Study overview
LUPUS-BEST is a prospective, multicentre, cluster-randomised trial that will enrol subjects across 15 study centres in Germany over a 4-year period. A schematic representation of the study design is presented in figure 1. The trial uses a cluster-randomised design, where the study centres will be randomly assigned 1:1:1 to either remission, LLDAS or standard of care (SoC). Patients with SLE above the age of 18 years will be screened end enrolled when eligible. With tight control and frequent treatment evaluations based on SDM, patients in the intervention arms will be treated to target and the primary outcome will be assessed at week 120, the end of the trial.
Figure 1Trial flow chart. °Remission training; °°LLDAS training. *Remission: cSLEDAI-2K=0 and GC ≤5 mg/day and PGA <0.5; ±immunomodulatory therapy. **LLDAS: SLEDAI-2K ≤4 and GC ≤7.5 mg/day and PGA ≤1 and no new disease activity. ***Documentation of reason for T2T refusal. GC glucocorticoids; LLDAS Lupus Low Disease Activity State; PGA, Physician Global Assessment; SDM, shared decision-making; SLEDAI-2K, SLE Disease Activity Index 2000; T2T, treat-to-target.
The trial will primarily be conducted on a national level, however, international extension would be encouraged. Public funding has been applied for. In addition, contact to pharmaceutical sponsors has been established in order to sort out unrestricted financial support.
Patient population and eligibility
The trial is accessible to all patients with SLE in the participating centres classified according to validated criteria (EULAR/American College of Rheumatology (ACR) criteria,18 Systemic Lupus International Collaborating Clinics (SLICC) criteria19), above the age of 18 years, with written informed consent and sufficient German language skills, regardless of their disease manifestations to represent the broad variety of SLE manifestations and real-life data. Exclusion criteria are life-threatening SLE manifestations that require intensive care treatment; active life-threatening diseases other than SLE; and active malignancies as well as active, chronic or recurrent viral infection that, based on the investigators’ clinical assessment, make the subject an unsuitable candidate for the study, including hepatitis, HIV and tuberculosis. In case of pregnancy or breast feeding during the trial, the intervention will set on hold if recommended and the patient will be documented according to the trial protocol. These criteria allow for inclusion of the vast majority of patients with SLE treated in the participating centres and the study population will thus reflect and represent the whole spectrum of patients with SLE in real life in Germany. Patients of all genders and >18 years of age will be included, hence generalisability is expected to the majority of adult patients with SLE.
Interventions
T2T in SLE is defined by tight control in terms of frequent visits and treatment optimisation based on SDM aiming for patients with SLE to reach remission on treatment (arm 2) or a state of LDA (LLDAS, arm 3). Remission is defined as the lack of clinical disease activity, a steroid dosage of ≤5 mg prednisolone per day and a Physician Global Assessment (PGA) of the current disease activity of <0.5 on a numerical rating scale from 0 to 3.8 LLDAS is characterised by LDA with no new disease activity, a steroid dose of ≤7.5 mg prednisolone per day and a PGA ≤1.20
The study personnel in the intervention centres will receive 8 hours of standardised training on T2T and SDM. The training will take place in an interactive group format at each centre and will be performed by an experienced SDM expert and the study organisers who have been treating patients with SLE for 30 years and follow T2T approaches in other rheumatic diseases.
For this purpose, an approved SDM training format21 22 will be combined with established T2T approaches. It will integrate SLE-specific case vignettes and decision support materials (Patient Decision Aids, decision boards, treatment flow charts, risk charts) to be generated according to International Patient Decision Aid Standards criteria23 and in close feedback loops between rheumatologists, SDM experts, patients and patient representatives beforehand.
All patients with SLE in the participating centres will be invited to join the trial. Those enrolled in the study after being screened for eligibility and giving informed consent will be documented in a standardised manner at every visit during the total trial period of 120 weeks. Approved medications consist of antimalarials as basic therapy, GC and/or immune-modulating agents like methotrexate, azathioprine, mycophenolate, cyclophosphamide and/or belimumab as well as rituximab. Treatment decisions are made according to the physicians’ discretion and SDM based on Good Clinical Practice and may also include other drugs.
In the intervention centres, patients will be assessed for being in target at every visit. Patients already in target at the screening visit will be documented in a standardised manner in 12 weekly assessments if still in target at the baseline visit thus skipping the T2T loop and entering the follow-up phase at once. Patients who do not meet remission/LLDAS should receive a treatment adjustment based on SDM: (a) modification of the current immunomodulator(s) and/or (b) addition of a new immunomodulator and/or (c) adjustment of the current GC dosage. In case of GC adaption, a GC tapering scheme will be assigned for the upcoming 6 weeks.
Depending on the clinical situation and based on SDM, the target (remission/LLDAS) can be addressed by one or more tight-control loop(s). As exception from this standardised process, the option of no treatment adjustment is available but must be documented and explained. In case of high PGA as the only ‘non-targetable’ item, which encapsulates the overall disease activity, the reason(s) for high PGA must be documented and addressed.
All patients, who do not meet remission/LLDAS criteria and thus receive a treatment adjustment, will be reassessed every 6 weeks and treatment may be modified at every visit based on SDM. Tapering or dose increase schemes may be applied and lead to dosing modifications in-between the visits.
After 24 weeks of tight control, patients fulfilling remission/LLDAS for at least 6 weeks since the last visit will change to 12 weekly assessments. If remission/LLDAS is not achieved at week 24, tight control continues until (a) the target is achieved in two consecutive visits (with 6-week interval), (b) the end of study after 120 weeks, or (c) physician and patient agree to refuse T2T. If patients fulfilling remission/LLDAS flare as measured by the SLE Disease Activity Index Flare Index or miss the target at any time during follow-up, they will be invited to reassign to tight control and T2T for another 24-week loop. If T2T is refused, the patient will receive 12 weekly assessments with the option to start tight control any time later in case of agreement.
Patients in the LLDAS arm, who reach their target, do not have to be retained in LLDAS but can reach remission as well by, that is, further steroid taper or an improvement in PGA. Hence, these patients could reach remission by SoC. However, patients in target in the LLDAS arm should not receive a treatment intensification to reach remission.
Pharmaceutical treatment decisions will be guided by a decision scheme based on the recently updated EULAR recommendations17 and will be taken in accordance with SDM between patients and treating physicians (experienced rheumatologist or rheumatologist in training). In the intervention centres, all handling physicians have to be trained for T2T and SDM. The flexibility of the intervention scheme with the option to leave and re-enter tight control reflects clinical care, and presumably more patients will achieve the aimed target.
Study endpoints
Primary and secondary endpoints (figure 2) will be evaluated at 120 weeks. The major outcome is the reduction in damage accrual (SLICC/ACR Damage Index, SDI). The patients’ relevant major secondary endpoint will be the HRQoL (36-Item Short Form Survey, SF-36).
Figure 2Study endpoints. ACR, American College of Rheumatology; FACIT, Functional Assessment of Chronic Illness Therapy; LLDAS, Lupus Low Disease Activity State; MARS, Medication Adherence Report Scale; SDI, SLICC/ACR Damage Index; SDM, shared decision-making; SDM-Q-Doc, SDM Questionnaire-Physician"s version; SDM-Q-9, 9-item SDM Questionnaire; SFI, SLEDAI Flare Index; SF-36, 36-Item Short Form Survey; SLAQ, SLE Activity Questionnaire; SLEDAI-2K, SLE Disease Activity Index 2000; SLICC, Systemic Lupus International Collaborating Clinics; WPAI, Work Productivity and Activity Impairment Questionnaire.
Justification of design aspects
Control/comparators
SoC was chosen as control as it reflects the clinical routine and allows for direct comparison of T2T versus routine treatment. The targets remission on therapy (ROT) and LLDAS will be used as comparators. They symbolise different goals for disease control and bear challenges that are important to evaluate (eg, GC reduction, amount of immunosuppression).
Dose, mode and scheme of intervention
We chose a 6-week interval over a period of 24 weeks for patients not in target to enable frequent clinical and laboratory check-ups in order to identify endangering situations and allow for short-term therapeutic adjustments as the foundation of T2T. Patients need to be stable in target for at least 6 weeks after a minimum of 24 weeks of tight control before changing to 12 weekly visits. A phase of stable disease is crucial to reduce the risk of sudden flares between subsequent 12 weekly follow-ups. In case of a flare, physician and patient decide to enter another tight control phase of 24 weeks. As this is the first trial on T2T in SLE, adaptation from T2T studies in RA was intended. However, follow-up intervals in these trials were 4 or 12 weeks and thus either too short or too long for the complex and potentially organ-threatening SLE. Thus, we chose the 6 weekly study visits and 12 weekly follow-up visits on recommendations and eminence-based experience. The period of 24 weeks tight control allows for small adjustments and was chosen to prevent overtreatment and a forced remission/LLDAS as the target does not have to be reached by the next visit. The study aim should be relevant to patients. Therefore, damage as surrogate of long-term outcome and HRQoL as a patient-reported outcome were chosen as endpoints. Damage accrues slowly and over time in SLE and follow-up-times need to be longer in damage-focused SLE trials, than in usual studies. Hence, a follow-up time of 120 weeks was chosen to allow for the detection of a clinically significant difference in damage accrual between the groups. SDM is crucial in T2T as patients should have the opportunity to decide about changes in treatment. SDM includes the option to reject T2T; some patients have LDA that can only be controlled by GC dosages slightly above the allowed threshold. However, in these cases, options to reach the target should still be explored at every visit.
The flexibility of the trial with the option to leave and re-enter tight control reflects clinical care, and presumably more patients will achieve the aimed target. Given that the T2T strategy is used regularly in clinical care of patients with SLE, the study is not limited to an inception cohort like most T2T trials in RA. In consequence, the individual medical treatment cannot be prescribed according to standard protocol. Still, pharmaceutical treatment decisions will be guided by a decision scheme based on the recently updated EULAR recommendations.17
Inclusion/exclusion criteria
The broadly defined inclusion and exclusion criteria allow for inclusion of the vast majority of patients with SLE treated in the participating centres and the study population will thus reflect and represent the heterogeneity of patients with SLE in real life. Patients of all genders and >18 years of age will be included; hence, generalisability is expected to the majority of adult patients with SLE.
Outcome measures
The prevention of damage accumulation and improvement of HRQoL by controlling disease activity and limiting the use of harmful drugs are our major aims. Best long-term outcome surrogate for SLE is damage (captured by the SDI, a validated, disease-specific index used to analyse the effects of ROT and LLDAS13 24). Thus, the primary trial outcome will be the SDI increase between (a) ROT and SoC and (b) LLDAS and SoC after 120 weeks. HRQoL is the key secondary outcome (measured by SF-36), as HRQoL is considered the most relevant parameter for patients. Other relevant factors listed above allow the evaluation of efficacy and feasibility of different steps and aspects of T2T in SLE. In addition, blood samples for biomarkers will be taken at study entry, after target achievement and the end of the study and stored in a biobank. To characterise the content of a patient’s visit in T2T versus control group, the patients will answer a questionnaire after every physician contact.
Methods against bias
The trial uses a cluster-randomised design, where the study centres constitute the single clusters. That is, all patients within a single study centre will be in the same treatment group and treated identically. We decided against individual randomisation on the patient level because this comes with a double risk of contaminating the intervention effect. First, patients within the same study centre will interact with each other and exchange information about the frequency and content of their treatments before and after their visits, and potentially also about the idea of T2T. Second, SDM and T2T training will influence the treating physicians in their approach and attitude towards the patients and their decisions, an effect that cannot deliberately be ‘switched off’ when treating patients who had been randomised to the control group. In contrast, actively deciding against T2T and reaching remission/LLDAS when treating a patient in the control group will be almost impossible for the treating physicians. Potential baseline imbalances of study centres will be reduced by matching them in strata of size 3 before randomisation using centres’ characteristics like patient numbers, hospital care type, type of services, existence of a multidisciplinary team and regional characteristics thus maximising homogeneity of centres within a matching stratum while maximising heterogeneity across matching strata. Randomising centres to one of the treatments will then be performed within each matching stratum. Blinding of patients for their aim is impossible, as SDM is part of T2T. Nonetheless, provided information regarding trial design and targets will be standardised and kept to a minimum. To secure similarity across all intervention centres, standardised training is mandatory for all team members. Disease heterogeneity will be addressed by including a high number of patients with potentially every disease manifestation to obtain a representative study cohort. A data monitoring committee will regularly monitor recruitment and application of tight control and T2T and will communicate irregularities.
Sample size calculation
Sample size calculation was performed with respect to the primary endpoint, damage accrual as measured by the SDI, and was based on a two-tailed t-test (α=0.05) with Bonferroni adjustment for two comparisons (LLDAS vs SoC and remission vs SoC) and power of 80% (ß=0.2). We assumed an SD of the SDI of 0.89,25 and a minimal clinically relevant difference in SDI of 0.3 points. This reduction in SDI corresponds, for example, to prevent one out of three patients from damage accrual or to avoid failure or insufficiency of one organ out of three affected organs. The design effect (Deff) for cluster-randomised controlled studies was taken into account as described by Murray.26 For calculating Deff, an average cluster size of 70 patients and an intracluster correlation of 0.015 were assumed.27 Based on these assumptions, a sample size of 1060 study participants was calculated. To allow some moderate dropout (20%), 1272 participants split up into three treatment arms (ie, 424 patients per arm) will be included into the study.
Statistical analysis
The statistical analysis for the primary outcome will be accomplished within a hierarchical (mixed) model. This will include the SDI at week 120 as the outcome, the intervention as well as baseline SDI, age, disease duration and gender as covariates, and two random intercept effects (one for the matching/randomisation stratum and for the single study centre) to account for the hierarchical/clustered structure of data.26 Corresponding to the sample size calculation, the two primary comparisons (LLDAS vs SoC and remission vs SoC) will be confirmatorily tested to the 2.5% level to ensure overall type I control to the 5% level. Analyses will be performed following the intention-to-treat principle. Missing values will be accounted for by multiple imputation following the ideas and guideline of Sterne et al.28 There will be no planned interim analysis for efficacy and no confirmatory subgroup analyses. The secondary outcomes will be analysed analogous to the primary outcome by the corresponding hierarchical model.
Moreover, the study data will be analysed in an explanatory way by using different data science and machine learning-based approaches to reveal additional insights into the collected data and thereby to obtain potential vital design aspects, which could guide the future treatment of patients with SLE. The idea is to use machine learning especially in a hypothesis-free way to enable to identify new and relevant patterns and to formulate additional data-driven hypotheses for further studies. One important task will be to obtain subgroups of patients within each arm via the application of different supervised or unsupervised clustering and classification approaches. Different subgroups might have distinct characteristic profiles, for example, in relation to disease activity and patient-reported outcomes. Another research task will be to investigate via machine learning-based approaches whether the length of remission/LLDAS phases of a patient can be predicted based on the data being collected at different time points before the event occurs. This might deliver first hints in relation to visit frequencies for potential future studies.