Improved strategies for designing lupus trials with targeted therapies: learning from 65 years of experience

Improving resource utilisation in SLE drug development through innovative trial design

SLE is a complex autoimmune disease with considerable unmet need. Numerous clinical trials designed to investigate novel therapies are actively enrolling patients straining limited resources and creating inefficiencies that increase enrolment challenges. This has motivated investigators developing novel drugs and treatment strategies to consider innovative trial designs that aim to improve the efficiency of generating evidence; these strategies propose conducting fewer trials, involving smaller numbers of patients, while maintaining scientific rigour in safety and efficacy data collection and analysis. In this review we present the design of two innovative phase IIb studies investigating efavaleukin alfa and rozibafusp alfa for the treatment of SLE which use an adaptive study design. This design was selected as a case study, investigating efavaleukin alfa, in the Food and Drug Administration's Complex Innovative Trial Design Pilot Program. The adaptive design approach includes prospectively planned modifications at predefined interim timepoints. Interim assessments of futility allow for a trial to end early when the investigational therapy is unlikely to provide meaningful treatment benefits to patients, which can release eligible patients to participate in other-potentially more promising-trials, or seek alternative treatments. Response-adaptive randomisation allows randomisation ratios to change based on accumulating data, in favour of the more efficacious dose arm(s), while the study is ongoing. Throughout the trial the placebo arm allocation ratio is maintained constant. These design elements can improve the statistical power in the estimation of treatment effect and increase the amount of safety and efficacy data collected for the optimal dose(s). Furthermore, these trials can provide the required evidence to potentially serve as one of two confirmatory trials needed for regulatory approval. This can reduce the need for multiple phase III trials, the total patient requirements, person-exposure risk, and ultimately the time and cost of investigational drug development programmes.

Type I Interferons in Systemic Lupus Erythematosus: A Journey from Bench to Bedside

Dysregulation of type I interferons (IFNs) has been implicated in the pathogenesis of systemic lupus erythematosus (SLE) since the late 1970s. The majority of SLE patients demonstrate evidence of type I IFN pathway activation; however, studies attempting to address the relationship between type I IFN signature and SLE disease activity have yielded conflicting results. In addition to type I IFNs, type II and III IFNs may overlap and also contribute to the IFN signature. Different genetic backgrounds lead to overproduction of type I IFNs in SLE and contribute to the breakdown of peripheral tolerance by activation of antigen-presenting myeloid dendritic cells, thus triggering the expansion and differentiation of autoreactive lymphocytes. The consequence of the continuous stimulation of the immune system is manifested in different organ systems typical of SLE (e.g., mucocutaneous and cardiovascular involvement). After the discovery of the type I IFN signature, a number of different strategies have been developed to downregulate the IFN system in SLE patients, finally leading to the successful trial of anifrolumab, the second biologic to be approved for the treatment of SLE in 10 years. In this review, we will discuss the bench to bedside translation of the type I IFN pathway and put forward some issues that remain unresolved when selecting SLE patients for treatment with biologics targeting type I IFNs.

A promising approach to targeting type 1 IFN in systemic lupus erythematosus

Despite advances in understanding systemic lupus erythematosus (SLE) pathogenesis, most clinical trials of new targeted therapies have been met with disappointment. The type I IFN pathway is believed to play an important role in SLE, and the proposed involvement of this pathway helps explain the frustration behind the failure at targeting either IFN-α or the type 1 IFN receptor itself. In this issue of the JCI, Furie et al. report on an intriguing phase 1b study that demonstrates an approach for inhibiting this pathway in the skin using an mAB (BIIB059) that targets the blood DC antigen 2 (BDCA-2) receptor on plasmacytoid DCs (pDCs). BIIB059 decreased IFN expression and improved cutaneous lupus disease activity, with a favorable safety profile. Whether or not this strategy will be effective in managing SLE in other organs remains unanswered. However, these results suggest that closing the door on targeting the type 1 IFN pathway in SLE may be premature and highlight the emerging question of whether an organ-specific approach toward lupus trials and treatment should be the wave of the future.

Current challenges in the development of new treatments for lupus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a considerable impact on patients' quality of life. Despite the plethora of clinical trials for SLE since the turn of the millennium, only one new treatment has been approved for the condition, and the overall pace of successful drug development remains slow. Nevertheless, the myriad of clinical studies has yielded insights that have informed and refined our understanding of eligibility criteria, outcome measures and trial design in SLE. In this review, we highlight the achievements of clinical trials as well as the major pitfalls that have been identified in drug development for SLE and, in doing so, identify areas where collaboration and consensus will be important to facilitate progress.