**2.4 Biologics**

Biologic drugs currently incorporated in SLE treatment are rituximab [87–89] and belimumab [90–93] (**Figure 1**). The sequential use of rituximab and belimumab is also under investigation [94, 95]. Other biologic agents targeting the B lymphocyte have also been applied [96]. Various biologic drugs have been used in treatment regimens for SLE patients with poor response or side effects to standard treatment [97]. The original goal of biologics was to induce disease remission and establish self-tolerance [98, 99]. This goal has not been achieved. It may be that the heterogeneity of disease mechanisms inherent in SLE may guide the introduction of cell- and cytokine- or pathway specific therapies which will be effective in various subgroups of SLE patients [97].
