Longterm Efficacy and Safety of Abatacept in Patients with Rheumatoid Arthritis Treated in Routine Clinical Practice: Effect of Concomitant Methotrexate after 24 Weeks

Objective.

Our study aimed to evaluate the longterm efficacy and safety of abatacept (ABA), and to explore factors that increase its longterm efficacy in patients with rheumatoid arthritis (RA) treated in routine clinical practice.

Methods.

There were 231 participants with RA treated with ABA who were prospectively registered in a Japanese multicenter registry. They were followed up for at least 52 weeks.

Results.

Mean age of the patients was 64.3 years, mean disease duration was 12.1 years, mean 28-joint Disease Activity Score (DAS28)-C-reactive protein was 4.49, and 48.5% of patients were concomitantly treated with methotrexate (MTX). Overall retention rate of ABA was 77.1% at 52 weeks; 14.8% of patients discontinued because of inadequate response and 3.5% because of adverse events. The proportion of patients achieving DAS28-defined low disease activity (LDA) significantly increased from baseline to 52 weeks (7.3% to 43.8%, p < 0.01); 40.9% of patients who did not achieve LDA at 24 weeks had more than 1 categorical improvement in DAS28-defined disease activity at 52 weeks. Multivariate logistic regression revealed concomitant MTX use to be an independent predictor of the categorical improvement in DAS28-defined disease activity from 24 to 52 weeks (adjusted OR 3.124, p = 0.010).

Conclusion.

In routine clinical practice, ABA demonstrated satisfactory clinical efficacy and safety in patients with established RA for 52 weeks. The clinical efficacy of ABA increased with time even after 24 weeks, and this was strongly influenced by concomitant MTX use. Our study provides valuable real-world findings on the longterm management of RA with ABA.

IFN-γ from lymphocytes induces PD-L1 expression and promotes progression of ovarian cancer

BACKGROUND

PD-L1 (programmed cell death 1 ligand 1) on tumour cells suppresses host immunity through binding to its receptor PD-1 on lymphocytes, and promotes peritoneal dissemination in mouse models of ovarian cancer. However, how PD-L1 expression is regulated in ovarian cancer microenvironment remains unclear.

METHODS

The number of CD8-positive lymphocytes and PD-L1 expression in tumour cells was assessed in ovarian cancer clinical samples. PD-L1 expression and tumour progression in mouse models under conditions of altering IFN-γ signals was assessed.

RESULTS

The number of CD8-positive cells in cancer stroma was very high in peritoneally disseminated tumours, and was strongly correlated to PD-L1 expression on the tumour cells (P<0.001). In mouse models, depleting IFNGR1 (interferon-γ receptor 1) resulted in lower level of PD-L1 expression in tumour cells, increased the number of tumour-infiltrating CD8-positive lymphocytes, inhibition of peritoneal disseminated tumour growth and longer survival (P=0.02). The injection of IFN-γ into subcutaneous tumours induced PD-L1 expression and promoted tumour growth, and PD-L1 depletion completely abrogated tumour growth caused by IFN-γ injection (P=0.01).

CONCLUSIONS

Interferon-γ secreted by CD8-positive lymphocytes upregulates PD-L1 on ovarian cancer cells and promotes tumour growth. The lymphocyte infiltration and the IFN-γ status may be the key to effective anti-PD-1 or anti-PD-L1 therapy in ovarian cancer.

Drosophila myeloid leukemia factor acts with DREF to activate the JNK signaling pathway

Drosophila myelodysplasia/myeloid leukemia factor (dMLF), a homolog of human MLF1, oncogene was first identified by yeast two-hybrid screen using the DNA replication-related element-binding factor (DREF) as bait. DREF is a transcription factor that regulates proliferation-related genes in Drosophila. It is known that overexpression of dMLF in the wing imaginal discs through the engrailed-GAL4 driver causes an atrophied wing phenotype associated with the induction of apoptosis. However, the precise mechanisms involved have yet to be clarified. Here, we found the atrophied phenotype to be suppressed by loss-of-function mutation of Drosophila Jun N-terminal kinase (JNK), basket (bsk). Overexpression of dMLF induced ectopic JNK activation in the wing disc monitored with the puckered-lacZ reporter line, resulting in induction of apoptosis. The DREF-binding consensus DRE sequence could be shown to exist in the bsk promoter. Chromatin immunoprecipitation assays in S2 cells with anti-dMLF IgG and quantitative real-time PCR revealed that dMLF binds specifically to the bsk promoter region containing the DRE sequence. Furthermore, using a transient luciferase expression assay, we provide evidence that knockdown of dMLF reduced bsk gene promoter activity in S2 cells. Finally, we show that dMLF interacts with DREF in vivo. Altogether, these data indicate that dMLF acts with DREF to stimulate the bsk promoter and consequently activates the JNK pathway to promote apoptosis.

Clinical efficacy of abatacept compared to adalimumab and tocilizumab in rheumatoid arthritis patients with high disease activity

Favourable clinical results in rheumatoid arthritis (RA) patients with high disease activity (HDA) are difficult to achieve. This study evaluated the clinical efficacy of abatacept according to baseline disease activity compared to adalimumab and tocilizumab. This study included all patients registered in a Japanese multicenter registry treated with abatacept (n = 214), adalimumab (n = 175), or tocilizumab (n = 143) for 24 weeks. Clinical efficacy of abatacept in patients with HDA (DAS28-CRP > 4.1) and low and moderate disease activity was compared. Clinical efficacy of abatacept, adalimumab, and tocilizumab was compared in patients with HDA at baseline. In patients treated with abatacept, multivariate logistic regression identified HDA at baseline as an independent predictor for achieving low disease activity (LDA; DAS28-CRP < 2.7) [OR 0.26, 95 % CI 0.14-0.50] or remission (DAS28-CRP < 2.3) [OR 0.26, 95 % CI 0.12-0.56] at 24 weeks. In patients with HDA at baseline, logistic regression did not identify treatment with adalimumab or tocilizumab as independent predictors of LDA or remission compared to abatacept. Retention rates based on insufficient efficacy were significantly higher in patients treated with abatacept compared to adalimumab and lower than tocilizumab. Retention rates based on adverse events in patients treated with abatacept were significantly lower compared to tocilizumab. Clinical efficacy of abatacept was affected by baseline disease activity. There were no significant differences between the three different classes of biologics regarding clinical efficacy for treating RA patients with HDA, although definitive conclusions regarding long-term efficacy will require further research.

Epidermal growth factor receptor localized to exosome membranes as a possible biomarker for lung cancer diagnosis

Detection of drug-target proteins and biomarkers that are expressed in cancer tissue has significant potential for both diagnosis and treatment of cancer. However, current immuno-histochemical and cytogenetic analyses of biopsy specimens for pre-operational diagnosis are highly invasive and often difficult to apply to lung cancer patients. The purpose of this study was to evaluate the possible utility of determining epidermal growth factor receptor (EGFR) expression on exosomal membranes using a targeted ELISA with an anti-CD81 antibody as a capture antibody for lung cancer diagnosis. While soluble EGFR (sEGFR) levels in plasma were not remarkably different between lung cancer patients and normal controls, significantly higher exosomal EGFR expression levels were observed in 5/9 cancer cases compared to normal controls. These results suggest that measurement of exosomal protein levels could be useful for in vitro diagnosis, and that exosomal EGFR is a possible biomarker for characterization of lung cancer.