Clinician-reported outcome measures in lupus trials: a problem worth solving

Targeting Interferon Signalling in Systemic Lupus Erythematosus: Lessons Learned

The development of new medicines for systemic lupus erythematosus (SLE) has not addressed unmet clinical need, with only three drugs receiving regulatory approval for SLE in the last 60 years, one of which was specifically licensed for lupus nephritis. In the last 20 years it has become clear that activation of type 1 interferons (IFN) is reproducibly detected in the majority of SLE patients, and the actions of IFN in the immune system and on target tissues is consistent with a pathogenic role in SLE. These findings led to considerable drug discovery activity, first with agents directly targeting IFN family cytokines, with results that were encouraging but underwhelming. In contrast, targeting the type I IFN receptor with the monoclonal antibody anifrolumab, thereby blocking all IFN family members, was effective in a phase II clinical trial. This led to a pair of phase III trials, one of which was negative and the other positive, reflecting the difficulty of obtaining outcomes from trials in this complex disease. Nonetheless, the balance of evidence resulted in approval of anifrolumab in multiple jurisdictions from 2021 onwards. Multiple approaches to targeting the type 1 IFN pathway have subsequently had positive phase II clinical trials, including antibodies targeting cells that produce IFN, and small molecules targeting the receptor kinase TYK2, required for IFN signalling. Despite multiple hurdles, it is clear that IFN targeting in SLE is here to stay. The story of IFN-targeting therapy in SLE has lessons for drug development overall in this disease.

TYK2: an emerging therapeutic target in rheumatic disease

Tyrosine kinase 2 (TYK2) is a member of the JAK kinase family of intracellular signalling molecules. By participating in signalling pathways downstream of type I interferons, IL-12, IL-23 and IL-10, TYK2 elicits a distinct set of immune events to JAK1, JAK2 and JAK3. TYK2 polymorphisms have been associated with susceptibility to various rheumatic diseases including systemic lupus erythematosus and dermatomyositis. In vitro and animal studies substantiate these findings, highlighting a role for TYK2 in diseases currently managed by antagonists of cytokines that signal through TYK2. Various inhibitors of TYK2 have now been studied in human disease, and one of these inhibitors, deucravacitinib, has now been approved for the treatment of psoriasis. Phase II trials of deucravacitinib have also reported positive results in the treatment of psoriatic arthritis and systemic lupus erythematosus, with a preliminary safety profile that seems to differ from that of the JAK1, JAK2 and JAK3 inhibitors. Two other inhibitors of TYK2, brepocitinib and ropsacitinib, are also in earlier stages of clinical trials. Overall, TYK2 inhibitors hold promise for the treatment of a distinct spectrum of autoimmune diseases and could potentially have a safety profile that differs from other JAK inhibitors.

What is the best instrument to measure disease activity in SLE? - SLE-DAS vs Easy BILAG

Systemic lupus erythematosus (SLE) is a heterogeneous condition making assessment of disease activity challenging. However, thorough assessment is essential to evaluate patients longitudinally, to guide therapeutic decisions, and for clinical trials. Currently, the most popular disease activity index in clinical practice and trials is SLEDAI-2K. Its main advantage is ease of use, but significant weaknesses of SLEDAI-2K are omission of several serious manifestations, inability to capture change within an organ system, and fixed severity weightings that are often inappropriate. Recently several groups have developing improved tools. We report here the debate held at CORA meeting on this issue. SLE-DAS includes 17 weighted clinical and laboratory parameters including continuous measures in 4 items with an online calculator. A higher sensitivity to change compared to SLEDAI-2K has been demonstrated in its validation studies. Easy BILAG is an improved format of the BILAG-2004 that retains its content but greatly simplified. Its scoring using a single-page form that incorporates concise definitions for key terms next to clinical items. Easy-BILAG demonstrates higher accuracy and less variability and increased and better user feedback compared to the standard BILAG-2004 format. Both the indices discussed at CORA showed an advantage in measuring disease activity compared to SLEDAI.

Assessment of disease activity and damage in SLE: Are we there yet?

Systemic Lupus Erythematosus is a systemic autoimmune disease characterized by a great heterogenicity in course and clinical manifestations. Although prognosis improved in the last decades of the 20th century, mortality remains higher than in the general population and uncontrolled disease activity and therapy-related adverse effects have been identified as major contributors to damage accrual and poor outcomes. Assessment of disease activity and damage in SLE represents a great challenge even to the expert rheumatologist. Global disease activity indices are tools developed to assess activity across multiple organ systems. Several disease activity indices have been developed over the years, each with its own strengths and weaknesses, and knowing them is essential for understanding research studies, such as clinical trials, in which they are used. Organ-specific activity indices have been developed concurrently to represent organ involvement such as glomerulonephritis, cutaneous and musculoskeletal lupus manifestations. Regarding damage, the SLICC/ACR damage index has proven to be an effective tool for damage accrual assessment, yet not devoid of drawbacks. This review provides an overview of the most frequently utilized indices developed for the assessment of activity and damage in SLE highlighting their pros and cons when applied to the research and clinical setting.

Towards a novel clinical outcome assessment for systemic lupus erythematosus: first outcomes of an international taskforce

Systemic lupus erythematosus (SLE) is a disease of high unmet therapeutic need. The challenge of accurately measuring clinically meaningful responses to treatment has hindered progress towards positive outcomes in SLE trials, impeding the approval of potential new therapies. Current primary end points used in SLE trials are based on legacy disease activity measures that were neither specifically designed for the clinical trial context, nor developed according to contemporary recommendations for clinical outcome assessments (COAs), such as that substantial patient input should be incorporated into their design. The Treatment Response Measure for SLE (TRM-SLE) Taskforce is a global collaboration of SLE clinician-academics, patients and patient representatives, industry partners and regulatory experts, established to realize the goal of developing a new COA for SLE clinical trials. The aim of this project is a novel COA designed specifically to measure treatment effects that are clinically meaningful to patients and clinicians, and intended for implementation in a trial end point that supports regulatory approval of novel therapeutic agents in SLE. This Consensus Statement reports the first outcomes of the TRM-SLE project, including a structured process for TRM-SLE development.

Baricitinib for systemic lupus erythematosus: a double-blind, randomised, placebo-controlled, phase 3 trial (SLE-BRAVE-I)

BACKGROUND

Baricitinib is an oral selective inhibitor of Janus kinase 1 and 2 approved for the treatment of rheumatoid arthritis, atopic dermatitis, and alopecia areata. In a 24-week phase 2 study in patients with systemic lupus erythematosus (SLE), baricitinib 4 mg significantly improved SLE disease activity compared with placebo. The objective of this trial was to evaluate the efficacy and safety of baricitinib in patients with active SLE in a 52-week phase 3 study.

METHODS

In a multicentre, double-blind, randomised, placebo-controlled, parallel-group, phase 3 study, SLE-BRAVE-I, patients (aged ≥18 years) with active SLE receiving stable background therapy were randomly assigned 1:1:1 to baricitinib 4 mg, 2 mg, or placebo once daily for 52 weeks with standard of care. Glucocorticoid tapering was encouraged but not required per protocol. The primary endpoint was the proportion of patients reaching an SLE Responder Index (SRI)-4 response at week 52 in the baricitinib 4 mg treatment group compared with placebo. The primary endpoint was assessed by logistic regression analysis with baseline disease activity, baseline corticosteroid dose, region, and treatment group in the model. Efficacy analyses were done on a modified intention-to-treat population, comprising all participants who were randomly assigned and received at least one dose of investigational product. Safety analyses were done on all randomly assigned participants who received at least one dose of investigational product and who did not discontinue from the study for the reason of lost to follow-up at the first post-baseline visit. This study is registered with ClinicalTrials.gov, NCT03616912.

FINDINGS

760 participants were randomly assigned and received at least one dose of baricitinib 4 mg (n=252), baricitinib 2 mg (n=255), or placebo (n=253). A significantly greater proportion of participants who received baricitinib 4 mg (142 [57%]; odds ratio 1·57 [95% CI 1·09 to 2·27]; difference with placebo 10·8 [2·0 to 19·6]; p=0·016), but not baricitinib 2 mg (126 [50%]; 1·14 [0·79 to 1·65]; 3·9 [-4·9 to 12·6]; p=0·47), reached SRI-4 response compared with placebo (116 [46%]). There were no significant differences between the proportions of participants in either baricitinib group reaching any of the major secondary endpoints compared with placebo, including glucocorticoid tapering and time to first severe flare. 26 (10%) participants receiving baricitinib 4 mg had serious adverse events, 24 (9%) participants receiving baricitinib 2 mg, and 18 (7%) participants receiving placebo. The safety profile of baricitinib in participants with SLE was consistent with the known baricitinib safety profile.

INTERPRETATION

The primary endpoint in this study was met for the 4 mg baricitinib group. However, key secondary endpoints were not. No new safety signals were observed.

FUNDING

Eli Lilly and Company.

Baricitinib for systemic lupus erythematosus: a double-blind, randomised, placebo-controlled, phase 3 trial (SLE-BRAVE-II)

BACKGROUND

Baricitinib is an oral selective inhibitor of Janus kinase 1 and 2 approved for the treatment of rheumatoid arthritis, atopic dermatitis, and alopecia areata. In a 24-week phase 2 study in patients with systemic lupus erythematosus (SLE), baricitinib 4 mg significantly improved SLE disease activity compared with placebo. In this Article, we report the evaluation of efficacy and safety of baricitinib in patients with SLE in a 52-week phase 3 study.

METHODS

In this phase 3 double-blind, randomised, placebo-controlled study, SLE-BRAVE-II, patients (aged ≥18 years) with active SLE receiving stable background therapy were randomly assigned 1:1:1 to baricitinib 4 mg, baricitinib 2 mg, or placebo once daily for 52 weeks. The primary endpoint was the proportion of patients with an SLE Responder Index (SRI)-4 response at week 52 in the baricitinib 4 mg treatment group compared with placebo. Glucocorticoid tapering was encouraged but not required per protocol. The primary endpoint was assessed by logistic regression analysis with baseline disease activity, baseline corticosteroid dose, region, and treatment group in the model. Efficacy analyses were done on an intention-to-treat population, comprising all participants who were randomly assigned and received at least one dose of investigational product and who did not discontinue from the study for the reason of lost to follow-up at the first post-baseline visit. Safety analyses were done on all randomly assigned participants who received at least one dose of investigational product and who did not discontinue. This study is registered with ClinicalTrials.gov, NCT03616964, and is complete.

FINDINGS

A total of 775 patients were randomly assigned and received at least one dose of baricitinib 4 mg (n=258), baricitinib 2 mg (n=261), or placebo (n=256). There was no difference in the primary efficacy outcome of the proportion of SRI-4 responders at week 52 between participants who received baricitinib 4mg (121 [47%]; odds ratio 1·07 [95% CI 0·75 to 1·53]; difference with placebo 1·5 [95% CI -7·1 to 10·2]), 2 mg (120 [46%]; 1·05 [0·73 to 1·50]; 0·8 [-7·9 to 9·4]) and placebo (116 [46%]). None of the major secondary endpoints, including glucocorticoid tapering and time to first severe flare, were met. Serious adverse events were observed in 29 (11%) participants in the baricitinib 4 mg group, 35 (13%) in the baricitinib 2 mg group, and 22 (9%) in the placebo group. The safety profile of baricitinib in patients with SLE was consistent with the known baricitinib safety profile.

INTERPRETATION

Although phase 2 data suggested baricitinib as a potential treatment for patients with SLE, which was supported in SLE-BRAVE-I, this result was not replicated in SLE-BRAVE-II. No new safety signals were observed.

FUNDING

Eli Lilly and Company.

Deucravacitinib, a Tyrosine Kinase 2 Inhibitor, in Systemic Lupus Erythematosus: A Phase II, Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVE

To assess the efficacy and safety of deucravacitinib, an oral, selective, allosteric inhibitor of TYK2, in a phase II trial in adult patients with active systemic lupus erythematosus (SLE).

METHODS

Adults with active SLE were enrolled from 162 sites in 17 countries. Patients (n = 363) were randomized 1:1:1:1 to receive deucravacitinib 3 mg twice daily, 6 mg twice daily, 12 mg once daily, or placebo. The primary end point was SLE Responder Index 4 (SRI-4) response at week 32. Secondary outcomes assessed at week 48 included SRI-4, British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) response, Cutaneous Lupus Erythematosus Disease Area and Severity Index 50 (CLASI-50), Lupus Low Disease Activity State (LLDAS), and improvements in active (swollen plus tender), swollen, and tender joint counts.

RESULTS

At week 32, the percentage of patients achieving SRI-4 response was 34% with placebo compared to 58% with deucravacitinib 3 mg twice daily (odds ratio [OR] 2.8 [95% confidence interval (95% CI) 1.5, 5.1]; P < 0.001 versus placebo), 50% with 6 mg twice daily (OR 1.9 [95% CI 1.0, 3.4]; P = 0.02 versus placebo), and 45% with 12 mg once daily (OR 1.6 [95% CI 0.8, 2.9]; nominal P = 0.08 versus placebo). Response rates were higher with deucravacitinib treatment for BICLA, CLASI-50, LLDAS, and joint counts compared to placebo. Rates of adverse events were similar across groups, except higher rates of infections and cutaneous events, including rash and acne, with deucravacitinib treatment. Rates of serious adverse events were comparable, with no deaths, opportunistic infections, tuberculosis infections, major adverse cardiovascular events, or thrombotic events reported.

CONCLUSION

Deucravacitinib treatment elicited higher response rates for SRI-4 and other end points compared with placebo, with an acceptable safety profile, in adult patients with active SLE.

Associations of improvement in laboratory tests with clinical outcomes in patients with active systemic lupus erythematosus: a multinational longitudinal cohort study

BACKGROUND

The selection and categorisation of laboratory tests in disease activity measures used within systemic lupus erythematosus (SLE) trial endpoints lack strong evidence. We aimed to determine whether longitudinal improvements in routinely measured laboratory tests are associated with measures of clinical improvement in patients with baseline active SLE.

METHODS

We included patients from a multicentre longitudinal cohort (recruited between May 1, 2013, and Dec 31, 2019) with active SLE (SLEDAI-2K ≥6) coinciding with an abnormality in at least one of 13 routine laboratory tests, at a visit designated as baseline. At 12 months, we analysed associations between thresholds of improvement in individual laboratory test results, measured as continuous variables, and five clinical outcomes using logistic regression. Primary outcomes were damage accrual and lupus low disease activity state (LLDAS), and secondary outcomes were modified SLE responder index (mSRI), physician global assessment (PGA) improvement of at least 0·3, and flare.

FINDINGS

We included 1525 patients (1415 [93%] women and 110 [7%] men, 1328 [87%] Asian ethnicity) in separate subsets for each laboratory test. The strongest associations with LLDAS and damage protection were seen with improvements in proteinuria (complete response: adjusted odds ratio [OR] 62·48, 95% CI 18·79-208·31 for LLDAS, OR 0·22, 95% CI 0·10-0·49 for damage accrual), albumin (complete response: adjusted OR 6·46, 95% CI 2·20-18·98 for LLDAS, OR 0·42, 95% CI 0·20-1·22 for damage accrual), haemoglobin (complete response: adjusted OR 1·97, 95% CI 1·09-3·53 for LLDAS, OR 0·33, 95% CI 0·15-0·71 for damage accrual), erythrocyte sedimentation rate (complete response: adjusted OR 1·71, 95% CI 1·10-2·67 for LLDAS, OR 0·53, 95% CI 0·30-0·94 for damage accrual), and platelets (complete response: adjusted OR 4·82, 95% CI 1·54-15·07 for LLDAS, OR 0·49, 95% CI 0·20-1·19 for damage accrual). Improvement in serological tests were mainly associated with PGA and mSRI. White cell and lymphocyte count improvements were least predictive.

INTERPRETATION

Improvements in several routine laboratory tests correspond with clinical outcomes in SLE over 12 months. Tests with the strongest associations were discrepant with laboratory tests included in current trial endpoints, and associations were observed across a range of improvement thresholds including incomplete resolution. These findings suggest the need to revise the use of laboratory test results in SLE trial endpoints.

FUNDING

Abbvie.

Long-Term Clinical Outcome in Systemic Lupus Erythematosus Patients Followed for More Than 20 Years: The Milan Systemic Lupus Erythematosus Consortium (SMiLE) Cohort

Tackling active disease to prevent damage accrual constitutes a major goal in the management of patients with systemic lupus erythematosus (SLE). Patients with early onset disease or in the early phase of the disease course are at increased risk of developing severe manifestations and subsequent damage accrual, while less is known about the course of the disease in the long term. To address this issue, we performed a multicentre retrospective observational study focused on patients living with SLE for at least 20 years and determined their disease status at 15 and 20 years after onset and at their last clinical evaluation. Disease activity was measured through the British Isles Lupus Assessment Group (BILAG) tool and late flares were defined as worsening in one or more BILAG domains after 20 years of disease. Remission was classified according to attainment of lupus low-disease-activity state (LLDAS) criteria or the Definitions Of Remission In SLE (DORIS) parameters. Damage was quantitated through the Systemic Lupus Erythematosus International Collaborating Clinics/American College of Rheumatology damage index (SLICC/ACR-DI). LLAS/DORIS remission prevalence steadily increased over time. In total, 84 patients had a late flare and 88 had late damage accrual. Lack of LLDAS/DORIS remission status at the 20 year timepoint (p = 0.0026 and p = 0.0337, respectively), prednisone dose ≥ 7.5 mg (p = 9.17 × 10−5) or active serology (either dsDNA binding, low complement or both; p = 0.001) were all associated with increased late flare risk. Late flares, in turn, heralded the development of late damage (p = 2.7 × 10−5). These data suggest that patients with longstanding SLE are frequently in remission but still at risk of disease flares and eventual damage accrual, suggesting the need for tailored monitoring and therapeutic approaches aiming at effective immunomodulation besides immunosuppression, at least by means of steroids.

Concordance and discordance in SLE clinical trial outcome measures: analysis of three anifrolumab phase 2/3 trials

Objectives

In the anifrolumab systemic lupus erythematosus (SLE) trial programme, there was one trial (TULIP-1) in which BILAG-based Composite Lupus Assessment (BICLA) responses favoured anifrolumab over placebo, but the SLE Responder Index (SRI(4)) treatment difference was not significant. We investigated the degree of concordance between BICLA and SRI(4) across anifrolumab trials in order to better understand drivers of discrepant SLE trial results.

Methods

TULIP-1, TULIP-2 (both phase 3) and MUSE (phase 2b) were randomised, 52-week trials of intravenous anifrolumab (300 mg every 4 weeks, 48 weeks; TULIP-1/TULIP-2: n=180; MUSE: n=99) or placebo (TULIP-1: n=184, TULIP-2: n=182; MUSE: n=102). Week 52 BICLA and SRI(4) outcomes were assessed for each patient.

Results

Most patients (78%–85%) had concordant BICLA and SRI(4) outcomes (Cohen’s Kappa 0.6–0.7, nominal p<0.001). Dual BICLA/SRI(4) response rates favoured anifrolumab over placebo in TULIP-1, TULIP-2 and MUSE (all nominal p≤0.004). A discordant TULIP-1 BICLA non-responder/SRI(4) responder subgroup was identified (40/364, 11% of TULIP-1 population), comprising more patients receiving placebo (n=28) than anifrolumab (n=12). In this subgroup, placebo-treated patients had lower baseline disease activity, joint counts and glucocorticoid tapering rates, and more placebo-treated patients had arthritis response than anifrolumab-treated patients.

Conclusions

Across trials, most patients had concordant BICLA/SRI(4) outcomes and dual BICLA/SRI(4) responses favoured anifrolumab. A BICLA non-responder/SRI(4) responder subgroup was identified where imbalances of key factors driving the BICLA/SRI(4) discordance (disease activity, glucocorticoid taper) disproportionately favoured the TULIP-1 placebo group. Careful attention to baseline disease activity and monitoring glucocorticoid taper variation will be essential in future SLE trials.

Trial registration numbers

NCT02446912 and NCT02446899.

'Not at target': prevalence and consequences of inadequate disease control in systemic lupus erythematosus-a multinational observational cohort study

Background

The unmet need in systemic lupus erythematosus (SLE) with the current standard of care is widely recognised, but few studies have quantified this. The recent definition of treat-to-target endpoints and other thresholds of uncontrolled disease activity provide an opportunity to formally define unmet need in SLE. In this study, we enumerated the prevalence of these states and examined their association with adverse outcomes.

Methods

Data were collected prospectively in a 13-country longitudinal SLE cohort between 2013 and 2019. Unmet need was defined as never attaining lupus low disease activity state (LLDAS), a time-adjusted mean SLEDAI-2K (AMS) > 4, or ever experiencing high disease activity status (HDAS; SLEDAI-2K ≥10). Health-related quality of life (HRQoL) was assessed using SF36 (v2) and damage accrual using the SLICC-ACR SLE Damage Index (SDI).

Results

A total of 3384 SLE patients were followed over 30,313 visits (median [IQR] follow-up 2.4 [0.4, 4.3] years). Eight hundred thirteen patients (24%) never achieved LLDAS. Median AMS was 3.0 [1.4, 4.9]; 34% of patients had AMS > 4. Twenty-five per cent of patients had episodes of HDAS. Each of LLDAS-never, AMS>4, and HDAS-ever was strongly associated with damage accrual, higher glucocorticoid use, and worse HRQoL. Mortality was significantly increased in LLDAS-never (adjusted HR [95% CI] = 4.98 [2.07, 12.0], p<0.001) and HDAS-ever (adjusted hazard ratio (HR) [95% CI] = 5.45 [2.75, 10.8], p<0.001) patients.

Conclusion

Failure to achieve LLDAS, high average disease activity, and episodes of HDAS were prevalent in SLE and were significantly associated with poor outcomes including organ damage, glucocorticoid exposure, poor quality of life, and mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02756-3.

Measurement of specific organ domains in lupus randomised controlled trials: a scoping review

OBJECTIVE

Randomised controlled trials (RCTs) in systemic lupus erythematosus (SLE, lupus) typically adopt composite responder definitions as primary efficacy endpoints, however outcomes within individual organ domains are also important to understand. The aim of this scoping review was to evaluate how organ-specific disease activity and therapeutic responses have been measured and reported in lupus RCTs.

METHODS

We searched MEDLINE, EMBASE, Cochrane registry and clinicaltrials.gov. Eligible studies were RCTs investigating efficacy of an immune-directed drug therapy in active SLE, published January 2000-March 2021, excluding studies limited to lupus nephritis. Data were extracted independently in duplicate into a template and summarised descriptively.

RESULTS

Thirty-four RCTs were included, of which 32 (94%) reported activity and/or responses in at least one organ domain. Study populations had a high, although variable, frequency of baseline musculoskeletal and mucocutaneous activity and low but also variable representation of other domains. Definitions of organ-specific responses were inconsistent, even within individual instruments. Response in most organ domains were evaluated using BILAG and SLEDAI components but meaningful comparison between treatment arms was limited by small subgroups analysed in a post hoc fashion. Specific mucocutaneous and arthritis instruments were also used, including within pre-specified organ-specific endpoints, which discriminated between treatment arms in some studies.

CONCLUSION

Mucocutaneous and musculoskeletal manifestations predominate in SLE RCTs. Organ-specific outcome measures are commonly reported, but definitions of involvement and response are inconsistent. Research into the development of new outcome measures for key organ domains, and validation and comparison of response definitions using existing instruments, is needed.