Gilbert A. Block

Rofecoxib No effect on Alzheimer’s disease in a 1-year, randomized, blinded, controlled study

BackgroundInflammatory mechanisms have been implicated in the pathogenesis of Alzheimer’s disease (AD) and may be mediated via the cyclo-oxygenase–2 enzyme. This study sought to evaluate the effect of rofecoxib, a nonsteroidal anti-inflammatory drug that selectively inhibits cyclo-oxygenase–2, in slowing the progression of dementia in patients with established AD. MethodsA double-blinded, multicenter trial was conducted in which 692 patients with mild or moderate AD aged 50 years or older were randomly assigned to receive 25 mg rofecoxib or placebo daily for 12 months. The key efficacy measures were mean change from baseline at month 12 on the cognitive subscale of the AD Assessment Scale (ADAS-cog) and score on the Clinician’s Interview Based Impression of Change with caregiver input (CIBIC+). ResultsFour hundred eighty-one patients (70%) completed assessments and remained on treatment at 12 months. No significant differences between treatments were found on the mean change from baseline error score for the ADAS-cog (rofecoxib = 4.84; placebo = 5.44; difference = −0.60) or mean score on the CIBIC+ (rofecoxib = 4.90; placebo = 4.87; difference = 0.03) over 12 months. This result persisted after adjusting for severity of dementia at baseline, presence of the APOE-&egr;4 allele, and donepezil use. Secondary analyses did not reveal any significant differences on any other measures. ConclusionThe failure of selective cyclo-oxygenase–2 inhibition to slow the progression of AD may indicate either that the disease process is too advanced to modify in patients with established dementia or that cyclo-oxygenase–2 does not play a significant role in the pathogenesis of the disorder.

A randomized, double-blind, study of rofecoxib in patients with mild cognitive impairment.

Inflammatory mechanisms have been implicated in Alzheimers disease (AD) and might be mediated via the COX-2 enzyme. Previous studies with the selective COX-2 inhibitors, rofecoxib and celecoxib, have shown that they do not alter the progression of AD. We conducted a double-blind study to investigate whether rofecoxib could delay a diagnosis of AD in patients with mild cognitive impairment (MCI), a group with an expected annual AD diagnosis rate of 10–15%. MCI patients ⩾65 years were randomized to rofecoxib 25 mg (N=725) or placebo (N=732) daily for up to 4 years. The primary end point was the percentage of patients with a clinical diagnosis of AD. The estimated annual AD diagnosis rate was lower than the anticipated 10–15%: 6.4% in the rofecoxib group vs 4.5% in the placebo group (rofecoxib : placebo hazard ratio=1.46 (95% CI: 1.09, 1.94), p=0.011). Analyses of secondary end points, including measures of cognition (eg the cognitive subscale of the AD Assessment Scale (ADAS-Cog)) and global function (eg the Clinical Dementia Rating (CDR)), did not demonstrate differences between treatment groups. There was also no consistent evidence that rofecoxib differed from placebo in post hoc analyses comparing ADAS-Cog and CDR-sum of boxes scores in overlapping subgroups of patients who had Mini Mental State Exam scores of 24–26 in the present MCI study and in a previous AD treatment study with a similar design. The results from this MCI study did not support the hypothesis that rofecoxib would delay a diagnosis of AD. In conjunction with the lack of effects observed in previous AD studies, the findings suggest that inhibition of COX-2 is not a useful therapeutic approach in AD.

Oral Rizatriptan Versus Oral Sumatriptan: A Direct Comparative Study in the Acute Treatment of Migraine

Rizatriptan is a potent, oral, 5‐HT1B/1D agonist with more rapid absorption and higher bioavailability than oral sumatriptan. It was postulated that this would result in more rapid onset of effect. This randomized, double‐blind, triple‐dummy, parallel‐groups study compared rizatriptan 5 mg, rizatriptan 10 mg, sumatriptan 100 mg, and placebo in 1268 outpatients treating a single migraine attack. Headache relief rates after rizatriptan 10 mg were consistently higher than sumatriptan at all time points up to 2 hours, with significance at 1 hour (37% versus 28%, P=0.010). All active agents were significantly superior to placebo with regard to headache relief and pain freedom at 2 hours (P≤0.001). The primary efficacy endpoint of time to pain relief through 2 hours demonstrated that, after adjustment for age imbalance, rizatriptan 10 mg had earlier onset than sumatriptan 100 mg (P=0.032; hazard ratio 1.21). Rizatriptan 10 mg was also superior to sumatriptan on pain‐free response (P=0.032), reduction in functional disability (P=0.015), and relief of nausea at 2 hours (P=0.010). Significantly fewer drug‐related clinical adverse events were reported after rizatriptan 10 mg (33%, P=0.014) compared with sumatriptan 100 mg (41%). We conclude that rizatriptan 10 mg has a rapid onset of action and relieves headache and associated symptoms more effectively than sumatriptan 100 mg.

Crossover Comparison of Rizatriptan 5 mg and 10 mg Versus Sumatriptan 25 mg and 50 mg in Migraine

Rizatriptan is a selective 5‐HT1B/1D receptor agonist with rapid oral absorption and early onset of action in the acute treatment of migraine. This double‐blind, placebo‐controlled, crossover study compared rizatriptan 5 mg versus sumatriptan 25 mg, and rizatriptan 10 mg versus sumatriptan 50 mg. A total of 1329 patients were allocated to one of five groups for treatment of two attacks: rizatriptan 5 mg/sumatriptan 25 mg; sumatriptan 25 mg/rizatriptan 5 mg; rizatriptan 10 mg/sumatriptan 50 mg; sumatriptan 50 mg/rizatriptan 10 mg; placebo/placebo. For each attack, patients rated headache severity, presence of associated symptoms, and functional disability prior to dosing and at intervals through 4 hours thereafter. Patients also rated their satisfaction with medication. Rizatriptan 5 mg and 10 mg provided faster relief of headache pain and greater relief of migraine symptoms than the 25‐mg and 50‐mg doses of sumatriptan, respectively. The response to rizatriptan was better than sumatriptan on additional measures including functional disability and satisfaction with medication. All active treatments were highly effective compared to placebo and acted as early as 30 minutes after dosing. All active treatments were well‐tolerated and showed comparable safety profiles.

Rizatriptan (MAXALT) for the Acute Treatment of Migraine and Migraine Recurrence. A Placebo‐Controlled, Outpatient Study

Rizatriptan is a novel 5‐HT1B/1D agonist which is rapidly absorbed after oral administration. The efficacy and tolerability of oral rizatriptan (5 mg and 10 mg) were examined in this multicenter, double‐blind, outpatient study of 1473 migraineurs which featured randomized, placebo‐controlled treatment of migraine recurrences. On experiencing moderate or severe migraine headaches, patients rated headache severity prior to dosing and at 30‐minute intervals for 2 hours after dosing. Onset of effect was seen as early as 30 minutes after dosing with rizatriptan 10 mg. At 2 hours postdose, the percentage of patients with pain relief was significantly higher after rizatriptan 5 mg (62%) or 10 mg (71%) compared with placebo (35%). Complete relief was also significantly higher after rizatriptan 5 mg (33%) and 10 mg (42%) compared with placebo (10%). In patients experiencing headache recurrence after initial benefit, further relief was obtained in 71% with rizatriptan 5 mg (placebo 54%) and in 82% with rizatriptan 10 mg (placebo 44%). Complete relief of recurrent headache was obtained in 36% with rizatriptan 5 mg, 49% with rizatriptan 10 mg, and 15% with placebo (P<0.05). The most common drug‐related adverse experiences were dizziness, somnolence, asthenia/fatigue, and nausea (the incidences of which were low and dose related). There was no increase in the incidence of adverse experiences after use of up to three doses of rizatriptan within 24 hours. We conclude that both doses of rizatriptan are effective and well tolerated in the acute treatment of migraine and migraine recurrence, with the l0‐mg dose preferred as it is more effective with a faster onset of action.

Telephone screening for amnestic mild cognitive impairment

Objectives: To evaluate the utility of telephone screening for identifying subjects with amnestic mild cognitive impairment (aMCI) for enrollment in a clinical trial and to identify which elements of the modified Telephone Interview for Cognitive Status (TICS-m) best predicted the in-clinic determination of aMCI. Methods: Subjects aged ≥65 years with memory complaints responded to an advertisement for a clinical trial by calling a central telephone recruiting agency. To determine eligibility, subjects went through a stepwise selection procedure involving a review of major protocol inclusion and exclusion criteria, followed by administration of the Category Fluency Test (CFT) and then the TICS-m. Subjects meeting entry criteria, who obtained a score of ≤13 on the CFT for “animals” and ≤24 on the CFT for “animals” and “fruits” and who scored between 19 and 38 on the TICS-m, were referred for a clinic appointment to determine whether they met clinical criteria for aMCI. Clinical criteria for aMCI required a score of ≥24 on the Mini-Mental State Examination and a score of ≤37 on the Rey Auditory Verbal Learning Test. A post hoc analysis was performed using factor analysis and logistic regression models to investigate which elements of the TICS-m best predicted the in-clinic determination of aMCI. Results: Of 16,988 subjects who called the telephone agency, 8,742 passed the review of inclusion/exclusion criteria; 6,090 met the CFT cut scores and received the TICS-m; 5,223 met cut scores on the TICS-m and were referred for an in-clinic appointment; 747 were seen in the clinic; and 324 met clinical criteria for aMCI. Factor analysis indicated three factors on the TICS-m: language/attention, orientation, and memory. The memory factor, comprising immediate and delayed recall of a word list, was the most important contributor for identifying subjects who met clinical criteria for aMCI. Conclusion: Only 2% of subjects who underwent telephone screening were recruited into the study, but 43% of those who passed telephone screening and were seen in the clinic met clinical criteria for aMCI. The word recall tests of the TICS-m were the most important items for identifying which subjects met clinical criteria for aMCI.

A multiple-dose safety trial of eptastigmine in Alzheimer's disease, with pharmacodynamic observations of red blood cell cholinesterase

A placebo-controlled multiple dose study was conducted to evaluate the safety, tolerability, and pharmacodynamics of multiple dose levels of eptastigmine in 25 patients with probable Alzheimers disease (AD). Twenty patients (12 M, 8 F; mean age 74, range 57-84) were randomized to receive 12mg (N = 3), 20mg (N = 6), 28mg (N = 6) or placebo (N = 5) tid on a double-blind basis for 14 days, followed by seven days of single blind placebo, in successively rising dose groups. All patients completed the study without intolerable or severe adverse events. All doses significantly (p < 0.001) reduced peak and trough RBC cholinesterase (AChE) activity as compared to baseline. Percent inhibition for Day 14 peak and trough RBC AChE peak and trough values, respectively, appeared proportional to dose: 18% and 21% (12mg); 36% and 35% (20mg); 40% and 44% (28mg). In order to determine the maximum tolerated dose of eptastigmine, an additional single-blind study was performed in five patients (2 M, 3 F; mean age 78, range 72-80) utilizing a rising dose schedule of eptastigmine (N = 4) or placebo (N = 1), starting with the previously tolerated 28mg tid dose and increasing by 4mg tid up to a potential maximum of 56mg tid. Dose-limiting adverse events occurred requiring discontinuation of medication in one patient at 48mg tid and two patients at 52mg tid; RBC AChE inhibition was proportional to dose, with peak values up to 70% inhibition at 48mg tid. The maximum tolerated dose of 48mg tid was identified as a basis for potential Phase II multicenter efficacy trials.