Safety and Efficacy of Long-Term Deutetrabenazine Use in Children and Adolescents with Tics Associated with Tourette Syndrome: An Open-Label Extension Study

Background

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by motor and phonic tics.

Objective

To assess the safety and efficacy of deutetrabenazine (Teva Neuroscience, Inc, Parsippany, NJ), a vesicular monoamine transporter 2 inhibitor, in children and adolescents with TS.

Methods

Alternatives for Reducing Tics in TS (ARTISTS) open-label extension (OLE) (NCT03567291) was a 54-week, global, phase 3, open-label extension study of deutetrabenazine (6-48 mg daily) conducted May 28, 2018 to April 3, 2020 with a 2-week randomized withdrawal period. Participants (6-16 years of age) had TS and active tics causing distress or impairment. Safety (primary outcome) was assessed by treatment-emergent adverse events (TEAEs) and clinical laboratory testing. Efficacy was measured by the Yale Global Tic Severity Scale-Total Tic Score (YGTSS-TTS).

Results

The intent-to-treat population (228 participants; mean age, 12.0 years; 79.8% male; 86.4% white) had a median (range) duration of exposure of 28.4 (0.3-52.9) weeks. Of 227 participants in the safety analysis, 161 (70.9%) reported ≥1 TEAE (exposure-adjusted incidence rate, 2.77/patient-year), of which 95 (41.9%) were treatment related. The most frequently reported TEAEs were headaches, somnolence, nasopharyngitis, weight increases, and anxiety. No additional safety signals were observed. Worsening of YGTSS-TTS after the 2-week randomized withdrawal was not statistically significant (least squares mean difference, -0.4; P = 0.78). Several exploratory measures showed sustained improvement throughout the treatment periods.

Conclusions

In this long-term, open-label trial, deutetrabenazine was well tolerated with low frequency of TEAEs. There was no significant difference in tics between treatment arms during the 2-week randomized withdrawal period, however, descriptive statistics and comparison with baseline showed a numeric improvement in tics, quality of life, and other measures.

Safety and Efficacy of Flexible-Dose Deutetrabenazine in Children and Adolescents With Tourette Syndrome: A Randomized Clinical Trial

IMPORTANCE

Tourette syndrome is a neurodevelopmental disorder characterized by childhood onset of motor and phonic tics; treatments for tics are associated with safety concerns. Deutetrabenazine is a selective vesicular monoamine transporter 2 inhibitor approved for the treatment of chorea associated with Huntington disease and tardive dyskinesia in adults.

OBJECTIVE

To examine whether deutetrabenazine is effective and safe for the treatment of Tourette syndrome in children and adolescents.

DESIGN, SETTING, AND PARTICIPANTS

This phase 2/3, randomized, double-masked, placebo-controlled, parallel-group, dose-titration study included children and adolescents (aged 6-16 years) with Tourette syndrome with active tics causing distress or impairment (ie, Yale Global Tic Severity Scale-Total Tic Score [YGTSS-TTS] ≥20). The trial was conducted over 12 weeks, with 1 week of follow-up from February 2018 to November 2019 at 36 centers in the United States, Canada, Denmark, Russia, Serbia, and Spain. Data analysis was conducted from January 31 to April 22, 2020.

INTERVENTION

Patients were randomized (1:1) to receive deutetrabenazine or placebo, titrated during 7 weeks to an optimal level, followed by a 5-week maintenance period. The maximum total daily deutetrabenazine dose was 48 mg/d.

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was change from baseline to week 12 in YGTSS-TTS. Key secondary end points included changes in Tourette Syndrome-Clinical Global Impression, Tourette Syndrome-Patient Global Impression of Impact, and Child and Adolescent Gilles de la Tourette Syndrome-Quality of Life Activities of Daily Living subscale score. Safety was assessed based on treatment-emergent adverse events, vital signs, questionnaires, and laboratory parameters.

RESULTS

A total of 119 participants were randomized to deutetrabenazine (59 participants; mean [SD] age, 11.5 [2.5] years; 53 [90%] boys; 49 [83%] White; 3 [5%] Black) and placebo (60 participants; mean [SD] age, 11.5 [2.6] years; 51 [85%] boys; 53 [88%] White; 3 [5%] Black). At week 12, the difference in YGTSS-TTS score was not significant between deutetrabenazine and placebo (least squares mean difference, -0.7; 95% CI, -4.1 to 2.8; P = .69; Cohen d, -0.07). There were no nominally significant differences between groups for key secondary end points. Treatment-emergent adverse events were reported for 38 patients (66%) and 33 patients (56%) receiving deutetrabenazine and placebo, respectively, and were generally mild or moderate.

CONCLUSIONS AND RELEVANCE

In this study of deutetrabenazine in children and adolescents with Tourette syndrome, the primary efficacy end point was not met. No new safety signals were identified. These results may be informative for future studies of treatments for tics in Tourette syndrome.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03452943.

Efficacy and Safety of Fixed-Dose Deutetrabenazine in Children and Adolescents for Tics Associated With Tourette Syndrome: A Randomized Clinical Trial

IMPORTANCE

Tourette syndrome is a neurodevelopmental disorder characterized by childhood onset of motor and phonic tics, often accompanied by behavioral and psychiatric comorbidities. Deutetrabenazine is a vesicular monoamine transporter 2 inhibitor approved in the US for the treatment of chorea associated with Huntington disease and tardive dyskinesia.

OBJECTIVE

To report results of the ARTISTS 2 (Alternatives for Reducing Tics in Tourette Syndrome 2) study examining deutetrabenazine for treatment of Tourette syndrome.

DESIGN, SETTING, AND PARTICIPANTS

This phase 3, randomized, double-blind, placebo-controlled, parallel-group, fixed-dose study was conducted over 8 weeks with a 1-week follow-up (June 21, 2018, to December 9, 2019). Children and adolescents aged 6 to 16 years with a diagnosis of Tourette syndrome and active tics causing distress or impairment were enrolled in the study. Children were recruited from 52 sites in 10 countries. Data were analyzed from February 4 to April 22, 2020.

INTERVENTIONS

Participants were randomized (1:1:1) to low-dose deutetrabenazine (up to 36 mg/d), high-dose deutetrabenazine (up to 48 mg/d), or a matching placebo, which were titrated over 4 weeks to the target dose followed by a 4-week maintenance period.

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was change from baseline to week 8 in the Yale Global Tic Severity Scale-Total Tic Score (YGTSS-TTS) for high-dose deutetrabenazine. Key secondary end points included changes in YGTSS-TTS for low-dose deutetrabenazine, Tourette Syndrome Clinical Global Impression score, Tourette Syndrome Patient Global Impression of Impact score, and Child and Adolescent Gilles de la Tourette Syndrome-Quality of Life Activities of Daily Living subscale score. Safety assessments included incidence of treatment-emergent adverse events, laboratory parameters, vital signs, and questionnaires.

RESULTS

The study included 158 children and adolescents (mean [SD] age, 11.7 [2.6] years). A total of 119 participants (75%) were boys; 7 (4%), Asian; 1 (1%), Black; 32 (20%), Hispanic; 4 (3%), Native American; 135 (85%), White; 2 (1%), multiracial; 9 (6%), other race; and 1 (0.6%), of unknown ethnic origin. Fifty-two participants were randomized to the high-dose deutetrabenazine group, 54 to the low-dose deutetrabenazine group, and 52 to the placebo group. Baseline characteristics for participants were similar between groups. Of the total 158 participants, 64 (41%) were aged 6 to 11 years, and 94 (59%) were aged 12 to 16 years at baseline. Mean time since Tourette syndrome diagnosis was 3.3 (2.8) years, and mean baseline YGTSS-TTS was 33.8 (6.6) points. At week 8, the difference in YGTSS-TTS was not significant between the high-dose deutetrabenazine and placebo groups (least-squares mean difference, -0.8 points; 95% CI, -3.9 to 2.3 points; P = .60; Cohen d, -0.11). There were no nominally significant differences between groups for key secondary end points. Treatment-emergent adverse events were reported for 34 participants (65%) treated with high-dose deutetrabenazine, 24 (44%) treated with low-dose deutetrabenazine, and 25 (49%) treated with placebo and were generally mild or moderate.

CONCLUSIONS AND RELEVANCE

In this fixed-dose randomized clinical trial of deutetrabenazine in children and adolescents with Tourette syndrome, the primary efficacy end point was not met. No new safety signals were identified.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03571256.

Pharmacokinetic evaluation of rofecoxib : comparison of tablet and suspension formulations

OBJECTIVE

Rofecoxib suspension is a formulation developed to increase the convenience of rofecoxib therapy for patients who have difficulty swallowing tablets. This open-label, two-part study compared the single-dose pharmacokinetics of rofecoxib tablets and rofecoxib suspension in healthy subjects.

DESIGN AND STUDY PARTICIPANTS

Part I was a two-period crossover study that assessed the bioequivalence of the 12.5mg/5mL rofecoxib suspension and the 12.5mg rofecoxib tablet in 24 healthy subjects (12 men and 12 women). Part II was a crossover study in 24 additional healthy subjects (12 men and 12 women) that determined the bioequivalence of the rofecoxib 25mg/5mL suspension and the 25mg rofecoxib tablet.

RESULTS

No clinically meaningful differences between rofecoxib tablet and suspension were apparent with respect to the rofecoxib area under the concentration-time curve from time zero to infinity (AUC(0-infinity)) and maximum plasma concentration (C(max)), the primary measures of bioequivalence. At the 12.5mg and 25mg doses, the 90% CI for the geometric mean ratio (suspension/tablet) of both AUC(0-infinity) and C(max) fell within the prespecified interval for bioequivalence (0.80-1.25).

CONCLUSIONS

The rofecoxib suspension is bioequivalent to the rofecoxib tablet at single oral doses of 12.5mg and 25mg in healthy volunteers. The convenience and ease of administration of rofecoxib suspension may translate into increased compliance with therapy compared with a conventional solid tablet formulation, particularly for elderly patients.

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.

Selective COX-2 inhibition and cardiovascular effects: a review of the rofecoxib development program

See related Editorials on pages 561 and 563. Cyclo-oxygenase-2 (COX-2) inhibitors appear to alter the balance of vasoactive eicosanoids (prostacyclin and thromboxane) and to suppress the inflammatory mediators implicated in the progression of atherogenesis and ischemic myocardial injury. Neutral, harmful, and beneficial cardiovascular (CV) effects have all been postulated to result from these changes. Investigations conducted with rofecoxib, a selective COX-2 inhibitor, have substantially contributed to our understanding of this scientific area. Rofecoxib had little or no effect on platelet aggregation or platelet-derived thromboxane synthesis but reduced systemic prostacyclin synthesis by 50% to 60%. These findings prompted extensive analyses of CV thrombotic events within the rofecoxib development program. Among 5435 osteoarthritis trial participants, similar rates of CV thrombotic events were reported with rofecoxib, placebo, and comparator, nonselective NSAIDs (ibuprofen, diclofenac, and nabumetone). In the VIGOR gastrointestinal outcomes trial of >8000 patients, naproxen (an NSAID with aspirin-like sustained antiplatelet effects throughout its dosing interval) was associated with a significantly lower risk of CV events than was rofecoxib. A subsequent pooled analysis from 23 studies (including VIGOR) encompassing multiple disease states and including more than 14,000 patient-years at risk also demonstrated that rofecoxib was not associated with excess CV thrombotic events compared with either placebo or nonnaproxen NSAIDs. Again, naproxen appeared to be the outlier, suggesting a cardioprotective benefit of naproxen. Finally, among the predominantly elderly, male population participating in Alzheimer trials, both rofecoxib- and placebo-treated patients had similar rates of CV thrombotic events. The totality of data is not consistent with an increased CV risk among patients taking rofecoxib.

Effects of renal insufficiency and hemodialysis on the pharmacokinetics of rofecoxib

Rofecoxib (VIOXX, Merck & Co., West Point, PA) is a COX-2-selective inhibitor that combines anti-inflammatory and analgesic efficacy with improved gastrointestinal (GI) safety. The present open-label study investigated the pharmacokinetics, safety, and tolerability of a single, oral dose of rofecoxib (50 mg) in patients with end-stage renal failure (creatinine clearance <5 mL/min/1.73 m(2)) requiring hemodialysis. Rofecoxib AUC(0-48 h), AUC(0- infinity), C(max), T(max), and t(1/2) obtained from renal failure patients on hemodialysis were not significantly different from those obtained from healthy subjects. With hemodialysis initiated 48 hours postdose, rofecoxib AUC(0-48 h) adjusted mean ratio (renal failure/healthy subjects) was 0.81, with a corresponding 90% confidence interval (CI; 0.66, 1.00). Hemodialysis per se had no clinically meaningful effect on rofecoxib pharmacokinetics: plasma rofecoxib concentration-time curves were virtually superimposable when hemodialysis was initiated at 4 or 48 hours following rofecoxib dosing, although mean rofecoxib C(max) was 18% lower during the former (325 versus 395 ng/mL; P = 0.014). Overall, rofecoxib was well tolerated in end-stage renal disease patients. In this study, end-stage renal disease and hemodialysis had little effect on rofecoxib pharmacokinetics. Although there are no clinical data to support the use of rofecoxib in patients with severe renal insufficiency (creatinine clearance, 5-30 mL/min/1.73 m(2)), these data suggest that dosage adjustment of rofecoxib is not needed for patients with impaired renal function.

Efficacy and safety of rofecoxib in patients with chronic low back pain: results from two 4-week, randomized, placebo-controlled, parallel-group, double-blind trials

STUDY DESIGN

Two replicate, 4-week, randomized, double-blind, placebo-controlled, trials of rofecoxib 25 and 50 mg versus placebo for chronic low back pain.

OBJECTIVES

To determine the efficacy and safety of two doses of rofecoxib compared to placebo in the treatment of chronic low back pain.

SUMMARY OF BACKGROUND DATA

Although nonsteroidal anti-inflammatory drugs are commonly prescribed for chronic low back pain, their efficacy is unproven and toxicity can be serious. These studies evaluated the efficacy and tolerability of rofecoxib, a selective COX-2 inhibitor, in the treatment of chronic low back pain.

METHODS

Patients with chronic low back pain were randomized 1:1:1 to rofecoxib 25 mg, 50 mg, or placebo once daily. Primary endpoint: Low Back Pain Intensity. Secondary endpoints: Pain Bothersomeness, Global Assessments of Response to Therapy, Global Assessment of Disease Status, Roland-Morris Disability Questionnaire, SF-12 Health Survey, Use of Rescue Acetaminophen, and Discontinuations Due to Lack of Efficacy.

RESULTS

Combining both studies, 690 patients were randomized to placebo (N = 228), rofecoxib 25 mg (N = 233), or rofecoxib 50 mg (N = 229). Mean (+/- SD) age was 53.4 (+/- 12.9) years, pain duration 12.1 (+/- 11.8) years, 62.3% female. Both rofecoxib groups improved significantly. Mean differences from placebo in pain intensity were -13.50 mm, -13.81 mm (25, 50 mg doses) respectively (P < 0.001). Both regimens were superior to placebo in eight of nine secondary endpoints. Fifty mg provided no advantage over 25 mg. Both rofecoxib regimens were well tolerated, although 25 mg had a slightly better safety profile.

CONCLUSIONS

Rofecoxib significantly reduced chronic low back pain in adults and was well tolerated.

Effect of rofecoxib on prednisolone and prednisone pharmacokinetics in healthy subjects

Patients receiving nonsteroidal anti-inflammatory drug therapy may also require administration of corticosteroids, particularly patients with rheumatoid arthritis. To investigate the effect of rofecoxib on the single-dose pharmacokinetics of oral prednisone and intravenous prednisolone, the authors conducted a randomized, double-blind, placebo-controlled crossover study in 12 healthy subjects. Oral rofecoxib (250.0 mg/day for 14 days) failed to influence prednisone or prednisolone pharmacokinetics after intravenous prednisolone or oral prednisone administration. The geometric mean ratio (GMR) (90% confidence interval) of prednisolone AUC infinity (rofecoxib/placebo) following intravenous and oral corticosteroid was 0.97 (0.94, 1.01) and 0.99 (0.91, 1.08), respectively. Similarly, the prednisone AUC infinity GMRs (rofecoxib/placebo) after intravenous and oral corticosteroid were 1.03 (0.95, 1.11) and 1.08 (0.92, 1.28), respectively. The absence of an effect of rofecoxib on the pharmacokinetics of oral prednisone or intravenous prednisolone indicates that no adjustment in dose of this corticosteroid is necessary when administered concurrently with rofecoxib.

Results of a randomized, dose-ranging trial of etoricoxib in patients with osteoarthritis

OBJECTIVES

To evaluate the clinical efficacy and tolerability of etoricoxib in the treatment of osteoarthritis (OA) of the knee and define the clinically active dose range for further clinical trials.

METHODS

This two-part, randomized, double-blind, placebo- and active comparator-controlled trial was conducted in 617 adults with knee OA. In Part 1 (6 weeks), patients received placebo, etoricoxib 5, 10, 30, 60 or 90 mg q.d. In Part 2 (8 weeks), patients received etoricoxib 30, 60 or 90 mg q.d. or diclofenac 50 mg t.i.d., predetermined at Part 1 allocation. Efficacy and safety were evaluated. Primary efficacy end-points were the Western Ontario and McMaster's University Osteoarthritis Index (WOMAC) Pain subscale, Patient Global Assessment of Response to Therapy, and Investigator Global Assessment of Disease Status.

RESULTS

At 6 weeks, etoricoxib 5, 10, 30, 60 and 90 mg each demonstrated clinical efficacy superior to placebo. Maximal efficacy was seen with 60 mg. In Part 2, etoricoxib 30, 60 and 90 mg were generally similar to diclofenac. Patients receiving etoricoxib 30, 60 or 90 mg in Parts I and II had sustained effects over 14 weeks. All treatments were well tolerated.

CONCLUSIONS

Etoricoxib 60 mg once daily showed maximal efficacy in treating OA in this study. Etoricoxib 5-90 mg once daily was generally well tolerated in OA patients for up to 14 weeks.

A randomized, controlled, clinical trial of etoricoxib in the treatment of rheumatoid arthritis

OBJECTIVE

To evaluate the efficacy and tolerability of the highly selective cyclooxygenase-2 (COX-2) inhibitor etoricoxib for the treatment of rheumatoid arthritis (RA).

METHODS

A double blind, randomized, placebo and active comparator controlled, 12 week study conducted at 88 US sites. Eligible patients were chronic nonsteroidal antiinflammatory drug (NSAID) users with clinical worsening of RA upon withdrawal of prestudy NSAID. Patients received either placebo, etoricoxib 90 mg once daily, or naproxen 500 mg twice daily (2:2:1 allocation ratio). Primary efficacy measures: patient and investigator global assessments of disease activity and direct assessment of arthritis by counts of tender and swollen joints. Key secondary measures: patient global assessment of pain, the Stanford Health Assessment Questionnaire, and the percentage of patients both completing the study and meeting the ACR20 criteria. Tolerability was assessed by tabulation of adverse events and routine laboratory evaluations.

RESULTS

In all, 816 patients were randomized (placebo = 323, etoricoxib = 323, naproxen = 170), and 448 completed 12 weeks of treatment (placebo = 122, etoricoxib = 230, naproxen = 96). Compared with patients receiving placebo, patients receiving etoricoxib and naproxen showed significant improvements in all efficacy endpoints (p < 0.01). Compared with patients receiving naproxen, patients receiving etoricoxib demonstrated significant improvements (p < 0.05) on all primary endpoints and most other endpoints including ACR20 criteria. The percentage of patients who achieved an ACR20 response and who completed the study was 21%, 53%, and 39% in the placebo, etoricoxib and naproxen groups, respectively. Etoricoxib and naproxen were both generally well tolerated.

CONCLUSION

In this study, etoricoxib 90 mg once daily was more effective than either placebo or naproxen 500 mg twice daily for treating patients with RA over 12 weeks. Etoricoxib 90 mg was generally well tolerated in patients with RA.

Comparison of rofecoxib, celecoxib, and naproxen on renal function in elderly subjects receiving a normal-salt diet

BACKGROUND

This study compared directly the renal effects of two selective cyclooxygenase (COX)-2 inhibitors (rofecoxib and celecoxib) with naproxen (dual COX-1/COX-2 inhibitor) and placebo in healthy elderly subjects on a sodium-replete diet.

METHODS

A total of 67 elderly subjects stabilized in the clinic for weight and urinary sodium on a controlled 200-mEq sodium diet were randomized in a double-blind fashion to receive rofecoxib, 25 mg daily (n = 17); celecoxib, 200 mg twice daily (n = 17); naproxen, 500 mg twice daily (n = 17); or matching placebo (n = 16) for 28 days. Subjects were sequestered in the clinic for the first 14 treatment days on the controlled diet.

RESULTS

Daily urinary sodium excretion during the first 72 hours of treatment (primary endpoint) significantly decreased in rofecoxib, celecoxib, and naproxen groups compared with baseline (P < or =.05). Rofecoxib and celecoxib decreases in urinary sodium excretion rates that were comparable with each other, on the basis of predefined boundaries (-39.5 versus -27.1 mEq/d, respectively) and to naproxen (-40.6, mEq/d). Rofecoxib, celecoxib, and naproxen increased mean systolic blood pressure to a similar degree (3.4, 4.3, and 3.1 mm Hg, respectively, versus -1.3 mm Hg for placebo) after 14 days of treatment; small changes also occurred in diastolic blood pressure (0.3, 0.8, and -0.4 mm Hg, respectively, versus -1.4 mm Hg for placebo). Changes from baseline in creatinine clearance, body weight, and urinary potassium excretion among active treatments were similar. After 28 days of treatment, findings were generally consistent with those at 14 days. No subject reported edema or discontinued treatment as the result of an adverse experience.

CONCLUSION

In healthy elderly subjects on a sodium-replete diet, the COX-2 inhibitors rofecoxib and celecoxib did not differ from a nonselective nonsteroidal anti-inflammatory drug (naproxen), in influencing renal function as measured by urinary sodium excretion, systolic and diastolic blood pressure, creatinine clearance, or weight change.

Prevention of cisplatin-induced acute and delayed emesis by the selective neurokinin-1 antagonists, L-758,298 and MK-869

BACKGROUND

Recent studies have suggested that antiemetic therapy with a triple combination of the neurokinin-1 receptor antagonist MK-869, a serotonin (5-HT(3)) antagonist, and dexamethasone provides enhanced control of cisplatin-induced emesis compared with standard therapy regimens. The authors compared the antiemetic activity of a dual combination of MK-869 and dexamethasone with that of a standard dual combination of ondansetron and dexamethasone to characterize further the efficacy and tolerability profile of MK-869.

METHODS

This was a multicenter, double-blind, randomized, active agent-controlled study of 177 cisplatin-naïve patients with malignant disease. On Day 1, MK-869 was given intravenously as its water-soluble prodrug, L-758,298. Patients were randomized to one of three groups as follows. Group I received L-758,298 100 mg intravenously (i.v.), then dexamethasone 20 mg i.v., and cisplatin >or= 70 mg/m(2) on Day 1 followed by 300 mg MK-869 (tablet) orally on Days 2-5; Group II received L-758,298 100 mg i.v., then dexamethasone 20 mg i.v., and cisplatin >or= 70 mg/m(2) on Day 1 followed by placebo on Days 2-5; and Group III received ondansetron 32 mg i.v., then dexamethasone 20 mg i.v., and cisplatin >or= 70 mg/m(2) on Day 1 followed by placebo on Days 2-5. Emesis was recorded over Days 1-5 in a diary. Nausea was assessed every 24 hours by visual analog scale. Additional medication was available for emesis or nausea at any time. The primary efficacy parameters of interest were the proportion of patients without emesis and the proportion without emesis or rescue therapy on Day 1 (acute phase) and on Days 2-5 (delayed phase).

RESULTS

No serious adverse events were attributed to L-758,298 or MK-869. On Day 1, the proportions of patients with no emesis and no use of rescue medication were 44% of patients in Group I, 36% of patients in Group II, 40% of patients in Groups I and II combined, and 83% of patients in Group III (P < 0.001 for Group III vs. the combined Groups I and II). The proportions of patients with no emesis and no use of rescue medication on Days 2-5 were 59% of patients in Group I, 46% of patients in Group II, and 38% of patients in Group III (P < 0.05 for Group I vs. Group III). The proportions of patients who were without emesis on Day 1 were 49% of patients in Group I, 47% of patients in Group II, and 84% of patients in Group III (P < 0.01 for Group I or II vs. Group III). On Days 2-5, however, the proportions of patients who were without emesis on Days 2-5 were 65% of patients in Group I, 61% of patients in Group II, and 41% of patients in Group III (P < 0.05 for Group I or II vs. Group III). Nausea scores in the acute phase were lower for Group III than for Group I, Group II, or Groups I and II combined (P < 0.05), although there was no significant difference among groups either for the delayed phase or overall for Days 1-5.

CONCLUSIONS

Although the L-758,298 and dexamethasone combination reduced acute (Day 1) emesis compared with historic rates, dual therapy with ondansetron and dexamethasone was superior in controlling acute emesis. Continued dosing with MK-869 may enhance control of other measures of delayed emesis, such as the use of rescue medication, although confirmation is required before a definitive conclusion may be drawn. MK-869 given as dual therapy with dexamethasone was superior to ondansetron with dexamethasone for the control of delayed emesis (Days 2-5) and control of the need for rescue medication on Days 2-5.

A multinational randomized, controlled, clinical trial of etoricoxib in the treatment of rheumatoid arthritis [ISRCTN25142273]

BACKGROUND

Etoricoxib is a highly selective COX-2 inhibitor which was evaluated for the treatment of rheumatoid arthritis (RA).

METHODS

Double-blind, randomized, placebo and active comparator-controlled, 12-week study conducted at 67 sites in 28 countries. Eligible patients were chronic NSAID users who demonstrated a clinical worsening of arthritis upon withdrawal of prestudy NSAIDs. Patients received either placebo, etoricoxib 90 mg once daily, or naproxen 500 mg twice daily (2:2:1 allocation ratio). Primary efficacy measures included direct assessment of arthritis by counts of tender and swollen joints, and patient and investigator global assessments of disease activity. Key secondary measures included the Stanford Health Assessment Questionnaire, patient global assessment of pain, and the percentage of patients who achieved ACR20 responder criteria response (a composite of pain, inflammation, function, and global assessments). Tolerability was assessed by adverse events and routine laboratory evaluations.

RESULTS

1171 patients were screened, 891 patients were randomized (N = 357 for placebo, N = 353 for etoricoxib, and N = 181 for naproxen), and 687 completed 12 weeks of treatment (N = 242 for placebo, N = 294 for etoricoxib, and N = 151 for naproxen). Compared with patients receiving placebo, patients receiving etoricoxib and naproxen showed significant improvements in all efficacy endpoints (p<0.05). Treatment responses were similar between the etoricoxib and naproxen groups for all endpoints. The percentage of patients who achieved ACR20 responder criteria response was 41% in the placebo group, 59% in the etoricoxib group, and 58% in the naproxen group. Etoricoxib and naproxen were both generally well tolerated.

CONCLUSIONS

In this study, etoricoxib 90 mg once daily was more effective than placebo and similar in efficacy to naproxen 500 mg twice daily for treating patients with RA over 12 weeks. Etoricoxib 90 mg was generally well tolerated in RA patients.

Induction of adipocyte complement-related protein of 30 kilodaltons by PPARgamma agonists: a potential mechanism of insulin sensitization

Adipocyte complement-related protein of 30 kDa (Acrp30, adiponectin, or AdipoQ) is a fat-derived secreted protein that circulates in plasma. Adipose tissue expression of Acrp30 is lower in insulin-resistant states and it is implicated in the regulation of in vivo insulin sensitivity. Here we have characterized the ability of PPARgamma agonists to modulate Acrp30 expression. After chronic treatment of obese-diabetic (db/db) mice with PPARgamma agonists (11 d), mean plasma Acrp30 protein levels increased (>3x). Similar effects were noted in a nongenetic type 2 diabetes model (fat-fed and low-dose streptozotocin-treated mice). In contrast, treatment of mice (db/db or fat-fed) with metformin or a PPARalpha agonist did not affect plasma Acrp30 protein levels. In a cohort of normal human subjects, 14-d treatment with rosiglitazone also produced a 130% increase in circulating Acrp30 levels vs. placebo. In addition, circulating Acrp30 levels were suppressed 5-fold in patients with severe insulin resistance in association with dominant-negative PPARgamma mutations. Thus, induction of adipose tissue Acrp30 expression and consequent increases in circulating Acrp30 levels represents a novel potential mechanism for PPARgamma-mediated enhancement of whole-body insulin sensitivity. Furthermore, Acrp30 is likely to be a biomarker of in vivo PPARgamma activation.

Effect of rofecoxib on the pharmacokinetics of chronically administered oral contraceptives in healthy female volunteers

The effect of rofecoxib, a highly selective cyclooxygenase (COX)-2 inhibitor, on the pharmacokinetics of ethinyl estradiol (EE) and norethindrone (NET), two common components of a combination oral contraceptive product, was examined. A double-blind, two-period crossover study was conducted in 18 healthy women who received ORTHO-NOVUM 1/35, a combination of EE (35 microg) and NET (1 mg), concurrently for 14 days with either 175 mg rofecoxib or matching placebo during two consecutive menstrual cycles. Plasma was sampled for EE, NET, sex hormone binding globulin (SHBG), and albumin. The AUC(0-24 h) geometric mean ratio (GMR: rofecoxib/placebo) with corresponding 90% confidence interval (CI) of EE and NET was 1.13 (1.06, 1.19) and 1.18 (1.13, 1.24), respectively. The Cmax GMR of EE and NET was 1.06 (0.98, 1.16) and 1.04 (0.99, 1.09), respectively. In each case, the 90% CIs satisfied the predefined bioequivalence limits of (0.80, 1.25). Measures of SHBG and albumin and routine clinical and laboratory safety parameters showed no clinically meaningful changes. The addition of rofecoxib to the oral contraceptive was not associated with any clinically important changes in EE or NET pharmacokinetics and thus would not be anticipated to influence the efficacy of this contraceptive regimen.

A comparison of adverse renovascular experiences among osteoarthritis patients treated with rofecoxib and comparator non-selective non-steroidal anti-inflammatory agents

BACKGROUND

Non-selective non-steroidal anti-inflammatory drugs (NSAIDs) inhibit both cyclo-oxygenase (COX) isoenzymes, i.e. COX-1 and COX-2. Rofecoxib, an agent that selectively inhibits COX-2, has been shown to provide equivalent anti-inflammatory and analgesic efficacy to comparator non-selective NSAIDs in osteoarthritis (OA) and other pain models with a significant improvement in gastrointestinal (GI) safety and tolerability. Based on renal physiology studies, it was predicted that rofecoxib would have renovascular effects similar to those observed with non-selective NSAIDs--specifically edema, blood pressure elevation, attenuation of the effects of ACE inhibitors, and (in rare circumstances), acute renal failure might be manifest in a small percentage of patients.

OBJECTIVE

To assess the renovascular safety profile of rofecoxib in OA patients compared to that of non-selective NSAID comparators.

METHODS

Renovascular adverse experiences (AEs) in over 5,000 participants in Phase IIb/III OA clinical trials were reviewed and compared between rofecoxib and non-selective NSAID comparators (ibuprofen 800mg tid, diclofenac 50 mg tid, nabumetone 1,500 mg qd).

RESULTS

The incidence of lower extremity edema (LEE) AEs was generally similar between rofecoxib 12.5 mg/day, rofecoxib 25 mg/day, and non-selective comparator NSAIDs. Treatment discontinuations due to LEE AEs and clinically significant weight gain (> or = 2 kg) associated with LEE AEs were infrequent and generally similar in all active treatment groups. Congestive heart failure (CHF) was rare in all treatment groups. The incidence of hypertension AEs was low in all active treatment groups. Discontinuations due to hypertension AEs and hypertension AEs requiring a change or adjustment in blood pressure medications were similar and uncommon in all treatment groups. There was only a single report of acute renal failure (in the ibuprofen treatment group).

CONCLUSIONS

In the rofecoxib phase IIb/III OA database, the renal safety profile for rofecoxib, a selective inhibitor of COX-2, was generally similar to that of the comparator, non-selective NSAIDs which were studied.

Cardiovascular thrombotic events in controlled, clinical trials of rofecoxib

BACKGROUND

In comparing aspirin, nonselective nonsteroidal antiinflammatory agents (NSAIDs), and cyclooxygenase (COX)-2 inhibitors, variation in platelet inhibitory effects exists that may be associated with differential risks of cardiovascular (CV) thrombotic events. Among the randomized, controlled trials with the COX-2 inhibitor rofecoxib, one study demonstrated a significant difference between rofecoxib and its NSAID comparator (naproxen) in the risk of CV thrombotic events. A combined analysis of individual patient data was undertaken to determine whether there was an excess of CV thrombotic events in patients treated with rofecoxib compared with those treated with placebo or nonselective NSAIDs.

METHODS AND RESULTS

CV thrombotic events were assessed across 23 phase IIb to V rofecoxib studies. Comparisons were made between patients taking rofecoxib and those taking either placebo, naproxen (an NSAID with near-complete inhibition of platelet function throughout its dosing interval), or another nonselective NSAIDs used in the development program (diclofenac, ibuprofen, and nabumetone). The major outcome measure was the combined end point used by the Antiplatelet Trialists' Collaboration, which includes CV, hemorrhagic, and unknown deaths; nonfatal myocardial infarctions; and nonfatal strokes. More than 28 000 patients, representing >14 000 patient-years at risk, were analyzed. The relative risk for an end point was 0.84 (95% CI: 0.51, 1.38) when comparing rofecoxib with placebo; 0.79 (95% CI: 0.40, 1.55) when comparing rofecoxib with non-naproxen NSAIDs; and 1.69 (95% CI: 1.07, 2.69) when comparing rofecoxib with naproxen.

CONCLUSIONS

This analysis provides no evidence for an excess of CV events for rofecoxib relative to either placebo or the non-naproxen NSAIDs that were studied. Differences observed between rofecoxib and naproxen are likely the result of the antiplatelet effects of the latter agent.

Lack of pharmacokinetic interaction between rofecoxib and methotrexate in rheumatoid arthritis patients

Rofecoxib is a highly selective and potent inhibitor of cyclooxgenase-2 (COX-2). Methotrexate is a disease-modifying agent with a narrow therapeutic index frequently prescribed for the management of rheumatoid arthritis. The objective of this study was to investigate the influence of clinical doses of rofecoxib on the pharmacokinetics of methotrexate in patients with rheumatoid arthritis. This was a randomized, double-blind, placebo-controlled study in 25 rheumatoid arthritis patients on stable doses of methotrexate. Patients received oral methotrexate (7.5 to 20 mg) on days -1, 7, 14, and 21. Nineteen patients received rofecoxib 12.5, 25, and 50 mg once daily on days 1 to 7, 8 to 14, and 15 to 21, respectively. Six patients received placebo on days 1 to 21 only to maintain a double-blinded design for assessment of adverse experiences. Plasma and urine samples were analyzed for methotrexate and its major although inactive metabolite, 7-hydroxymethotrexate. The AUC(0-infinity) geometric mean ratios (GMR) and their 90% confidence intervals (90% CI) (rofecoxib + methotrexate/methotrexate alone) for day 7/day -1, day 14/day -1, and day 21/day -1, for rofecoxib 12.5, 25, and 50 mg, were 1.03 (0.93, 1.14), 1.02 (0.92, 1.12), and 1.06 (0.96, 1.17), respectively (p > 0.2 for all comparisons to day -1). All AUC(0-infinity), GMR and Cmax GMR 90% CIs fell within the predefined comparability limits of (0.80, 1.25). Similar results were observed for renal clearance of methotrexate and 7-hydroxymethotrexate at the highest dose of rofecoxib tested (50 mg). It was concluded that rofecoxib at doses of 12.5, 25, and 50 mg once daily has no effect on the plasma concentrations or renal clearance (tested at the highest dose of rofecoxib) of methotrexate in rheumatoid arthritis patients.

Effects of oral administration of ibutamoren mesylate, a nonpeptide growth hormone secretagogue, on the growth hormone-insulin-like growth factor I axis in growth hormone-deficient children

Ibutamoren mesylate (MK-0677), an orally active nonpeptide growth hormone (GH) secretagogue, stimulates GH release through a pituitary and hypothalamic receptor that is different from the GH-releasing hormone receptor. We evaluated the safety and tolerability and the GH-insulin-like growth factor (IGF) responses to two dosages of oral ibutamoren mesylate given to children with GH deficiency for 7 to 8 days. The patients, 18 prepubertal children (15 male, 3 female) with idiopathic GH deficiency, had a chronologic age of 10.6 +/- 0.8 years (mean +/- SD), bone age of 7.4 +/- 0.7 years, growth velocity < 10th percentile for age, height < 10th percentile for age, and a maximum GH response of < or = 10 microg/L to two different GH stimulation tests. The children were assigned as follows to one of three treatment groups with ibutamoren mesylate: 0.2 mg/kg per day for 7 days (days 1-7 or 8-14) and matching placebo for the alternate 7 days (groups I and II, respectively) or 0.8 mg/kg per day for 7 days (days 8-14, group III). On day 15 all patients received an 0.8-mg/kg dose of ibutamoren mesylate. Patients in groups I and II were studied first to assess safety at the low dose before advancement to the high dose. Hormonal profiles were evaluated on day -1 (baseline) and day 15, and the results were expressed as the change from baseline within each group. After administration of ibutamoren mesylate 0.8 mg/kg for 8 days (group III), the median increases (on day 15) from baseline were as follows: 3.8 microg/L (range, 0 to 34.3) for serum GH peak concentration (P = .001), 4.3 microg x h/L (range, 1.3 to 35.6) for the GH area under the concentration-time curve from time zero to 8 hours (AUC(0-8)) (P < .001), 12 microg/L (range, -4 to 116) for serum IGF-I (P = .01), and 0.4 microg/L (range, -0.9 to 1.5) for serum IGF-binding protein 3 (IGFBP-3) (P = .01). There was no change in serum prolactin, glucose, triiodothyronine, thyroxine, thyrotropin, peak serum cortisol, and insulin concentrations or 24-hour urinary free cortisol after administration of 0.8 mg/kg per day of ibutamoren mesylate for 8 days. We conclude that short-term administration of ibutamoren mesylate can increase GH, IGF-I, and IGFBP-3 levels in some children with GH deficiency. Thus this compound is applicable for testing its effect on growth velocity.

Comparison of L-758,298, a prodrug for the selective neurokinin-1 antagonist, L-754,030, with ondansetron for the prevention of cisplatin-induced emesis

Substance P is localised in brainstem regions associated with emesis. Based on studies in the ferret, it was postulated that a neurokinin-1 (NK1) receptor antagonist would have antiemetic activity as monotherapy in humans receiving chemotherapy. L-758,298 is a water-soluble, intravenous (i.v.) prodrug for L-754,030, a potent and selective NK1 receptor antagonist. This double-blind, randomised, active-agent (ondansetron)-controlled study enrolled 53 cisplatin-naïve patients and evaluated the prevention of both acute (0-24 h) and delayed (days 2-7) emesis after cisplatin treatment (50-100 mg/m(2)). All patients received i.v. L-758,298 (60 or 100 mg) (n=30) or ondansetron (32 mg) (n=23) before cisplatin and efficacy was evaluated up to day 7 post-cisplatin. Nausea was assessed by means of a four-point ordinal scale at intervals over the 7 day period. In the acute period, the proportion of patients without emesis in the L-758,298 and ondansetron groups was 37 and 52%, respectively (no significant difference between the groups). Comparing the distribution of average nausea scores over the entire first 24 h revealed no significant difference between the groups. In the delayed period, the proportion of patients without emesis in the L-758,298 and ondansetron treatment groups was 72 and 30%, respectively (P=0.005). The distribution of average nausea scores in the delayed period was lower in the L-758,298 group compared with the ondansetron group (P=0.15 for the entire delayed period and P=0.043 for day 2 only). No serious adverse events were attributed to L-758,298. A single dose of L-758,298 substantially suppressed the delayed nausea and vomiting characteristic of high dose cisplatin and also appeared to reduce acute emesis post-cisplatin. The data also support the proposition that the underlying mechanism(s) of acute and delayed emesis are different.

Prevention of cisplatin-induced emesis by the oral neurokinin-1 antagonist, MK-869, in combination with granisetron and dexamethasone or with dexamethasone alone

PURPOSE

The NK1-receptor antagonist MK-869 (L-754,030) has demonstrated antiemetic activity in humans receiving chemotherapy. Objectives of the present trial included the first assessment of oral MK-869 plus dexamethasone compared with a 5HT(3) antagonist plus dexamethasone for prevention of acute and delayed emesis after high-dose cisplatin. Furthermore, the study sought to confirm that addition of MK-869 to a 5HT(3) antagonist plus dexamethasone was more effective than just the 5HT(3) antagonist plus dexamethasone for prevention of acute and delayed emesis.

METHODS

This multicenter, double-blind, parallel-group trial in 351 cisplatin-naïve patients evaluated prevention of acute (0 to 24 hours) and delayed emesis (primary efficacy parameter; days 2 to 5) after cisplatin (> or =70 mg/m(2)). Patients were randomized to four groups (I to IV) (n = number randomized; number evaluable): granisetron (10 microg/kg intravenously) pre-cisplatin followed by placebo on days 2 to 5 (group I) (n = 90; 90); granisetron and MK-869 (400 mg PO [by mouth]) pre-cisplatin, followed by MK-869 (300 mg PO) on days 2 to 5 (group II) (n = 86; 84); MK-869 (400 mg PO) the evening before and pre-cisplatin, followed by MK-869 (300 mg PO) on days 2 to 5 (group III) (n = 89; 88); or MK-869 (400 mg PO) pre-cisplatin, followed by MK-869 (300 mg PO) on days 2 to 5 (group IV) (n = 86; 84). All patients also received dexamethasone (20 mg PO) before cisplatin. Additional medication was available to treat emesis or nausea at any time.

RESULTS

In the acute period, 57%, 80%, 46%, and 43% of patients were without emesis in groups I, II, III, and IV, respectively (P <.01 for group II v group I). In the delayed period, the proportion of patients without emesis in groups I, II, III, and IV was 29%, 63%, 51%, and 57%, respectively (P <.01 for groups II, III, and IV v group I). The distribution of nausea scores in the delayed period was lower when comparing group II with group I (P <.05 for days 1 to 5 and days 2 to 5). One serious adverse event (dizziness) was rated as possibly related to MK-869.

CONCLUSION

Once daily oral administration of MK-869 was effective in reducing delayed emesis and nausea after high-dose cisplatin. However, the combination of the 5HT3 antagonist plus dexamethasone was numerically superior to MK-869 plus dexamethasone in reducing acute emesis. Confirming and extending previous findings, the triple combination of a 5HT(3) antagonist, MK-869, and dexamethasone provided the best control of acute emesis.

Rofecoxib, a COX-2 inhibitor, does not inhibit human gastric mucosal prostaglandin production

BACKGROUND & AIMS

Rofecoxib, an inhibitor of the inducible cyclooxygenase (COX)-2 enzyme, appears not to cause acute gastroduodenal injury or chronic ulceration. To attribute this to COX-2 selectivity with sparing of gastric mucosal prostaglandin synthesis requires direct proof.

METHODS

Twenty-four healthy, nonsmoking Helicobacter pylori-negative volunteers were randomized to 1 of 2 separate concurrent blinded crossover studies. Sixteen volunteers received rofecoxib, 50 mg once daily, for 5 days in one treatment period and placebo in the other. Eight volunteers similarly received naproxen, 500 mg twice daily, and placebo. On day 5 of each period, antral mucosal prostaglandin E2 (PGE2) synthesis was measured by radioimmunoassay after vortexing for 3 minutes. Whole blood COX-1 activity was measured as serum thromboxane (TXB)2- and COX-2 activity as lipopolysaccharide (LPS)-induced PGE2.

RESULTS

Naproxen decreased gastric mucosal PGE2 synthesis by 65% (90% confidence interval [CI], 53%-74%; P = 0.001 vs. placebo) in contrast to an 18% increase after rofecoxib (90% CI, -11% to 57%; P = 0.313 vs. placebo). Naproxen also significantly inhibited both serum TXB2 by 94% and LPS-induced PGE2 production by 77% (both P < or = 0.002 vs. placebo), but rofecoxib only inhibited COX-2-dependent LPS-induced PGE(2) (by 79%; P < 0.001 vs. placebo).

CONCLUSIONS

Rofecoxib (50 mg) lacked naproxen's ability to reduce the availability of gastroprotective prostaglandins.

Effect of alendronate and MK-677 (a growth hormone secretagogue), individually and in combination, on markers of bone turnover and bone mineral density in postmenopausal osteoporotic women

GH increases bone turnover and stimulates osteoblast activity. We hypothesized that administration of MK-677, an orally active GH secretagogue, together with alendronate, a potent inhibitor of bone resorption, would maintain a higher bone formation rate relative to that seen with alendronate alone, thereby generating greater enhancement of bone mineral density (BMD) in women with postmenopausal osteoporosis. We determined the individual and combined effects of MK-677 and alendronate administration on insulin-like growth factor I levels and biochemical markers of bone formation (osteocalcin and bone-specific alkaline phosphatase) and resorption [urinary N-telopeptide cross-links (NTx)] for 12 months and BMD for 18 months. In a multicenter, randomized, double blind, placebo-controlled, 18-month study, 292 women (64-85 yr old) with low femoral neck BMD were randomly assigned in a 3:3:1:1 ratio to 1 of 4 daily treatment groups for 12 months: MK-677 (25 mg) plus alendronate (10 mg); alendronate (10 mg); MK-677 (25 mg); or a double dummy placebo. Patients who received MK-677 alone or placebo through month 12 received MK-677 (25 mg) plus alendronate (10 mg) from months 12-18. All other patients remained on their assigned therapy. All patients received 500 mg/day calcium. The primary results, except for BMD, are provided for month 12. MK-677, with or without alendronate, increased insulin-like growth factor I levels from baseline (39% and 45%; P < 0.05 vs. placebo). MK-677 increased osteocalcin and urinary NTx by 22% and 41%, on the average, respectively (P < 0.05 vs. placebo). MK-677 and alendronate mitigated the reduction in bone formation compared with alendronate alone based on mean relative changes in serum osteocalcin (-40% vs. -54%; P < 0.05, combination vs. alendronate) and reduced the effect of alendronate on resorption (NTx) as well (-52% vs. -61%; P < 0.05, combination vs. alendronate). MK-677 plus alendronate increased BMD at the femoral neck (4.2% vs. 2.5% for alendronate; P < 0.05). However, similar enhancement was not seen with MK-677 plus alendronate in BMD of the lumbar spine, total hip, or total body compared with alendronate alone. GH-mediated side effects were noted in the groups receiving MK-677, although adverse events resulting in discontinuation from the study were relatively infrequent. In conclusion, the anabolic effect of GH, as produced through the GH secretagogue MK-677, attenuated the indirect suppressive effect of alendronate on bone formation, but did not translate into significant increases in BMD at sites other than the femoral neck. Although the femoral neck is an important site for fracture prevention, the lack of enhancement in bone mass at other sites compared with that seen with alendronate alone is a concern when weighed against the potential side effects of enhanced GH secretion.

Renal effects of COX-2-selective inhibitors

Although nonsteroidal anti-inflammatory drugs (NSAIDs) effectively treat a variety of inflammatory diseases, these agents may cause deleterious effects on kidney function, especially with respect to solute homeostasis and maintenance of renal perfusion and glomerular filtration. NSAIDs act by reducing prostaglandin biosynthesis through inhibition of cyclooxygenase (COX) which exists as two isoforms (COX-1 and COX-2). NSAID-induced gastrointestinal toxicity is generally believed to occur through blockade of COX-1 activity, whereas the anti-inflammatory effects of NSAIDs are thought to occur primarily through inhibition of the inducible isoform, COX-2. However, the situation in the kidney may be somewhat different. Recent studies have demonstrated that COX-2 is constitutively expressed in renal tissues of all species; this isoform may, therefore, be intimately involved in prostaglandin-dependent renal homeostatic processes. Drugs that selectively inhibit COX-2 might, therefore, be expected to produce effects on renal function similar to nonselective NSAIDs which inhibit both COX-1 and COX-2. This assertion is borne out by recent clinical studies showing that the COX-2 inhibitors rofecoxib and celecoxib procedure qualitative changes in urinary prostaglandin excretion, glomerular filtration rate, sodium retention, and their consequences similar to nonselective NSAIDs. It, therefore, seems unlikely that these COX-2 inhibitors (and perhaps their successors) will offer renal safety benefits over nonselective NSAID therapies, and, at this juncture, it is reasonable to assume that all NSAIDs, including COX-2-selective inhibitors, share a similar risk for adverse renal effects.

Effect of rofecoxib on the pharmacokinetics of digoxin in healthy volunteers

The authors examined the effect of the cyclooxygenase-2 (COX-2) inhibitor, rofecoxib, at steady state on the pharmacokinetics of digoxin following a single dose in healthy subjects. Each healthy subject (N = 10) received rofecoxib (75 mg once daily) or placebo for 11 days in a double-blind, randomized, balanced, two-period crossover study. A single 0.5 mg oral dose of digoxin elixir was administered on the 7th day of each 11-day period. Each treatment period was separated by 14 to 21 days. Samples for plasma and urine immunoreactive digoxin concentrations were collected through 120 hours following the digoxin dose. No statistically significant differences between treatment groups were observed for any of the calculated digoxin pharmacokinetic parameters. For digoxin AUC(0-infinity), AUC(0-24), and Cmax, the geometric mean ratios (90% confidence interval) for (rofecoxib + digoxin/placebo + digoxin) were 1.04 (0.94, 1.14), 1.02 (0.94, 1.09), and 1.00 (0.91, 1.10), respectively. The digoxin median tmax was 0.5 hours for both treatments. The harmonic mean elimination half-life was 45.7 and 43.4 hours for rofecoxib + digoxin and placebo + digoxin treatments, respectively. Digoxin is eliminated renally. The mean (SD) cumulative urinary excretion of immunoreactive digoxin after concurrent treatment with rofecoxib or placebo was 228.2 (+/- 30.8) and 235.1 (+/- 39.1) micrograms/120 hours, respectively. Transient and minor adverse events occurred with similar frequency on placebo and rofecoxib treatments, and no treatment-related pattern was apparent. Rofecoxib did not influence the plasma pharmacokinetics or renal elimination of a single oral dose of digoxin.

The effect of rofecoxib on the pharmacodynamics and pharmcokinetics of warfarin

OBJECTIVE

The objective of this study was to examine the effect of 3 doses of rofecoxib (12.5, 25, and 50 mg) on the pharmacodynamics and pharmacokinetics of warfarin.

METHODS

Two single-dose (12.5 or 50 mg of rofecoxib with 25 mg or 30 mg of oral warfarin, respectively, on day 7 of each period) trials (N = 12 men) and 1 steady-state warfarin trial (25 mg rofecoxib; N = 15, 13 men and 2 women) were completed as two-period, randomized, balanced, crossover, double-blind designs. The prothrombin time international normalized ratio (INR) and S(-) and R(+) warfarin enantiomers were assessed during 144 hours after the single warfarin doses. In the steady-state warfarin trial, after the attainment of a stable INR (1.4-1.7), the stable warfarin dose was co-administered with rofecoxib (25 mg) and placebo over two 21-day periods. After the dose of warfarin on day 21, INR and S(-) and R(+) warfarin were assessed during 24 hours.

RESULTS

Compared with placebo, rofecoxib slightly increased the INR by approximately 5% (90% confidence interval on the geometric ratio, 1.03, 1.08) and 11% (1.04, 1.19) for the two single-dose warfarin trials with 12.5 and 50 mg of rofecoxib, respectively. In the steady-state warfarin study with 25 mg of rofecoxib, the INR was increased by 8% (1.02, 1.15). Rofecoxib had no significant effect (versus placebo) on the pharmacokinetics of S(-) warfarin. However, in the 3 studies, treatment with 12.5, 25, and 50 mg of rofecoxib was associated with a 27%, 38%, and 40% increase in the area under the plasma concentration-time curve of the biologically less active R(+) warfarin.

CONCLUSIONS

Rofecoxib increased plasma concentrations of the biologically less active R(+) warfarin, which accounted for a small increase in INR. The approximately 8% increase in INR at steady state with warfarin co-administered with 25 mg of rofecoxib is not likely to be clinically important in most patients taking warfarin. However, standard monitoring of INR values should be conducted when therapy with rofecoxib is initiated or changed, particularly in the first few days, for patients receiving warfarin.

Comparative inhibitory activity of rofecoxib, meloxicam, diclofenac, ibuprofen, and naproxen on COX-2 versus COX-1 in healthy volunteers

Steady-state inhibitory activity of rofecoxib (Vioxx) on COX-2 versus COX-1 was compared with that of commonly used nonsteroidal anti-inflammatory drugs (NSAIDs) in 76 healthy volunteers randomized to placebo, rofecoxib 12.5 mg qd, rofecoxib 25 mg qd, diclofenac 50 mg tid, ibuprofen 800 mg tid, sodium naproxen 550 mg bid, or meloxicam 15 mg qd. All of these doses include the high end of the approved clinical dose range. Ex vivo whole-blood assays were used to determine the effect on COX-2 and COX-1 activity, respectively. Urinary prostanoids were also measured. Mean inhibition of COX-2 (measured as the weighted average inhibition [WAI] of lipopolysaccharide [LPS]-induced PGE2 generation over 8 hours on day 6 vs. baseline) was -2.4%, 66.7%, 69.2%, 77.5%, 93.9%, 71.4%, and 71.5% for placebo, rofecoxib 12.5 mg, rofecoxib 25 mg, meloxicam, diclofenac, ibuprofen, and naproxen, respectively. Corresponding values for mean inhibition of COX-1 (measured as TXB2 generation in clotting whole blood) were -5.15%, 7.98%, 6.65%, 53.3%, 49.5%, 88.7%, and 94.9%. Rofecoxib had no significant effect on urinary excretion of 11-dehydro TXB2, a COX-1-derived product. These data support the contention that rofecoxib is the only drug of the regimens tested that uniquely inhibits COX-2 without affecting COX-1.

Effect of cyclooxygenase-2 inhibition on renal function in elderly persons receiving a low-salt diet. A randomized, controlled trial

BACKGROUND

Most nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit both cyclooxygenase-1 (COX-1), whose inhibition is associated with gastrointestinal ulceration, and COX-2, whose inhibition is associated with therapeutic benefits. Although agents that do not produce COX-1 activity may have fewer adverse effects, targeted disruption of the COX-2 allele in mice has resulted in severe renal problems, suggesting that COX-2 inhibition may also produce adverse effects.

OBJECTIVE

To determine the effect of rofecoxib, a member of the coxib class of drugs and a specific inhibitor of the COX-2 enzyme, on renal function in elderly patients.

DESIGN

A randomized, three-period, single-dose crossover study and a randomized, parallel-group, multiple-dose study.

SETTING

Clinical research units.

PATIENTS

75 patients 60 to 80 years of age.

INTERVENTION

In the first study, single doses of rofecoxib, 250 mg (about 5-fold to 20-fold the recommended dose); indomethacin, 75 mg; and placebo were administered to 15 patients. In the second study, multiple doses of rofecoxib, 12.5 or 25 mg/d; indomethacin, 50 mg three times daily; or placebo were administered to 60 patients. Patients in both studies received a low-sodium diet

MEASUREMENTS

Glomerular filtration rate, creatinine clearance, and urinary and serum sodium and potassium values.

RESULTS

Compared with placebo, single doses of rofecoxib and indomethacin decreased the glomerular filtration rate by 0.23 m/s (P < 0.001) and 0.18 mL/s (P = 0.003), respectively. In contrast, respective decreases of 0.14, 0.13, and 0.10 mL/s were observed after multiple doses of rofecoxib, 12.5 mg/d (P = 0.019); rofecoxib, 25 mg (P = 0.029), and indomethacin (P = 0.086) were administered. Changes in creatinine clearance and serum and urinary sodium and potassium were less pronounced.

CONCLUSIONS

The effects of COX-2 inhibition on renal function are similar to those observed with nonselective NSAIDs. Thus, COX-2 seems to play an important role in human renal function.

Pharmacokinetics, COX-2 specificity, and tolerability of supratherapeutic doses of rofecoxib in humans

OBJECTIVE

Prostaglandin synthesis is catalyzed by a constitutive cyclo-oxygenase isoform (COX-1) and an inducible isoform (COX-2). It is hypothesized that the analgesic and anti-inflammatory effects of nonsteroidal anti-inflammatory drugs (nonspecific COX-1/COX-2 inhibitors) such as ibuprofen principally derive from COX-2 inhibition. The purpose of this study was to evaluate steady-state pharmacokinetics, biochemical selectivity and tolerability of rofecoxib (Vioxx), characterized in vitro as a COX-2 inhibitor.

METHODS

Four panels of healthy men (n = 8 per panel) were administered rofecoxib (n = 6) (25, 100, 250, 375 mg) or placebo (n = 2) once daily on day 1 and days 3-14. Blood samples for assays of rofecoxib plasma concentration and COX isoform activity were obtained pre-dose and at specified time points post-dose.

RESULTS

Rofecoxib pharmacokinetics were found to be complex and nonlinear. Elimination half-life ranged from 9.9 h to 17.5 h after multiple dosing with an accumulation ratio close to 2 for all doses. COX-2 inhibitory activity as assessed by average inhibition of whole blood lipopolysaccharide-stimulated prostaglandin E2 over the 8-h post-dose period on day 14 was 0.3, 67, 96, 92 and 96% for the placebo and the 25-, 100-, 250- and 375-mg treatment groups, respectively. No treatment group showed significant inhibition of COX-1 as assessed by thromboxane B2 generation in clotting whole blood. Side effects were mild and transient.

CONCLUSION

The results indicate that rofecoxib is a potent and specific inhibitor of COX-2 in humans even at doses more than tenfold higher than those associated with efficacy in patients with osteoarthritis.

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.

Concurrent administration of the erythromycin breath test (EBT) and oral midazolam as in vivo probes for CYP3A activity

Given the prominent role of CYP3A in the metabolism of drugs, it is important to identify whether new chemical entities will affect this enzyme system and produce clinically relevant drug interactions. This study evaluated concomitant administration of intravenous [14C N-methyl] erythromycin (3 microCi) (erythromycin breath test; EBT) and 2 mg oral midazolam as probes of systemic and of systemic plus presystemic CYP3A activity, respectively. Twelve males received the probes in a two-period crossover fashion: one period included the probes on two occasions, 5 days apart; in the second period, 200 mg ketoconazole was given orally 2 hours prior to the probes. The within-subject CV for EBT (%14CO2/h) and midazolam AUC0-last was 4.9% and 16.9%, respectively. Ketoconazole reduced %14CO2/h by 43% and increased midazolam AUC0-last by approximately fivefold. In a nonrandomized third period (N = 5), ketoconazole was given simultaneously with midazolam (no EBT); midazolam AUC0-last was similar whether ketoconazole was given 2 hours prior to or simultaneously with the midazolam. The low midazolam dose was generally well tolerated; mild sedation was occasionally seen. Concurrent administration of the EBT and oral midazolam is a sensitive and reproducible tool to screen new chemical entities for potentially important CYP3A interactions.

Effect of specific COX-2 inhibition in osteoarthritis of the knee: a 6 week double blind, placebo controlled pilot study of rofecoxib. Rofecoxib Osteoarthritis Pilot Study Group

OBJECTIVE

To determine the efficacy and safety of the cyclooxygenase 2 (COX-2) specific inhibitor, rofecoxib in patients with osteoarthritis (OA) of the knee.

METHODS

Rofecoxib, 25 mg or 125 mg once daily, was compared with placebo in a 6 week, double blind, parallel group, randomized, multicenter study of 219 patients with knee OA.

RESULTS

Both doses of rofecoxib produced clinically significant improvement as assessed by primary (e.g., WOMAC Pain Subscale 0-100 mm, decrease from baseline: placebo: 7.1 mm; rofecoxib 25 mg: 28.1 mm, rofecoxib 125 mg: 28.0 mm; p < 0.001 rofecoxib vs placebo) and secondary efficacy (p < 0.05) criteria compared with placebo. Clinical improvement with the 25 mg dose was similar to that with the 125 mg dose. Both rofecoxib doses were generally well tolerated.

CONCLUSION

Specific inhibition of COX-2 by 25 and 125 mg rofecoxib, administered once daily, resulted in clinically meaningful improvements in patients with OA. This study confirms that COX-2 derived prostanoids are important clinical mediators of pain and other symptoms of knee OA and that inhibition of COX-1 is not required to provide clinical benefit.

Substance P-induced vasodilatation is mediated by the neurokinin type 1 receptor but does not contribute to basal vascular tone in man

AIMS

Following intravenous administration of its prodrug, L-758,298, we assessed the pharmacodynamics of L-754,030, a novel and highly selective NK1 receptor antagonist, by examining systemic haemodynamics and the blood flow responses to intra-arterial substance P infusion.

METHODS

Sixteen healthy male volunteers participated in a double-blind, randomised, placebo controlled crossover trial of L-758 298. Forearm blood flow was measured using venous occlusion plethysmography during intrabrachial substance P infusion (0.125-128 pmol min-1 ). In part 1, eight subjects received substance P infusions before and during placebo, 0.25 mg, 1 mg or 5 mg of L-758 298. In part 2, eight subjects received substance P infusions 24 h after placebo or 1.43 mg of L-758 298.

RESULTS

L-758 298 caused dose dependent inhibition of substance P induced vasodilatation (P<0.001). Placebo adjusted differences (95% CI) in baseline forearm blood flow, mean arterial pressure and heart rate showed no relevant changes with 5 mg of L-758 298 (>1400-fold shift in substance P response): 0.00 (-0.49 to +0.49) ml 100 ml-1 min-1, 1. 0 (-3.2 to +5.2) mmHg and 1.9 (-5.9 to +9.7) beats min-1, respectively. Twenty-four hours after 1.43 mg of L-758,298, there was approximately 34-fold shift in response to substance P induced vasodilatation (P<0.008) at plasma L-754 030 concentrations of 2-3 ng ml-1. L-758 298 was generally well tolerated without serious adverse events.

CONCLUSIONS

Substance P induced forearm vasodilatation is mediated by the endothelial cell NK1 receptor in man but endogenous substance P does not appear to contribute to the maintenance of peripheral vascular tone or systemic blood pressure.

Montelukast dose selection in 6- to 14-year-olds: comparison of single-dose pharmacokinetics in children and adults

Montelukast, an oral leukotriene-receptor antagonist, has demonstrated efficacy and tolerability for the treatment of chronic asthma in adults. A once-daily 10 mg dose (film-coated tablet) was selected as the optimal adult dose based on dose-ranging studies. Asthma is a similar disease and is treated with the same medications in children and adults. These observations suggested that a dose of montelukast in children providing overall drug exposure (i.e., montelukast plasma concentrations) similar to that of the 10 mg film-coated tablet dose in adults would be efficacious, well tolerated, and obviate the need for separate dose-ranging studies in children. Therefore, the dose of montelukast for 6- to 14-year-old children was selected by identifying the chewable tablet dose of montelukast yielding a single-dose area under the plasma concentration-time curve (AUC) comparable to that achieved with the adult 10 mg film-coated tablet dose. Based on this approach, which included dose normalization of data from several pediatric pharmacokinetic studies, a 5 mg chewable tablet dose of montelukast was selected for use in clinical efficacy studies in 6- to 14-year-old children with asthma.

Oral administration of the growth hormone secretagogue MK-677 increases markers of bone turnover in healthy and functionally impaired elderly adults. The MK-677 Study Group

Growth hormone (GH) stimulates osteoblasts in vitro and increases bone turnover and stimulates osteoblast activity when given to elderly subjects. Probably a major effect of GH on bone is mediated through stimulation of either circulating or locally produced insulin-like growth factor I (IGF-I). We determined the effect of chronic administration of the GH secretagogue, MK-677, on serum IGF-I and markers of bone turnover in 187 elderly adults (65 years or older) enrolled in three randomized, double-blind, placebo-controlled clinical studies lasting 2-9 weeks. Urine was collected for determination of N-telopeptide cross-links (NTXs), a marker of bone resorption, and blood was collected for determination of serum osteocalcin and bone-specific alkaline phosphatase (BSAP), as bone formation markers, and serum IGF-I levels pre- and post-treatment. Dose response data were initially obtained in healthy elderly subjects who received oral doses of 10 mg or 25 mg of MK-677 or placebo for 2 weeks (n = 10-12/group). Treatment with 10 mg and 25 mg of MK-677 for 2 weeks increased mean urine NTXs 10% and 17%, respectively (p < 0.05 vs. placebo). Additionally, 50 healthy elderly subjects received either placebo (n = 20) for 4 weeks or 25 mg of MK-677 (n = 30) daily for 2 weeks followed by 50 mg daily for 2 weeks. MK-677 increased mean serum osteocalcin by 8% (p < 0.05 vs. placebo). In both studies, MK-677 increased serum IGF-I levels significantly (55-94%). Subsequently, the biological effects of MK-677 were studied in 105 elderly subjects who met objective criteria for functional impairment. Subjects were randomized to receive oral doses of placebo for 9 weeks or either 5, 10, or 25 mg of MK-677 daily for an initial 2 weeks followed by 25 mg of MK-677 daily for the next 7 weeks(n = 63 on MK-677 and n = 28 on placebo completed 9 weeks of therapy). Treatment with MK-677 (all MK-677 groups combined) for 9 weeks increased mean serum osteocalcin by 29.4% and BSAP by 10.4% (p < 0.001 vs. placebo) and mean urinary NTX excretion by 22.6% (p < 0.05 vs. placebo). The change from baseline serum osteocalcin correlated with the change from baseline serum IGF-I in the MK-677 group (r = 0.37; p < 0.01). In conclusion, once daily dosing with MK-677, an orally active GH secretagogue, stimulates bone turnover in elderly subjects based on elevations in biochemical markers of bone resorption and formation.

Cyclooxygenase-2 inhibition by rofecoxib reverses naturally occurring fever in humans

Cyclooxygenase (COX) exists as constitutive (COX-1) and inducible (COX-2) isoforms. Nonsteroidal antiinflammatory drugs (NSAIDs) such as ibuprofen and diclofenac inhibit both COX-1 and COX-2. The role of COX-2 in the genesis of fever in monkeys and humans was examined with use of the specific COX-2 inhibitor rofecoxib. Rofecoxib was administered to monkeys made febrile by 6 microg/kg intravenous lipopolysaccharide. Induced pyrexia was followed by oral rofecoxib (1 or 3 mg/kg), diclofenac (3 mg/kg), or vehicle. Rofecoxib and diclofenac rapidly reversed the elevated temperature (P < .05 versus vehicle for 3 mg/kg rofecoxib and diclofenac at 70 to 90 minutes after dosing). A single-dose, parallel-group, double-blind randomized trial was conducted in 94 patients with fever caused by a viral-type illness. Mean baseline temperature was similar for all groups (-38.5 degrees C). Patients received oral doses of 12.5 mg rofecoxib, 25 mg rofecoxib, 400 mg ibuprofen, or placebo and the mean +/- SE change in oral temperature at 4 hours after dosing was -0.97 degrees C +/- 0.11 degrees C, -1.19 degrees C +/- 0.09 degrees C, -1.20 degrees C +/- 0.11 degrees C, and 0.01 C +/- 0.17 C, respectively (P < .001 for active treatments versus placebo). Specific inhibition of COX-2 by rofecoxib results in antipyretic activity in monkeys and humans comparable to dual COX-1/COX-2 inhibitors such as diclofenac or ibuprofen. The data support the hypothesis that it is the COX-2 isoform that is primarily involved in the genesis of fever in humans.

Pharmacokinetics of alendronate

Alendronate (alendronic acid; 4-amino-1-hydroxybutylidene bisphosphonate) has demonstrated effectiveness orally in the treatment and prevention of postmenopausal osteoporosis, corticosteroid-induced osteoporosis and Paget's disease of the bone. Its primary mechanism of action involves the inhibition of osteoclastic bone resorption. The pharmacokinetics and pharmacodynamics of alendronate must be interpreted in the context of its unique properties, which include targeting to the skeleton and incorporation into the skeletal matrix. Preclinically, alendronate is not metabolised in animals and is cleared from the plasma by uptake into bone and elimination via renal excretion. Although soon after administration the drug distributes widely in the body, this transient state is rapidly followed by a nonsaturable redistribution to skeletal tissues. Oral bioavailability is about 0.9 to 1.8%, and food markedly inhibits oral absorption. Removal of the drug from bone reflects the underlying rate of turnover of the skeleton. Renal clearance appears to involve both glomerular filtration and a specialised secretory pathway. Clinically, the pharmacokinetics of alendronate have been characterised almost exclusively based on urinary excretion data because of the extremely low concentrations achieved after oral administration. After intravenous administration of radiolabelled alendronate to women, no metabolites of the drug were detectable and urinary excretion was the sole means of elimination. About 40 to 60% of the dose is retained for a long time in the body, presumably in the skeleton, with no evidence of saturation or influence of one intravenous dose on the pharmacokinetics of subsequent doses. The oral bioavailability of alendronate in the fasted state is about 0.7%, with no significant difference between men and women. Absorption and disposition appear independent of dose. Food substantially reduces the bioavailability of oral alendronate; otherwise, no substantive drug interactions have been identified. The pharmacokinetic properties of alendronate are evident pharmacodynamically. Alendronate treatment results in an early and dose-dependent inhibition of skeletal resorption, which can be followed clinically with biochemical markers, and which ultimately reaches a plateau and is slowly reversible upon discontinuation of the drug. These findings reflect the uptake of the drug into bone, where it exerts its pharmacological activity, and a time course that results from the long residence time in the skeleton. The net result is that alendronate corrects the underlying imbalance in skeletal turnover characteristic of several disease states. In women with postmenopausal osteoporosis, for example, alendronate treatment results in increases in bone mass and a reduction in fracture incidence, including at the hip.

Effects of specific inhibition of cyclooxygenase-2 on sodium balance, hemodynamics, and vasoactive eicosanoids

Conventional nonsteroidal anti-inflammatory drugs inhibit both cyclooxygenase (Cox) isoforms (Cox-1 and Cox-2) and may be associated with nephrotoxicity. The present study was undertaken to assess the renal effects of the specific Cox-2 inhibitor, MK-966. Healthy older adults (n = 36) were admitted to a clinical research unit, placed on a fixed sodium intake, and randomized under double-blind conditions to receive the specific Cox-2 inhibitor, MK-966 (50 mg every day), a nonspecific Cox-1/Cox-2 inhibitor, indomethacin (50 mg t.i.d.), or placebo for 2 weeks. All treatments were well tolerated. Both active regimens were associated with a transient but significant decline in urinary sodium excretion during the first 72 h of treatment. Blood pressure and body weight did not change significantly in any group. The glomerular filtration rate (GFR) was decreased by indomethacin but was not changed significantly by MK-966 treatment. Thromboxane biosynthesis by platelets was inhibited by indomethacin only. The urinary excretion of the prostacyclin metabolite 2,3-dinor-6-keto prostaglandin F1alpha was decreased by both MK-966 and indomethacin and was unchanged by placebo. Cox-2 may play a role in the systemic biosynthesis of prostacyclin in healthy humans. Selective inhibition of Cox-2 by MK-966 caused a clinically insignificant and transient retention of sodium, but no depression of GFR. Inhibition of both Cox isoforms by indomethacin caused transient sodium retention and a decline in GFR. Our data suggest that acute sodium retention by nonsteroidal anti-inflammatory drugs in healthy elderly subjects is mediated by the inhibition of Cox-2, whereas depression of GFR is due to inhibition of Cox-1.

Pharmacokinetics of intravenous alendronate

Alendronate is a potent bisphosphonate that has been studied for the treatment of osteoporosis and Paget's disease of the bone. To examine the pharmacokinetics of this drug, several groups of postmenopausal women were dosed intravenously in several studies. Twelve patients with metastatic bone disease were administered an intravenous dose of 10 mg of 14C-labeled alendronate (approximately 26 muCi), and plasma, feces, and urine samples were collected for 72 hours. Radioactivity was excreted almost exclusively in urine, and all of it was accounted for by alendronate. Overall recovery accounted for 47% of dose, with the remainder presumed to be retained in bone. Metabolism of alendronate was not observed. Renal clearance of alendronate was 71 mL/min. An additional 10 subjects were given repeated i.v. administrations of alendronate to demonstrate that previous exposure does not alter the pharmacokinetic behavior of the drug. Examination of the findings from these and other studies in which alendronate was administered intravenously revealed that disposition of single doses is linear in the range of 0.125 to 10 mg. With the possible exception of a somewhat greater skeletal retention of a systemically administered dose, the pharmacokinetics of i.v. alendronate were found to be similar to those of other bisphosphonates.

Characterization of rofecoxib as a cyclooxygenase-2 isoform inhibitor and demonstration of analgesia in the dental pain model

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen, and indomethacin (INN, indometacin) inhibit both the constitutive (COX-1) and inducible (COX-2) isoforms of cyclooxygenase. The induction of COX-2 after inflammatory stimuli has led to the hypothesis that COX-2 inhibition primarily accounts for the therapeutic properties of NSAIDs.

METHODS

Chinese hamster ovary (CHO) cell lines that express each COX isoform were used to characterize the in vitro selectivity of rofecoxib. Single oral doses of rofecoxib and indomethacin were then assessed in subjects with use of ex vivo COX-isoform specific assays (serum thromboxane B2 [TXB2] and lipopolysaccharide [LPS]-stimulated whole blood prostaglandin E2 and assays of COX-1 and COX-2 activity, respectively). A double-blind, parallel-group study compared the analgesic efficacy of rofecoxib to placebo and ibuprofen in 102 patients with dental pain.

RESULTS

Rofecoxib showed a >800-fold COX-2 selectivity with use of CHO cells that express human COX-1 and COX-2. In subjects, dose- and concentration-dependent inhibition of LPS-stimulated prostaglandin E2 was observed with both rofecoxib (IC50 [the concentration estimated to produce 50% inhibition], 0.77 micromol/L) and indomethacin (IC50, 0.33 micromol/L). Whereas indomethacin inhibited TXB2, (IC50, 0.14 micromol/L), no inhibition was observed with rofecoxib even at doses of up to 1000 mg. In the dental pain study, total pain relief (TOTPAR) over the 6 hours after dosing was similar between 50 mg and 500 mg rofecoxib and 400 mg ibuprofen (P > .20). All active treatments showed greater improvement than placebo (P < .001)

CONCLUSIONS

Rofecoxib inhibited COX-2 without evidence of COX-1 inhibition, even at oral doses of up to 1000 mg. Nonetheless, rofecoxib showed analgesic activity indistinguishable from that observed with ibuprofen, a nonisoform-selective COX inhibitor. These results support the hypothesis that the analgesic effects of NSAIDs primarily derive from inhibition of COX-2.

Reduction of cisplatin-induced emesis by a selective neurokinin-1-receptor antagonist. L-754,030 Antiemetic Trials Group

BACKGROUND

The localization of substance P in brain-stem regions associated with vomiting, and the results of studies in ferrets, led us to postulate that a neurokinin-1-receptor antagonist would be an antiemetic in patients receiving anticancer chemotherapy.

METHODS

In a multicenter, double-blind, placebo-controlled trial involving 159 patients who had not previously received cisplatin, we evaluated the prevention of acute emesis (occurring within 24 hours) and delayed emesis (on days 2 to 5) after a single dose of cisplatin therapy (70 mg or more per square meter of body-surface area). Before receiving cisplatin, all the patients received granisetron (10 microg per kilogram of body weight intravenously) and dexamethasone (20 mg orally). The patients were randomly assigned to one of three treatments in addition to granisetron and dexamethasone: 400 mg of an oral trisubstituted morpholine acetal (also known as L-754,030) before cisplatin and 300 mg on days 2 to 5 (group 1), 400 mg of L-754,030 before cisplatin and placebo on days 2 to 5 (group 2), or placebo before cisplatin and placebo on days 2 to 5 (group 3). Additional medication was available at any time to treat occurrences of vomiting or nausea.

RESULTS

In the acute-emesis phase, 93 percent of the patients in groups 1 and 2 combined and 67 percent of those in group 3 had no vomiting (P<0.001). In the delayed-emesis phase, 82 percent of the patients in group 1, 78 percent of those in group 2, and 33 percent of those in group 3 had no vomiting (P<0.001 for the comparison between group 1 or 2 and group 3). The median nausea score in the delayed-emesis phase was significantly lower in group 1 than in group 3 (P=0.003). No serious adverse events were attributed to L-754,030.

CONCLUSIONS

The neurokinin-1-receptor antagonist L-754,030 prevents delayed emesis after treatment with cisplatin. Moreover, combining L-754,030 with granisetron plus dexamethasone improves the prevention of acute emesis.

Application of a new serum assay for type I collagen cross-linked N-telopeptides: assessment of diurnal changes in bone turnover with and without alendronate treatment

Biochemical markers of bone turnover are finding increased application in the investigation and management of skeletal diseases such as osteoporosis. The present study assessed for the first time the diurnal variation of serum type I collagen cross-linked N-telopeptides (NTx), a new serum-based marker of bone resorption, and the effect of antiresorptive therapy with alendronate on this marker in elderly osteopenic women. The concentrations of serum NTx were monitored over 24 hours in a randomly selected subset of 38 women (placebo n = 13, 69 +/- 3 (SD) year; alendronate n = 25, 69 +/- 3 year), who had completed 12-15 months of a larger (n = 120) randomized, double-blind, parallel group, placebo-controlled trial with alendronate 5 mg/day. Blood was obtained every 4 hours for measurement of serum NTx using a new chemiluminescent-based immunoassay. There was a significant diurnal variation of serum NTx (p = 0.001) in both the placebo and alendronate groups. Mean peak levels occurred at approximately 0504 h with a mean nadir at approximately 1320 h in the placebo group, with no significant difference on alendronate. Serum NTx was approximately 25% lower in the alendronate group over the entire 24-hour period. Mean (SE) daytime (0800-2000) and nighttime (2200-0800) serum NTx values were 6.40 +/- 0.30 versus 8.45 +/- 0.58 nmol BCE/liter, and 7.42 +/- 0.23 versus 10.01 +/- 0.53 nmol BCE/liter for alendronate versus placebo, respectively (P < or = 0.003 for both comparisons). Combining the data of both treatment groups, serum NTx was significantly (P < 0.05) correlated with serum osteocalcin (r = 0.753) and urine NTx (r = 0.628) measurements previously obtained over the entire 24-hour period. Serum NTx has a significant diurnal variation and is responsive to antiresorptive therapy with alendronate. Alendronate reduces the amplitude but maintains the pattern of the 24-hour serum NTx profile. These data suggest that serum NTx may be a useful new marker of bone resorption.

MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism

The reversal of diet-induced negative nitrogen balance by GH suggests a possible therapeutic role for GH treatment in catabolic patients. A double-blind, randomized, placebo-controlled, two-period cross-over study was designed to investigate whether MK-677, an orally active nonpeptide mimic of GH-releasing peptide, can reverse diet-induced protein catabolism. Eight healthy volunteers (ages 24-39 yr) were calorically restricted (18 kcal/kg.day) for two 14-day periods. During the last 7 days of each diet period, subjects received either oral MK-677 25 mg or placebo once daily. There was a 14- to 21-day washout interval between periods. During the first week of caloric restriction (i.e. diet alone), daily nitrogen losses were similar for both treatment groups (mean +/- SE; MK-677 group -2.67 +/- 0.40 g/day vs. placebo group -2.83 +/- 0.26 g/day). During the second week (diet and study drug), mean daily nitrogen balance was 0.31 +/- 0.21 g/day in the MK-677 treatment group compared with -1.48 +/- 0.21 g/day in the placebo group (P < 0.01). MK-677 improved nitrogen balance integrated over the 7 days of treatment; area under the curve day 8-14 nitrogen balance response was +2.69 +/- 5.0 (SE) for MK-677 and -8.97 +/- 5.26 g.day for placebo (P < 0.001). MK-677 produced a peak GH response of 55.9 +/- 31.7 micrograms/L after single dose (day 1 of treatment) and 22.6 +/- 9.3 micrograms/L after a week of dosing compared with placebo treatment peak GH values of approximately 9 (treatment day 1) and approximately 7 micrograms/L (treatment day 7). Following the initial 7-day caloric restriction, insulin-like growth factor-I (IGF-I) declined from 232 +/- 25 to 186 +/- 19 ng/mL in the MK-677 group and from 236 +/- 19 to 174 +/- 23 ng/mL in the placebo group. Mean IGF-I concentration increased significantly during MK-677 to 264 +/- 31 ng/mL (mean for the last 5 days of treatment) compared with 188 +/- 19 ng/mL with placebo (P < 0.01). No significant difference in IGF binding protein-2 was found between the MK-677 and placebo treatments. However, the mean in IGF binding protein-3 for the last 5 days of MK-677 treatment was also significantly increased to 3273 +/- 330 ng/mL (mean +/- SE) compared with placebo 2604 +/- 253 ng/mL (P < 0.01). Neither the serum cortisol nor the PRL response was significantly greater after 7 days of MK-677 dosing compared with 7 days of placebo. MK-677 (25 mg) was generally well tolerated and without clinically significant adverse experiences. In conclusion, MK-677 reverses diet-induced nitrogen wasting, suggesting that if these short-term anabolic effects are maintained in patients who are catabolic because of certain acute or chronic disease states, it may be useful in treating catabolic conditions.

Metabolic profiles of montelukast sodium (Singulair), a potent cysteinyl leukotriene1 receptor antagonist, in human plasma and bile

Montelukast sodium [1-([(1(R)-(3-(2-(7-chloro-2-quinolinyl)-(E)- ethenyl)phenyl)-3-(2-(1-hydroxy-1-methylethyl)phenyl)propyl)thio]methyl)cyclopropylacetic acid sodium salt] (MK-476, Singulair) is a potent and selective antagonist of the cysteinyl leukotriene (Cys-LT1) receptor and is under investigation for the treatment of bronchial asthma. To assess the metabolism and excretion of montelukast, six healthy subjects received single oral doses of 102 mg of [14C]montelukast, and the urine and feces were collected. Most of the radioactivity was recovered in feces, with </=0.2% appearing in urine. Based on these results and the reported modestly high oral bioavailability of montelukast, it could be concluded that a major part of the radioactivity was excreted via bile. A second clinical study was conducted to identify biliary metabolites of montelukast. The bile was aspirated using a modified procedure involving a nasogastric tube placed fluoroscopically near the ampulla of Vater, after an oral dose of 54.8 mg of [14C]montelukast. This technique appears to be a new application for drug metabolism studies. The study was conducted with fasted and nonfasted subjects, with the bile being aspirated continuously under suction over periods of 2-8 hr and 8-12 hr after the dose, respectively. Two hours before the end of the collection procedure, cholecystokinin carboxyl-terminal octapeptide was administered iv to stimulate gallbladder contraction. Plasma samples also were collected periodically over 10 hr. Due to the nature of the collection procedure and the limited sampling time, recovery of radioactivity in bile was incomplete and varied from 3 to 20% of the dose. Radiochromatographic and LC-MS/MS analyses of bile showed the presence of one major and several minor metabolites, along with small amounts of unchanged parent drug. The minor metabolites were identified, by LC-MS/MS comparison with synthetic standards or by NMR, as acyl glucuronide (M1), sulfoxide (M2), 25-hydroxy (a phenol, M3), 21-hydroxy (diastereomers of a benzylic alcohol, M5a and M5b), and 36-hydroxy (diastereomers of a methyl alcohol, M6a and M6b) analogs of montelukast. The major metabolite was characterized as a dicarboxylic acid (M4), a product of further oxidation of the hydroxymethyl metabolite M6. Chiral LC-MS/MS analyses of M4 revealed that this diacid, like M5 and M6, was formed in both diastereomeric forms. The levels of metabolites in the systemic circulation were low in the fed as well as fasted subjects, with <2% of the circulating radioactivity being due to metabolites M5a, M5b, M6a, and M6b. Overall, this bile aspiration technique, which is less invasive than either T-tube drainage or fine-needle percutaneous puncture, provided a convenient and expedient means of identifying the biliary metabolites of montelukast, relatively free of contributions from colonic microflora.

Elimination and biochemical responses to intravenous alendronate in postmenopausal osteoporosis

Postmenopausal women with established vertebral osteoporosis were studied for 2 years to determine the terminal elimination half-life and the duration of response to treatment with intravenous alendronate (30 mg) given over 4 days. The urinary excretion of alendronate followed a multiexponential decline. Approximately 50% of the total dose was excreted over the first 5 days, and a further 17% was excreted in the succeeding 6 months. Thereafter, there was a much slower elimination phase with an estimated mean terminal half-life of greater than 10 years (n = 11). Urinary excretion of hydroxyproline and calcium decreased significantly from pretreatment values by day 3, reaching a nadir by 1 week (40% and 67% decrease, respectively). Thereafter, hydroxyproline remained suppressed for the following 2 years. In contrast, urinary calcium excretion returned gradually toward pretreatment values over the first year and during the second year was comparable to pretreatment values. Serum activity of alkaline phosphatase activity decreased over 3 months (23% reduction), increased gradually thereafter, and returned to pretreatment values at month 24. Bone mineral density measured at the spine increased by approximately 5% during the first year and remained significantly higher than pretreatment values at 2 years. We conclude that a short course of high doses of intravenous alendronate is associated with a prolonged skeletal retention of the agent. This open study also suggests that this regimen has a sustained effect on bone turnover persisting for at least 1 year.

MK-386, an inhibitor of 5alpha-reductase type 1, reduces dihydrotestosterone concentrations in serum and sebum without affecting dihydrotestosterone concentrations in semen

Two isozymes (types 1 and 2) of 5alpha-reductase (5alphaR; EC 1.3.99.5), with differential tissue distribution, catalyze the reduction of testosterone (T) to dihydrotestosterone (DHT) in humans. This study examined sequentially increasing oral doses of MK-386 (4,7beta-dimethyl-4-aza-5alpha-cholestan-3-one), an azasteroid that specifically inhibits the human 5alphaR1 isozyme in vitro. Finasteride, a selective inhibitor of 5alphaR2, was included for comparison. One hundred men were evaluated in a double blind, randomized, placebo-controlled, sequential, increasing dose, parallel group trial. Ten to 20 subjects received MK-386, and 2 to 5 received placebo in each of 6 panels. In 1 panel, 10 subjects received finasteride (5 mg), and 5 received placebo. Treatments were given once daily for 14 days, except in 1 panel in which MK-386 was administered 10 mg twice daily for comparison to 20 mg daily. Serum, sebum, and semen DHT concentrations and serum and sebum T concentrations were measured before and after treatment. The mean changes from baseline on day 14 for serum DHT after placebo and 0.1, 0.5, 5, 20, and 50 mg MK-386 were 6.9%, 4.6%, -2.7%, -1.2%, -14.1% (P < 0.05 vs. placebo), and -22.2% (P < 0.05 vs. placebo), respectively. No significant alterations in serum T were observed after any dose of MK-386. Serum DHT fell 65.8% from the baseline 14 days after finasteride treatment (P < 0.05 vs. placebo). The mean changes from baseline on day 14 in sebum DHT were 5.0%, 3.0%, -25.4% (P < 0.05 vs. placebo), -30.1% (P < 0.05 vs. placebo), and -49.1% (P < 0.05 vs. placebo) for the placebo and 0.5, 5, 20, and 50 mg MK-386 groups, respectively. Finasteride also reduced sebum DHT, but to a lesser extent (- 14.9%; P < 0.05 vs. placebo). Reciprocal increases in sebum T concentration were noted at doses of 5 mg or more of MK-386, but not with finasteride. The mean reduction in semen DHT with 5 mg finasteride was approximately 88% (P < 0.01 vs. placebo); no significant change in semen DHT was noted with 20 or 50 mg MK-386. Serum 3alpha-androstanediol glucuronide values were also reduced after the 20- and 50-mg MK-386 treatments in parallel with the changes in serum DHT. No meaningful changes were observed in serum LH after MK-386 treatment. MK-386 was generally well tolerated by all subjects; reversible aspartate aminotransferase/alanine aminotransferase elevations were observed in two subjects at the 50-mg dose. The differential responses in serum, sebum, and semen DHT concentrations associated with MK-386 and finasteride treatments are consistent with those changes anticipated for selective inhibitors of the human 5alphaR isozymes. Dose-dependent suppression of sebum DHT by a 5alphaR1 inhibitor suggests the potential utility of such compounds in the treatment of acne.

Intra-arterial substance P mediated vasodilatation in the human forearm: pharmacology, reproducibility and tolerability

AIMS

The current studies were designed to characterize the pharmacology, reproducibility and tolerability of the vasodilator response to intra-arterial substance P infusion in the forearm of healthy man.

METHODS

On different occasions, eight healthy male volunteers received brachial artery infusions of substance P at doubling doses ranging from 0.5 to 128 pmol min(-1). Blood flow was measured in both arms using venous occlusion plethysmography.

RESULTS

Substance P induced dose-dependent vasodilatation in the human forearm which had a log-linear relationship to dose. At doses of 1-8 pmol min(-1), mean responses were highly reproducible both within and between days. There were no differences between responses to discontinuous doses and continuous doses of substance P. Substance P was generally well tolerated at doses of < or = 64 pmol min(-1) with no significant alteration in arterial blood pressure or heart rate. Skin oedema in the infused forearm and systemic vasodilatation, manifested by facial flushing and non-infused forearm vasodilatation, occurred at doses of > or = 16 pmol min(-1).

CONCLUSIONS

Forearm vasodilatation to substance P represents a reproducible and useful model in the assessment of peripheral endothelial cell NK1 receptor function.