This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Efficacy of AIN457 in Adults (18-65 Years) With Psoriatic Arthritis (NCT00809614), a randomized phase 2 study. The primary outcome is Percentage of ACR Responders Per Treatment at Week 6.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00809614 |
| Phase | Phase 2 |
| Condition | Psoriatic Arthritis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 42 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Novartis Pharmaceuticals |
| Results posted | Yes |
2. Clinical Question
Population
Adults aged 18–65 years with psoriatic arthritis. The trial record lists an enrollment of 42. The primary endpoint description refers to a pharmacodynamic analysis set and notes that five patients were excluded because of protocol deviations.
Intervention
AIN457, given intravenously at 10 mg/kg on Day 1 and Day 22. The study summary describes two doses administered three weeks apart.
Comparator
Matching placebo, given intravenously at 10 mg/kg on Day 1 and Day 22.
Primary question
What percentage of participants in each treatment group met ACR response criteria at week 6? The registry record defines response using ACR20, ACR50, or ACR70 criteria, but the observed response results are not reported in the registry record.
This is a question about short-term clinical response in a randomized comparison, not simply whether participants received treatment or completed follow-up. The endpoint required improvement in joint counts as well as improvement across other disease-related measures. That structure is intended to capture change across more than one aspect of psoriatic arthritis.
The study was described as a proof-of-concept evaluation. Its summary says efficacy was to be assessed at 6 and up to 24 weeks after the two doses. The primary endpoint named in the record is specifically at week 6; results for that endpoint are not reported in the registry record. The record also lists secondary outcomes addressing response criteria and measures of joint, skin, entheseal, and disease activity, along with a pharmacokinetic measure. Their results are not reported in the registry record.
3. Trial Design
This was a randomized, double-blind, parallel-group, placebo-controlled phase 2 study. Its official title describes it as a multi-center proof-of-concept study in patients with psoriatic arthritis. The registry record reports an enrollment of 42 and identifies adults aged 18–65 years as the population in the study title.
Participants assigned to AIN457 received 10 mg/kg intravenously on Day 1 and Day 22. The placebo group received matching placebo intravenously at the same stated dose and on the same days. The study summary describes the two AIN457 doses as three weeks apart and says efficacy was to be evaluated at 6 and up to 24 weeks after dosing. The primary endpoint was the percentage of ACR responders per treatment at week 6.
Random allocation is intended to reduce systematic differences between treatment groups at assignment. Double masking is intended to limit the influence of treatment knowledge on participant experience, clinical assessment, and other trial processes. The parallel design means the comparison is between groups assigned to different treatments, rather than a crossover in which participants receive both study treatments.
The registry record lists the study as completed and identifies Novartis Pharmaceuticals as the sponsor. The recorded start is 2009-03, and primary completion is recorded as 2010-12. Details of the randomization procedure, allocation concealment, masking procedures, site count, and treatment adherence are not reported in the registry record. The record also does not describe whether the planned follow-up through 24 weeks was completed for all participants.
Although the record identifies a randomized design and gives the enrollment, it does not provide enough detail to reconstruct participant flow or to establish how many people were included in each efficacy analysis. The safety group counts are reported separately. They should not be treated as the denominators for the primary efficacy endpoint without an explicit statement linking those populations.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | AIN457 (2x 10mg/kg) | Placebo |
|---|---|---|
| STARTED | 28 | 14 |
| Pharmacokinetic Safety Set | 27 | 14 |
| Pharmacodynamic (PD) Set | 24 | 13 |
| COMPLETED | 25 | 10 |
| NOT COMPLETED | 3 | 4 |
Reasons for not completing this period:
| Reason | AIN457 (2x 10mg/kg) | Placebo |
|---|---|---|
| Lack of Efficacy | 2 | 3 |
| Withdrawal by Subject | 1 | 1 |
Analysis population for the primary outcome, as defined in the registry: For pharmacodynamic (PD) analysis set five patients were excluded due to protocol deviations.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
Population: All patients who received at least one dose of study drug were included in the safety and tolerability evaluation.
| Characteristic | Unit | AIN457 (2x 10mg/kg) | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 28 | 14 | 42 | |
| Age, Continuous | Years | 46.7 (SD 11.3) | 47.6 (SD 8.1) | 47.0 (SD 10.2) |
| Sex: Female, Male: Female | Participants | 19 | 8 | 27 |
| Sex: Female, Male: Male | Participants | 9 | 6 | 15 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of ACR Responders Per Treatment at Week 6, measured over week 6.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Percentage of ACR responders |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the percentage of ACR responders per treatment at week 6. The record describes response using ACR20, ACR50, or ACR70 criteria. A participant had to meet the relevant improvement threshold in both tender joint count and swollen joint count, and also in at least 3 of 5 additional measures: the participant’s assessment of pain, the participant’s global assessment of disease activity, the physician’s global assessment of disease activity, the Health Assessment Questionnaire score, and C-reactive protein.
In general, a composite response endpoint combines several measures so that response reflects more than one dimension of a condition. Requiring improvement in joint counts and in additional measures makes the criterion more demanding than relying on a single symptom or laboratory measure. The graded ACR criteria distinguish response thresholds of 20%, 50%, and 70%; the registry record does not report how many participants met any of those thresholds at week 6.
A percentage endpoint expresses the frequency of responders relative to the relevant analysis group. Interpreting it depends on knowing both the responder count and the denominator used. Neither the week 6 response counts nor the efficacy denominators are reported in the registry record. The endpoint description identifies a pharmacodynamic analysis set and notes exclusions due to protocol deviations, but it does not give a full account of the analysis population or missing observations.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the primary clinical outcome and its assessment time, but does not report the observed week 6 ACR response results. It therefore does not establish the response percentage in either treatment group, the difference between groups, or the precision of any treatment comparison. Those quantities are necessary to describe the direction, size, and uncertainty of the primary result. They are not reported in the registry record.
The endpoint is a percentage, so a complete interpretation would need the number of responders and the denominator in each group. Percentages without denominators can be difficult to assess, particularly in a small study. The registry record gives an enrollment of 42, but that enrollment figure alone does not establish how many participants contributed to the primary endpoint. The safety counts should not be substituted for efficacy denominators, because the registry record does not state that the two analysis populations are the same.
The study is described as phase 2 and proof-of-concept. Such a design can provide an initial assessment of a treatment comparison, but the label does not substitute for the observed endpoint data or their uncertainty. Since no primary outcome estimates or statistical tests are reported in the registry record, neither the strength of evidence nor the precision of the comparison can be evaluated from this record. A conclusion that one treatment group had a higher or lower response would go beyond the reported results.
The record lists secondary outcomes, including ACR response thresholds, PsARC response, several disease-activity measures, and pharmacokinetic timing. Listing an outcome indicates that it was part of the registered study description; it does not show what result was observed. The results for these secondary outcomes are not reported in the registry record. The registry record has no posted analysis entries, so it does not provide a basis for comparing the primary and secondary findings or judging whether different measures point in the same direction.
Precision also cannot be assessed. In general, a confidence interval describes a range of values compatible with the data under the analysis assumptions, and its width conveys how uncertain an estimate is. No confidence interval, standard error, or other uncertainty measure for the primary endpoint is reported in the registry record. No p-value for the primary comparison is reported either. The absence of these results does not show that the treatments were equivalent or that there was no difference; it means the registry record does not report the information needed to make that statistical assessment.
The study summary says assessments were planned at week 6 and up to 24 weeks, while the named primary endpoint is at week 6. Without outcome results at either time, the record cannot support conclusions about change over time, persistence of response, or how week 6 findings relate to later follow-up. It also does not report whether any comparison was adjusted for baseline characteristics or other factors. Any interpretation should therefore remain limited to the registered design and endpoint definition, not an unreported treatment effect.
9. Statistical Methods Explained
The registry record describes a randomized, double-blind, parallel-group comparison of AIN457 with matching placebo. These design features define how the intended comparison was organized, but they do not reveal the statistical analysis used for the outcome. The statistical plan, including the method used to estimate or test the week 6 response comparison, is not reported in the registry record.
What does randomization contribute?
In general, randomization assigns participants to study groups using a chance-based process. Its purpose is to reduce systematic differences in participant characteristics between groups at the time of assignment. It does not guarantee that groups will be identical, especially in a modest-sized study, and it does not address biases introduced after assignment, such as missing outcome data or departures from the intended treatment. The record says allocation was randomized but does not describe the sequence-generation method, allocation concealment, or any checks of baseline balance.
What does double masking mean for interpretation?
In general, masking means that specified people involved in the trial are not told which treatment was assigned. This can help limit differences in expectations, reporting, and assessment. The registry record labels the study double-blind and describes placebo as matching, but it does not identify which roles were masked or explain how masking was maintained. The label alone cannot establish whether masking was successful.
How should a response percentage be understood?
A response percentage is a proportion: it depends on both the responder count and the number of participants included in the relevant analysis. For this endpoint, the responder definition uses ACR20, ACR50, or ACR70 criteria. Each threshold has its own meaning under the endpoint definition, and interpreting an arm-level percentage requires knowing which threshold is being reported, its denominator, and how participants with missing data were handled. The registry record does not report the week 6 response counts, percentages, denominators, or uncertainty estimates.
In general, a treatment comparison for a binary response can be expressed using a difference in response proportions or another contrast. Different measures answer related but not identical questions, and each should be accompanied by an uncertainty estimate. No effect estimate, confidence interval, or p-value for the primary comparison is reported in the registry record. No statistical test or model for that comparison is described either.
What can a confidence interval tell a reader?
In general, a confidence interval describes uncertainty around an estimated quantity under the assumptions of the analysis. A narrow interval indicates greater precision than a wide interval, but precision is not the same as clinical importance. Whether an interval includes a value corresponding to no difference can inform an inferential assessment, but it does not by itself establish equivalence. Because the record does not report an interval or point estimate for the primary endpoint, the precision and direction of the comparison cannot be assessed.
What do the planning assumptions mean?
The registry record describes sample-size illustrations as planning calculations based on a fraction of the observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. It states that the illustrations are not the trial’s own design and that reported sample sizes are participants per arm for 80% power, except that time-to-event calculations would use total events. These are planning assumptions, not observed power. No sample-size illustration values are reported in the registry record, and the record does not report the effect estimate on which the illustrations are based.
In general, a planning calculation asks how much information a future study might need for a specified statistical objective under stated assumptions. It does not describe how likely the completed study was to detect an effect, and it is not an outcome of the trial. The trial’s enrollment and the planning illustrations should therefore be understood as separate concepts. The record does not report the original sample-size justification or explain whether the trial’s enrollment was chosen using these assumptions.
What cannot be inferred from the record?
The record does not report an analysis plan for repeated assessments, adjustment for multiple outcomes, covariate adjustment, handling of protocol deviations beyond the noted exclusions, or a missing-data method. It also does not provide an interim-analysis description. These details can affect the interpretation of estimates and uncertainty, but their absence from the record is not evidence that a particular method was or was not used. The trial’s statistical analysis cannot be reconstructed from the endpoint definition and design labels alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry record names a primary endpoint at week 6 and lists secondary outcomes. These include ACR20, ACR50, or ACR70 response, PsARC response, MASES, PASI, SPARCC, LDI, DA28, and a pharmacokinetic measure of time to maximum concentration after drug administration. The record lists 15 outcome measures, but it does not report their results or explain how analyses across outcomes or time points were handled.
When a study evaluates several outcomes, response thresholds, or assessment times, multiple statistical comparisons may arise. In general, conducting many comparisons can increase the chance of at least one apparently notable finding by chance. A prespecified multiplicity strategy can clarify which findings are confirmatory and how statistical error is controlled. Such a strategy is not reported in the registry record. The record also does not state whether secondary outcomes were exploratory or whether any hierarchy of testing was used.
The primary endpoint description identifies a pharmacodynamic analysis set and says five patients were excluded due to protocol deviations. It does not provide the full eligibility rules for that set, the reasons for individual exclusions, or the number included in the week 6 response analysis. The record’s enrollment figure should not be read as the primary endpoint denominator.
Missing-data handling is not reported in the registry record. In general, the treatment of participants whose week 6 outcomes are unavailable can affect a response percentage and a group comparison. The record does not state whether missing outcomes were imputed, treated as non-response, or analyzed using another approach. It also does not describe sensitivity analyses for missingness. The registry record has no posted analysis entries, so neither a multiplicity procedure nor a missing-data analysis can be assessed from the reported results.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| AIN457 2x10mg/kg | 4 | 28 | 14.3% |
| Placebo | 1 | 14 | 7.1% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| AIN457 2x10mg/kg | 23 of 28 |
| Placebo | 11 of 14 |
Most frequent serious adverse event terms
| Event term | Organ system | AIN457 2x10mg/kg | Placebo |
|---|---|---|---|
| Cellulitis | Infections and infestations | 1 of 28 | 0 of 14 |
| Fall | Injury, poisoning and procedural complications | 1 of 28 | 0 of 14 |
| Tendon rupture | Injury, poisoning and procedural complications | 1 of 28 | 0 of 14 |
| Obesity | Metabolism and nutrition disorders | 1 of 28 | 0 of 14 |
| Polyarthritis | Musculoskeletal and connective tissue disorders | 0 of 28 | 1 of 14 |
| Breast cancer in situ | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1 of 28 | 0 of 14 |
| Carpal tunnel syndrome | Nervous system disorders | 1 of 28 | 0 of 14 |
Most frequent non-serious adverse event terms
| Event term | Organ system | AIN457 2x10mg/kg | Placebo |
|---|---|---|---|
| Nasopharyngitis | Infections and infestations | 7 of 28 | 5 of 14 |
| Headache | Nervous system disorders | 6 of 28 | 1 of 14 |
| Nausea | Gastrointestinal disorders | 4 of 28 | 1 of 14 |
| Vertigo | Ear and labyrinth disorders | 1 of 28 | 3 of 14 |
| Diarrhoea | Gastrointestinal disorders | 3 of 28 | 1 of 14 |
| Dizziness | Nervous system disorders | 4 of 28 | 0 of 14 |
| Pruritus | Skin and subcutaneous tissue disorders | 3 of 28 | 1 of 14 |
| Abdominal pain upper | Gastrointestinal disorders | 3 of 28 | 0 of 14 |
| Fatigue | General disorders | 3 of 28 | 0 of 14 |
| Contusion | Injury, poisoning and procedural complications | 2 of 28 | 1 of 14 |
Serious events with the highest arm-level rate: polyarthritis (7.1%), cellulitis (3.6%), fall (3.6%), tendon rupture (3.6%), obesity (3.6%).
The safety information lists serious adverse events and other adverse events by group. For AIN457 2x10mg/kg, the serious-event group count at risk is 28 and the number affected is 4; the other-event group count at risk is 28 and the number affected is 23. For placebo, the serious-event group count at risk is 14 and the number affected is 1; the other-event group count at risk is 14 and the number affected is 11.
These counts describe participants affected, not necessarily the total number of event occurrences. A participant may experience more than one event, and the registry record does not state whether the event listings represent people, event episodes, or both for every reported term. The listed serious-event terms and percentages are Polyarthritis at 7.1%, Cellulitis at 3.6%, Fall at 3.6%, Tendon rupture at 3.6%, Obesity at 3.6%, and Breast cancer in situ at 3.6%. The record does not provide further context for interpreting these terms or their relation to treatment.
Deaths are not reported in the registry record. The safety counts do not establish that an event was caused by a study treatment, and they should not be interpreted as a treatment comparison without additional context. The record does not describe event ascertainment, follow-up completeness, or statistical comparisons of safety outcomes.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized, double-blind, placebo-controlled phase 2 study was conducted in adults with psoriatic arthritis and that its primary endpoint was the percentage of ACR responders at week 6. It also documents the ACR response definition, the treatment schedules, and several secondary outcomes. These are useful details for understanding the intended clinical question and the measurement strategy.
The record does not report the week 6 response results. It therefore cannot show what proportion of participants met the ACR criteria in either group, how the groups compared, or how uncertain the comparison was. No conclusion that AIN457 had a greater response, a smaller response, or a similar response to placebo is justified by the endpoint description alone. A missing result in the registry record is not evidence of no effect.
Likewise, the record’s description of a proof-of-concept study does not itself demonstrate that a treatment works or does not work. In general, proof-of-concept describes an early evaluative purpose; interpretation still depends on observed outcomes, analysis methods, and uncertainty. Those primary efficacy results and methods are not reported in the registry record.
The safety section reports affected-participant counts by group and lists serious-event terms, but those observations do not establish causality. They also do not provide a complete basis for comparing safety, because the registry record does not explain all relevant analysis details or report deaths. The listed figures should be read as descriptive registry entries, not as proof for or against a treatment-related risk.
More broadly, the record cannot establish whether results persisted through the planned follow-up, how secondary outcomes behaved, or whether the study met a statistical objective. Those questions require results and analysis details not reported in the registry record. The defensible interpretation is limited to the registered design, endpoint definition, and recorded safety counts.
13. Why This Trial Matters Statistically
This trial illustrates why an endpoint definition and an endpoint result are different kinds of information. The registry record gives a detailed description of the week 6 ACR response rule, including joint counts and other clinical and laboratory measures. That description explains what would qualify as response, but without responder counts and analysis denominators it cannot answer how often response occurred or how the treatment groups compared.
The distinction matters especially for composite outcomes. In general, combining measures can make an endpoint reflect several dimensions of disease, but the interpretation depends on the rule for combining them and on the distribution of participants who meet each component. Here, the record specifies improvement thresholds and supporting measures, yet does not report the observed endpoint results. A well-defined measure can therefore coexist with an unanswerable treatment-effect question in the registry record.
The trial also emphasizes the importance of linking populations across analyses. The endpoint description notes that five patients were excluded from the pharmacodynamic analysis set because of protocol deviations, while the safety information gives its own at-risk counts. Without a full participant-flow account and explicit efficacy denominators, readers cannot assume that those populations align.
Finally, a randomized design and masking are important design features, but they do not replace reporting of estimates, uncertainty, and analysis choices. The registry record does not report the primary comparison, statistical plan, multiplicity approach, or missing-data handling. Statistically, this leaves a gap between a clearly stated question and the evidence needed to evaluate its answer. The record is informative about trial structure, but it does not provide the primary efficacy findings.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The central limitation for interpreting efficacy is that the primary endpoint results are not reported in the registry record. There are no week 6 response counts, percentages, denominators, effect estimates, confidence intervals, or p-values. The record therefore does not permit an assessment of the direction or precision of the primary comparison.
The endpoint description says five patients were excluded from the pharmacodynamic analysis set due to protocol deviations, but does not describe the full analysis population or how exclusions were determined. Participant flow, missing week 6 assessments, adherence, and the handling of unavailable outcomes are not reported in the registry record. The safety at-risk counts cannot be assumed to represent the efficacy analysis population.
Statistical methods are also insufficiently documented for a complete appraisal. The analysis plan, model or test for the primary endpoint, any adjustment for baseline characteristics, multiplicity strategy, and sensitivity analyses are not reported in the registry record. The record does not explain how outcomes at different times were analyzed or whether all planned assessments were completed.
The study summary refers to evaluation at 6 and up to 24 weeks, but the record does not provide efficacy results for those time points. The number and nature of sites, randomization implementation, and masking procedures are not detailed beyond the design labels. These gaps limit assessment of conduct and generalizability. The enrollment figure and proof-of-concept designation do not resolve those uncertainties or substitute for the unreported findings.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Efficacy of AIN457 in Adults (18-65 Years) With Psoriatic Arthritis — NCT00809614.
- Registry record last updated 2015-11-13; status last verified 2015-10.
- Results first posted 2015-11-13.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry record describes a completed phase 2, randomized, double-blind, parallel, placebo-controlled, multi-center proof-of-concept study of AIN457 in adults aged 18–65 years with psoriatic arthritis. Enrollment is listed as 42. AIN457 and matching placebo were each administered intravenously at 10 mg/kg on Day 1 and Day 22.
The primary endpoint was the percentage of ACR responders per treatment at week 6. The definition uses ACR20, ACR50, or ACR70 criteria and requires improvement in joint counts and at least 3 of 5 additional measures. The endpoint results are not reported in the registry record. Its description notes that five patients were excluded from the pharmacodynamic analysis set because of protocol deviations.
Secondary outcomes cover response criteria, disease-activity measures, and pharmacokinetics. The safety record lists serious and other adverse-event counts by treatment group and several serious-event terms. Deaths are not reported in the registry record. The record does not report the primary statistical comparison, its uncertainty, or the analysis methods needed to interpret an efficacy effect.