Recent advances in the biologic therapy of lupus: the 10 most important areas to look for common pitfalls in clinical trials

Signaling Pathways of Type I and Type III Interferons and Targeted Therapies in Systemic Lupus Erythematosus

Type I and type III interferons (IFNs) share several properties in common, including the induction of signaling pathways, the activation of gene transcripts, and immune responses, against viral infection. Recent advances in the understanding of the molecular basis of innate and adaptive immunity have led to the re-examination of the role of these IFNs in autoimmune diseases. To date, a variety of IFN-regulated genes, termed IFN signature genes, have been identified. The expressions of these genes significantly increase in systemic lupus erythematosus (SLE), highlighting the role of type I and type III IFNs in the pathogenesis of SLE. In this review, we first discussed the signaling pathways and the immunoregulatory roles of type I and type III IFNs. Next, we discussed the roles of these IFNs in the pathogenesis of autoimmune diseases, including SLE. In SLE, IFN-stimulated genes induced by IFN signaling contribute to a positive feedback loop of autoimmunity, resulting in perpetual autoimmune inflammation. Based on this, we discussed the use of several specific IFN blocking strategies using anti-IFN-α antibodies, anti-IFN-α receptor antibodies, and IFN-α-kinoid or downstream small molecules, which intervene in Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathways, in clinical trials for SLE patients. Hopefully, the development of novel regimens targeting IFN signaling pathways will shed light on promising future therapeutic applications for SLE patients.

Lessons learned from the failure of several recent trials with biologic treatment in systemic lupus erythematosus

INTRODUCTION

Treatment of systemic lupus erythematosus (SLE) represents a challenge due to variable disease manifestations, clinical course, and outcome. Long-term outcome in SLE remain unsatisfactory and a search for new therapeutic options is definitely warranted. Despite expectations, most clinical trials performed in SLE and lupus nephritis in the last decade did not reach primary outcome, and the only drug that has been licensed is belimumab.

AREAS COVERED

Results of negative trials testing monoclonal antibodies and other biologic agents in SLE are briefly summarized. Reasons for the failure of the trials are listed and discussed.

EXPERT OPINION

Future studies should recruit patients with similar organ involvement, better defined disease manifestations, higher activity, and similar severity. In addition to testing higher efficacy if given as add-on treatment to standard-of-care, the trials should be aimed at reducing dosing, or completely eliminating some parts of the current standard treatment, especially corticosteroids. Median follow-up of the patients should be longer. Moreover, specific biomarkers are needed to help to identify eligible patients and to better define response to treatment. An urgent unmet need is testing these new drugs in patients with severe SLE (including those refractory to current treatment).

Current and future therapies for SLE: obstacles and recommendations for the development of novel treatments

SLE is a serious, debilitating autoimmune disease that affects various organs and body systems. Of all the heterogeneous autoimmune diseases, SLE is perhaps the most heterogeneous. Patients with SLE, who are primarily female, have diverse disease manifestations and severity. SLE is characterised by substantial concentrations of autoantibodies against nuclear antigens, which are thought to be caused by immune cell dysregulation. Until recently, several immunosuppressant agents were used to treat this disease. Efforts to develop drugs against targets potentially involved in disease mechanisms have resulted in the identification and use of BAFF (B-cell activating factor)/APRIL (a proliferation-inducing ligand) inhibitors to treat SLE. Drugs in late-stage development that focus on pathways that are dysregulated in SLE include those that target the interferon pathway, T-cell signalling and B-cell signalling. New therapeutic agents are still necessary because of the unmet medical needs associated with this disease, including insufficient disease control, poor health-related quality of life, comorbidities, toxicity of the majority of therapies and diminished survival. Despite the substantial long-term investment of research, clinical activity and resources for identifying new treatments for this disease, only one new therapy, the biological belimumab, has been approved in the past 50 years. Efforts to develop drugs to address these needs are challenged by problems associated with disease heterogeneity, variable disease mechanisms and trial design. This review provides an overview of current and future treatments, discusses challenges in the SLE drug development process and offers recommendations for overcoming these challenges.