Reducing affinity as a strategy to boost immunomodulatory antibody agonism.

Antibody responses during infection and vaccination typically undergo affinity maturation to achieve high-affinity binding for efficient neutralization of pathogens1,2. Similarly, high affinity is routinely the goal for therapeutic antibody generation. However, in contrast to naturally occurring or direct-targeting therapeutic antibodies, immunomodulatory antibodies, which are designed to modulate receptor signalling, have not been widely examined for their affinity-function relationship. Here we examine three separate immunologically important receptors spanning two receptor superfamilies: CD40, 4-1BB and PD-1. We show that low rather than high affinity delivers greater activity through increased clustering. This approach delivered higher immune cell activation, in vivo T cell expansion and antitumour activity in the case of CD40. Moreover, an inert anti-4-1BB monoclonal antibody was transformed into an agonist. Low-affinity variants of the clinically important antagonistic anti-PD-1 monoclonal antibody nivolumab also mediated more potent signalling and affected T cell activation. These findings reveal a new paradigm for augmenting agonism across diverse receptor families and shed light on the mechanism of antibody-mediated receptor signalling. Such affinity engineering offers a rational, efficient and highly tuneable solution to deliver antibody-mediated receptor activity across a range of potencies suitable for translation to the treatment of human disease.

Correlation between immune-related adverse events and therapeutic effects of nivolumab in patients with malignant pleural mesothelioma.

BACKGROUND: Nivolumab is used for the treatment of malignant pleural mesothelioma (MPM). However, immune-related adverse events (irAEs) occur in patients treated with nivolumab. Several studies have reported the correlation between irAEs and therapeutic effects of immune checkpoint inhibitor, but none have reported the correlation in MPM. Here we report a retrospective study which shows the correlation between irAEs and therapeutic effects of nivolumab in patients with MPM. METHODS: This study included patients treated with nivolumab at Tokushima University Hospital from February 2009 to September 2021. We retrospectively reviewed the medical records to evaluate the several clinical factors, such as the presence or absence of irAEs, their severities, progression-free survival (PFS), overall survival (OS) or objective response to the treatment. RESULTS: Eleven patients received treatment with nivolumab. Objective response rate was 18.2% and the disease control rate was 90.9%. Median PFS was 6.8 months (95% confidence interval, 1.3 to 11.9 months) and median OS was 15.2 months (95% confidence interval, 8.9 to 21.5 months). IrAEs occurred in eight patients (72.7%), and grade ≥ 2 irAEs occurred in six patients (54.5%). PFS and OS were significantly longer in the grade ≥ 2 irAEs group than in grade < 2 irAEs group (median PFS 13.6 vs. 3.8 months, p = 0.0093; median OS not reached vs. 8.6 months, p = 0.0108). CONCLUSIONS: This is the first study to report the correlation between irAEs and therapeutic effects in patients with MPM. Because the presence of irAEs may be associated with a favorable clinical outcome, early detection and appropriate management of irAEs will increase the therapeutic benefits to patients.

Bioanalytical Challenges due to Prior Checkpoint Inhibitor Exposure: Interference and Mitigation in Drug Concentration and Immunogenicity Assays.

Monoclonal antibodies (mAbs) are a leading class of biotherapeutics. In oncology, patients often fail on early lines of biologic therapy to a specific target. Some patients may then enroll in a new clinical trial with a mAb specific for the same target. Therefore, immunoassays designed to quantify the current mAb therapy or assess immunogenicity to the drug may be susceptible to cross-reactivity or interference with residual prior biologics. The impact of two approved anti-PD-1 mAbs, pembrolizumab and nivolumab, was tested in several immunoassays for cemiplimab, another approved anti-PD-1 mAb. The methods included a target-capture drug concentration assay, a bridging anti-drug antibody (ADA) assay and a competitive ligand-binding neutralizing antibody (NAb) assay. We also tested bioanalytical strategies to mitigate cross-reactivity or interference in these assays from other anti-PD-1 biologics. Both pembrolizumab and nivolumab cross-reacted in the cemiplimab drug concentration assay. This was mitigated by addition of antibodies specific to pembrolizumab or nivolumab. ADA specific for pembrolizumab and nivolumab did not interfere in the cemiplimab ADA assay. However, pembrolizumab and nivolumab generated a false-positive response in a target-capture NAb assay. Our results demonstrate that similar exogenous pre-existing anti-PD-1 mAbs (biotherapeutics) such as pembrolizumab and nivolumab are detected and accurately quantified in the cemiplimab drug concentration assay. However, once steady state is achieved for the new therapy, prior biologics would likely not be detected. Cross-reactivity and interference in immunoassays from previous treatment with class-specific biotherapeutic(s) pose significant bioanalytical challenges, especially in immuno-oncology.

Blockade of the checkpoint PD-1 by its ligand PD-L1 and the immuno-oncological drugs pembrolizumab and nivolumab.

We investigate the interaction between the programmed cell death protein 1 (PD-1) and the programmed cell death ligand 1 (PD-L1), as well as the immuno-oncological drugs pembrolizumab (PEM), and nivolumab (NIV), through quantum chemistry methods based on the Density Functional Theory (DFT) and the molecular fractionation with conjugate caps (MFCC) scheme, in order to map their hot-spot regions. Our results showed that the total interaction energy order of the three complexes is in good agreement with the experimental binding affinity order: PD-1/PEM > PD-1/NIV > PD-1/PD-L1. Besides, a detailed investigation revealed the energetically most relevant residue-residue pairs-interaction for each complex. Our computational results give a better understanding of the interaction mechanism between the protein PD-1 and its ligands (natural and inhibitors), unleashing the immune surveillance to destroy the cancer cells by decreasing their immune evasion. They are also an efficient alternative towards the development of new small-molecules and antibody-based drugs, pointing out to new treatments for cancer therapy.

Anti-PD1 Immunotherapy for Metastatic Renal Cancer Boosted Humoral Immunity In a Hemodialysis Patient.

Immune checkpoint inhibitors by blocking specific inhibitory pathways induce T-cell-mediated tumor lysis. However, many remain to be elucidated about their effect on human humoral immunity. We evaluated the effect of the PD1 inhibitor nivolumab on humoral immunity by following the levels of antibodies against hepatitis B surface antigen (anti-HBs) in a hemodialysis patient successfully vaccinated against hepatitis B virus 5 years ago and now starting nivolumab for renal cell carcinoma lung metastases. Anti-HBs kinetics after administration of an extra vaccine dose were also evaluated. Nivolumab increased anti-HBs and facilitated a further increase following an additional vaccine dose. The observed time frame indicates that nivolumab boosts humoral immune response by affecting long-lived plasma cells and at least memory B cells. This may protect cancer patients from pathogens encountered in the past or against which vaccination has been performed and provide information for the emerging immune checkpoint inhibitors administration concept against chronic infectious diseases.

T Cells Expanded from PD-1+ Peripheral Blood Lymphocytes Share More Clones with Paired Tumor-Infiltrating Lymphocytes.

Both tumor-infiltrating lymphocytes (TIL) and PD-1+ peripheral blood lymphocytes (PBL) are enriched for tumor-reactive clones recognizing known and unknown tumor antigens. However, the relationship between the T-cell receptor-ß (TCRß) repertoires of the TILs and T cells expanded from paired PD-1+ PBLs, and whether T cells expanded from PD-1+ PBLs can be used to treat patients with cancer as TIL substitutes remain unclear. Here, we established a highly efficient protocol to prepare polyclonal T cells from PD-1+ PBLs. A functional T-cell assay and tetramer staining revealed that cells from PD-1+ PBLs were relatively enriched for tumor-reactive T cells. Furthermore, deep TCRß sequencing data revealed that an average of 11.29% (1.32%-29.06%; P = 0.015; n = 8) tumor-resident clonotypes were found in T cells expanded from paired PD-1+ PBLs, and the mean accumulated frequency of TIL clones found in T cells expanded from PD-1+ PBLs was 35.11% (7.23%-78.02%; P = 0.017; n = 8). Moreover, treatment of four patients, who failed multiline therapy and developed acquired resistance to anti-PD-1, with autologous T cells expanded from PD-1+ PBLs combined with anti-PD-1 antibody elicited objective responses from three of them. These results indicate that T cells expanded from PD-1+ PBLs share more clones with paired TILs and could be used to treat patients with cancer as TIL substitutes. SIGNIFICANCE: This study harnesses the tumor reactivity of PD-1+ PBLs, developing a method to expand T cells from these clones as a potential therapeutic strategy and TIL substitute in patients with cancer.See related commentary by Ladle, p. 1940.

Anti-drug antibody detection with label-free electrolyte-gated organic field-effect transistors.

The efficacy of immunotherapy can be undermined by the development of an immune response against a drug/antibody mediated by anti-drug antibodies (ADAs) in treated patients. We present the first label-free EGOFET immunosensor that integrates a biological drug, Nivolumab (Opdivo©), as a specific recognition moiety to quantitatively and selectively detect ADAs against the drug. The limit of detection is 100 fM. This demonstration is a prelude to the detection of ADAs in a clinical setting in the treatment of different pathologies, and it also enables rapid screening of biological drugs for immunogenicity.

Exploring the conformational dynamics of PD1 in complex with different ligands: What we can learn for designing novel PD1 signaling blockers?

Activation of T cells triggers the expression of regulatory molecules like the programmed cell death 1 (PD1) protein. The association of PD1 with the natural ligands PDL1 and PDL2 induces an inhibitory signal that prevents T cells from proliferating and exerting effector functions. However, little is known about how the binding of the ligands induce the PD1 inhibitory signal over T cells effector functions. Here, we explore the dynamics of PD1 free, and in complex with different PDL1 variants as well as the therapeutic antibodies nivolumab and pembrolizumab in order to assess the conformational changes in PD1 related to the signaling process. Our simulations suggest a pre-conformational selection mechanism for the binding of the different PDL1 variants, while an induced-fit model fits better for the molecular recognition process of the therapeutic antibodies. A deep analysis of the changes on PD1 movement upon the binding to different ligands revealed that as larger is the difference in the conformation adopted by loop C'D with respect to the complex with PDL1 is higher the ligand ability to reduce the PD1 inhibitory signaling. This behavior suggests that targeting specific conformations of this loop can be useful for designing therapies able to recover T cells effector functions.

Characterization of a single chain variable fragment of nivolumab that targets PD-1 and blocks PD-L1 binding.

Activated T-cells express Programmed cell Death protein 1 (PD-1), a key immune checkpoint receptor. PD-1 functions primarily in peripheral tissues, where T cells may encounter tumor-derived immunosuppressive ligands. Monoclonal antibodies that disrupt the interaction between T-cell derived PD-1 and immunosuppressive ligands, such as PD-L1, have revolutionized approaches to cancer therapy. For instance, Nivolumab is a monoclonal Ab that targets human PD-1 and has played an important role in immune checkpoint therapy. Herein we report the purification and initial characterization of a ~27 kDa single chain variable fragment (scFv) of Nivolumab that targets human PD-1 and blocks binding by PD-L1. The possibility that the anti-PD-1 scFv can serve as both an anti-tumor agent and as an anti-viral agent is discussed. IMPORTANCE: The clinical significance of anti-PD-1 antibodies for treatment of a range of solid tumors is well documented (reviewed in [1-4]). In this report, we describe the results of studies that establish that an anti-PD-1 scFv purified from E. coli binds tightly to human PD-1. Furthermore, we demonstrate that upon binding, the anti-PD-1 scFv disrupts the interaction between PD-1 and PD-L1. Thus, the properties of this scFv, including its small size, stability and affinity for human PD-1, suggest that it has the potential to be a useful reagent in subsequent immunotherapeutic, diagnostic and anti-viral applications.

Molecular dynamics of the immune checkpoint programmed cell death protein I, PD-1: conformational changes of the BC-loop upon binding of the ligand PD-L1 and the monoclonal antibody nivolumab.

BACKGROUND: The immune checkpoint receptor programmed cell death protein I (PD-1) has been identified as a key target in immunotherapy. PD-1 reduces the risk of autoimmunity by inducing apoptosis in antigen-specific T cells upon interaction with programmed cell death protein ligand I (PD-L1). Various cancer types overexpress PD-L1 to evade the immune system by inducing apoptosis in tumor-specific CD8+ T cells. The clinically used blocking antibody nivolumab binds to PD-1 and inhibits the immunosuppressive interaction with PD-L1. Even though PD-1 is already used as a drug target, the exact mechanism of the receptor is still a matter of debate. For instance, it is hypothesized that the signal transduction is based on an active conformation of PD-1. RESULTS: Here we present the results of the first molecular dynamics simulations of PD-1 with a complete extracellular domain with a focus on the role of the BC-loop of PD-1 upon binding PD-L1 or nivolumab. We could demonstrate that the BC-loop can form three conformations. Nivolumab binds to the BC-loop according to the conformational selection model whereas PD-L1 induces allosterically a conformational change of the BC-loop. CONCLUSION: Due to the structural differences of the BC-loop, a signal transduction based on active conformation cannot be ruled out. These findings will have an impact on drug design and will help to refine immunotherapy blocking antibodies.

Immune-related myositis resulting from combination therapy of ipilimumab and nivolumab in patient with metastatic renal cell carcinoma.

Immune-related myositis is one of the rare immune-related adverse events whose underlying precise mechanisms are not fully understood. Here, we describe a case of immune-related myositis that developed after four cycles of combination therapy with nivolumab plus ipilimumab for the treatment of metastatic renal cell carcinoma. Negative results of autoimmune antibodies, including anti-acetylcholine receptor and anti-muscle-specific kinase antibodies suggested a T-cell-mediated mechanism. After recovery with steroid therapy, the patient resumed nivolumab monotherapy and survived without any evidence of disease progression or refractory of myositis. Differential diagnosis between T-cell-mediated and B-cell-mediated immune-related myositis and its impact on optimal management are discussed.

Relationship of hypothyroidism and immune response to pegylated IL-10/nivolumab.

Aim: We describe a case of an advanced disease non-small-cell lung cancer patient with low PD-L1 expression, but high tumor mutation burden (35 muts/Mb) who developed immune-related hypothyroidism and achieved subsequent partial response, while on clinical trial (NCT03382912) with nivolumab and PEGylated IL-10 (Pegilodecakin, ARMO BioSciences/Eli Lilly and Company, IN, USA). Results/conclusion: Results suggest positive antitumor activity to combination IL-10/nivolumab despite low PD-L1 expression but in likely relationship to high tumor mutation burden and in association with immune-mediated thyroid dysfunction in this case.

Mechanism of acquired resistance to nivolumab in lung squamous cell carcinoma: case report and review of the literature.

Background: Immune checkpoint inhibitors targeting PD-1 and PD-L1 have noticeably improved the treatment landscape of advanced non-small-cell lung cancer, including lung squamous cell carcinoma (SCC). Although patients with immune checkpoint therapy can achieve long-term survival, acquired resistance has been recognized more frequently, while the underlying mechanisms are currently poorly understood. Materials and methods: Here, we report a patient with metastatic lung SCC treated with nivolumab as a first-line treatment for 28 months. Conclusion: The analysis of specimens prenivolumab and postnivolumab treatment suggests that genetic alterations in SOX2 and CDKN2A/CDKN2B and changes in the tumor microenvironment could be reasons for the acquired resistance to nivolumab observed in the lung SCC patient.

Clinical course of COVID-19 infection in elderly patient with melanoma on nivolumab.

Outbreak of the new type coronavirus infection, known as coronavirus infection 2019 (COVID-19), has begun in December 2019, in Wuhan, China. As of today, 3 April 2020, 972,640 people affected and 50,325 people died from Severe Acute Respiratory Syndrome-Coronavirus 2. There is not any standard treatment for coronavirus infection 2019; however, there are promising data for hydroxychloroquine and some anti-retroviral drugs. Programmed death-1 (PD-1)/programmed death ligand-1 (PDL-1) pathway is an important target for the cancer immunotherapy. However, there is a robust pre-clinical and clinical data regarding inhibitor effect of this pathway on the acute or chronic viral infections. Thus, blockade of this pathway may lead to an anti-viral effect and decrease viral load. Here, we report the clinical course of coronavirus infection 2019 infection of a patient in whom older aged, having multiple co-morbidities, and taking nivolumab for metastatic malignant melanoma. In contrast to her older age, comorbidities, and cancer diagnosis, she was in a good condition, and there was also no pneumonia finding. We think that this good clinical course of coronavirus infection 2019 infection may be related to blockade of PD-1/PDL-1 pathway with nivolumab. It is impossible to say that blockade of PD-1/PDL-1pathway is a treatment option for COVID-19; however, we want to share our experience.

A measuring method for occupancy of immune checkpoint inhibitors in the cell surface.

Monoclonal antibodies, including immune-checkpoint inhibitors, are becoming popular in treatments of many cancers and connective tissue diseases. However, little is known about how long the antibodies combine with antigens on targeted cells or how this duration of binding associates with therapeutic efficacy or potential adverse events. Here, we show the principle and the results of a feasible method for measuring the antibodies' occupancy on the targeted cells using two different detecting antibodies in conjunction with different fluorochromes. Nivolumab occupancy was measured using two detecting antibodies, MIH4 and EH12.2, which are commercially available in vitro (programmed cell death-1 [PD-1] expressing the cell line MIT9 and human T cells) and in T cells from patients treated with nivolumab. Our method has potential for use as a simple and feasible monitoring system in the clinical setting.

Epitope and Paratope Mapping of PD-1/Nivolumab by Mass Spectrometry-Based Hydrogen-Deuterium Exchange, Cross-linking, and Molecular Docking.

Programmed cell death-1 (PD-1), an antigen co-receptor on cell surfaces, is one of the conspicuous immune checkpoints. Nivolumab, a monoclonal antibody therapeutic approved by the FDA, binds to PD-1 and efficiently blocks its pathways. In this study, an integrated approach was developed to map the epitope/paratope of PD-1/nivolumab. The approach includes hydrogen-deuterium exchange mass spectrometry (HDX-MS) followed by electron-transfer dissociation (ETD), chemical cross-linking, and molecular docking. HDX-ETD offers some binding-site characterization with amino acid resolution. Chemical cross-linking provides complementary information on one additional epitope (i.e., the BC-loop) and a potential paratope at the N-terminus of the heavy chain. Furthermore, cross-linking identifies another loop region (i.e., the C'D-loop) that undergoes a remote conformational change. The distance restraints derived from the cross-links enable building high-confidence models of PD-1/nivolumab, evaluated with respect to a resolved crystal structure. This integrated strategy is an opportunity to characterize comprehensively other antigen-antibody interactions, to enable the understanding of binding mechanisms, and to design future antibody therapeutics.

Nivolumab for the treatment of hepatocellular carcinoma.

INTRODUCTION: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide and up to recently, sorafenib was the only approved systemic treatment options. In recent years, many other treatment options have received approval for advanced HCC, including nivolumab, a Programmed-Death-1 (PD-1) inhibitor. AREAS COVERED: We review the current treatment landscape of HCC, an overview of the characteristics of nivolumab and current ongoing and completed trials of nivolumab. EXPERT OPINION: Nivolumab is generally well tolerated and has modest single-agent activity as a monotherapy in advanced HCC. Further studies are required to better explore its role as part of combination approaches, in adjuvant/neoadjuvant setting, as well as to understand the impact of sequencing of its use with other systemic therapy options.

Nivolumab-induced hepatitis: A rare side effect of an immune check point inhibitor.

Immune checkpoint inhibitors have ushered in a new era in cancer management. Nivolumab is a human immunoglobulin G4 (IgG4) monoclonal antibody that selectively inhibits programmed cell death-1 (PD-1) activity by binding to the PD-1 receptor. This inhibits suppression of the T-cell activity, which can in turn cause increased killing of cancer cells. This alteration in the activity of the T cells can cause them to lose their ability to identify host cells and leads to immune-related adverse effects (irAE). Nivolumab-induced hepatotoxicity is rare and accounts for 3-6% of all irAE. We present a case of nivolumab-induced hepatitis. A woman who was treated for recurrent renal cell carcinoma presented with hepatitis. Workup for other causes was negative and the hepatitis was attributed to the administration of nivolumab. She was started on oral steroids followed which she initially improved. However, she later presented with massive upper gastrointestinal bleeding secondary to gastroduodenal ulcers and subsequently developed acute tubular necrosis and passed from the complications. Immune checkpoint inhibitors have proven to be a promising approach in the management of a wide array of neoplasms by immunomodulation. As these agents are becoming standard of therapy in the management of cancers, a heightened vigilance in the diagnosis of irAE is warranted. With heightened vigilance, early recognition can lead to decreased mortality and morbidity.

A review of checkpoint inhibitors in the management of renal cell carcinoma.

Renal cell carcinoma is a common malignancy of the genitourinary system and is the eight most common cancer type in the United States. The overall incidence of renal cell carcinoma appears to be increasing but death rates have been declining. Patients with poor risk, advanced disease have a two-year survival rate of approximately 7%. Prior to the advent of tyrosine kinase inhibitors, anti-vascular endothelial growth factor antibodies, mammalian target of rapamycin inhibitors, and checkpoint inhibitors, IFN-α and high-dose IL-2, were standard of care treatment options but, conversely, their use is now limited to select patients. Immunotherapies have played a significant role in the treatment of various cancers and have continued to expand. It is of utmost importance that practitioners include checkpoint inhibitors as treatment options for renal cell carcinoma as they mark a new era in the treatment of advanced or relapsed setting. Nivolumab, pembrolizumab, avelumab, ipilimumab, and atezolizumab all play a role in management of disease as either monotherapy or in combination with other agents. Ongoing clinical trials are ongoing to further assess the benefits of inducing cellular immunity in the treatment of renal cell carcinoma. In this article, the available data on immune checkpoint inhibitors for the treatment of advanced or relapsed renal cell carcinoma and their place in therapy are reviewed.

Structural and In Vitro Functional Analyses of Novel Plant-Produced Anti-Human PD1 Antibody.

Immunotherapy has emerged as a promising and effective treatment for cancer. The frequently used immunotherapy agents are immune checkpoint inhibitors, such as antibodies specific to PD1, PD-L1, or CTLA-4. However, these drugs are highly expensive, and most people in the world cannot access the treatment. The development of recombinant protein production platforms that are cost-effective, scalable, and safe is needed. Plant platforms are attractive because of their low production cost, speed, scalability, lack of human and animal pathogens, and post-translational modifications that enable them to produce effective monoclonal antibodies. In this study, an anti-PD1 IgG4 monoclonal antibody (mAb) was transiently produced in Nicotiana benthamiana leaves. The plant-produced anti-PD1 mAb was compared to the commercial nivolumab produced in CHO cells. Our results showed that both antibodies have similar protein structures, and the N-glycans on the plant-produced antibody lacks plant-specific structures. The PD1 binding affinity of the plant-produced and commercial nivolumab, determined by two different techniques, that is, enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR), are also comparable. Plant-produced nivolumab binds to human PD1 protein with high affinity and specificity, blocks the PD-1/PD-L1 interaction, and enhances T cell function, comparable to commercial nivolumab. These results confirmed that plant-produced anti-PD1 antibody has the potential to be effective agent for cancer immunotherapy.