Etorikoksib at oral intake in therapeutic concentrations is a selective inhibitor of cyclooxygenase type 2 (COX-2).
In studies on clinical pharmacology etorikoksib dose-dependent inhibition of COX-2 without affecting COX-1 when administered at doses up to 150 mg per day. Etoricoxib did not inhibit the synthesis of prostaglandins in the gastric mucosa and did not affect the function of platelets.
COX is responsible for the synthesis of prostaglandins. Two isoforms of this enzyme, COX-1 and COX-2, are isolated. COX-2 is an isoenzyme that is induced by the action of proinflammatory mediators and is considered as the main enzyme responsible for the synthesis of prostanoid mediators of pain, inflammation and fever. COX-2 is involved in the processes of ovulation, implantation and closure of the arterial duct, regulation of kidney function, central nervous system (induction of fever, sensation of pain, cognitive function), and may play a role in the healing of ulcers. COX-2 was found in the tissues surrounding the stomach ulcer in humans, but its significance for ulcer healing is not established.
Efficiency
In patients with osteoarthritis (OA) etorikoksib when used at a dose of 60 mg once a day caused a significant reduction in pain and an improvement in the assessment of their condition by patients. These beneficial effects were observed on the second day of treatment and persisted for 52 weeks.Studies of etorikoksib in a dose of 30 mg once a day (using similar methods of evaluation) demonstrated the effectiveness of the drug compared with placebo during the entire treatment period (12 weeks). In a study to determine the optimal dose, etorikoksib in a dose of 60 mg showed a significantly more marked improvement than a dose of 30 mg for all 3 primary endpoints after 6 weeks of treatment. The use of a dose of 30 mg for the treatment of OA joints of the hands has not been studied.
In patients with rheumatoid arthritis (RA), taking etorikoksib in a dose of 60 mg or 90 mg once a day provided a significant reduction in pain, inflammation and improved mobility. These beneficial effects persisted for a 12-week treatment period. A comparison of the use of etorikoksib in a dose of 60 mg and 90 mg once daily for the treatment of RA showed that both dosing regimes provided superior efficacy compared with placebo. The dose of etorikoksib 90 mg once a day exceeded the dose of 60 mg once a day in assessing the effect with the Global Patient Evaluation Scale (0-100 mm visual-analog scale), the mean improvement was -2.71 mm (95 % confidence interval (CI): -4.98 mm, -0.45 mm).
Patients with acute gouty arthritis etorikoksib in a dose of 120 mg once a day during the entire treatment period (8 days) reduced moderate and severe pain in the joints and inflammation compared with indomethacin at a dose of 50 mg 3 times a day. Reduction of pain was noted only 4 hours after the start of treatment.
In patients with ankylosing spondylitis etorikoksib when applied at a dose of 90 mg once a day, provided a reliable reduction in back pain, inflammation, stiffness, and also improvement of motor function. The clinical efficacy of etorikoksib was already observed on the second day of treatment and persisted throughout the treatment period (52 weeks).
In another study, which compared the efficacy of using etorikoksiba at a dose of 90 mg once a day and 60 mg once a day, this drug showed equal efficacy compared with naproxen 1000 mg once a day. Among patients who did not achieve an adequate clinical response to therapy for 6 weeks with the use of etorikoksiba at a dose of 60 mg once daily, an increase a daily dose of up to 90 mg allowed to improve the results of treatment,evaluated with the intensity scale of back pain (0-100 mm visual analogue scale), compared with the continuation of therapy with etoricoxib at a dose of 60 mg once a day. The mean improvement was -2.70 mm (95% CI: 4.88 mm, -0.52 mm).
In a clinical study on pain after dental surgery etorikoksib in a dose of 90 mg was administered once a day for three days. In a subgroup of patients with moderate pain (with baseline assessment) etorikoksib in a dose of 90 mg showed an analgesic effect similar to ibuprofen at a dose of 600 mg (16.11 compared with 16.39, P = 0.722) and greater than with a combination of paracetamol / codeine at a dose of 600 mg / 60 mg (11.00 ; P <0.001) and placebo (6.84; P <0.001) according to a general assessment of pain reduction during the first 6 h (TOPAR6). The proportion of patients requiring rapid-action analgesics during the first 24 hours after taking the study drugs was 40.8% for etorikoksiba at a dose of 90 mg, 25.5% for ibuprofen 600 mg every 6 hours and 46.7% for paracetamol / codeine combinations at a dose of 600 mg / 60 mg every 6 hours compared with 76.2% in the placebo group. In this study, the median onset of action (a measurable reduction in pain) with etoricoxib 90 mg was 28 minutes after taking the drug.
Security
Program MEDAL (Multinational Evaluation Program for Long-Term Prescribing of Etoricoxib and Diclofenac in Arthritis)
Program MEDAL was a prospective safety assessment program based on cardiovascular events from the combined data of three randomized, double-blind, actively-controlled studies: MEDAL, EDGE II and EDGE.
Study MEDAL was a study, the duration of which was determined by the achievement of end points (cardiovascular events), it included 17,804 patients with OA and 5,700 patients with RA, who received etorikoksib in a dose of 60 mg (OA) or 90 mg (OA and RA) or diclofenac in a dose of 150 mg per day on average for 20.3 months (a maximum of 42.3 months, a median of 21.3 months). In this study, only serious adverse events and cases of drop-out from the study were recorded due to any undesirable phenomenon.
In studies EDGE and EDGE II compared the safety of taking etorikoksib and diclofenac for the gastrointestinal tract (GIT). In the study EDGE 7111 patients with OA who received etorikoksib in a dose of 90 mg per day (1.5 times the dose recommended for OA) or diclofenac in a dose of 150 mg per day for an average of 9.1 months (a maximum of 16.6 months, a median of 11.4 months).In the study EDGE II included 4086 patients with RA who received etorikoksib in a dose of 90 mg per day or diclofenac in a dose of 150 mg per day for an average of 19.2 months (a maximum of 33.1 months, a median of 24 months).
In the joint program MEDAL analyzed data on the treatment of 34701 patients with OA or RA, the average duration of treatment was 17.9 months (maximum 42.3 months, median 16.3 months), with approximately 12 800 patients receiving treatment for more than 24 months. Patients included in the program, with the initial evaluation, had a wide range of cardiovascular and gastrointestinal risk factors. Patients who had a recent history of myocardial infarction (MI), coronary artery bypass grafting, or percutaneous coronary intervention for 6 months prior to enrollment were excluded. In studies, it was permitted to use gastroprotectors and low doses of aspirin.
General security
There were no significant differences between etorikoksibom and diclofenac with respect to the incidence of cardiovascular thrombotic events. Cardiorenal adverse events were more often observed with etorikoksib compared with diclofenac, the effect was dose-dependent (see results below). Adverse events from the gastrointestinal tract and liver significantly more often with diclofenac than with etorikoksib.
Frequency of adverse events in studies EDGE and EDGE II and undesirable phenomena recognized as serious or requiring withdrawal of treatment, in the study MEDAL was higher when taking etorikoksiba compared with diclofenac.
Results of the safety study for the cardiovascular system
The incidence of confirmed serious thrombotic cardiovascular adverse events (including cardiac, cerebrovascular and peripheral vascular events) was comparable between the groups receiving etorikoksib or diclofenac (the data are given in the table below). There were no statistically significant differences in the incidence of thrombotic events between etorikoksibom and diclofenac in all of the subgroups analyzed, including those in patients with an increased risk of cardiovascular complications. The relative risk for confirmed serious cardiovascular thrombotic adverse events was similar when taking etorikoksiba at a dose of 60 mg or 90 mg and diclofenac at a dose of 150 mg.
The incidence of confirmed thrombotic cardiovascular serious adverse events (Joint Program MEDAL) |
| Etoricoxib (N = 16819) 25,836 patient-years
| Diclofenac (N = 16483) 24,766 patient-years
| Comparison between treatments |
Frequency1 (95% CI) | Frequency1 (95% CI) | Relative risk (95% CI) |
Confirmed thrombotic cardiovascular serious adverse events |
When fulfilling protocol requirements (Per protocol) | 1,24 (1,11; 1,38) | 1,30 (1,17; 1,45) | 0,95 (0,81; 1,11) |
Depending on the treatment prescribed (Intent-to-treat) | 1,25 (1,14; 1,36) | 1,19 (1,08; 1,30) | 1,05 (0,93; 1,19) |
Evidence from the heart |
When fulfilling protocol requirements (Per protocol) | 0,71 (0,61; 0,82) | 0,78 (0,68; 0,90) | 0,90 (0,74; 1,10) |
Depending on the treatment prescribed (Intent-to-treat) | 0,69 (0,61; 0,78) | 0,70 (0,62; 0,79) | 0,99 (0,84; 1,17) |
Confirmed cerebrovascular events |
When fulfilling protocol requirements (Per protocol) | 0,34 (0,28; 0,42) | 0,32 (0,25; 0,40) | 1,08 (0,80; 1,46) |
Depending on the treatment prescribed (Intent-to-treat) | 0,33 (0,28; 0,39) | 0,29 (0,24; 0,35) | 1,12 (0,87; 1,44) |
Confirmed phenomena from the peripheral vascular system |
When fulfilling protocol requirements (Per protocol) | 0,20 (0,15; 0,27) | 0,22 (0,17; 0,29) | 0,92 (0,63; 1,35) |
Depending on the treatment prescribed (Intent-to-treat) | 0,24 (0,20; 0,30) | 0,23 (0,18; 0,28) | 1,08 (0,81; 1,44) |
1 the number of phenomena per 100 patient-years; CI = confidence interval; N = total number of patients who fulfilled the protocol requirements. When fulfilling the requirements of the protocol: all the phenomena that developed against the background of the therapy being studied or within 14 days after its termination (patients who took <75% of the study drug or took non-NSAIDs> 10% of the time were excluded). Depending on the treatment prescribed: all confirmed events that developed before the end of the study (including patients who may have been subjected to non-intervention interventions after discontinuing the study medications). Total number of randomized patients: n = 17 412 for etoricoxib and n = 17 289 for diclofenac. |
Mortality from cardiovascular events, as well as overall mortality in treatment groups with ethoricoxib and diclofenac were comparable.
Cardiorenal phenomena
Approximately 50% of patients included in the study MEDAL, at an initial assessment in the history the arterial hypertensia has been registered. In the study, the dropout rate due to adverse events associated with hypertension was statistically significantly higher with etorikoksib compared with diclofenac. The incidence of adverse events associated with chronic heart failure (dropout or serious adverse events) was similar in the 60 mg and 56 mg diclofenac groups, but was higher for etoricoxib 90 mg than diclofenac indose 150 mg (and statistically significantly higher for etorikoksiba at a dose of 90 mg compared with diclofenac at a dose of 150 mg in the study MEDAL in patients with OA). The incidence of confirmed adverse events associated with chronic heart failure (serious, leading to hospitalization or the need for emergency care) was slightly higher for etorikoksiba compared with diclofenac at a dose of 150 mg, the effect was dose-dependent. The frequency of dropout cases due to adverse events associated with edema was higher for etorikoksiba compared with diclofenac 150 mg, the effect was dose-dependent (statistically significant for etorikoksiba at a dose of 90 mg, but not for etorikoksiba at a dose of 60 mg).
Results of assessing cardiorenal safety in studies EDGE and EDGE II are consistent with the results in the study MEDAL
In separate studies of the program MEDAL The absolute drop-out rate in any treatment group with etorikoksib (60 mg or 90 mg) was 2.6% with arterial hypertension, 1.9% with edema, and 1.1% with chronic heart failure. In patients who took etorikoksib in a dose of 90 mg, the drop-out rate was higher than in patients taking etorikoksib in a dose of 60 mg.
Results of the evaluation of gastrointestinal tolerance in the Program MEDAL
In each of the three studies included in the program MEDAL, the frequency of dropout from the study for any clinical adverse events on the part of the digestive tract (for example, dyspepsia, abdominal pain, ulcers) was significantly lower for etorikoksiba compared with diclofenac. The dropout rate due to undesirable GIT clinical events per 100 patient-years for the entire study period was 3.23 for etoricoxib and 4.96 for diclofenac in the study MEDAL; 9.12 for etoricoxib and 12.28 for diclofenac in the study EDGE; 3.71 for etoricoxib and 4.81 for diclofenac in the study EDGE II.
The results of the evaluation of GI safety in the Program MEDAL
To undesirable phenomena from the upper part of the gastrointestinal tract were perforations, ulcers and bleeding. Complicated undesirable phenomena from the upper gastrointestinal tract included perforation, obstruction and complicated bleeding; uncomplicated phenomena included uncomplicated bleeding and uncomplicated ulcers.When taking etorikoksiba compared with diclofenac, the overall incidence of adverse events from the upper gastrointestinal tract was significantly lower. There were no significant differences between etorikoksibom and diclofenac in the frequency of complicated adverse events. For cases of bleeding from the upper gastrointestinal tract (complicated and uncomplicated), there were no significant differences between etorikoksib and diclofenac. The advantage of etorikoksib compared with diclofenac for complications from the upper gastrointestinal tract was not statistically significant in patients taking aspirin at low doses (about 33% of patients).
The incidence of confirmed complicated and uncomplicated clinical adverse events from the upper gastrointestinal tract for 100 patient-years (perforation, ulcers and bleeding) was 0.67 (95% CI: 0.57, 0.77) for etoricoxib and 0.97 (95 % CI: 0.85, 1.10) for diclofenac, the relative risk was 0.69 (95% CI: 0.57, 0.83).
In assessing the incidence of confirmed clinical adverse events from the upper GI tract in elderly patients, a maximum reduction was observed in patients aged ≥75 years in the etorikoksib group compared with diclofenac 1.35 (95% CI: 0.94, 1.87) and 2.78 (95% CI: 2.14, 3.56) per 100 patient-years, respectively.
The incidence of confirmed adverse events from the lower part of the digestive tract (perforation of the small or large intestine, obstruction, bleeding) did not differ significantly between the groups taking etorikoksib and diclofenac.
The results of the liver safety assessment in the Program MEDAL
When taking etorikoksiba compared with diclofenac, a statistically significantly lower incidence of dropout from the study due to adverse events on the part of the liver was observed. In the joint program MEDAL 0.3% of patients taking etorikoksib, and 2.7% of patients taking diclofenac, withdrew from the study due to adverse events on the part of the liver. The incidence of adverse events per 100 patient-years was 0.22 for etoricoxib and 1.84 for diclofenac (p <0.001 for etoricoxib compared to diclofenac). Most of the adverse events on the part of the liver in the Program MEDAL were not serious.
Additional safety data associated with thrombotic cardiovascular events
In clinical trials, with the exception of the Program MEDAL, approximately 3100 patients received etorikoksib in a dose of ≥60 mg per day for 12 weeks or longer. In these studies, there were no significant differences in the incidence of confirmed serious thrombotic cardiovascular events in patients who received etorikoksib in a dose ≥60 mg, placebo or NSAIDs that do not contain naproxen. However, in comparison with patients receiving naproxen in a dose of 500 mg twice a day, the frequency of these events was higher in patients who received etorikoksib. The difference in antiaggregant activity between some NSAIDs that inhibit COX-1 and selective inhibitors of COX-2 may be of clinical importance in patients at risk of thromboembolic events. Selective inhibitors of COX-2 inhibit the formation of systemic (and, possibly, endothelial) prostacyclin without affecting platelet thromboxane. The clinical significance of these observations is not established.
Additional safety data for the digestive tract In two 12-week, double-blind endoscopic studies, the cumulative incidence of gastroduodenal ulcers was significantly lower in patients receiving etorikoksib in a dose of 120 mg once a day than in patients who received naproxen 500 mg twice daily or ibuprofen 800 mg three times a day. The frequency of ulceration in the appointment of etorikoksib was higher compared with placebo.
The study of renal function in elderly patients
In a randomized, double-blind, placebo-controlled study in parallel groups, the effect of 15-day therapy with etoricoxib (90 mg), celecoxib (200 mg twice daily), naproxen (500 mg twice daily), compared with placebo for kidney sodium excretion , blood pressure (BP) and other parameters of kidney function in patients aged 60 to 85 years who received a diet with limited sodium intake up to 200 meq / day.
Etoricoxib, celecoxib and naproxen had similar effects on the excretion of sodium by the kidneys after 2 weeks of treatment. All active comparators showed an increase in systolic blood pressure compared with placebo, however, etorikoksib caused a statistically significant increase in systolic blood pressure on the 14th day compared with celecoxib and naproxen (mean change in systolic blood pressure compared to baseline: etorikoksib 7.7 mm Hg. Art. celecoxib 2.4 mm Hg. Art. naproxen 3.6 mm of mercury. st.).