*ACR20 is a composite measure defined as an improvement of 20% in the number of tender and swollen joints and a 20% improvement in three of the following five criteria: patient global assessment, physician global assessment, functional ability measure [most often Health Assessment Questionnaire (HAQ)], visual analog pain scale, and erythrocyte sedimentation rate or C-reactive protein (CRP).
ACR50 and ACR70 are the same instruments with improvement levels defined as 50% and 70% respectively versus 20% for ACR20.
| Reference | Study type | Population | Intervention and comparison | Outcomes | Risk of bias |
|---|---|---|---|---|---|
| «Antoni CE, Kavanaugh A, Kirkham B, et al. Sustaine...»1 IMPACT |
RCT | 104 adult patients with active PsA defined as five or more swollen joints and tender joints and either CRP levels of at least 15 mg/l, erythrocyte sedimentation rate >28 mm/hour or morning stiffness lasting 45 minutes or longer. A negative rheumatoid factor, exclusion of latent tuberculosis and an inadequate response disease modifying antirheumatic drugs also required. | Infliximab 5 mg/kg or placebo at weeks 0, 2, 6, and 14. | ACR 20 (main outcome), ACR 50, ACR 70 Adverse events (and skin responses, dactylitis, enthesopathy) |
Low |
| «Antoni C, Krueger GG, de Vlam K, et al. Infliximab...»2 IMPACT |
RCT | 200 adult patients with active PsA defined as five or more swollen joints and tender joints and either CRP levels of at least 15 mg/l or morning stiffness lasting 45 minutes or longer, or both. A negative rheumatoid factor and an inadequate response to current or previous disease modifying antirheumatic drugs or non-steroidal anti-inflammatory drugs (NSAIDs) were also required. | Infliximab 5 mg/kg or placebo at weeks 0, 2, 6, 14, and 22 | ACR 20, 50, 70 Adverse events (and skin responses, dactylitis, entesopahty, quality of life) |
Low |
RCT=randomized controlled trial; SR=systematic review; MA=meta-analysis
| Reference | Comments |
|---|---|
| overall comment on the effect of infliximab vs placebo | There were four network meta-analyses that included the same RCTs as those two included in this evidence summary, however, none of the meta-analyses reported absolute number of events in intervention and control groups, only pooled estimates. This is why the original RCTs were examined separately. |
| «Antoni CE, Kavanaugh A, Kirkham B, et al. Sustaine...»1 | Concomitant treatment with one of the following were allowed: methotrexate, leflunomide, sulfasalazine, hydroxychloroquine, gold, atsatioprine or penicillamine. NSAIDs and oral corticosteroids were also allowed. Doses of concomitant medications were required to be stable 2 weeks before and during the study. |
| «Antoni C, Krueger GG, de Vlam K, et al. Infliximab...»2 | Concomitant methotrexate treatment (up to 25 mg/wk) was allowed but not mandatory. |
Results
Overall effectiveness and safety of infliximab vs placebo in the treatment of psoriatic arthritis
OUTCOME 1
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Absolute number of events (I) | Absolute number of events (%) C | Relative effect (95% CI) |
|---|---|---|---|---|---|
| «Antoni CE, Kavanaugh A, Kirkham B, et al. Sustaine...»1 | 52 / 52 | 16 weeks | 34/52 (65.4%) | 5/52 (9.6%) | NR |
| «Antoni C, Krueger GG, de Vlam K, et al. Infliximab...»2 | 100/100 | 24 weeks | 54/100 (54%) | 16/100 (16%) | NR |
| Level of evidence: high | |||||
I= intervention; C=comparison; CI=confidence interval; NR=not reported
OUTCOME 2
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Absolute number of events (I) | Absolute number of events (%) C | Relative effect (95% CI) |
|---|---|---|---|---|---|
| «Antoni CE, Kavanaugh A, Kirkham B, et al. Sustaine...»1 | 52 / 52 | 16 weeks | 24/52 (46.2%) | 0/52 (0.0%) | NR |
| «Antoni C, Krueger GG, de Vlam K, et al. Infliximab...»2 | 100/100 | 24 weeks | 41/100 (41%) | 4/100 (4%) | NR |
| Level of evidence: high | |||||
I= intervention; C=comparison; CI=confidence interval; NR=not reported
OUTCOME 3
| Reference | Number of studies and number of patients (I/C) | Follow-up time | Absolute number of events (I) | Absolute number of events (%) C | Relative effect (95% CI) |
|---|---|---|---|---|---|
| «Antoni CE, Kavanaugh A, Kirkham B, et al. Sustaine...»1 | 52 / 51 | 16 weeks | Any adverse event 38/52 (73%) Severe adverse event 3/52 (6%) |
33/51 (65%) 2/51 (4%) |
NR |
| «Antoni C, Krueger GG, de Vlam K, et al. Infliximab...»2 | 150*/97 | 24 weeks | Any adverse event 100/150 (67%) Serious adverse event 13 (9%) |
65 (67%) 6 (6%) |
NR |
| Level of evidence: high *some patients entered "early escape" and received infliximab after week 16, therefore the groups are not equal in numbers |
|||||
I= intervention; C=comparison; CI=confidence interval; NR=not reported