Further assessment of the clinically effective dose range of etoricoxib: a randomized, double-blinded, placebo-controlled trial in rheumatoid arthritis

OBJECTIVE

To further assess the clinically active dose range of etoricoxib, a COX-2 selective inhibitor, in rheumatoid arthritis (RA).

METHODS

RA patients were randomized to etoricoxib 10, 30, 60, or 90 mg or placebo in a double-blind, 12-week study. DMARDs (methotrexate, biologics) or low-dose corticosteroids were allowed in stable doses. The primary endpoint was the proportion of patients completing the study and achieving an American College of Rheumatology 20% (ACR20) response. Secondary endpoints included individual components of the ACR index and Patient Global Assessment of Pain. Safety was assessed by physical exam and adverse experiences (AEs) occurrences.

RESULTS

Etoricoxib 90 mg was the only dose to reach a statistically significant difference from placebo (p < 0.001) on the primary endpoint; etoricoxib 60 mg approached significance (p = 0.057). Significant pain improvement vs. placebo was observed with etoricoxib 90 mg (p < 0.001), 60 mg (p = 0.018), and 30 mg (p = 0.017). Despite the use of background biologics and corticosteroids, a dose response was still apparent. A higher proportion of etoricoxib 60 and 90 mg patients had renovascular AEs (i.e., edema and hypertension) compared with placebo, although discontinuations for renovascular AEs were rare. Etoricoxib 90 mg had a higher incidence of serious AEs (n = 5; 1 was considered drug-related) versus placebo (n = 0).

LIMITATIONS

The present study was not powered to detect differences in cardiovascular or gastrointestinal safety by dose. Additionally, further research is needed to clarify the role of doses less than the etoricoxib 90 mg dose for pain management in RA patients.

CONCLUSION

Etoricoxib 90 mg demonstrated statistically superior efficacy (ACR20) compared with placebo and numerical superiority over the other doses of etoricoxib studied. Etoricoxib 30 and 60 mg demonstrated significant pain improvement versus placebo, suggesting utility for some patients.

Risk factors for NSAID-associated upper GI clinical events in a long-term prospective study of 34 701 arthritis patients

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAID)-related GI effects vary based on patient characteristics.

AIMS

To assess risk factors for NSAID-associated upper GI clinical events and dyspepsia.

METHODS

Patients ≥50 years with osteoarthritis or rheumatoid arthritis were randomized to etoricoxib or diclofenac in a prespecified intent-to-treat analysis of three double-blind randomized trials. Potential risk factors for upper GI clinical events (bleeding, perforation, obstruction, or ulcer), complicated events (perforation, obstruction, bleeding) and discontinuations due to dyspepsia were assessed with Cox proportional hazard models.

RESULTS

Significant predictors of clinical events and complicated events included age ≥65 years [hazards ratios (HRs) = 2.25 (1.84-2.76), 4.09 (2.82-5.92)], prior event [HRs = 2.57 (1.94-3.39), 3.23 (2.09-5.00)], low-dose aspirin [HRs = 2.34 (1.87-2.92), 3.41 (2.33-5.00)] and corticosteroid [HRs = 1.85 (1.41-2.43), 2.09 (1.29-3.38)]. Predictors of discontinuation due to dyspepsia included prior dyspepsia [HR = 1.78 (1.44-2.00)], prior event [HR = 1.78 (1.40-2.27)] and age ≥65 years [HR = 1.35 (1.16-1.57)].

CONCLUSIONS

Assessment for age ≥65 years, prior upper GI clinical events and low-dose aspirin use are key in identifying patients who should either avoid NSAIDs or employ management strategies to reduce NSAID-associated upper GI events. Prior dyspepsia or upper GI clinical events and age ≥65 years also predict an increased risk of developing dyspepsia severe enough to necessitate discontinuation of NSAIDs.

Prescription rates of protective co-therapy for NSAID users at high GI risk and results of attempts to improve adherence to guidelines

BACKGROUND

Protective co-therapy is recommended in NSAID users with GI risk factors, but adherence is poor.

AIM

To assess the proportion of NSAID users receiving co-therapy and strategies to improve adherence.

METHODS

Arthritis patients > or =50 years of age received etoricoxib or diclofenac in a double-blind randomized trial. Reminders that high-risk patients (age > or = 65; previous ulcer/haemorrhage; corticosteroid, anticoagulant, aspirin use) should receive co-therapy were given at study initiation. Free PPI was provided. An intervention midway through the study included a written reminder and required written response regarding co-therapy.

RESULTS

16,244/23,504 (69%) patients had GI risk factors. Pre-intervention, co-therapy was most common with previous ulcer/haemorrhage [706/1107 (64%)] and 3-4 risk factors [331/519 (64%)]. In the 10,026 patients enrolled pre-intervention and remaining in the study > or =6 months after, co-therapy in high-risk patients increased from 2958/6843 (43%) to 4177/6843 (61%) (difference = 18%; 95% CI 16%,19%). The increase was greater outside the US (22%; 19%,24%) than in the US (15%; 13%,17%).

CONCLUSIONS

Less than 50% of NSAID users with GI risk factors are given protective co-therapy--even if prescribers are given reminders and cost is not an issue. Direct communication requiring written response significantly increased adherence to guidelines, but achieving higher levels of adherence will require additional strategies.

Evaluation of the efficacy and safety of etoricoxib compared with naproxen in two, 138-week randomised studies of patients with osteoarthritis

OBJECTIVES

To assess the efficacy and safety of etoricoxib 60 mg once daily and naproxen 500 mg twice daily over a 138-week treatment period in patients with osteoarthritis (OA).

METHODS

Two 1-year randomised, double blind, parallel group two-part base studies (part I 12 weeks; part II 40 weeks), followed by an 86-week extension, in patients with OA (hip or knee) were conducted at 80 clinical centres (19 countries). The studies had identical designs. Patients taking placebo in part I received etoricoxib or naproxen (1:1 ratio) in part II and the extension; patients taking etoricoxib or naproxen in part I continued to receive the same treatment throughout the entire length of the studies. Co-primary efficacy end points were patient global assessment of disease status, and WOMAC questionnaire pain subscale and physical function subscale (100 mm VAS). Efficacy over 138 weeks was assessed by graphical analysis. Safety was assessed by observation of adverse experiences and laboratory and physical evaluations.

RESULTS

997 patients entered (615 completed) the base studies. Of these patients, 463 patients entered the extensions. A total of 161 and 152 patients in the etoricoxib and naproxen groups, respectively, completed 138 treatment weeks. Etoricoxib and naproxen showed similar efficacy throughout the 138 weeks of treatment. For etoricoxib and naproxen, respectively, WOMAC pain assessments were 67 and 67 mm (baseline); 28 and 29 mm (1 year), and 34 and 33 mm (138 weeks). Results for the other efficacy end points were similar to those seen with the WOMAC pain assessments. Both etoricoxib and naproxen were generally well tolerated.

CONCLUSION

Both etoricoxib and naproxen demonstrated long-term clinical efficacy for the treatment of OA. Etoricoxib and naproxen were generally well tolerated.

Effects of ibuprofen on molecular markers of cartilage and synovium turnover in patients with knee osteoarthritis

OBJECTIVE

The aim of this study was to evaluate the effect of ibuprofen on the urinary excretion of C-terminal crosslinking telopeptide of type II collagen (CTX-II) and urinary glucosyl galactosyl pyridinoline (Glc-Gal-PYD), two new molecular markers of cartilage and synovial tissue metabolism, respectively, in patients with knee osteoarthritis (OA).

METHODS

We studied 201 patients with knee pain and radiographic evidence of knee OA who were on treatment with non-steroidal anti-inflammatory drugs (NSAIDs) prior to study initiation. After an initial screening visit, patients were withdrawn from their pre-study NSAID and, following a flare of their OA symptoms, were randomised to ibuprofen (2400 mg/day) or placebo. Urinary CTX-II and Glc-Gal-PYD levels were measured at time of randomisation (baseline) and after 4-6 weeks of treatment.

RESULTS

After 4 to 6 weeks, urinary CTX-II (+17%, p = 0.023) and Glc-Gal-PYD (+10%, p = 0.020) increased significantly from baseline in the placebo group whereas marginal or no increase was observed in the ibuprofen group (CTX-II +2%, NS and Glc-Gal-PYD +4%, p = 0.045). For urinary CTX-II, the difference in the change from baseline between placebo and ibuprofen treated groups was significant (13%, p = 0.017). At baseline, urinary levels of CTX-II and Glc-Gal-PYD were higher in patients with knee swelling (n = 127) than in those without (n = 74) (p<0.02 for both markers). When patients were stratified according to presence or absence of knee swelling at baseline, the increases over 4-6 weeks of urinary CTX-II and Glc-Gal-PYD in the placebo group were restricted to patients with knee swelling (+22% from baseline, p = 0.001 and +12%, p = 0.011, for urinary CTX-II and Glc-Gal-PYD respectively). In patients with knee swelling who were treated with ibuprofen this increase was not observed and the difference from placebo was significant for urinary CTX-II (p = 0.014).

CONCLUSION

In patients with a flare of knee OA, specifically in patients with evidence of joint inflammation documented by knee swelling, there was a significant increase in markers reflecting cartilage and synovium metabolism that could partly be prevented by high doses of ibuprofen. These data suggest that patients with a flare of knee OA are characterised by increased cartilage and synovial tissue degradation, which may be partly prevented by high doses of NSAIDs.

Single dose methodology to assess the influence of an alpha1-adrenoceptor antagonist on uroflowmetric parameters in patients with benign prostatic hyperplasia

AIMS

To establish methodology which rapidly and reliably assesses the effect of an alpha1-adrenoceptor antagonist on peak urine flow rates in men with benign prostatic hyperplasia (BPH). This methodology could then be applied to screening new drugs to treat BPH.

METHODS

Twenty-five patients with BPH enrolled in a double-blind, placebo-controlled, two-period crossover study. Patients were either withdrawn from their current alpha1-adrenoceptor antagonist therapy (n = 22) or were untreated prestudy (n = 3) and all met prespecified uroflowmetric criteria including: (1) a peak urine flow rate (Qmax) < 12 ml s-1 off therapy (or < 10 ml s-1 if untreated prestudy) and (2) a decrease in peak urine flow rate (Qmax) of > 2 ml s-1 after withdrawal from therapy. Study treatment consisted of tamsulosin 0.4 mg (or matching placebo) once daily for 8 days in a two-period crossover. Uroflowmetry was performed predose and once postdose (4.5-5.5 h postdose) on day 1, and once postdose (4.5-5.5 h postdose) on day 8 of each treatment period.

RESULTS

After a single dose of tamsulosin, the least-square mean difference between tamsulosin and placebo in the change from baseline Qmax was 2.8 ml s-1 (P = 0.017 vs placebo). After 8 days dosing of tamsulosin, the least-square mean difference between tamsulosin and placebo in the change from baseline Qmax was also 2.8 ml s-1 (P = 0.044 vs placebo). Additionally, there was no significant difference observed between the single and multiple dose results (P > 0.200 for between group difference).

CONCLUSIONS

Both single and multiple doses of tamsulosin 0.4 mg increased Qmax in men with BPH. A single dose produced a comparable response to multiple dose administration. The magnitude of the effect was greater than the effect generally seen in longer term clinical trials, but this difference may be explained by the patient population in this study which was preselected for 'responsiveness' to an alpha1-adrenoceptor antagonist. These results support the utility of single dose uroflowmetric measurements in rapidly providing preliminary data on new investigational agents, specifically agents which act to increase urine flow in men with BPH. However, clinical efficacy would still need to be confirmed with longer term clinical trials.

Human immunodeficiency virus type 1 Gag polyprotein multimerization requires the nucleocapsid domain and RNA and is promoted by the capsid-dimer interface and the basic region of matrix protein

The human immunodeficiency virus type 1 (HIV-1) Gag polyprotein directs the formation of virions from productively infected cells. Many gag mutations disrupt virion assembly, but little is known about the biochemical effects of many of these mutations. Protein-protein interactions among Gag monomers are believed to be necessary for virion assembly, and data suggest that RNA may modify protein-protein interactions or even serve as a bridge linking Gag polyprotein monomers. To evaluate the primary sequence requirements for HIV-1 Gag homomeric interactions, a panel of HIV-1 Gag deletion mutants was expressed in bacteria and evaluated for the ability to associate with full-length Gag in vitro. The nucleocapsid protein, the major RNA-binding domain of Gag, exhibited activity comparable to that of the complete polyprotein. In the absence of the nucleocapsid protein, relatively weak activity was observed that was dependent upon both the capsid-dimer interface and basic residues within the matrix domain. The relevance of the in vitro findings was confirmed with an assay in which nonmyristylated mutant Gags were assessed for the ability to be incorporated into virions produced by wild-type Gag expressed in trans. Evidence of the importance of RNA for Gag-Gag interaction was provided by the demonstration that RNase impairs the Gag-Gag interaction and that HIV-1 Gag interacts efficiently with Gags encoded by distantly related retroviruses and with structurally unrelated RNA-binding proteins. These results are consistent with models in which Gag multimerization involves indirect contacts via an RNA bridge as well as direct protein-protein interactions.

HIV in UK prisons: a review of seroprevalence, transmission and patterns of risk

Prisons contain individuals at high risk of HIV infection, notably through intravenous drug use. For complex political, social and legal reasons penal institutions in the UK are unable to provide condoms and clean needles. The outbreak of HIV and hepatitis B that occurred in a Scottish prison in 1993 focused attention on the potential problems. Debate about the issue is hampered by a lack of useful information. Current data about risk behaviour and seroprevalence is reviewed, and compared with experience in other countries. Injecting drug use in prison appears to be common, and the majority who inject in prison share equipment, which can be used many times. Sexual activity may be a smaller risk factor, but does occur between men in prison. In addition, prisoners appear to have high rates of partner change between sentences. The true prevalence of HIV in UK prisons is difficult to assess, but the available data suggest it is between 0.1 and 4.5%, lower than in Southern Europe and the USA. A window of opportunity still exists to prevent further outbreaks of HIV in UK penal institutions and to maintain these low prevalence rates. Strenuous, and possibly unpalatable measures are needed now.

Effect of cooling on the responsiveness of canine tracheal muscle

Airway cooling causes bronchoconstriction in many persons who have asthma. To determine the direct effect of cooling on the response of tracheal muscle to parasympathetic and muscarinic stimuli in situ, the temperature of a segment of canine cervical trachea was adjusted to 37 degrees, 30 degrees, or 25 degrees C by superfusing temperature-controlled saline over its epithelial surface. The contractile response of the tracheal muscle to electrical stimulation of the vagus nerves and to intra-arterial acetylcholine was then determined. Cooling the segment to 25 degrees C decreased the contraction induced by parasympathetic stimulation. However, cooling did not alter the contraction induced by intra-arterial acetylcholine. Parallel studies were conducted in vitro using nine excised tracheal muscle strips taken from the same section of trachea in three additional dogs. Cooling the tracheal muscle to 25 degrees C in vitro increased the maximal contraction induced by both electrical field stimulation and by acetylcholine. Thus, cooling in situ does not alter the response of tracheal muscle to muscarinic stimuli and inhibits the response to parasympathetic stimuli. These data indicate that augmentation of the tracheal muscle response elicited by cooling in vitro does not reflect the response in situ. They suggest that a direct effect of cooling on airway smooth muscle response to parasympathetic and muscarinic stimuli does not account for cooling-induced bronchoconstriction in vivo.

Effect of PAF on parasympathetic contraction of canine airways

Platelet-activating factor (PAF) increases the bronchoconstrictor response of mammalian airways to cholinergic agonists and is thus implicated as a potential mediator of airway hyperreactivity. This study further defines the nature of the increase in airway responsiveness induced by PAF. We employed an in situ canine tracheal preparation, which allows differentiation of the effects PAF has on airway smooth muscle contraction from confounding effects it has on inducing airway edema and secretions. We found that PAF, infused regionally into tracheal arteries, increases the responsiveness of the trachealis muscle to parasympathetic stimuli in a dose-dependent manner. This effect occurred within 15 min. To determine whether the increase in trachealis muscle responsiveness resulted from effects localized to the trachea, we compared the effect of PAF on the tracheal segment with effects of the lower airways of the lung. Delivered to the arteries perfusing the tracheal segment, PAF did not increase lung resistance during vagus nerve stimulation. These data indicate that airway hyperresponsiveness elicited by PAF results from regional stimulation and/or release of mediators that augment tracheal contractility and that this effect is distinct from systemic effects elicited by PAF.