Is B Cell-Targeted Therapy Effective in Systemic Lupus Erythematosus?

In the past decade we have witnessed a dramatic change in the management of autoimmune diseases, such as rheumatoid arthritis, due to the development of new biologic drugs designed to target key mediators in the autoimmune process. However, the development of similar target-specific drugs for the management of SLE has not been as successful. The B cell has long been considered central to the pathogenesis of SLE and has been regarded as an important target for biologic drugs. Several B cell-targeted drugs have been developed and although the mechanisms seem promising, most of the studies published to date have failed to achieve their primary endpoints, leading to an ongoing debate regarding the role of B cell therapy in SLE. The present report discusses the pros and cons of B cell-targeted therapy in SLE, reviews the clinical studies, and offers possible explanations forthe discrepancies between randomized control studies and real-life experience.

In-/off-label use of biologic therapy in systemic lupus erythematosus.

Current therapies for systemic lupus erythematosus (SLE) include corticosteroids as a persistent mainstay and traditional immunosuppressants which are given according to disease severity, organ involvement and patient status. No treatment entails certain efficacy devoid of mild-to-moderate adverse effects. Nowadays, novel therapies are being developed aiming to target specific molecules involved in SLE development and progression which show variable effectiveness and safety. Biologic agents considered for SLE comprise monoclonal antibodies (chimeric, humanized or fully human) as well as fusion molecules or antibody fragments mostly consisting of B cell-targeted therapies beside anti-cytokines as well as T cell-targeted therapies. Encouraging evidence on biologics is mostly provided by case series or uncontrolled studies; conversely, larger randomized controlled clinical trials have frequently missed their primary endpoints with the exception of BLISS-52 and BLISS-76 trials. Actually, apart from belimumab, biologics are employed in clinical practice as off-label treatments for lupus and results are often promising, depending on specific SLE features, dose regimens and individual responsiveness.

Amphipathic weak acid glucocorticoid prodrugs remote-loaded into sterically stabilized nanoliposomes evaluated in arthritic rats and in a Beagle dog: a novel approach to treating autoimmune arthritis.

OBJECTIVE: The use of glucocorticoids (GCs) in rheumatoid arthritis is limited by side effects related to unfavorable pharmacokinetics and biodistribution. Liposomal GC formulations have been studied since the 1970s in an attempt to overcome this obstacle, but none has entered clinical use. We undertook this study to determine whether a novel approach could overcome the limitations that have thus far prevented the clinical use of these formulations: low drug:lipid ratio, low encapsulation efficiency, and lack of controlled release. METHODS: We used approximately 80-nm sterically stabilized (pegylated) nanoliposomes (NSSLs), which were remote-loaded with an amphipathic weak acid GC (such as methyl prednisolone hemisuccinate) utilizing an intraliposome (aqueous compartment)-high/extraliposome (bulk medium)-low transmembrane calcium acetate gradient. This unique method actually "traps" the GC in the liposomal aqueous phase as a calcium-GC precipitate. RESULTS: Our liposome formulation exhibited high encapsulation efficiency (94%) and a high drug:lipid mole ratio (0.41) and demonstrated controlled release of the encapsulated GC during systemic circulation and in inflamed paws in rats with adjuvant-induced arthritis. In addition, both in arthritic rats and in a Beagle dog, we showed the pharmacokinetic advantage of using liposomes as GC carriers. Finally, we demonstrated the superior therapeutic efficacy of our liposome formulation over that of free GCs in arthritic rats, both in early and in peak disease stages. CONCLUSION: Amphipathic weak acid GCs remote-loaded into approximately 80-nm NSSLs overcome past limitations of liposomal GC formulations. The unique loading method, which also leads to controlled release, improves the therapeutic effect both systemically and locally. Such a development has great potential for improving GC therapy.