Introduction: ‘Why is there persistent disease despite aggressive therapy of rheumatoid arthritis?’

Comparison of the tissue distribution and metabolism of AN1284, a potent anti-inflammatory agent, after subcutaneous and oral administration in mice

This study is to compare the tissue distribution and metabolism of AN1284 after subcutaneous and oral administration at doses causing maximal reductions in IL-6 in plasma and tissues of mice. Anti-inflammatory activity of AN1284 and its metabolites was detected in lipopolysaccharide (LPS) activated RAW 264.7 macrophages. Mice were given AN1284 by injection or gavage, 15 min before LPS. IL-6 protein levels were measured after 4 h. Using a liquid chromatography/mass spectrometry method we developed, we showed that AN1284 is rapidly metabolized to the indole (AN1422), a 7-OH derivative (AN1280) and its glucuronide. AN1422 has weaker anti-inflammatory activity than AN1284 in LPS-activated macrophages and in mice. AN1284 (0.5 mg/kg) caused maximal reductions in IL-6 in the plasma, brain, and liver when injected subcutaneously and after gavage only in the liver. Similar reductions in the plasma and brain required a dose of 2.5 mg/kg, which resulted in 5.5-fold higher hepatic levels than after injection of 0.5 mg/kg, but 7, 11, and 19-fold lower ones in the plasma, brain, and kidneys, respectively. Hepatic concentrations produced by AN1284 were 2.5 mg/kg/day given by subcutaneously implanted mini-pumps that were only 12% of the peak levels seen after acute injection of 0.5 mg/kg. Similar hepatic concentrations were obtained by (1 mg/kg/day), administered in the drinking fluid. These were sufficient to decrease hepatocellular damage and liver triglycerides in previous experiments in diabetic mice. AN1284 can be given orally by a method of continuous release to treat chronic liver disease, and its preferential concentration in the liver should limit any adverse effects.

Characteristics of difficult-to-treat rheumatoid arthritis: results of an international survey

Objectives

Patients with difficult-to-treat rheumatoid arthritis (RA) remain symptomatic despite treatment according to current European League Against Rheumatism (EULAR) management recommendations. These focus on early phases of the disease and pharmacological management. We aimed to identify characteristics of difficult-to-treat RA and issues to be addressed in its workup and management that are not covered by current management recommendations.

Methods

An international survey was conducted among rheumatologists with multiple-choice questions on disease characteristics of difficult-to-treat RA. Using open questions, additional items to be addressed and items missing in current management recommendations were identified.

Results

410 respondents completed the survey: 50% selected disease activity score assessing 28 joints >3.2 OR presence of signs suggestive of active disease as characteristics of difficult-to-treat RA; 42% selected fatigue; 48% selected failure to ≥2 conventional synthetic disease-modifying antirheumatic drugs (DMARDs) AND ≥2 biological/targeted synthetic DMARDs; 89% selected inability to taper glucocorticoids below 5 mg or 10 mg prednisone equivalent daily. Interfering comorbidities, extra-articular manifestations and polypharmacy were identified as important issues missing in current management recommendations.

Conclusions

There is wide variation in concepts of difficult-to-treat RA. Several important issues regarding these patients are not addressed by current EULAR recommendations.