Methotrexate safety and efficacy in combination therapies in patients with early rheumatoid arthritis : a post-hoc analysis of a randomized controlled trial (NORD-STAR)

This article is protected by copyright. All rights reserved.OBJECTIVE: To investigate methotrexate safety and influence of dose on efficacy outcomes in combination with three different biological treatments and with active conventional treatment (ACT) in early rheumatoid arthritis (RA). METHODS: This post-hoc analysis included 812 treatment-naïve early RA patients who were randomized (1:1:1:1) in the NORD-STAR trial (NCT01491815) to receive methotrexate in combination with ACT, certolizumab-pegol, abatacept, or tocilizumab. Methotrexate safety, doses, and dose effects on Clinical Disease Activity Index (CDAI) remission were assessed after 24 weeks of treatment. RESULTS: Compared with ACT, the prevalence of methotrexate-associated side effects was higher when methotrexate was combined with tocilizumab (HR 1.48 [95% CI 1.20 to 1.84]), but not with certolizumab-pegol (HR 0.99 [0.79 to 1.23]) or with abatacept (HR 0.93 [0.75 to 1.16]). With ACT as the reference, methotrexate dose was significantly lower when used in combination with tocilizumab (β -4.65 [95% CI -5.83 to -3.46], p<0.001), with abatacept (β -1.15 [-2.27 to -0.03], p=0.04), and numerically lower in combination with certolizumab-pegol (β -1.07 [-2.21 to 0.07], p=0.07). Methotrexate dose reductions were not associated with decreased CDAI remission rates within any of the treatment combinations. CONCLUSION: Methotrexate was generally well tolerated in combination therapies, but adverse events were a limiting factor in receiving the target dose of 25 mg/week, and these were more frequent in combination with tocilizumab versus active conventional treatment. On the other hand, methotrexate dose reductions were not associated with decreased CDAI remission rates within any of the four treatment combinations at 24 weeks. This article is protected by copyright. All rights reserved.Peer reviewe

Neurostimulation of the cholinergic anti-inflammatory pathway ameliorates disease in rat collagen-induced arthritis.

The inflammatory reflex is a physiological mechanism through which the nervous system maintains immunologic homeostasis by modulating innate and adaptive immunity. We postulated that the reflex might be harnessed therapeutically to reduce pathological levels of inflammation in rheumatoid arthritis by activating its prototypical efferent arm, termed the cholinergic anti-inflammatory pathway. To explore this, we determined whether electrical neurostimulation of the cholinergic anti-inflammatory pathway reduced disease severity in the collagen-induced arthritis model.Rats implanted with vagus nerve cuff electrodes had collagen-induced arthritis induced and were followed for 15 days. Animals underwent active or sham electrical stimulation once daily from day 9 through the conclusion of the study. Joint swelling, histology, and levels of cytokines and bone metabolism mediators were assessed.Compared with sham treatment, active neurostimulation of the cholinergic anti-inflammatory pathway resulted in a 52% reduction in ankle diameter (p = 0.02), a 57% reduction in ankle diameter (area under curve; p = 0.02) and 46% reduction overall histological arthritis score (p = 0.01) with significant improvements in inflammation, pannus formation, cartilage destruction, and bone erosion (p = 0.02), accompanied by numerical reductions in systemic cytokine levels, not reaching statistical significance. Bone erosion improvement was associated with a decrease in serum levels of receptor activator of NF-κB ligand (RANKL) from 132±13 to 6±2 pg/mL (mean±SEM, p = 0.01).The severity of collagen-induced arthritis is reduced by neurostimulation of the cholinergic anti-inflammatory pathway delivered using an implanted electrical vagus nerve stimulation cuff electrode, and supports the rationale for testing this approach in human inflammatory disorders

Hormone, metabolic peptide, and nutrient levels in the earliest phases of rheumatoid arthritis-contribution of free fatty acids to an increased cardiovascular risk during very early disease

Rheumatoid arthritis (RA) is a chronic autoimmune disease associated with changes in several hormones and metabolic peptides. Crosstalk between these factors and the immune system may be important for homeostasis during inflammation. Here, we studied the levels of hormones, metabolic peptides, and nutrients in individuals at risk for developing RA (at risk). In total, 18 hormones, metabolic peptides, and nutrients were measured in fasting serum samples from 45 autoantibody-positive individuals at risk, 22 RA patients, and 16 healthy subjects. Triglyceride (TG) levels were also measured in an independent validation cohort of 32 individuals at risk, 20 early arthritis patients, and 20 healthy controls. We found an elevated TG level in individuals at risk and significantly higher TG levels in RA patients compared to healthy controls. These results were confirmed in the validation cohort. Similarly, free fatty acid (FFA) levels showed an increase in individuals at risk and were significantly higher in RA patients compared to healthy controls. In RA patients, FFA levels were positively correlated with disease activity. Pancreatic polypeptide (PP) and norepinephrine levels were highly significantly increased in individuals at risk and RA patients compared to healthy controls. TG and FFA levels are increased in RA patients and positively correlated with disease activity parameters. The results presented here suggest a role for FFAs in the pathogenesis of RA. Furthermore, PP and norepinephrine may be a biomarker that could assist in the identification of individuals at ris

Two novel α7 nicotinic acetylcholine receptor ligands: in vitro properties and their efficacy in collagen-induced arthritis in mice

The cholinergic anti-inflammatory pathway can downregulate inflammation via the release of acetylcholine (ACh) by the vagus nerve. This neurotransmitter binds to the α7 subunit of nicotinic acetylcholine receptors (α7nAChR), expressed on macrophages and other immune cells. We tested the pharmacological and functional profile of two novel compounds, PMP-311 and PMP-072 and investigated their role in modulating collagen-induced arthritis (CIA) in mice. Both compounds were characterized with binding, electrophysiological, and pharmacokinetic studies. For in vivo efficacy studies in the CIA model the compounds were administered daily by oral gavage from day 20 till sacrifice at day 34. Disease progression was monitored by visual clinical scoring and measurement of paw swelling. Inflammation and joint destruction were examined by histology and radiology. Treatment with PMP-311 was effective in preventing disease onset, reducing clinical signs of arthritis, and reducing synovial inflammation and bone destruction. PMP-072 also showed a trend in arthritis reduction at all concentrations tested. The data showed that while both compounds bind to α7nAChR with high affinity, PMP-311 acts like a classical agonist of ion channel activity, and PMP-072 can actually act as an ion channel antagonist. Moreover, PMP-072 was clearly distinct from typical competitive antagonists, since it was able to act as a silent agonist. It synergizes with the allosteric modulator PNU-120596, and subsequently activates desensitized α7nAChR. However, PMP-072 was less efficacious than PMP-311 at both channel activation and desensitization, suggesting that both conducting and non-conducting states maybe of importance in driving an anti-inflammatory response. Finally, we found that the anti-arthritic effect can be observed despite limited penetration of the central nervous system. These data provide direct evidence that the α7nAChR in immune cells does not require typical ion channel activation to exert its antiinflammatory effect

Two novel α7 nicotinic acetylcholine receptor ligands: in vitro properties and their efficacy in collagen-induced arthritis in mice.

INTRODUCTION:The cholinergic anti-inflammatory pathway can downregulate inflammation via the release of acetylcholine (ACh) by the vagus nerve. This neurotransmitter binds to the α7 subunit of nicotinic acetylcholine receptors (α7nAChR), expressed on macrophages and other immune cells. We tested the pharmacological and functional profile of two novel compounds, PMP-311 and PMP-072 and investigated their role in modulating collagen-induced arthritis (CIA) in mice. METHODS:Both compounds were characterized with binding, electrophysiological, and pharmacokinetic studies. For in vivo efficacy studies in the CIA model the compounds were administered daily by oral gavage from day 20 till sacrifice at day 34. Disease progression was monitored by visual clinical scoring and measurement of paw swelling. Inflammation and joint destruction were examined by histology and radiology. RESULTS:Treatment with PMP-311 was effective in preventing disease onset, reducing clinical signs of arthritis, and reducing synovial inflammation and bone destruction. PMP-072 also showed a trend in arthritis reduction at all concentrations tested. The data showed that while both compounds bind to α7nAChR with high affinity, PMP-311 acts like a classical agonist of ion channel activity, and PMP-072 can actually act as an ion channel antagonist. Moreover, PMP-072 was clearly distinct from typical competitive antagonists, since it was able to act as a silent agonist. It synergizes with the allosteric modulator PNU-120596, and subsequently activates desensitized α7nAChR. However, PMP-072 was less efficacious than PMP-311 at both channel activation and desensitization, suggesting that both conducting and non-conducting states maybe of importance in driving an anti-inflammatory response. Finally, we found that the anti-arthritic effect can be observed despite limited penetration of the central nervous system. CONCLUSIONS:These data provide direct evidence that the α7nAChR in immune cells does not require typical ion channel activation to exert its antiinflammatory effects

Vagus nerve stimulation inhibits cytokine production and attenuates disease severity in rheumatoid arthritis

Rheumatoid arthritis (RA) is a heterogeneous, prevalent, chronic autoimmune disease characterized by painful swollen joints and significant disabilities. Symptomatic relief can be achieved in up to 50% of patients using biological agents that inhibit tumor necrosis factor (TNF) or other mechanisms of action, but there are no universally effective therapies. Recent advances in basic and preclinical science reveal that reflex neural circuits inhibit the production of cytokines and inflammation in animal models. One well-characterized cytokine-inhibiting mechanism, termed the "inflammatory reflex," is dependent upon vagus nerve signals that inhibit cytokine production and attenuate experimental arthritis severity in mice and rats. It previously was unknown whether directly stimulating the inflammatory reflex in humans inhibits TNF production. Here we show that an implantable vagus nerve-stimulating device in epilepsy patients inhibits peripheral blood production of TNF, IL-1β, and IL-6. Vagus nerve stimulation (up to four times daily) in RA patients significantly inhibited TNF production for up to 84 d. Moreover, RA disease severity, as measured by standardized clinical composite scores, improved significantly. Together, these results establish that vagus nerve stimulation targeting the inflammatory reflex modulates TNF production and reduces inflammation in humans. These findings suggest that it is possible to use mechanism-based neuromodulating devices in the experimental therapy of RA and possibly other autoimmune and autoinflammatory disease

NCAP Effect on Mediators of Bone Metabolism.

<p>Study day 16 serum was assayed for RANKL (A), and OPG (B), and the ratio of OPG/RANKL group means calculated (C). Data are shown as mean+SE level, *p≤0.05, t-test versus CIA/Sham NCAP. Osteocalcin (D), P1NP (E), TRAP-5b (F) and CTX-1 (G) data are shown as mean+SE level, *p≤0.05 t-test versus CIA/Sham NCAP.</p

Treatment Groups.

<p>Treatment Groups.</p

NCAP Reduces Histological Measures of Joint Damage.

<p>(A–B) Ankle joints were harvested on study day 16, stained with Toluidine Blue, and scored on a scale of 0-5 for inflammation, pannus formation, cartilage damage and bone resorption (A), with a composite summated score of 0–20 (B). Data are shown as mean+SE score. *p≤0.05 t-test versus CIA/Sham NCAP. (C–D) Representative 50X photomicrographs of ankle joints are shown which have the approximate mean summed score as that of the entire treatment group. Ankle from CIA/Sham NCAP group (C) demonstrates marked inflammation and synovitis (<b>S</b>) and mild cartilage damage (large arrow) and bone resorption (small arrow). Ankle from CIA/NCAP group (D) demonstrates mild inflammation and synovitis (S) and minimal cartilage damage (large arrow) and minimal bone resorption (small arrow).</p

NCAP Effect on Circulating Cytokines.

<p>Study day 16 serum was assayed for IL-1α, IL-1β, IL-2, IL-6, IFN-γ and TNF. Data are shown as mean+SE level, t-test p = NS for all individual cytokine comparisons between CIA/NCAP and CIA/Sham NCAP.</p