Pharmacokinetics of modified-release prednisone tablets in healthy subjects and patients with rheumatoid arthritis

In rheumatoid arthritis (RA), nocturnal release of proinflammatory cytokines is not adequately counteracted by endogenous glucocorticoid and is associated with symptoms of morning stiffness and pain. Taking exogenous glucocorticoid during the night reduces morning stiffness significantly more than treatment at the conventional time in the morning, although waking to take tablets is unacceptable for patients. Modified-release prednisone tablets were developed to allow administration at bedtime for programmed delivery of glucocorticoid during the night. Single-center crossover studies were conducted, each in ≤24 healthy subjects, to compare the pharmacokinetics of a single 5-mg oral dose of modified-release prednisone and conventional prednisone, as well as the effect of food on bioavailability. There was no substantial difference in pharmacokinetic parameters of the formulations apart from the programmed delay in release of glucocorticoid from the modified-release tablets (C(max) 97%, AUC(0-∞) 101%, 90% confidence intervals within the requisite range for bioequivalence). Administration after a full or light meal did not affect pharmacokinetic characteristics, but bioavailability was reduced under fasted conditions. Pharmacokinetic evaluation in 9 patients with RA confirmed that modified-release prednisone tablets taken at bedtime (around 22:00 h) with or after an evening meal result in programmed release of glucocorticoid 4 to 6 hours after intake.

Targeting pathophysiological rhythms: prednisone chronotherapy shows sustained efficacy in rheumatoid arthritis

Objective

This 9-month open-label extension of the Circadian Administration of Prednisone in Rheumatoid Arthritis Study (CAPRA 1) investigated the long-term safety and efficacy of prednisone chronotherapy with a novel modified-release (MR) prednisone for up to 12 months.

Methods

Of 288 patients with rheumatoid arthritis originally randomised to MR or immediate-release (IR) prednisone, 249 continued with prednisone chronotherapy (2–10 mg/day) in the 9-month open-label extension. Duration of morning stiffness of the joints (MS), disease activity scores (DAS28), American College of Rheumatology (ACR20) responses and plasma levels of interleukin 6 (IL-6) were assessed. Safety was analysed from adverse event reports and laboratory investigations.

Results

During the 3-month double-blind phase, patients in the MR group achieved a reduction in MS of 33.1% while no change was observed in the IR group. After 6 months of treatment, MS was reduced in the IR/MR group by 54% and in the MR/MR group by 56%. MS reduction after 12 months was 45% (IR/MR group) and 55% (MR/MR group). Plasma levels of IL-6 declined on MR treatment. DAS28 was reduced from 5.8 to 4.8 (MR/MR group) and 4.9 (IR/MR group), respectively. 37% of the 219 patients who completed the 12-month study achieved improvement according to the ACR20 criteria. Adverse events did not differ from the known profile of low-dose prednisone.

Conclusions

Prednisone chronotherapy with the MR tablet was safe and well tolerated and provided a sustained improvement which resulted in a better benefit to risk ratio of low-dose glucocorticoid treatment for at least 12 months.

Efficacy of modified-release versus standard prednisone to reduce duration of morning stiffness of the joints in rheumatoid arthritis (CAPRA-1): a double-blind, randomised controlled trial

BACKGROUND

Circadian rhythms are changed in patients with rheumatoid arthritis. A new modified-release delivery system has been developed which adapts the release of the administered glucocorticoid to the circadian rhythms of endogenous cortisol and disease symptoms to improve the benefit-risk ratio of glucocorticoid therapy in rheumatoid arthritis. We aimed to assess the efficacy and safety of a new modified-release prednisone tablet compared with immediate-release prednisone in patients with this disease.

METHODS

In a 12-week, multicentre, randomised, double-blind trial, 288 patients with active rheumatoid arthritis were randomly assigned to either a modified-release prednisone tablet (n=144) or to an immediate-release prednisone tablet (n=144). The modified-release tablet was taken at bedtime and prednisone was released with a delay of 4 h after ingestion. This treatment was compared with morning administration of immediate-release prednisone as an active comparator. The primary outcome measure was duration of morning stiffness of the joints. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00146640.

FINDINGS

The mean relative change in duration of morning stiffness of the joints from baseline to end of treatment was significantly higher with modified-release prednisone than with immediate-release prednisone (-22.7%vs -0.4%; difference=22.4% [95% CI 0.49-44.30]; p=0.045). Patients in the prednisone modified-release group achieved a mean reduction of 44.0 (SD 136.6) min compared with baseline. The absolute difference between the treatment groups was 29.2 min (95% CI -2.59 to 61.9) in favour of modified-release prednisone (p=0.072). The safety profile did not differ between treatments.

INTERPRETATION

Modified-release prednisone is well tolerated, convenient to administer, and produces a clinically relevant reduction of morning stiffness of the joints in addition to all known therapeutic effects of immediate-release prednisone.

Transcription factors Sp1 and AP-2 mediate induction of acid sphingomyelinase during monocytic differentiation

Cells from the human monocytic leukemia cell line THP-1 differentiate towards a macrophage-like phenotype when stimulated with phorbol 12-myristate -13- acetate (PMA), 1,25-dihydroxy-vitamin D3, and various other agents. We demonstrate here that the expression of the lysosomal enzyme acid sphingomyelinase (ASM; E.C. 3.1.4.12) is induced during this process and is strongly elevated in differentiated THP-1 cells, as well as in differentiated human mononuclear phagocytes. Using Northern blotting, RNase protection assay, and nuclear run-on analyses, we show that the up-regulation of ASM expression is regulated mainly at the level of transcription and that new protein synthesis is required for enhanced ASM activity. This cell-type specific induction by PMA treatment was further investigated with respect to transcriptional control. A series of 5' deletion derivatives of the upstream regulatory region were used in transient transfection assays to identify promoter elements required for basal and inducible gene expression. A PMA responsive element was localized to a region between -319 and -219 bp upstream of the initiation codon and co-transfections with transcription factor expression plasmids for AP-2 and Sp1 resulted in augmented ASM promoter activity, which was abolished when the binding sites for these two factors were deleted. Using electrophoretic mobility shift assays and supershift assays we demonstrate that this region is specifically bound by Sp1 and AP-2. These factors are present in nuclear extracts prepared from both induced and uninduced THP-1 cells. However, the intensity of the complex formed appeared to increase when nuclear extracts from PMA-treated cells were used. From these studies, we conclude that a concerted action of the transcription factors AP-2 and Sp1 is essential for the up -regulation of ASM expression during the process of macrophage differentiation.