Conditions: Gout
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 185
Healthy volunteers: yes

Brief summary:
This study is a multicenter, randomized, double-blind, placebo-controlled, parallel group, dose-comparison to determine the efficacy and safety of a standard-dose of colchicine (4.8 mg) versus low-dose colchicine (1.8 mg) or placebo for acute gout flares.

Detailed description:
This study is a multi-center, randomized, double-blind, placebo-controlled, parallel group trial to compare the efficacy and safety of standard-dose colchicine (STD)(total dose = 4.8 mg) versus low-dose colchicine (total dose 1.8 mg) or placebo for the treatment of acute gout flares. Eight hundred and thirteen patients with a confirmed diagnosis of gout were screened. 238 of the screened patients failed screening; 235(98.7%) failed because they did not meet inclusion/exclusion criteria. The 575 eligible patients were randomly assigned (1:1:1) to one of three treatment groups . At the randomization visit the investigator dispensed a blister card containing eight identical looking capsules (in a combination of active drug and placebo capsules) in a double blind fashion for use during their next gout flare. Patients were instructed to self-initiate treatment with the study medication within 12 hours of a gout flare onset. Gout flares were determined by calling a Gout Flare Call Center established for this purpose. At Investigator discretion, rescue medication could also be provided, but patients were encouraged not to use rescue medication within the first 24 hours after starting treatment with study drug. Of the 575 study participants, 185 had a qualifying gout flare and 390 did not. Patients used a diary to record study drug administration, pain score, the presence or absence of gastrointestinal adverse events (nausea, vomiting, diarrhea, and abdominal pain) and the timing of any rescue medication use prior to beginning treatment and 1, 2, 3, 4, 5, 6, 7, 8, 16, 24, 32, 40, 48, 56, 64, and 72 hours after the start of dosing.

The pain score was based on a scale of 1 - 10 where 1 was no pain and 10 was the worst pain imaginable. Efficacy was defined as a 50% reduction in pain score in the target joint at 24 hours in patients who did not use rescue medicine. The primary efficacy analysis was to be based on an Intent-to-Treat (ITT) population, defined as all patients who were randomized, contacted the Call Center, and were instructed to begin taking study drug. An otherwise qualified patient was excluded from the ITT population only if the patient returned a study drug blister pack completely unused.

Secondary outcome measures compared the efficacy of STD dose colchicine to a low dose regimen and placebo using the same criteria for efficacy as for the primary outcome measure.

Additional secondary outcome measures were time to 50% and 90% reduction in pain in the target joint analyzed by treatment group using Kaplan-Meier methods, and the change in mean pain intensity from 0 to 72 hours plotted by time point for each treatment group.

All safety analyses were carried out using the safety population defined as all patients who received at least one dose of study medication regardless of authorization by the Call Center To determine the safety of colchicine when administered via two different dose regimens all patients who had a gout flare were seen by the investigator as soon as possible after onset and evaluated until the flare and any adverse events resolved. All adverse effects, whether recorded by the patient in the diary or obtained by systematic evaluation by the investigator were recorded and reported in tabular form. Treatment-emergent adverse events (TEAE) were summarized by MedDRA System Organ Class and preferred terms and tabulated according treatment arm, overall incidence, severity and relationship to study medication. Multiple events within a patient were counted once and at greatest severity and closest relationship to study medication.

Arms:
arm 1: After confirmation of a gout flare, patients were to begin standard dosing of colchicine 4.8mg (two capsules (1.8mg) initially followed by additional one capsule doses (0.6mg) every hour for an additional 6 doses). arm 2: Within 12 hours of a confirmed gout flare, patients were to begin the low dose colchicine regimen consisting of a total dose of 1.8 mg - two colchicine capsules initially (1.2 mg)followed an hour later by a single additional capsule of active drug(0.6 mg)then by 5 additional hourly doses of an identical looking placebo capsules arm 3: None

Interventions: intervention 1: High Dose Colchicine (4.8 mg total dose) intervention 2: Low Dose Colchicine (1.8mg total dose) intervention 3: Placebo Control
Intervention descriptions: intervention 1: At randomization, patients were given an identical looking blister pack containing (8) over encapsulated colchicine 0.6 mg tablets identical in appearance to placebo capsules. Patients were instructed to take 2 capsules initially (1.2 mg) followed by an additional capsule (0.6 mg) every hour for a total of six additional doses (total colchicine dose 4.8 mg) beginning within 12 hours of onset of a qualifying gout flare as confirmed by calling the gout flare call center. intervention 2: At randomization, patients were given an identical looking blister pack containing (3) over encapsulated colchicine 0.6 mg tablets identical in appearance to placebo capsules and five placebo capsules. Patients were instructed to take 2 capsules initially (0.6 mg x 2) followed by an additional capsule every hour for a total of six additional doses (one active (0.6 mg) and 5 placebo capsules), a total colchicine dose = 1.8 mg) beginning within 12 hours of onset of a qualifying gout flare as confirmed by calling the gout flare call center intervention 3: At randomization, patients were given an identical looking blister pack containing (8) placebo capsules identical in appearance to the study drug. Patients were instructed to take 2 capsules initially followed by an additional capsule every hour for a total of six additional doses beginning within 12 hours of onset of a qualifying gout flare as confirmed by calling the gout flare call center.

Protocol document: