1 Introduction
Psoriatic arthritis (PsA) is a chronic inflammatory musculoskeletal condition characterized by a wide range of symptoms including arthritis, spondylitis, dactylitis, enthesitis, psoriasis and nail disease [
1,
2]. PsA is also associated with several comorbidities [
1‐
3], and can significantly worsen health-related quality of life (HR-QOL) [
1]. Traditional pharmacological treatment options for PsA include NSAIDs and conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) such as methotrexate [
1,
3]. Over recent decades, the development of biological DMARDs (bDMARDs) has considerably changed the PsA treatment landscape [
1]. The first bDMARDs to be approved were the tumour necrosis factor inhibitors (TNFi), based on the finding that TNF-α is a key mediator of acute inflammation in PsA [
4]. In addition to TNF-α, other proinflammatory cytokines, such as interleukin (IL)-12, IL-17 and IL-23, have been shown to play a key role in the pathogenesis of PsA [
1,
4,
5]. IL-17A (a member of the IL-17 family) is up-regulated in psoriatic lesional skin and in the synovial fluid of PsA patients [
1,
4,
5], providing a rationale for the development of targeted anti-IL-17 therapies [
5].
Secukinumab (Cosentyx
®) is a recombinant, high affinity, fully human monoclonal antibody targeted against IL-17A. It is approved in numerous countries, including the USA [
6] and those of the EU [
7], for the treatment of adult patients with active PsA. The pharmacological properties of secukinumab have been reviewed in detail previously [
8] and are summarized in Table
1. This review focuses on the clinical use of secukinumab in patients with PsA. Secukinumab is also approved for the treatment of plaque psoriasis [
9], ankylosing spondylitis (AS) [
10,
11] and non-radiographic axial spondyloarthritis (nr-axSpA); however, discussion of the use of secukinumab in these indications is beyond the scope of this review.
Table 1
Overview of key pharmacological properties of secukinumab [
6‐
8]
Pharmacodynamic properties |
Recombinant, high affinity, fully human IgG1/κ monoclonal antibody; selectively binds to and neutralizes IL-17A and inhibits its interaction with the IL-17 receptor; inhibits the release of proinflammatory cytokines, chemokines and mediators of tissue damage |
Initial ↑ in serum levels of total IL-17A (free + SEC-bound IL-17A), then slow ↓ due to reduced clearance of SEC-bound cytokine |
Clinically relevant levels of SEC reach the skin, leading to ↓ local inflammatory markers and ↓ erythema, induration and desquamation |
↓ Psoriatic epidermal abnormalities (i.e. epidermal thickening, parakeratosis, acanthosis) with parallel ↓ in epidermal neutrophil counts in plaques; ↓ pathological infiltration of psoriasis lesions by T cells, macrophages and inflammatory dendritic cell subsets |
↓ Synovial inflammation and no progression of catabolic and anabolic bone changes in joints of pts with PsA [ 66] |
↓ Levels of C-reactive protein (inflammatory biomarker) in pts with PP, PsA and AS |
↓ Serum levels of β-defensin 2 (proposed surrogate marker of disease activity) in pts with PsA |
Pts receiving SEC should not be administered live vaccines; non-live vaccines may be given during SEC treatment; SEC did not impair immune response to a meningococcal polysaccharide conjugate vaccine and an inactivated influenza vaccine |
Pharmacokinetic propertiesa |
Pharmacokinetics of SEC in pts with PsA are similar to those in pts with PP or other autoimmune diseases |
Dose-proportional exposure over dose range of 25–300 mg; bioavailability 85%; Cmax reached ≈ 6 days following a single dose; mean Cmax at steady state after loading and maintenance doses estimated to be 31 and 62 µg/mL with 150 and 300 mg doses |
Administration via Sensoready® pen resulted in mean trough concentrations at weeks 4 and 12 that were 23–30% higher than after administration of reconstituted lyophilized powder and 23–26% higher than after administration via prefilled syringe |
Low total Vd; estimated Vd 3.66 and 2.45 L for the central and peripheral compartments |
Majority of elimination occurs through intracellular catabolism (following endocytosis); systemic clearance ≈ 0.19 L/day; average terminal elimination half-life 25 days |
Special populationsb | ↑ SEC clearance and Vd with ↑ bodyweight |
Hepatic impairment or abnormal kidney function is not expected to influence SEC elimination or clearance |
No dosage adjustment required in pts aged ≥ 65 years |
No clinically relevant differences in SEC pharmacokinetics based on age, gender or race (after adjusting for bodyweight) |
Drug interactionsb | No specific drug interaction studies have been performed |
No interaction when SEC is coadministered with methotrexate ± oral glucocorticoids |
Formation of some CYP450 enzymes can be altered by ↑ levels of certain cytokines during chronic inflammation; SEC could potentially affect CYP450 levels; consider monitoring and dosage adjustment when initiating or discontinuing SEC in pts receiving concomitant CYP450 substrates (particularly those with a narrow therapeutic index) |
3 Tolerability of Secukinumab
Subcutaneous secukinumab 150 or 300 mg was generally well tolerated in clinical trials, including in patients with PsA, plaque psoriasis, AS and other autoimmune conditions [
7]. The tolerability profile was consistent across all indications. The most common adverse events (AEs) with secukinumab in clinical trials and post-marketing reports were upper respiratory tract infections (URTIs), most commonly nasopharyngitis and rhinitis [
7].
During the 16- or 24-week placebo-controlled periods of FUTURE 1–3 and 5, AEs occurred in 55–65% of secukinumab recipients and 56–62% of placebo recipients, with serious AEs reported in 1–5% of secukinumab and 2–7% of placebo recipients, and discontinuations due to AEs reported in 0–4% of secukinumab and 2–4% of placebo recipients [
12‐
14,
16]. During this period, the most common (incidence ≥ 5%) AEs with secukinumab were URTI, nasopharyngitis and headache [
12‐
14,
16].
In the head-to-head EXCEED trial, the safety profiles of secukinumab and adalimumab were consistent with previous reports [
19]. During the 52-week treatment period, AEs were reported in 77% of secukinumab recipients and 79% of adalimumab recipients. The most common (incidence ≥ 10%) AEs were nasopharyngitis (19% with secukinumab vs 19% with adalimumab) and URTI (10 vs 11%). Injection-site reactions occurred in 4% of secukinumab recipients and 11% of adalimumab recipients. Four percent of patients in the secukinumab group and 7% of patients in the adalimumab group discontinued treatment due to AEs [
19].
Over the entire safety periods of FUTURE 1–5 (52 weeks in FUTURE 3 and 5 [
14,
20], 104 weeks in FUTURE 4 [
15], and 260 weeks in FUTURE 1 and 2 [
24,
27]), the long-term tolerability profile of secukinumab was generally consistent with that reported previously, with no new or unexpected safety signals. The exposure-adjusted incidence rate (EAIR) of any AE during 5 years of secukinumab treatment was 126.7 per 100 patient-years (PY) in FUTURE 1 [
24] and 140.5 per 100 PY in FUTURE 2 [
27]. In a pooled analysis of FUTURE 1–3 (
n = 1380; total exposure 3866.9 PY), the EAIR of any AE with secukinumab across the entire safety period was 147.0 per 100 PY [
48]. Post-marketing safety surveillance data based on cumulative secukinumab exposure of ≈ 285,811 PY across three indications (PsA, plaque psoriasis and AS) confirmed that secukinumab was generally well tolerated over the longer-term [
49].
3.1 Adverse Events of Special Interest
Treatment with secukinumab may increase the risk of infections [
6,
7], with the incidence of some types of infections appearing to be dose-dependent [
6]. In placebo-controlled trials in patients with PsA, plaque psoriasis, AS or nr-axSpA, higher rates of common infections such as URTI, nasopharyngitis and mucocutaneous
Candida infections were observed with secukinumab relative to placebo [
6,
7]. However, these infections were of mild to moderate severity and did not require discontinuation of secukinumab [
7]. In a pooled analysis of FUTURE 1–5 (
n = 2678; total exposure 5984.6 PY), serious infections and
Candida infections occurred at EAIRs of 1.8 and 1.5 per 100 PY of exposure to secukinumab during the entire safety period [
49]. Caution is advised when considering the use of secukinumab in patients with chronic infections or a history of recurrent infection [
6,
7]. If signs or symptoms of an infection occur, patients should seek medical advice. Patients who develop a serious infection while receiving secukinumab should be closely monitored and secukinumab should be discontinued until the infection resolves [
6,
7].
No cases of active tuberculosis (TB) or latent TB infection reactivation were reported in the secukinumab clinical trial programme [
50]. However, patients should be evaluated for TB infection prior to initiating secukinumab, and should be closely monitored for signs and symptoms of active TB during and after treatment [
6]. Secukinumab should not be given to patients with active TB, and anti-TB therapy should be considered prior to initiation of secukinumab in patients with latent TB [
6,
7].
There have been reports of new-onset or exacerbations of inflammatory bowel disease (IBD), including some serious cases, in patients receiving secukinumab [
6,
7]. In the pooled analysis of FUTURE 1–5, the EAIRs of IBD, Crohn’s disease and ulcerative colitis with secukinumab during the entire safety period were 0.03, 0.1 and 0.1 per 100 PY, respectively [
49]. Data on a year-on-year basis showed no increase in the EAIR of IBD with secukinumab treatment over time [
49]. Caution is advised when prescribing secukinumab to patients with IBD, and patients receiving secukinumab should be closely monitored for signs and symptoms of IBD [
6,
7].
Hypersensitivity reactions including anaphylaxis and urticaria have occurred in patients receiving secukinumab [
6,
7]. Serious allergic reactions to secukinumab should be treated with appropriate therapy, and the drug should be discontinued immediately [
6,
7].
In the pooled analysis of FUTURE 1–5, the EAIRs for a number of other AEs of special interest were low and stable during the entire safety period, namely malignancy (1.0 per 100 PY), major adverse cardiovascular events (MACE; 0.4 per 100 PY) and uveitis (0.1 per 100 PY) [
49]. Similar results were seen in post-marketing surveillance. Across five consecutive periodic safety update reporting periods between December 2014 and December 2018, the rates of serious infections, malignancy, total IBD and MACE were 1.4, 0.3, 0.2 and 0.2 per 100 PY, respectively [
49].
Like all therapeutic proteins, secukinumab has the potential for immunogenicity [
6]. Over 52 weeks of treatment in FUTURE 1–3, five (0.4%) secukinumab recipients developed anti-drug antibodies (ADAs) [
51]. In four of these cases, the antibodies were non-neutralizing. The emergence of ADAs was not associated with immunogenicity-related AEs, loss of clinical response or deviations in the expected pharmacokinetics of secukinumab [
51].
4 Dosage and Administration of Secukinumab
Subcutaneous secukinumab is approved in the USA [
6] and the EU [
7] for the treatment of adult patients with active PsA (when the response to previous DMARD therapy has been inadequate [
7]), and may be administered with or without concomitant methotrexate [
6,
7]. Secukinumab is available as a lyophilized powder (150 mg) in a vial for reconstitution, or as a 150 mg/mL solution for injection in a prefilled syringe or Sensoready
® pen. The lyophilized powder for reconstitution is to be administered by healthcare providers only, while secukinumab in a prefilled syringe or pen may be self-injected after proper training in subcutaneous injection technique [
6,
7]. Each injection should be administered at a different site (e.g. upper arm, thigh or abdomen) than the previous injection [
6], avoiding areas of skin affected by psoriasis (if possible) [
6,
7].
The recommended dose of secukinumab in patients with PsA and concomitant moderate to severe plaque psoriasis (or an inadequate response to TNFi [
7]) is 300 mg administered at weeks 0, 1, 2, 3 and 4, followed by 4-weekly (USA) or monthly (EU) maintenance dosing [
6,
7]. For other patients with PsA, the recommended dose of secukinumab is 150 mg administered at weeks 0, 1, 2, 3 and 4 (i.e. loading doses), followed by 4-weekly (USA) or monthly (EU) maintenance dosing [
6,
7]; or alternatively, in the USA [
6], 150 mg administered every 4 weeks without loading doses. The dose of secukinumab can be increased to 300 mg based on clinical response [
7] or if active disease persists [
6]. Consult local prescribing information for further detailed information regarding contraindications, warnings and precautions, drug interactions and use in special populations.
5 Place of Secukinumab in the Management of Psoriatic Arthritis
The main goals in the treatment of PsA are to control symptoms, prevent structural damage, optimize physical function and improve HR-QOL [
52]. The choice of treatment is dependent on the clinical presentation of the disease. Consideration should be given to each musculoskeletal manifestation, as well as to non-musculoskeletal manifestations and comorbidities [
52]. Treatment guidelines from the Group for Research and Assessment of Psoriasis and PsA (GRAPPA) [
53] and EULAR [
52] recommend a csDMARD (preferably methotrexate [
52]) as first-line therapy for peripheral arthritis, followed by a bDMARD [i.e. TNFi, interkeukin-12/23 inhibitor (IL-12/23i) or interleukin-17 inhibitor (IL-17i)] if treatment targets are not achieved. In patients with predominantly axial disease, EULAR guidelines recommend the use of an IL-17i over a TNFi when there is relevant skin involvement [
52]. Joint ACR and National Psoriasis Foundation (NPF) guidelines conditionally recommend a TNFi over an oral small molecule (i.e. csDMARD or apremilast) for treatment-naïve PsA, with IL-12/23i and IL-17i conditionally recommended after TNFi or in patients with contraindications to TNFi [
54].
Secukinumab is a fully human monoclonal antibody that inhibits the proinflammatory effects of IL-17A (Table
1), and was the first IL-17i to be approved for the treatment of active PsA (Sect.
4). Subcutaneous secukinumab 150 or 300 mg was effective in the treatment of PsA in phase III clinical trials (Sect.
2). In the FUTURE trials, which included patients with different subtypes of PsA [
6,
7], secukinumab improved clinical signs and symptoms compared with placebo, with these benefits maintained over the longer term (Sect.
2.1.1.1). The efficacy of secukinumab was seen across all key clinical domains of PsA, including ACR and PASI response rates, DAS28-CRP, and resolution of dactylitis and enthesitis. Of note, secukinumab was associated with clinically relevant improvements in some of the more stringent endpoints, such as ACR50, PASI90 (Sect.
2.1.1.1), MDA, VLDA and DAPSA remission (Sect.
2.1.1.4).
The clinical benefits of secukinumab were seen regardless of whether patients had or had not received previous TNFi and irrespective of concomitant methotrexate use (Sect.
2.1.1.1). The finding that secukinumab may be effective in both TNFi-naïve and –experienced patients is important, given that GRAPPA and EULAR treatment guidelines recommend switching to either another TNFi or to a different bDMARD class (i.e. IL-17i or IL-12/23i) if treatment targets are not met with the first TNFi [
52,
53]. Current ACR/NPF guidelines conditionally recommend switching to a different TNFi after failure of the first TNFi [
54].
PsA is a chronic and multifaceted disease which has a significant impact on HR-QOL in terms of physical dysfunction, pain, fatigue, work disability and emotional/social impairment [
4]. In clinical trials, secukinumab was associated with clinically meaningful improvements in patient-reported measures of physical function and HR-QOL (including pain, fatigue and work productivity) compared with placebo, with these improvements sustained over the longer term (Sect.
2.1.1.3).
Bone erosions are evident in approximately half of patients with PsA within 2 years of diagnosis, and many patients experience irreversible joint damage and disability [
16]. Therefore, the prevention of structural damage is a fundamental goal in the management of PsA [
52]. In FUTURE 1 and 5, secukinumab inhibited structural joint damage, with sustained low rates of radiographic progression seen over the longer term (Sect.
2.1.1.2). Notably, switching to secukinumab inhibited further radiographic progression in patients initially randomized to placebo (Sect.
2.1.1.2).
Axial disease is reported to affect 25–70% of patients with longstanding PsA [
17]. Its burden of disease is underestimated, and it is distinct from axial spondyloarthritis [
17]. The effect of secukinumab on axial disease was not assessed in the FUTURE trials, which was specifically noted as a potential limitation of FUTURE 1 and 2 [
12,
13]. MAXIMISE was the first randomized controlled trial to evaluate the efficacy of a biological agent in the management of axial manifestations of PsA [
17]. Final 52-week results demonstrated that secukinumab improved ASAS responses and reduced inflammatory MRI lesions in the spine and sacroiliac joints in PsA patients with axial involvement (Sect.
2.1.2). Further clinical trials with other bDMARDs would be of interest.
In the head-to-head EXCEED trial, secukinumab did not quite attain statistical significance for superiority versus the TNFi adalimumab in the joint domain (Sect.
2.2). Nevertheless, the trial provides new information regarding the comparative efficacy of two bDMARDs with differing mechanisms of action [
55], and may help guide clinical decision-making regarding treatment choices for PsA after csDMARD failure or intolerance [
19]. Additional well-designed clinical trials directly comparing secukinumab with other pharmacological agents in patients with PsA are needed. A phase III head-to-head trial comparing the efficacy of secukinumab and the IL-12/23i ustekinumab in patients with PsA and TNFi failure (AGAIN; NCT04632927) is currently underway. In addition, a number of systematic reviews and meta-analyses have indirectly compared the efficacy of bDMARDs (e.g. TNFi, ustekinumab, the IL-17i ixekizumab, secukinumab) and targeted synthetic DMARDs (e.g. apremilast) in patients with PsA [
56‐
61]. However, the findings of these analyses require cautious interpretation due to the indirect nature of the comparisons and the heterogeneity of the studies and patient populations assessed.
Secukinumab was generally well tolerated in clinical trials (Sect.
3). The tolerability profile of secukinumab in patients with PsA was consistent with the profile of the drug used in other approved indications, including plaque psoriasis and AS. Secukinumab remained generally well tolerated over the longer term (up to 5 years), with no new or unexpected safety signals. Post-marketing safety surveillance data based on cumulative secukinumab exposure of > 285,000 PY were consistent with data from clinical trials (Sect.
3).
Treatment retention is a composite measure of a drug’s efficacy and tolerability [
47], and low adherence rates and/or high discontinuation rates may indicate suboptimal treatment [
45]. In real-world studies, rates of adherence, retention and persistence with secukinumab were better than or similar to those with other bDMARDs (Sect.
2.3). Additional studies would help to further elucidate the position of secukinumab in the real-world setting. The ongoing, longitudinal, observational SERENA study (
n = 2932) will assess the long-term (up to 5 years) retention of secukinumab in routine clinical practice across three indications (plaque psoriasis, AS and PsA) [
62].
The choice of treatment for PsA is individualized and should take into account factors such as comorbidities and patient preferences (e.g. route of administration, ease of use) [
53,
54]. Like all newer bDMARDs, secukinumab is administered subcutaneously. After appropriate training, secukinumab can be self-administered via a prefilled syringe or pen (Sect.
4). Such devices offer patients convenience and ease of administration, both of which may improve their adherence to treatment. In the FUTURE 3 trial, most patients were satisfied or very satisfied with the autoinjector and found it easy or very easy to use (Sect.
2.1.1.3). In real-world clinical practice, secukinumab was associated with high levels of patient and physician satisfaction (Sect.
2.3).
Cost is another factor that can influence the choice of therapy in PsA. Current National Institute for Health and Care Excellence guidance indicates that secukinumab is cost effective in some clinical settings [
63]. Semi-Markov models were used to evaluate the cost effectiveness of secukinumab in patients with PsA from the perspectives of the German statutory health insurance system [
64] and the Argentinean social security healthcare system [
65]. Results suggest that, over a lifetime horizon, secukinumab is cost effective compared with other bDMARDs (adalimumab, certolizumab pegol, etanercept, golimumab, infliximab and ustekinumab) in both biological-experienced patients and biological-naïve patients (without or without concomitant moderate to severe psoriasis) [
64,
65]. Additional pharmacoeconomic data relevant to the EU and the USA would be useful.
In conclusion, subcutaneous secukinumab is effective across all key PsA domains and is generally well tolerated, with efficacy and tolerability sustained over the longer term. Thus, secukinumab represents a useful treatment alternative to TNFi and other bDMARDs in adult patients with active PsA.