Rituximab: the Lupus Journey

Targeted Therapy for SLE-What Works, What Doesn't, What's Next

For many years, the failure of randomized controlled trials (RCTs) has prevented patients with systemic lupus erythematosus (SLE) from benefiting from biological drugs that have proved to be effective in other rheumatological diseases. Only two biologics are approved for SLE, however they can only be administered to a restricted proportion of patients. Recently, several phase II RCTs have evaluated the efficacy and safety of new biologics in extra-renal SLE and lupus nephritis. Six drug trials have reported encouraging results, with an improvement in multiple clinical and serological outcome measures. The possibility of combining B-cell depletion and anti-BLyS treatment has also been successfully explored.

Initial Preserved Renal Function as a Predictor of Favorable Renal Response to Rituximab in Refractory or Relapsing Lupus Nephritis: A Single-center Cohort Study in Korea

OBJECTIVE

Previous studies investigating the beneficial effect of rituximab on lupus nephritis (LN) reported controversial results There have been few reports of renal response to rituximab according to renal function We investigated the efficacy of rituximab in refractory/relapsing LN and the role of renal function as a predictor of renal response.

METHODS

From 2016 to 2019, we retrospectively reviewed 22 patients with refractory/relapsing LN receiving rituximab Renal responses (complete and partial) at 6 and 12 months were compared between normal (glomerular filtration rate [GFR]≥90 mL/min/173 m², n=11) and decreased (GFR<90 mL/min/173 m², n=11) GFR groups Multivariate Cox regression analysis was used to assess predictors of renal response.

RESULTS

At baseline, the decreased GFR group had a higher urine proteinuria to creatinine ratio (p=0008) and proportion of refractory LN (p=0010) and previous cyclophosphamide therapy (p=0035) than the normal GFR group The overall renal response rate was 455% (10 patients) at 6 months and 545% (12 patients) at 12 months Renal response rates were higher in the normal GFR group (818% and 909% at 6 and 12 months, respectively) than in the decreased GFR group (91% and 182% at 6 and 12 months, respectively; p<0001) Normal GFR and anti-La were associated with renal response to rituximab, with hazard ratios of 9256 (p=0008) and 5478 (p=0041), respectively.

CONCLUSION

Rituximab is an effective therapy for refractory/relapsing LN, particularly in patients with preserved renal function.

New developments in systemic lupus erythematosus

In this review, the results of recent and ongoing clinical trials in patients with SLE are discussed. After many unsuccessful trials in the past decade, belimumab was the first biologic specifically designed for SLE that met its primary end point. At the same time, studies on the pathophysiology of SLE have further elucidated the pathways involved in the disease, which has led to the identification of new possible therapeutics and has encouraged the initiation of new trials. These new drugs include biologics that target B cells, T cells and type 1 interferons, and small molecules that inhibit kinases. Other therapeutics aim to restore immunological balance by restoring tolerance. Results from phase II and even phase III trials are promising and it is likely that some of the therapeutics discussed will receive approval in the following years. Hopefully, this will allow for more tailor-made medicine for SLE patients in the future.

Anti-IFNαR Mabs for the treatment of systemic lupus erythematosus

INTRODUCTION

The type 1 interferon pathway is known to play a role in the immunopathology of systemic lupus erythematosus (SLE). As a result, biologic agents targeting this pathway have been developed and are currently being investigated in clinical trials.

AREAS COVERED

We review the biologic agents which have been developed to antagonize type I interferons in SLE. We focus on anifrolumab, a type I interferon receptor antagonist, and consider the complexities of defining efficacy in SLE clinical trials.

EXPERT OPINION

Anifrolumab shows promise as an addition to the SLE therapeutic armamentarium. Despite discordant results between its two phase III studies, there is a convincing suggestion of benefit in both trials to encourage the view that this approach might be effective. Data acquired thus far look particularly useful for cutaneous disease. We await data on its effect on renal, pulmonary, cardiac, and central nervous system involvement, on patient reported outcomes, and its safety and efficacy with long-term use.

New therapies for systemic lupus erythematosus - past imperfect, future tense

The failure of many new, mostly biologic, drugs to meet their primary end points in double-blind clinical trials in patients with systemic lupus erythematosus (SLE) has caused a profound sense of disappointment among both physicians and patients. Arguably, the success of B cell depletion with rituximab in open-label clinical trials, the approval of belimumab (which blocks B cell-activating factor (BAFF)) for use in patients with lupus nephritis in the USA and in difficult-to-treat patients with SLE in the UK and the recognition that clinical trial design can be improved have given some cause for hope. However, changes to therapies in current use and the development of new approaches are urgently needed. The results of the latest studies investigating the use of several new approaches to treating SLE are discussed in this Review, including: fully humanized anti-CD20 and anti-CD19 monoclonal antibodies; inhibition of tyrosine-protein kinase BTK; CD40 ligand blockade; interfering with the presentation of antigen to autoreactive T cells using a peptide approach; a receptor decoy approach using an analogue of Fcγ receptor IIB; dual blockade of IL-12 and IL-23; and inhibition of Janus kinases.

Adverse infusion reactions to rituximab in systemic lupus erythematosus: a retrospective analysis

Background

To undertake a retrospective review of patients with SLE who had received Rituximab in order to determine the rates and associated patient characteristics of clinically significant adverse infusion reactions.

Methods

A descriptive analysis was undertaken of each infusion reaction, which was then assessed using the clinical information available to hypothesise on the possible underlying mechanism(s).

Results

Records of 136 SLE patients previously treated with 481 individual infusions of Rituximab were reviewed. A total of 22 patients (17.6%) had 28 (5.8% of total infusions) documented clinically significant adverse infusion reactions. Average age at first Rituximab infusion in patients without a reaction was 37 years (range 16–73) compared with 30 years (range 18–56) in those with a reaction. A high proportion of men (18.2%) experienced an infusion reaction. Severity and type of reaction varied. 6.4% of those who had a reaction were not retreated.

Conclusions

While Rituximab remains an important tool in the treatment of SLE it is important to be aware that rates of infusion reactions may be more significant in SLE than in other diseases. A prospective study is required to better characterise the reactions.

Efficacy and safety of anti-CD20 antibody rituximab for patients with refractory systemic lupus erythematosus

Objective

We examined the efficacy and safety of rituximab in patients with refractory systemic lupus erythematosus (SLE).

Methods

The study enrolled 63 SLE patients who were treated with rituximab between 2002 and 2015. The participants underwent a battery of tests before treatment and at one year. Treatment ranged from two to four times at 500 or 1000 mg.

Results

Baseline characteristics were males:females = 6:57, age 33.9 years, and disease duration 87.2 months. The primary endpoint: The rate of major clinical response (MCR) was 60% while the partial clinical response (PCR) was 25%. Thirty of 36 (83%) patients with lupus nephritis (WHO II: 2, III: 5, IV: 22, V: 4, IV+V: 2, not assessed: 1) and 22 of 24 patients (92%) with neuropsychiatric SLE, who could be followed at one year, showed changes from BILAG A or B score to C or D score at one year. Multivariate analysis identified high anti-dsDNA antibody and shorter disease duration as significant determinants of MCR at one year. Repeat examination was conducted at five years. Primary failure was recorded in 8.8% and secondary failure in 32.4% (time to relapse: 24.4 months). Rituximab was well tolerated although 65 adverse events, mostly infections, were recorded within one year.

Conclusion

Rituximab is potentially efficacious for the treatment of patients with refractory SLE.

Improving B-cell depletion in systemic lupus erythematosus and rheumatoid arthritis

INTRODUCTION

Rituximab-based B-cell depletion (BCD) therapy is effective in refractory rheumatoid arthritis (RA) and although used to treat patients with refractory systemic lupus erythematosus (SLE) in routine clinical practice, rituximab failed to meet the primary endpoints in two large randomised controlled trials (RCTs) of non-renal (EXPLORER) and renal (LUNAR) SLE. Areas covered: We review how BCD could be improved to achieve better clinical responses in RA and SLE. Insights into the variability in clinical response to BCD in RA and SLE may help develop new therapeutic strategies. To this end, a literature search was performed using the following terms: rheumatoid arthritis, systemic erythematosus lupus, rituximab and B-cell depletion. Expert commentary: Poor trial design may have, at least partly, contributed to the apparent lack of response to BCD in the two RCTs of patients with SLE. Enhanced B-cell depletion and/or sequential therapy with belimumab may improve clinical response at least in some patients with SLE.