Acthar Gel (repository corticotropin injection) for persistently active SLE: study design and baseline characteristics from a multicentre, randomised, double-blind, placebo-controlled trial

The multifunctional human ocular melanocortin system

Immune privilege in the eye involves physical barriers, immune regulation and secreted proteins that together limit the damaging effects of intraocular immune responses and inflammation. The neuropeptide alpha-melanocyte stimulating hormone (α-MSH) normally circulates in the aqueous humour of the anterior chamber and the vitreous fluid, secreted by iris and ciliary epithelium, and retinal pigment epithelium (RPE). α-MSH plays an important role in maintaining ocular immune privilege by helping the development of suppressor immune cells and by activating regulatory T-cells. α-MSH functions by binding to and activating melanocortin receptors (MC1R to MC5R) and receptor accessory proteins (MRAPs) that work in concert with antagonists, otherwise known as the melanocortin system. As well as controlling immune responses and inflammation, a broad range of biological functions is increasingly recognised to be orchestrated by the melanocortin system within ocular tissues. This includes maintaining corneal transparency and immune privilege by limiting corneal (lymph)angiogenesis, sustaining corneal epithelial integrity, protecting corneal endothelium and potentially enhancing corneal graft survival, regulating aqueous tear secretion with implications for dry eye disease, facilitating retinal homeostasis via maintaining blood-retinal barriers, providing neuroprotection in the retina, and controlling abnormal new vessel growth in the choroid and retina. The role of melanocortin signalling in uveal melanocyte melanogenesis however remains unclear compared to its established role in skin melanogenesis. The early application of a melanocortin agonist to downregulate systemic inflammation used adrenocorticotropic hormone (ACTH)-based repository cortisone injection (RCI), but adverse side effects including hypertension, edema, and weight gain, related to increased adrenal gland corticosteroid production, impacted clinical uptake. Compared to ACTH, melanocortin peptides that target MC1R, MC3R, MC4R and/or MC5R, but not adrenal gland MC2R, induce minimal corticosteroid production with fewer amdverse systemic effects. Pharmacological advances in synthesising MCR-specific targeted peptides provide further opportunities for treating ocular (and systemic) inflammatory diseases. Following from these observations and a renewed clinical and pharmacological interest in the diverse biological roles of the melanocortin system, this review highlights the physiological and disease-related involvement of this system within human eye tissues. We also review the emerging benefits and versatility of melanocortin receptor targeted peptides as non-steroidal alternatives for inflammatory eye diseases such as non-infectious uveitis and dry eye disease, and translational applications in promoting ocular homeostasis, for example, in corneal transplantation and diabetic retinopathy.

Post Hoc Biomarker Analyses from a Phase 4, Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial of Repository Corticotropin Injection (Acthar® Gel) for Persistently Active Systemic Lupus Erythematosus

INTRODUCTION

We conducted post hoc analyses of biomarker results from a multicenter, randomized, double-blind, placebo-controlled study of repository corticotropin injection (RCI; Acthar® Gel) in patients with persistently active systemic lupus erythematosus (SLE) despite treatment with moderate-dose glucocorticoids.

METHODS

Adults with active SLE and moderate to severe rash and/or arthritis were enrolled in the primary study. Patients had active SLE despite treatment with stable glucocorticoids, antimalarials, and nonsteroidal anti-inflammatory drugs and/or immunosuppressants. Patients were randomly assigned to 80 U of RCI or placebo subcutaneously every other day for 4 weeks and then twice weekly through week 24. Blood samples were analyzed for serum cytokines and complement proteins using enzyme-linked immunosorbent or Luminex assays and for circulating leukocytes using flow cytometry. Biomarker levels were reported as percentages of the baseline and were further evaluated in subgroups stratified by baseline SLE Disease Activity Index-2000 (SLEDAI-2K) scores (< 10 vs. ≥ 10), baseline anti-double-stranded DNA levels (< 15 IU/mL vs. ≥ 15 IU/mL), and BILAG-based Combined Lupus Assessment (BICLA) responses at week 20 and 24.

RESULTS

RCI treatment resulted in reduced levels of B cell-activating factor and interleukin-6 cytokines in all subgroups compared with placebo. RCI treatment also resulted in lower levels of CD19⁺ B cells and CD19⁺IgD^-CD27^-CD95⁺ atypical activated memory B cells than did placebo in the higher baseline disease activity subgroups and in BICLA non-responders. Furthermore, RCI treatment led to greater increases in complement component (C)3 and C4 levels than did placebo in the higher baseline disease activity subgroups and in BICLA responders.

CONCLUSIONS

RCI may reduce inflammation through B cell immunomodulation in patients with persistently active SLE, particularly in those with higher disease activity.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02953821.

Patient-Reported Outcomes from a Phase 4, Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial of Repository Corticotropin Injection (Acthar® Gel) for Persistently Active Systemic Lupus Erythematosus

Introduction

We assessed patient-reported outcomes from a multicenter, randomized, double-blind, placebo-controlled study of repository corticotropin injection (RCI; Acthar^® Gel) in patients with persistently active systemic lupus erythematosus (SLE) despite treatment with moderate-dose glucocorticoids.

Methods

The trial enrolled adults with active SLE and moderate-to-severe rash and/or arthritis despite use of stable glucocorticoids (7.5 mg/day to 30 mg/day prednisone equivalent), antimalarials, and nonsteroidal anti-inflammatory drugs for ≥ 4 weeks and/or immunosuppressants for ≥ 8 weeks before screening. Patients were randomly assigned to 80 U of RCI or placebo subcutaneously every other day through week 4, then twice weekly through week 24. Primary analyses evaluated the change from baseline to week 24 in the Lupus Quality of Life (QoL) and Work Productivity and Activity Impairment (WPAI)-Lupus questionnaires. Post hoc analyses stratified results by baseline disease activity (SLE Disease Activity Index-2000 [SLEDAI-2K] < 10 or ≥ 10; Cutaneous Lupus Erythematosus Disease Area and Severity Index [CLASI]-Activity < 11 or ≥ 11; and British Isles Lupus Assessment Group [BILAG]-2004 < 20 or ≥ 20) and by BILAG-based Combined Lupus Assessment (BICLA) response at weeks 20 and 24.

Results

RCI treatment resulted in greater improvement in the LupusQoL pain domain at week 16 and planning domain at week 24 compared with placebo. Post hoc analyses demonstrated greater improvements with RCI in the pain, planning, and fatigue domains than with placebo at multiple time points in patients with higher disease activity by baseline SLEDAI-2K ≥ 10, CLASI-Activity ≥ 11, and BILAG-2004 ≥ 20 and/or in BICLA responders. Compared with placebo, RCI also resulted in greater improvements in percentage work time missed at week 24 in patients with baseline CLASI-Activity < 11 and in percentage impairment while working at week 16 in BICLA responders.

Conclusions

RCI may improve QoL and work productivity in patients who have persistently active SLE despite treatment with standard SLE therapy.

Trial Registration

ClinicalTrials.gov identifier NCT02953821.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00294-z.

Repository Corticotropin Injection for Persistently Active Systemic Lupus Erythematosus: Results from a Phase 4, Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

INTRODUCTION

We assessed the efficacy and safety of repository corticotropin injection (RCI; Acthar® Gel) for persistently active systemic lupus erythematosus (SLE) despite use of moderate-dose glucocorticoids.

METHODS

This multicenter, double-blind, randomized, placebo-controlled study enrolled patients ≥ 18 years with active SLE and moderate to severe rash and/or arthritis despite stable glucocorticoid doses (7.5-30 mg/day prednisone equivalent) and antimalarials for ≥ 4 weeks and/or immunosuppressants for ≥ 8 weeks before screening. Stable glucocorticoid doses were required through week 16 with optional taper from weeks 16 to 24. Patients were randomized (1:1) to 80 U RCI subcutaneously or placebo every other day to week 4, then twice weekly to week 24. Endpoints included the proportion of SLE Responder Index (SRI)-4 responders at week 16; changes from baseline to week 16 in 28 Swollen Joint Count/Tender Joint Count (28 SJC/TJC) and Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI)-Activity score; and changes from baseline to week 24 in inflammatory cytokines. Safety was assessed by adverse events.

RESULTS

In the modified intention-to-treat population (RCI, n = 84; placebo, n = 85), the proportion of SRI-4 responders at week 16 was not significantly different between groups (RCI, 47.6%; placebo, 43.5%; OR [95% CI] 1.2 [0.6 to 2.2]; p = 0.5762). RCI treatment resulted in a reduction from baseline to week 16 in 28 SJC/TJC and CLASI-Activity score and from baseline to week 8 in a proliferation-inducing ligand cytokine. Post hoc analyses demonstrated a greater proportion of BILAG-based Combined Lupus Assessment responders for RCI than placebo at weeks 4, 12, and 20 and greater SRI-4 response in RCI-treated patients with baseline SLE Disease Activity Index-2000 ≥ 10 and CLASI-Activity ≥ 11. No new safety signals were identified.

CONCLUSIONS

Despite failure to achieve the primary endpoint, these results support the utility of RCI for treating persistently active SLE.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02953821.