first part of this review aims at delineating the pivotal roles played by IL-1ß and TNF-α in RA physiopathology, leading to the development of anti-TNF and anti-IL-1 therapeutic agents. In a second part, an emphasis will be made on explaining the rationale of using multiple therapeutic targets, including both IL-1ß and TNF-α in 2LARTH® medicine. Particular attention will be paid to the ULD of those two main pro-inflammatory factors in order to counteract their overexpression through the lens of their molecular implication in RA pathogenesis.