CD56(bright) natural killer cells and response to daclizumab HYP in relapsing-remitting MS

Effect of Ocrelizumab in Blood Leukocytes of Patients With Primary Progressive MS

OBJECTIVE

To analyze the changes induced by ocrelizumab in blood immune cells of patients with primary progressive MS (PPMS).

METHODS

In this multicenter prospective study including 53 patients with PPMS who initiated ocrelizumab treatment, we determined effector, memory, and regulatory cells by flow cytometry at baseline and after 6 months of therapy. Wilcoxon matched paired tests were used to assess differences between baseline and 6 months' results. p Values were corrected using the Bonferroni test.

RESULTS

Ocrelizumab reduced the numbers of naive and memory B cells (p < 0.0001) and those of B cells producing interleukin (IL)-6, IL-10, granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNFα) (p < 0.0001 in all cases). By contrast, the proportions of plasmablasts and B cells producing GM-CSF and TNFα increased significantly, suggesting the need for treatment continuation. We also observed a decrease in CD20+ T-cell numbers (p < 0.0001) and percentages (p < 0.0001), and a clear remodeling of the T-cell compartment characterized by relative increases of the naive/effector ratios in CD4+ (p = 0.002) and CD8+ (p = 0.002) T cells and relative decreases of CD4+ (p = 0.03) and CD8+ (p = 0.004) T cells producing interferon-gamma. Total monocyte numbers increased (p = 0.002), but no changes were observed in those producing inflammatory cytokines. The immunologic variations were associated with a reduction of serum neurofilament light chain (sNfL) levels (p = 0.008). The reduction was observed in patients with Gd-enhanced lesions at baseline and in Gd- patients with baseline sNfL >10 pg/mL.

CONCLUSIONS

In PPMS, effector B-cell depletion changed T-cell response toward a low inflammatory profile, resulting in decreased sNfL levels.

Safety and efficacy of daclizumab beta in patients with relapsing multiple sclerosis in a 5-year open-label study (EXTEND): final results following early termination

Background:

EXTEND (NCT01797965), an open-label extension study, evaluated the safety and efficacy of daclizumab beta in participants with relapsing multiple sclerosis (MS) who had completed the randomized DECIDE study.

Methods:

Eligible participants who received either daclizumab beta or interferon beta-1a in DECIDE received daclizumab beta 150 mg subcutaneously every 4 weeks for up to 5 years in EXTEND, followed by 24 weeks of post-dosing follow-up. Safety and tolerability were evaluated, as were clinical efficacy and magnetic resonance imaging (MRI). EXTEND was terminated ahead of schedule by the sponsors.

Results:

The total safety population (N = 1203) received at least one dose of daclizumab beta in EXTEND. In the DECIDE and EXTEND combined periods, the median number of doses of daclizumab beta was 53; median time on treatment was 196 weeks. By 24 September 2018, the end of the study, 110/1203 (9%) participants had completed the protocol-specified treatment period and 1101/1203 (92%) had experienced an adverse event (AE). The most commonly reported AEs were MS relapse, nasopharyngitis, and upper respiratory tract infection. Hepatic events (18%), cutaneous events (45%), and infections (62%) were common treatment-related AEs. The incidence of serious AEs was 29%, most commonly MS relapse and infections. The incidence of immune-mediated disorders was 2%; three of seven were encephalitis. Two of six deaths were considered treatment related. In participants who received continuous daclizumab beta throughout DECIDE and EXTEND, the treatment effects on clinical and MRI outcomes were maintained for up to 6 years.

Conclusion:

Results from the combined DECIDE-EXTEND study elucidate outcomes of longer-term treatment with daclizumab beta in the clinical trial setting and underscore the importance of pharmacovigilance with immunomodulatory therapies in the real-world setting.

NK/T cell ratios associate with interleukin-2 receptor alpha chain expression and shedding in multiple sclerosis

NK/T-cell ratios predict disease activity in relapsing remitting multiple sclerosis (RRMS). We investigated in 50 RRMS patients whether interleukin-2 receptor alpha-chain (IL-2Rα) expression and shedding associates with NK/T-cell balance, as suggested by daclizumab-trials in RRMS. A subsample (N = 31) was genotyped for IL2RA-associated MS risk SNPs. CD56^bright NK-cell/IL-17A⁺CD4⁺ T-cell ratios correlated negatively with plasma and PBMC-culture supernatant sIL-2Rα-levels [R = -0.209; p = 0.038 and R = -0.254; p = 0.012, resp.], and with CD4⁺ T-cell CD25 MFI [R = -0.341; p = 0.001]. Carriers of the rs3118470 risk-allele showed higher sIL-2Rα-levels (P = 0.031) and a lower CD56^bright NK-cell/IL-17A⁺CD4⁺ T-cell ratio (P = 0.038). Therefore, IL-2Rα may be involved in the interplay between NK-cells and T-cells.

Regulatory T Cells Maintain Selective Access to IL-2 and Immune Homeostasis despite Substantially Reduced CD25 Function

IL-2 is a critical regulator of immune homeostasis through its impact on both regulatory T (Treg) and effector T cells. However, the precise role of IL-2 in the maintenance and function of Treg cells in the adult peripheral immune system remains unclear. In this study, we report that neutralization of IL-2 in mice abrogated all IL-2R signaling in Treg cells, but was well tolerated and only gradually impacted Treg cell function and immune homeostasis. By contrast, despite substantially reduced IL-2 sensitivity, Treg cells maintained selective IL-2 signaling and prevented immune dysregulation following treatment with the inhibitory anti-CD25 Ab PC61. Reduction of Treg cells with a depleting version of the same CD25 Ab permitted CD8+ effector T cell proliferation before progressing to more widespread immune dysregulation. Thus, despite severely curtailed CD25 expression and function, Treg cells retain selective access to IL-2 that supports their anti-inflammatory functions in vivo. Ab-mediated targeting of CD25 is being actively pursued for treatment of autoimmune disease and prevention of allograft rejection, and our findings help inform therapeutic manipulation and design for optimal patient outcomes.

CD56bright Natural Killer Cells: A Possible Biomarker of Different Treatments in Multiple Sclerosis

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system, which leads, in many cases, to irreversible disability. More than 15 disease-modifying treatments (DMTs) are available for the treatment of MS. Clinical activity or activity at magnetic resonance imaging (MRI) are now used to assess the efficacy of DMTs, but are negative prognostic factors per se. Therefore, a biomarker permitting us to identify patients who respond to treatment before they develop clinical/radiological signs of MS activity would be of high importance. The number of circulating CD56^bright natural killer (NK) cells may be such a biomarker. CD56^bright NK cells are a regulatory immune population belonging to the innate immune system. The number of CD56^bright NK cells increases upon treatment with interferon-beta, alemtuzumab, dimethyl fumarate, after autologous hematopoietic stem cell transplantation, and is higher in those who respond to fingolimod. In some cases, an increased number of CD56^bright NK cells is associated with an increase in their regulatory function. In the current review, we will evaluate the known effect on CD56^bright NK cells of DMTs for MS, and will discuss their possible role as a biomarker for treatment response in MS.

Characterization of the Impact of Daclizumab Beta on Circulating Natural Killer Cells by Mass Cytometry

Daclizumab beta is a humanized monoclonal antibody that binds to CD25 and selectively inhibits high-affinity IL-2 receptor signaling. As a former treatment for relapsing forms of multiple sclerosis (RMS), daclizumab beta induces robust expansion of the CD56^bright subpopulation of NK cells that is correlated with the drug’s therapeutic effects. As NK cells represent a heterogeneous population of lymphocytes with a range of phenotypes and functions, the goal of this study was to better understand how daclizumab beta altered the NK cell repertoire to provide further insight into the possible mechanism(s) of action in RMS. We used mass cytometry to evaluate expression patterns of NK cell markers and provide a comprehensive assessment of the NK cell repertoire in individuals with RMS treated with daclizumab beta or placebo over the course of 1 year. Treatment with daclizumab beta significantly altered the NK cell repertoire compared to placebo treatment. As previously reported, daclizumab beta significantly increased expression of CD56 on total NK cells. Within the CD56^bright NK cells, treatment was associated with multiple phenotypic changes, including increased expression of NKG2A and NKp44, and diminished expression of CD244, CD57, and NKp46. These alterations occurred broadly across the CD56^bright population, and were not associated with a specific subset of CD56^bright NK cells. While the changes were less dramatic, CD56^dim NK cells responded distinctly to daclizumab beta treatment, with higher expression of CD2 and NKG2A, and lower expression of FAS-L, HLA-DR, NTB-A, NKp30, and Perforin. Together, these data indicate that the expanded CD56^bright NK cells share features of both immature and mature NK cells. These findings show that daclizumab beta treatment is associated with unique changes in NK cells that may enhance their ability to kill autoreactive T cells or to exert immunomodulatory functions.

Flow cytometry and targeted immune transcriptomics identify distinct profiles in patients with chronic myeloid leukemia receiving tyrosine kinase inhibitors with or without interferon-α

Background

Tumor cells have evolved complex strategies to escape immune surveillance, a process which involves NK cells and T lymphocytes, and various immunological factors. Indeed, tumor cells recruit immunosuppressive cells [including regulatory T-cells (Treg), myeloid-derived suppressor cells (MDSC)] and express factors such as PD-L1. Molecularly targeted therapies, such as imatinib, have off-target effects that may influence immune function. Imatinib has been shown to modulate multiple cell types involved in anti-cancer immune surveillance, with potentially detrimental or favorable outcomes. Imatinib and other tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML) have dramatically changed disease course. Our study aimed to characterize the different populations of the immune system in patients with CML affected by their treatment.

Methods

Forty-one patients with CML [33 treated with TKIs and 8 with TKIs plus interferon (IFN)-α] and 20 controls were enrolled in the present study. Peripheral blood populations of the immune system [referred to as the overview of immune system (OVIS) panel, Treg cells and MDSCs] and PD-1 expression were evaluated by flow cytometry. The immunological profile was assessed using the mRNA Pan-Cancer Immune Profiling Panel and a NanoString nCounter FLEX platform.

Results

Patients receiving combination therapy (TKIs + IFN-α) had lower numbers of lymphocytes, particularly T cells [838/µL (95% CI 594–1182)] compared with healthy controls [1500/µL (95% CI 1207 – 1865), p = 0.017]. These patients also had a higher percentage of Treg (9.1%) and CD4⁺PD-1⁺ cells (1.65%) compared with controls [Treg (6.1%) and CD4⁺/PD-1⁺(0.8%); p ≤ 0.05]. Moreover, patients treated with TKIs had more Mo-MDSCs (12.7%) whereas those treated with TKIs + IFN-α had more Gr-MDSC (21.3%) compared to controls [Mo-MDSC (11.4%) and Gr-MDSC (8.48%); p ≤ 0.05]. CD56^bright NK cells, a cell subset endowed with immune-regulatory properties, were increased in patients receiving TKIs plus IFN-α compared with those treated with TKIs alone. Interestingly, serum IL-21 was significantly lower in the TKIs plus IFN-α cohort. Within the group of patients treated with TKI monotherapy, we observed that individuals receiving 2nd generation TKIs had lower percentages of CD4⁺ Treg (3.63%) and Gr-MDSC (4.2%) compared to patients under imatinib treatment (CD4⁺ Treg 6.18% and Gr-MDSC 8.2%), but higher levels of PD-1-co-expressing CD4⁺ cells (1.92%).

Conclusions

Our results suggest that TKIs in combination with IFN-α may promote an enhanced immune suppressive state.

NK Cell Induced T Cell Anergy Depends on GRAIL Expression

NK cells (natural killer cells) being a part of the innate immune system have been shown to be involved in immunoregulation of autoimmune diseases. Previously we have shown that HINT1/Hsp70 treatment induced regulatory NK cells ameliorating experimental autoimmune encephalomyelitis (EAE) course and CD4+ T cells proliferation. NK cells were isolated from mice treated with HINT1/Hsp70 and co-cultured with proteolipid protein (PLP)-stimulated CD4+ T cells isolated from EAE mice. Cell proliferation was assessed by thymidine uptake, cytotoxicity by lactate dehydrogenase (LDH) release assay and fluorescence activated cell sorting (FACS) analysis, protein expression by Western blot, mRNA by quantitative RT-PCR. Gene related to anergy in lymphocytes (GRAIL) expression was downregulated by specific siRNA and GRAIL overexpression was induced by pcDNA-GRAIL transfection. HINT1/Hsp70 pretreatment of EAE SJL/J mice ameliorated EAE course, suppressed PLP-induced T cell proliferation by enhancing T cell expression of GRAIL as GRAIL downregulation restored T cell proliferation. HINT1/Hsp70 treatment induced immunoregulatory NK cells which inhibited PLP-stimulated T cell proliferation not depending on T cell necrosis and apoptosis. This immunoregulatory NK cell function depended on NK cell expression of GRAIL as GRAIL downregulation diminished inhibition of NK cell suppression of T cell proliferation. Similarly GRAIL overexpression in NK cells induced their regulatory function. HINT1/Hsp70 treatment generated regulatory NK cells characterized by expression of GRAIL.

Innate, innate-like and adaptive lymphocytes in the pathogenesis of MS and EAE

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) in which the immune system damages the protective insulation surrounding the nerve fibers that project from neurons. A hallmark of MS and its animal model, experimental autoimmune encephalomyelitis (EAE), is autoimmunity against proteins of the myelin sheath. Most studies in this field have focused on the roles of CD4⁺ T lymphocytes, which form part of the adaptive immune system as both mediators and regulators in disease pathogenesis. Consequently, the treatments for MS often target the inflammatory CD4⁺ T-cell responses. However, many other lymphocyte subsets contribute to the pathophysiology of MS and EAE, and these subsets include CD8⁺ T cells and B cells of the adaptive immune system, lymphocytes of the innate immune system such as natural killer cells, and subsets of innate-like T and B lymphocytes such as γδ T cells, natural killer T cells, and mucosal-associated invariant T cells. Several of these lymphocyte subsets can act as mediators of CNS inflammation, whereas others exhibit immunoregulatory functions in disease. Importantly, the efficacy of some MS treatments might be mediated in part by effects on lymphocytes other than CD4⁺ T cells. Here we review the contributions of distinct subsets of lymphocytes on the pathogenesis of MS and EAE, with an emphasis on lymphocytes other than CD4⁺ T cells. A better understanding of the distinct lymphocyte subsets that contribute to the pathophysiology of MS and its experimental models will inform the development of novel therapeutic approaches.

Daclizumab: Mechanisms of Action, Therapeutic Efficacy, Adverse Events and Its Uncovering the Potential Role of Innate Immune System Recruitment as a Treatment Strategy for Relapsing Multiple Sclerosis

Daclizumab (DAC) is a humanized, monoclonal antibody that blocks CD25, a critical element of the high-affinity interleukin-2 receptor (IL-2R). DAC HYP blockade of CD25 inhibits effector T cell activation, regulatory T cell expansion and survival, and activation-induced T-cell apoptosis. Because CD25 blockade reduces IL-2 consumption by effector T cells, it increases IL-2 bioavailability allowing for greater interaction with the intermediate-affinity IL-2R, and therefore drives the expansion of CD56^bright natural killer (NK) cells. Furthermore, there appears to be a direct correlation between CD56^bright NK cell expansion and DAC HYP efficacy in reducing relapses and MRI evidence of disease activity in patients with RMS in phase II and phase III double-blind, placebo- and active comparator-controlled trials. Therapeutic efficacy was maintained during open-label extension studies. However, treatment was associated with an increased risk of rare adverse events, including cutaneous inflammation, autoimmune hepatitis, central nervous system Drug Reaction with Eosinophilia Systemic Symptoms (DRESS) syndrome, and autoimmune Glial Fibrillary Acidic Protein (GFAP) alpha immunoglobulin-associated encephalitis. As a result, DAC HYP was removed from clinical use in 2018. The lingering importance of DAC is that its use led to a deeper understanding of the underappreciated role of innate immunity in the potential treatment of autoimmune disease.

Ozanimod for the treatment of relapsing remitting multiple sclerosis

INTRODUCTION

Ozanimod is a selective sphingosine 1-phosphate receptor 1 and 5 modulator under development by Celgene, for the treatment of relapsing remitting multiple sclerosis. Extensive clinical experience has become available for the related compound fingolimod, favoring the sphingosine 1-phosphate therapeutic concept. Off-target effects have been attributed to its low receptor specificity and have prompted the development of next generation sphingosine 1-phosphate receptor modulators. Areas covered: The authors evaluate the literature of ozanimod, using the PubMed database as well as repositories of the European Committee for Treatment and Research in Multiple Sclerosis and the American and European Academy of Neurology. Specifically, the authors cover and discuss the preclinical data on ozanimod, pharmacokinetics and dynamics, and data on efficacy and safety from the pivotal trials. Expert opinion: Superiority of ozanimod over intramuscular interferon β-1a with regard to reduction in annualized relapse rate and magnetic resonance imaging outcomes has been shown in two phase III trials. The beneficial effect on brain volume and gray matter loss are encouraging and in line with data on other newer immunomodulators. Ozanimod is a valuable contribution to the therapeutic armamentarium in MS, although the effect on disability progression is unclear and requires further investigations.

Steering through complexity: management approaches in multiple sclerosis

PURPOSE OF REVIEW

This review evaluates current and late-phase developing therapies for multiple sclerosis in regard to therapeutic efficacy and patient safety in light of recent published and presented observations from 2015.

RECENT FINDINGS

We describe data that provide supportive evidence for comparisons of therapeutic efficacy of multiple sclerosis therapies and review available data on rare but serious adverse events associated with these therapies.

SUMMARY

Serious adverse events that are sometimes rare and unpredictable may substantially alter current approaches to multiple sclerosis treatments. New therapies that have proved superior effects compared with older therapies will also impact multiple sclerosis treatment practice in the near future.

Drugs approved for the treatment of multiple sclerosis: review of their safety profile

INTRODUCTION

Multiple sclerosis (MS) is a chronic immune-mediated inflammatory disorder of the brain and spinal cord characterized by inflammation, demyelination, and axonal degeneration. Area covered: Even though the pharmacological armamentarium for MS treatment is considerably improved in the last 20 years, safety data especially for the second-line and innovative treatments are lacking. In order to analyze the safety profile of drugs used for the treatment of MS, a literature review of pre-marketing, post-marketing studies and case reports was performed. Expert opinion: Nowadays, the numerous drugs approved in the last years for the treatment of MS allow a better control of the disease and a better patient compliance. The main advantages of the new disease-modifying agents for MS (DMTs), in fact, derive from the new oral administration and the prolonged half-life with consequent improvement in compliance compared to first-line therapy which required subcutaneous administrations. However, DMTs can cause serious, sometimes life-threatening or fatal, drug adverse reactions. Due to the lack of safety data and given the recent marketing approval of the last DMTs for MS, observational studies and post-marketing surveillance activities will be necessary in order to improve the knowledge about the safety profile of these drugs and the improvement of their use in clinical practice.

Daclizumab: Development, Clinical Trials, and Practical Aspects of Use in Multiple Sclerosis

Daclizumab is a humanized monoclonal antibody directed towards CD25, the alpha subunit of the high-affinity interleukin (IL)-2 receptor. Daclizumab exerts its effects via multiple mechanisms, including reduction of IL-2-mediated lymphocyte activation and upregulation of CD56-bright natural killer cells. Intravenous daclizumab (Zenapax™) was initially approved for prevention of rejection in renal transplant. In subsequent early testing, followed by larger-scale phase II and phase III trials, both intravenous and subcutaneous daclizumab have demonstrated clinical efficacy in the treatment of multiple sclerosis. The subcutaneous daclizumab prepared by high-yield process was utilized in the advanced phase II and phase III trials (SELECT and DECIDE). High-yield process daclizumab is now approved by the US Food and Drug Administration for relapsing-remitting multiple sclerosis, and is now formally termed daclizumab beta (DAC-beta; Zinbryta™). In this review, the early development of anti-IL-2 receptor alpha monoclonal antibodies and the properties of IL-2 and its receptor are discussed, and diverse mechanisms of action for daclizumab are presented. Results of the CHOICE, SELECT, and DECIDE clinical trials are discussed in detail. Adverse events observed in clinical trials included cutaneous reactions, liver enzyme elevations, infections, and autoimmune phenomena. DAC-beta is a monthly, patient-administered subcutaneous injection that requires enrollment in a safety monitoring (REMS) program for monthly liver function testing. Prescribers should be aware of the potential adverse events, as early recognition and management is important, particularly in cutaneous and hepatic reactions. Continued clinical experience with DAC-beta, including observations from the REMS program, will define its place in the armamentarium of immunotherapeutics for relapsing-remitting multiple sclerosis.

Daclizumab for the treatment of multiple sclerosis

Daclizumab is a monoclonal antibody that targets the α-chain of the IL-2 receptor. Results of Phase II and III clinical trials showed efficacy of daclizumab in relapsing-remitting multiple sclerosis, with reduction of annualized relapse rate by 50–54% versus placebo and 45% versus intramuscular IFN-β-1a. Certain aspects of the immunomodulatory mode of action of daclizumab were only discovered during its clinical development, such as the expansion of a subpopulation of natural killer cells. In this article, we outline the putative mechanisms of action and the key clinical data on daclizumab, with a focus on the efficacy and safety profile. We also evaluate its potential role in future treatment algorithms of multiple sclerosis.

Consistent efficacy of daclizumab beta across patient demographic and disease activity subgroups in patients with relapsing-remitting multiple sclerosis

BACKGROUND

Daclizumab beta is a humanized monoclonal antibody specific for the human interleukin-2 receptor alpha chain (CD25). In two pivotal studies in relapsing multiple sclerosis (MS), patients treated with daclizumab beta exhibited lower annualized relapse rates (ARR) when compared with placebo or with intramuscular (IM) interferon beta-1a.

OBJECTIVES

To determine if the efficacy of daclizumab beta demonstrated in the phase 2 SELECT study and the phase 3 DECIDE study was consistent in patient subgroups.

METHODS

In the SELECT study, patients received daclizumab beta 150 or 300mg administered subcutaneously every 4 weeks for 52 weeks, and were compared with patients who received placebo. In the DECIDE study, patients received daclizumab beta 150mg administered subcutaneously every 4 weeks for 96-144 weeks, and were compared with patients who received IM interferon beta-1a 30µg. Subgroups were defined by sex, age, the number of relapses in the year before the study, disease duration, baseline disability measured by EDSS, presence of Gd-enhancing lesions, T2 hyperintense lesion volume at baseline, and previous interferon beta-1a use.

RESULTS

Treatment with daclizumab beta was associated with relative lower ARR, with 95% confidence intervals (CIs) below 1 in 13 of 15 subgroups (SELECT study) compared with placebo and in all 17 subgroups compared with interferon beta-1a (DECIDE study). In 2 subgroups in the SELECT study (patients who were older than 35 years of age or who had a disease duration of 10 or more years), the rate ratio point estimate for the ARR was in favor of daclizumab beta but the 95% CI overlapped with 1. The clinical benefits in ARR achieved with daclizumab beta treatment compared with placebo or interferon beta-1a across subgroups were similarly supported by reductions in lesion activity on magnetic resonance images (MRIs).

CONCLUSIONS

These findings suggest that treatment with daclizumab beta is consistently effective among clinically important patient subgroups and support its potential as a viable therapeutic option across the spectrum of relapsing MS.

Daclizumab: A Review in Relapsing Multiple Sclerosis

Daclizumab (Zinbryta^®; previously known as daclizumab high-yield process) is a therapeutic monoclonal antibody that has recently been approved for the treatment of relapsing forms of multiple sclerosis (MS) in adults. Daclizumab is a humanized IgG1 monoclonal antibody directed against CD25, the alpha subunit of the high-affinity interleukin-2 receptor. As demonstrated in the phase III DECIDE trial, once-monthly subcutaneous daclizumab was superior to once-weekly intramuscular interferon (IFN) β-1a in reducing the clinical relapse rate and radiological measures of disease in patients with relapsing-remitting MS. In addition, daclizumab has demonstrated efficacy in reducing disability progression and in improving health-related quality of life in patients with relapsing MS. Ongoing open-label clinical trials indicate that daclizumab's efficacy is maintained in the longer term (3 years or more). Daclizumab appears to be generally well tolerated, with adverse events of interest (including hepatic, infectious and cutaneous events) generally manageable with regular monitoring and/or standard therapies. The place of daclizumab in MS treatment remains to be fully determined. However, based on available evidence, daclizumab provides a useful alternative option to other currently available disease-modifying therapies in the treatment of relapsing MS.

Monoclonal Antibodies for Relapsing Multiple Sclerosis: A Review of Recently Marketed and Late-Stage Agents

Treatment of multiple sclerosis (MS) has improved considerably over the last decade because of new insights into MS pathology and biotechnological advances. This has led to the development of new potent pharmaceutical compounds targeting different processes in the complex autoimmune pathology leading to chronic central nervous system (CNS) demyelination, neural loss, and, finally, neurological disability. Although a number of disease-modifying treatments are available for the treatment of the inflammatory phase of MS, there is still a need for highly efficacious therapies with an acceptable safety profile in order to gain therapeutic control early in the disease course. Monoclonal antibodies have proven to be some of the most efficacious disease-modifying therapies in the field of MS, and recent developments in clinical research hold promise for new compounds fulfilling the need for improved safety and high efficacy. We review recent developments in the field of therapeutic monoclonal antibodies used for the treatment of MS and current information on the mode of action, efficacy, and safety of existing and emerging therapeutic monoclonal antibodies as well as their place within the context of different treatment strategies. Finally, we consider the most important future developments.

No evidence of disease activity in patients receiving daclizumab versus intramuscular interferon beta-1a for relapsing-remitting multiple sclerosis in the DECIDE study

Background:

No evidence of disease activity (NEDA) is a composite endpoint being increasingly applied as an outcome measure in clinical trials as well as proposed for individual therapeutic decisions in multiple sclerosis (MS).

Objective:

Assess the proportion of patients with relapsing-remitting MS achieving NEDA in the DECIDE study of daclizumab 150 mg subcutaneous versus intramuscular interferon beta-1a 30 µg for 96–144 weeks.

Methods:

NEDA was defined as no relapses, no onset of 12-week confirmed disability progression (CDP), no new/newly enlarging T2 hyperintense lesions (NET2), and no gadolinium-enhancing (Gd+) lesions. Logistic regression models adjusted for baseline covariates compared treatment groups for baseline to week 96, weeks 0–24, and weeks 24–96.

Results:

From baseline to week 96, more daclizumab versus intramuscular interferon beta-1a patients achieved NEDA (24.6% vs 14.2%; odds ratio (OR; 95% confidence interval): 2.059 (1.592−2.661); p < 0.0001). ORs for clinical NEDA (no relapses, no CDP) and magnetic resonance imaging (MRI) NEDA (no NET2, no Gd+ lesions) were 1.651 (1.357−2.007; p < 0.0001) and 2.051 (1.628−2.582; p < 0.0001), respectively. ORs in favor of daclizumab for weeks 24–96 were consistently higher than for weeks 0–24.

Conclusion:

More daclizumab versus intramuscular interferon beta-1a patients achieved NEDA early in DECIDE, with effects increasing over time.

Daclizumab

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Spotlight on daclizumab: its potential in the treatment of multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory-demyelinating disease of the central nervous system of a putative autoimmune etiology. Although the exact pathogenic mechanisms underlying demyelination and axonal damage in MS are not fully understood, T-cells are believed to play a central role in the pathogenesis of the disease. Daclizumab is a humanized binding monoclonal antibody that binds to the Tac epitope on the α-subunit (CD25) of the interleukin-2 (IL-2) receptor, thus effectively blocking the formation of the high-affinity IL-2 receptor, which is expressed mainly on T-cells. A series of clinical trials in patients with relapsing MS demonstrated a profound effect of daclizumab on inflammatory disease activity and improved clinical outcomes compared with placebo or interferon-β, which led to the recent approval of daclizumab (Zinbryta™) for the treatment of relapsing forms of MS. Enhancement of endogenous mechanisms of immune regulation rather than inhibition of effector T-cells might explain the effects of daclizumab in MS. These include expansion and improved function of regulatory CD56bright NK cells, inhibition of the early activation of T-cells through blockade of IL-2 transpresentation by dendritic cells and reduction in the number of intrathecal proinflammatory lymphoid tissue inducer cells. The enhanced efficacy of daclizumab is accompanied by an increased frequency of adverse events and risks of serious adverse events, thus placing it as a second-line therapy and calling for the implementation of a strict risk management program. This review details the mechanisms of action of daclizumab, discusses its efficacy and safety in patients with MS, and provides an insight into the place of this novel therapy in the treatment of MS.

Therapeutic efficacy of monthly subcutaneous injection of daclizumab in relapsing multiple sclerosis

Despite the availability of multiple disease-modifying therapies for relapsing multiple sclerosis (MS), there remains a need for highly efficacious targeted therapy with a favorable benefit-risk profile and attributes that encourage a high level of treatment adherence. Daclizumab is a humanized monoclonal antibody directed against CD25, the α subunit of the high-affinity interleukin 2 (IL-2) receptor, that reversibly modulates IL-2 signaling. Daclizumab treatment leads to antagonism of proinflammatory, activated T lymphocyte function and expansion of immunoregulatory CD56(bright) natural killer cells, and has the potential to, at least in part, rectify the imbalance between immune tolerance and autoimmunity in relapsing MS. The clinical pharmacology, efficacy, and safety of subcutaneous daclizumab have been evaluated extensively in a large clinical study program. In pivotal studies, daclizumab demonstrated superior efficacy in reducing clinical and radiologic measures of MS disease activity compared with placebo or intramuscular interferon beta-1a, a standard-of-care therapy for relapsing MS. The risk of hepatic disorders, cutaneous events, and infections was modestly increased. The monthly subcutaneous self-injection dosing regimen of daclizumab may be advantageous in maintaining patient adherence to treatment, which is important for optimal outcomes with MS disease-modifying therapy. Daclizumab has been approved in the US and in the European Union and represents an effective new treatment option for patients with relapsing forms of MS, and is currently under review by other regulatory agencies.

Human CD56bright NK Cells: An Update

Human NK cells can be subdivided into various subsets based on the relative expression of CD16 and CD56. In particular, CD56(bright)CD16(-/dim) NK cells are the focus of interest. They are considered efficient cytokine producers endowed with immunoregulatory properties, but they can also become cytotoxic upon appropriate activation. These cells were shown to play a role in different disease states, such as cancer, autoimmunity, neuroinflammation, and infection. Although their phenotype and functional properties are well known and have been extensively studied, their lineage relationship with other NK cell subsets is not fully defined, nor is their precise hematopoietic origin. In this article, we summarize recent studies about CD56(bright) NK cells in health and disease and briefly discuss the current controversies surrounding them.

Population PK-PD analyses of CD25 occupancy, CD56bright NK cell expansion, and regulatory T cell reduction by daclizumab HYP in subjects with multiple sclerosis

AIM

Daclizumab high yield process (HYP) is a humanized IgG1 monoclonal antibody that binds to the α-subunit of the interleukin-2 receptor and is being developed for treatment of multiple sclerosis (MS). This manuscript characterized the pharmacokinetic-pharmacodynamic (PK-PD) relationships of daclizumab HYP in subjects with MS.

METHODS

Approximately 1400 subjects and 7000 PD measurements for each of three biomarkers [CD25 occupancy, CD56^bright natural killer (NK) cell count, regulatory T cell (Treg) count] from four clinical trials were analyzed using non-linear mixed effects modelling. Evaluated regimens included 150 or 300 mg subcutaneous (s.c.) every 4 weeks.

RESULTS

CD25 occupancy was characterized using a sigmoidal maximum response (E_max ) model. Upon daclizumab HYP treatment, CD25 saturation was rapid with complete saturation occurring after approximately 7 h and maintained when daclizumab HYP serum concentration was ≥5 mg l^-1 . After the last 150 mg s.c. dose, unoccupied CD25 returned to baseline levels in approximately 24 weeks, with daclizumab HYP serum concentration approximately ≤1 mgl^-1 1L. CD56^bright NK cell expansion was characterized using an indirect response model. Following daclizumab HYP 150 mg s.c. every 4 weeks, expansion plateaus approximately at week 36, at which the average maximum expansion ratio is 5.2. After the last dose, CD56^bright NK cells gradually declined to baseline levels within 24 weeks. Treg reduction was characterized by a sigmoidal E_max model. Average maximum reduction of 60% occurred approximately 4 days post 150 mg s.c. dose. After the last dose, Tregs were projected to return to baseline levels in approximately 20 weeks.

CONCLUSIONS

Robust PK-PD models of CD25 occupancy, CD56^bright NK cell expansion and Treg reduction by daclizumab HYP were developed to characterize its key pharmacodynamic effects in the target patient population.

Cutaneous Adverse Events in the Randomized, Double-Blind, Active-Comparator DECIDE Study of Daclizumab High-Yield Process Versus Intramuscular Interferon Beta-1a in Relapsing-Remitting Multiple Sclerosis

Introduction

Cutaneous adverse events (AEs) have been observed in clinical studies of daclizumab high-yield process (HYP) in relapsing-remitting multiple sclerosis (RRMS). Here, we report cutaneous AEs observed in the randomized, double-blind, active-comparator DECIDE study (ClinicalTrials.gov identifier, NCT01064401).

Methods

DECIDE was a randomized, double-blind, active-controlled phase 3 study of daclizumab HYP 150 mg subcutaneous every 4 weeks versus interferon (IFN) beta-1a 30 mcg intramuscular (IM) once weekly in RRMS. Treatment-emergent AEs were classified and recorded by investigators. Investigators also assessed the severity of each AE, and whether it met the criteria for a serious AE. Cutaneous AEs were defined as AEs coded to the Medical Dictionary for Regulatory Activities System Organ Class of skin and subcutaneous tissue disorders. The incidence, severity, onset, resolution, and management of AEs were analyzed by treatment group.

Results

Cutaneous AEs were reported in 37% of daclizumab HYP-treated patients and 19% of IFN beta-1a-treated patients. The most common investigator-reported cutaneous AEs with daclizumab HYP were rash (7%) and eczema (4%). Most patients with cutaneous AEs remained on treatment (daclizumab HYP, 81%; IM IFN beta-1a, 90%) and had events that were mild or moderate (94% and 98%) and subsequently resolved (78% and 82%). Most patients with cutaneous AEs did not require treatment with corticosteroids or were treated with topical corticosteroids (daclizumab HYP, 73%; IM IFN beta-1a, 81%). Serious cutaneous AEs were reported in 14 (2%) daclizumab HYP patients and one (<1%) IM IFN beta-1a patient.

Conclusion

There was an increased risk of cutaneous AEs with daclizumab HYP. While physicians should be aware of the potential for serious cutaneous AEs, the typical cutaneous AEs were mild-to-moderate in severity, manageable, and resolved over time.

Funding

Biogen and AbbVie Biotherapeutics Inc.

Trial registration

ClinicalTrials.gov identifier, NCT01064401.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-016-0353-2) contains supplementary material, which is available to authorized users.

Anti-CD25 monoclonal antibody Fc variants differentially impact regulatory T cells and immune homeostasis

Interleukin-2 (IL-2) is a critical regulator of immune homeostasis through its non-redundant role in regulatory T (Treg) cell biology. There is major interest in therapeutic modulation of the IL-2 pathway to promote immune activation in the context of tumour immunotherapy or to enhance immune suppression in the context of transplantation, autoimmunity and inflammatory diseases. Antibody-mediated targeting of the high-affinity IL-2 receptor α chain (IL-2Rα or CD25) offers a direct mechanism to target IL-2 biology and is being actively explored in the clinic. In mouse models, the rat anti-mouse CD25 clone PC61 has been used extensively to investigate the biology of IL-2 and Treg cells; however, there has been controversy and conflicting data on the exact in vivo mechanistic function of PC61. Engineering antibodies to alter Fc/Fc receptor interactions can significantly alter their in vivo function. In this study, we re-engineered the heavy chain constant region of an anti-CD25 monoclonal antibody to generate variants with highly divergent Fc effector function. Using these anti-CD25 Fc variants in multiple mouse models, we investigated the in vivo impact of CD25 blockade versus depletion of CD25(+) Treg cells on immune homeostasis. We report that immune homeostasis can be maintained during CD25 blockade but aberrant T-cell activation prevails when CD25(+) Treg cells are actively depleted. These results clarify the impact of PC61 on Treg cell biology and reveal an important distinction between CD25 blockade and depletion of CD25(+) Treg cells. These findings should inform therapeutic manipulation of the IL-2 pathway by targeting the high-affinity IL-2R.

Increased prevalence of lymphoid tissue inducer cells in the cerebrospinal fluid of patients with early multiple sclerosis

BACKGROUND

Inflammatory cytokines produced by cells of the immune system are believed to play a central role in the pathogenesis of multiple sclerosis (MS). Innate lymphoid cells (ILCs) have been shown to produce and secrete a wide range of the cytokines involved in MS pathogenesis; however, a possible implication of ILCs in MS development and disease progression has not been investigated.

OBJECTIVE

With this study, we aimed to clarify a potential role of ILCs in the early stages of MS.

METHODS AND RESULTS

Using flow cytometry, we analysed the prevalence and phenotype of ILCs in the cerebrospinal fluid (CSF) of patients experiencing their first or second demyelinating event. We found a substantial increase in both frequency and number of ILCs, in particular the LTi subset, as compared to healthy controls. We also found an association between CSF pleocytosis and an increased frequency of LTi cells in the CSF, suggesting a favoured recruitment of blood derived LTi cells.

CONCLUSION

Our data suggests a role for ILCs, and in particular the LTi subset, in the early stages of MS. This finding represents an important contribution to the understanding of early inflammation in MS, and adds new knowledge beneficial for future MS therapies.

A critical appraisal of daclizumab use as emerging therapy in multiple sclerosis

INTRODUCTION

Daclizumab (DAC) is a mAb that binds to CD25, a receptor on the surface of lymphocytes for IL-2, a chemical messenger in the immune system. This prevents activation and proliferation of lymphocytes, which are involved in the immune attack in multiple sclerosis (MS).

AREAS COVERED

In this review, we will focus on newly emerging DAC-high-yield process (HYP) therapy for MS. Based on published original articles and citable meeting abstracts, we will discuss its mode of action as well as data on efficacy and safety.

EXPERT OPINION

DAC has been observed to have multiple (biological) effects, which may contribute to beneficial effects in immune-related disease and particularly in relapsing-remitting MS. The positive results in the clinical studies represent achievement of an important milestone in the development of DAC-HYP as a potential new treatment option for MS patients. The benefit/risk ratios of this new biological agent in MS therapy are still being evaluated. Soon, DAC-HYP might qualify as MS therapy. A safety monitoring program is recommended in the clinical practice.