Risankizumab versus Ustekinumab for Moderate-to-Severe Plaque Psoriasis.

BACKGROUND: Interleukin-23 is thought to be critical to the pathogenesis of psoriasis. We compared risankizumab (BI 655066), a humanized IgG1 monoclonal antibody that inhibits interleukin-23 by specifically targeting the p19 subunit and thus prevents interleukin-23 signaling, and ustekinumab, an interleukin-12 and interleukin-23 inhibitor, in patients with moderate-to-severe plaque psoriasis. METHODS: We randomly assigned a total of 166 patients to receive subcutaneous injections of risankizumab (a single 18-mg dose at week 0 or 90-mg or 180-mg doses at weeks 0, 4, and 16) or ustekinumab (45 or 90 mg, according to body weight, at weeks 0, 4, and 16). The primary end point was a 90% or greater reduction from baseline in the Psoriasis Area and Severity Index (PASI) score at week 12. RESULTS: At week 12, the percentage of patients with a 90% or greater reduction in the PASI score was 77% (64 of 83 patients) for risankizumab (90-mg and 180-mg groups, pooled), as compared with 40% (16 of 40 patients) for ustekinumab (P<0.001); the percentage of patients with a 100% reduction in the PASI score was 45% in the pooled 90-mg and 180-mg risankizumab groups, as compared with 18% in the ustekinumab group. Efficacy was generally maintained up to 20 weeks after the final dose of 90 or 180 mg of risankizumab. In the 18-mg and 90-mg risankizumab groups and the ustekinumab group, 5 patients (12%), 6 patients (15%), and 3 patients (8%), respectively, had serious adverse events, including two basal-cell carcinomas and one major cardiovascular adverse event; there were no serious adverse events in the 180-mg risankizumab group. CONCLUSIONS: In this phase 2 trial, selective blockade of interleukin-23 with risankizumab was associated with clinical responses superior to those associated with ustekinumab. This trial was not large enough or of long enough duration to draw conclusions about safety. (Funded by Boehringer Ingelheim; ClinicalTrials.gov number, NCT02054481 ).

Phenotypic and functional analysis of EBV-specific memory CD8 cells in SLE.

T cell dysfunction has been described in systemic lupus erythematosus (SLE). However, the specific phenotype and function of antigen-specific CD8 cells is less clear. Here we determined phenotype and function of Epstein-Barr virus (EBV)-specific CD8 cells at the single-cell level in SLE. HLA-A2-restricted EBV-BMLF-1-specific CD8 cells were enumerated by flow cytometry using tetramers in SLE and healthy control subjects. Antigen-specific CD8 cells were analyzed for expression of differentiation, activation, proliferation, and anti-apoptotic markers. EBV-specific, other virus-specific (specific against a viral peptide pool consisting of cytomegalovirus, EBV and influenza virus peptides), and mitogen-induced CD8 cell function was assessed by INF-gamma ELISPOT assay. Frequencies of EBV-specific CD8 cells tended to be greater in SLE subjects than in healthy control subjects (p=0.07). While over 10% of EBV-specific CD8 cells were capable of producing IFN-gamma in four out of five healthy control subjects, such proportions of EBV-specific CD8 cells capable of IFN-gamma production were observed in only one out of six SLE subjects (p=0.04). In contrast, viral peptide pool-specific and mitogen-induced IFN-gamma-producing T cell function was intact in SLE subjects. Phenotypic analysis revealed EBV-specific CD8 cells to be in an early to intermediate differentiation and resting memory state in both groups. While EBV-specific CD8 cells are similar in phenotype, their frequency tends to be increased, and function appears to be decreased in SLE. Therefore, an impaired EBV-specific CD8 immune response may exist in SLE, potentially contributing to disease pathogenesis.

Islet-cell antigen-reactive T cells show different expansion rates and Th1/Th2 differentiation in type 1 diabetic patients and healthy controls.

The low frequency of islet-cell antigen-reactive T cells in type 1 diabetes makes their direct measurement difficult. Commonly used in vitro expansion could alter in vivo frequencies and Th1/Th2 differentiation states. Using IFN-gamma/IL-4 double color ELISPOT, we tested longitudinally the reactivity of PBMC from HLA-matched diabetic patients and healthy controls to GAD65, IA-2, and proinsulin peptides ex vivo and after in vitro culture. The peptide-reactive T cells showed IFN-gamma bias in the patients' PBMC in the primary assay. During in vitro culture, both IFN-gamma- and IL-4-producing cells were induced in controls, suggesting that the precursor cells were uncommitted naive T cells in vivo. In contrast, in diabetic patients, the ex vivo IFN-gamma response was conserved during culture, suggesting their Th1 commitment. Using CFSE-dye-dilution, we demonstrate that naive T cells expand in vitro at a faster rate than memory cells, which might account for the differences in expansion rates between diabetic patients and controls.

Very low-dose tolerance with nucleosomal peptides controls lupus and induces potent regulatory T cell subsets.

We induced very low-dose tolerance by injecting lupus prone (SWR x NZB)F1 (SNF1) mice with 1 mug nucleosomal histone peptide autoepitopes s.c. every 2 wk. The subnanomolar peptide therapy diminished autoantibody levels and prolonged life span by delaying nephritis, especially by reducing inflammatory cell reaction and infiltration in kidneys. H4(71-94) was the most effective autoepitope. Low-dose tolerance therapy induced CD8+, as well as CD4+ CD25+ regulatory T (Treg) cell subsets containing autoantigen-specific cells. These adaptive Treg cells suppressed IFN-gamma responses of pathogenic lupus T cells to nucleosomal epitopes at up to a 1:100 ratio and reduced autoantibody production up to 90-100% by inhibiting nucleosome-stimulated T cell help to nuclear autoantigen-specific B cells. Both CD4+ CD25+ and CD8+ Treg cells produced and required TGF-beta1 for immunosuppression, and were effective in suppressing lupus autoimmunity upon adoptive transfer in vivo. The CD4+ CD25+ T cells were partially cell contact dependent, but CD8+ T cells were contact independent. Thus, low-dose tolerance with highly conserved histone autoepitopes repairs a regulatory defect in systemic lupus erythematosus by generating long-lasting, TGF-beta-producing Treg cells, without causing allergic/anaphylactic reactions or generalized immunosuppression.

CD28 costimulation enhances the sensitivity of the ELISPOT assay for detection of antigen-specific memory effector CD4 and CD8 cell populations in human diseases.

The frequencies of antigen-specific memory cells are often low in chronic disease states related to infection and autoimmunity, making detection of such populations difficult, even with high sensitivity assays such as the cytokine enzyme-linked immunospot (ELISPOT). The spectrum and function of antigen presenting cells (APC) in the peripheral compartment can differ considerably from the inflamed target organ. In order to approximate the costimulatory environment of the target organ, we measured T cell responses with and without the addition of agonistic anti-CD28 antibody in the ELISPOT assay. CD4 and CD8 IFN-gamma responses to viral (hepatitis C) and autoimmune antigens (islet cell) were tested in 10 hepatitis C and 8 type 1 diabetic as well as healthy control subjects. IFN-gamma responses to tetanus toxoid, mumps and cytomegalovirus (CMV) protein antigen, as well as Epstein-Barr virus and CMV peptides were also measured in healthy control subjects. We found higher frequencies of T cells reactive to protein and peptide antigens when anti-CD28 antibody was present, often detecting responses only in the presence of anti-CD28 antibody. These results demonstrate that anti-CD28 antibody signal enhanced ELISPOT assays can facilitate the identification of low precursor frequency T cells in chronic infectious and autoimmune disease states where suboptimal costimulatory environment may exist in the periphery. The use of such costimulation may also enable a more quantitative assessment of circulating memory effector T cell frequency.