Type I interferon receptor blockade with anifrolumab corrects innate and adaptive immune perturbations of SLE

Abstract

Objective: Anifrolumab is a fully human immunoglobulin G1 κ monoclonal antibody specific for subunit 1 of the type I interferon (IFN) α receptor. In a phase IIb study of adults with moderate to severe SLE, anifrolumab treatment demonstrated substantial reductions in multiple clinical endpoints. Here, we evaluated serum proteins and immune cells associated with SLE pathogenesis, type I interferon gene signature (IFNGS) test status and disease activity, and how anifrolumab affected these components.

Methods: Whole blood samples were collected from patients enrolled in MUSE (NCT01438489) for serum protein and cellular assessments at baseline and subsequent time points. Data were parsed by IFNGS test status (high/low) and disease activity. Protein expression and immune cell subsets were measured using multiplex immunoassay and flow cytometry, respectively. Blood samples from healthy donors were analysed for comparison.

Results: Baseline protein expression differed between patients with SLE and healthy donors, IFNGS test-high and -low patients, and patients with moderate and severe disease. Anifrolumab treatment lowered concentrations of IFN-induced chemokines associated with B, T and other immune cell migration in addition to proteins associated with endothelial activation that were dysregulated at baseline. IFNGS test-high patients and those with high disease activity were characterised by low baseline numbers of lymphocytes, circulating memory T-cell subsets and neutrophils. Anifrolumab treatment reversed lymphopenia and neutropenia in the total population, and normalised multiple T-cell subset counts in IFNGS test-high patients compared with placebo.

Conclusions: Anifrolumab treatment reversed IFN-associated changes at the protein and cellular level, indicating multiple modes of activity.

Trial registration number: NCT01438489.

Keywords: disease activity; monoclonal antibody; systemic lupus erythematosus; type I interferon.

Conflict of interest statement

Competing interests: KAC, XG, MAS, SW, DS and WW are employees of MedImmune and hold stock and/or stock options in AstraZeneca. MAS was an employee of MedImmune at the time that this analysis was conducted; he is now an employee of Bristol-Myers Squibb. LW was an employee of MedImmune at the time that this analysis was conducted; he is now an employee of AstraZeneca. GI was an employee of MedImmune at the time that this analysis was conducted; he is now an employee of Viela Bio.

Figures

Figure 1

Serum proteins dysregulated at baseline in patients enrolled in the MUSE study subsetted by IFNGS test status, Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) scores, and the proportions of these proteins that are significantly upregulated or downregulated following treatment with anifrolumab. The Venn diagram is area-proportional to the numbers of serum proteins that are dysregulated at baseline in patients classified as IFNGS test-high (n=229) versus test-low (n=75), patients with a CLASI score ≥10 (n=77) versus

Figure 2

Immune cell populations associated with type I IFNGS test status and disease activity. Data are mean fold change of baseline flow cytometry measurements±95% CIs of immune cell subsets in IFNGS test-high versus IFNGS test-low patients, patients with Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) ≥10 versus patients with CLASI 2 transformation was applied. Statistical analysis was carried out using a Student’s t-test. Significant p-values <0.05 are reported. DC, dendritic cells; IFN, interferon; IFNGS, IFN gene signature; n.s., not significant; WB, whole blood; WBC, white blood cells.

Figure 3

Mean change from baseline in complete blood count (CBC) lymphocyte (A), neutrophil (B), platelet (C), and monocyte (D) counts over time for patients enrolled in the MUSE study, split by treatment group and IFNGS test status; mean change from baseline in CBC lymphocyte (E) and neutrophil counts (F) over time for patients treated with placebo enrolled in the MUSE study, split by oral corticosteroid (OCS) tapering history. (A, B) Anifrolumab significantly increased the mean number of lymphocytes and neutrophils from baseline at all time points (±SEM). Placebo group: patient numbers ranged from 68 (at days 337 and 365) to 101 (at day 1). Anifrolumab 300 mg group: patient numbers ranged from 82 (at day 365) to 99 (at day 1). Anifrolumab 1000 mg group: patient numbers ranged from 68 (at day 337) to 97 (at day 1). *P<0.05 (Student’s t-test for the comparison of anifrolumab vs placebo). (C, D) Anifrolumab significantly increased the mean number of platelets and monocytes from baseline at multiple time points (±SEM). Placebo group: patient numbers ranged from 101 (at day 1) to 68 (at day 337). Anifrolumab 300 mg group: patient numbers ranged from 98 (at day 1) to 81 (at day 337). Anifrolumab 1000 mg group: patient numbers ranged from 98 (at day 1) to 71 (at day 337). *P<0.05 (Student’s t-test for the comparison of anifrolumab vs placebo). (E and F) Lymphocytes and neutrophil concentrations were not affected by steroid tapering. Tapering was defined as a reduction of OCS dosage at day 365 by ≤7.5 mg/day in patients who were receiving ≥10 mg/day at baseline. Sample sizes ranged from 16 to 42 patients, dependent on steroid tapering regimen group. *P<0.05 (Student′s t-test for the comparison of steroid taper vs no steroid taper). Low steroids group: patient numbers ranged from 23 (on days 253 and 365) to 38 (on day 1). No steroid taper group: patient numbers ranged from 26 (on day 337) to 44 (on day 1). Steroid taper group: patient numbers ranged from 16 (on day 337) to 19 (on days 1–141 and 197–225). CBC, complete blood count; IFN, interferon; IFNGS, IFN gene signature; MUSE, a Phase II, Randomized Study to Evaluate the Efficacy and Safety of MEDI-546 in Subjects with Systemic Lupus Erythematosus; OCS, oral corticosteroid; SEM, SE of the mean.

Figure 4

Change over time in percentage of baseline concentrations of selected proteins which were dysregulated in patients with SLE enrolled in the MUSE study. ANGPT2, angiopoietin 2; B2M, beta-2 microglobulin; BAFF, B-cell activating factor; BLC, B lymphocyte chemoattractant; CCL, chemokine (C-C motif) ligand; CXCL, chemokine (C-X-C motif) ligand; FCN3, ficolin-3; FRTN, ferritin; GRN, granulin; IL1R2, interleukin-1 receptor type 2; IP10, interferon gamma–induced protein 10; ITAC, interferon-inducible T cell alpha chemoattractant; MCP, monocyte chemoattractant protein; MIP-3, macrophage inflammatory protein 3; MUSE, a Phase II, Randomized Study to Evaluate the Efficacy and Safety of MEDI-546 in Subjects with Systemic Lupus Erythematosus; TNFRSF10C, tumour necrosis factor receptor superfamily member 10c; TNFSF13B, tumour necrosis factor ligand superfamily member 13b; TRAIL-R3, tumour necrosis factor-related apoptosis-inducing ligand receptor 3; VCAM-1, vascular cell adhesion molecule 1; VWF, von Willebrand factor.

Figure 5

The effect of anifrolumab treatment on the prevalence of multiple immune cell subtypes in patients stratified by IFNGS test status (A) and on specific T-cell subsets in IFNGS test-high patients (B). (A) Summary table for the comparison of mean change from baseline in the anifrolumab 300 mg group versus placebo for all flow cytometry populations across six time points separated by IFNGS test-high and test-low patients. Red boxes represent statistically significant increases from baseline for the comparison between the 300 mg dosage group and placebo (p<0.05 as calculated using Student’s t-test). Grey boxes represent nonsignificant changes. Placebo group (IFNGS test-high): day 1 (n=13); week 85 (n=10); day 141 (n=10); week 169 (n=10); day 253 (n=7); week 337 (n=8); day 365 (n=4). Anifrolumab 300 mg group (IFNGS test-high): day 1 (n=17); day 85 (n=13); day 141 (n=14); day 169 (n=14); day 253 (n=12); day 337 (n=14); day 365 (n=13). Placebo group (IFNGS test-low): day 1 (n=12); day 85 (n=12); day 141 (n=7); day 169 (n=11); day 253 (n=9); day 337 (n=8); day 365 (n=11). Anifrolumab 300 mg group (IFNGS test-low): day 1 (n=7); day 85 (n=7); day 141 (n=4); day 169 (n=7); day 253 (n=6); day 337 (n=6); day 365 (n=4). (B) Data are mean change from baseline (±SEM) in absolute numbers of T-cell subsets in IFNGS test-high patients. *P<0.05 (Student’s t-test for the comparison of anifrolumab vs placebo). Placebo group: day 1 (n=13); day 85 (n=10); day 141 (n=10); day 169 (n=10); day 253 (n=7); day 337 (n=8); day 365 (n=4). Anifrolumab 300 mg group: day 1 (n=17); day 85 (n=13); day 141 (n=14); day 169 (n=14); day 253 (n=12); day 337 (n=14); day 365 (n=13). Anifrolumab 1000 mg group: day 1 (n=18); day 85 (n=18); day 141 (n=18); day 169 (n=17); day 253 (n=14); day 337 (n=8); day 365 (n=5). DC, dendritic cells; IFN, interferon; IFNGS, IFN gene signature; n.s., not significant; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index; WB, whole blood; WBC, white blood cells.