A Study of Laquinimod in Participants With Systemic Lupus Erythematosus (SLE) Active Lupus Arthritis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Laquinimod in Participants With Systemic Lupus Erythematosus (SLE) Active Lupus Arthritis (NCT01085084), a randomized phase 2 study. The primary outcome is Number of Participants With Adverse Events (AEs).

2. Clinical Question

3. Trial Design

The registry identifies NCT01085084 as a Phase IIa, randomized, parallel-group, triple-masked, placebo-controlled study of laquinimod in participants with systemic lupus erythematosus and active lupus arthritis. The official title describes the study as multicenter and double-blind, while the registry’s masking classification is triple. The record does not identify which parties were included in that classification.

The study enrolled 82 participants and is marked completed. The listed study start was 2010-10-04 and the primary completion date was 2012-11-12. Participants were assigned to placebo, Laquinimod 0.5 mg, or Laquinimod 1 mg. Each regimen was oral and once daily for 12 weeks. The primary endpoint timeframe extended from baseline up to Week 16.

Although the study was randomized, the primary safety analysis set was defined by receipt of at least 1 dose. Within that set, participants were grouped according to treatment actually received, regardless of assigned treatment. This is the population used for the posted primary outcome counts. Details of the randomization procedure, allocation concealment, and the reasons for any differences between assigned and received treatment are not reported in the registry record.

The registry lists three outcome measures and no posted secondary outcomes. It does not report a detailed protocol for the statistical analysis or a sample-size justification for the trial. The sample-size illustrations accompanying the posted results are planning calculations based on an observed effect, not evidence about the original trial design.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Safety analysis set included all randomized participants who received at least 1 dose of study drug. In this set, treatment was assigned based upon the treatment actually received regardless of the assigned treatment.

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: Intent-To-Treat (ITT) analysis set included all participants who were randomly assigned to a treatment, regardless of which treatment they actually received.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Adverse Events (AEs), measured over Baseline up to Week 16.

The primary endpoint is the number of participants with adverse events, assessed from baseline up to Week 16. An adverse event was defined as any untoward medical occurrence in a participant who received study drug, without regard to whether it might have been caused by treatment. The endpoint includes serious and non-serious adverse events.

This outcome is used to describe safety experience across treatment groups. It counts participants who had at least one event rather than the total number of separate events, so it does not express how often events recurred in an individual participant. It also does not, by itself, describe event severity, duration, or causal relationship to treatment.

The safety analysis set included randomized participants who received at least 1 dose. The registry states that participants were analyzed according to treatment actually received, regardless of assigned treatment. In this set, the primary outcome was 21 of 25 participants with placebo, 29 of 29 with Laquinimod 0.5 mg, and 25 of 28 with Laquinimod 1 mg. Those counts are descriptive safety findings; they are not a direct measure of clinical benefit for lupus arthritis.

7. Results Posted in the Registry

• Laquinimod 0.5 mg: 100.0% (29/29) versus 84.0% (21/25) on control; risk difference 16.0 percentage points (95% CI 1.6 to 30.4), risk ratio 1.19 (1.00–1.41); unadjusted two-proportion z-test p = 0.025.
• Laquinimod 1 mg: 89.3% (25/28) versus 84.0% (21/25) on control; risk difference 5.3 percentage points (95% CI -13.1 to 23.7), risk ratio 1.06 (0.86–1.32); unadjusted two-proportion z-test p = 0.570.

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count measure?

The endpoint counts participants with at least one adverse event, rather than counting every event episode. The denominators are the numbers in the safety analysis set for each treatment group. This makes the outcome binary at the participant level: a participant either met the definition of having an adverse event or did not. The registry’s definition includes serious and non-serious events and does not require the event to be judged related to study drug.

How should the risk difference be read?

A risk difference compares the proportion of participants with an event in one group with the proportion in the comparator group. A positive value means the event proportion was higher in the active-treatment group for the comparison as presented; a negative value would mean it was lower. The 0.5 mg comparison has a reported risk difference of 0.16. The 1 mg comparison has a reported risk difference of 0.053. These are unadjusted comparisons derived from the posted arm counts, not adjusted estimates from a reported sponsor model.

What does the confidence interval add?

A confidence interval describes the range of effect estimates compatible with the observed data under the method used. It helps show precision, which a point estimate alone cannot convey. For the 0.5 mg comparison with placebo, the reported interval does not include zero. For the 1 mg comparison, the interval includes zero. An interval that includes zero is compatible with no risk difference as well as with differences in either direction within the interval. It does not prove that the groups are the same.

What does the p-value say?

The reported p-values are unadjusted: p = 0.025 for Laquinimod 0.5 mg versus placebo and p = 0.57 for Laquinimod 1 mg versus placebo. In general, a p-value measures how surprising data at least as incompatible with a specified null hypothesis would be if that hypothesis and the analysis assumptions were true. It is not the probability that the null hypothesis is true, nor a measure of clinical importance. The registry record does not report whether these comparisons were prespecified or whether any multiplicity procedure was planned.

Why consider a relative measure too?

The posted results also include relative risk estimates. A relative risk compares the event proportions as a ratio, so a value of 1 represents equal proportions. For the 0.5 mg comparison, the reported relative risk is 1.19; for the 1 mg comparison it is 1.063. Relative and absolute measures describe the same comparison from different perspectives, and neither removes the uncertainty due to the small group sizes. The registry record does not report a separate adjusted analysis for these relative measures.

What do the planning illustrations mean?

The planning calculations are explicitly based on the observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They illustrate participants per arm for 80% power and participants per arm for 90% power if the effect to detect were 100%, 75%, or 50% of the observed effect. For 100% of the observed effect, the illustrations are 650 participants per arm for 80% power and 869 for 90% power. For 75% of the observed effect, they are 1,203 and 1,610 participants per arm. For 50% of the observed effect, they are 2,814 and 3,767 participants per arm.

These are planning illustrations, not observed power and not the trial’s original sample-size justification. They concern the comparison for which the planning calculations are posted, not every treatment contrast or every endpoint. In general, detecting a smaller effect with a chosen level of power requires a larger sample, all else being equal. The registry record does not report the assumptions or justification used to set the actual enrollment target.

10. Confidence Intervals and Precision

The arm counts are based on 25 participants receiving placebo, 29 receiving Laquinimod 0.5 mg, and 28 receiving Laquinimod 1 mg. Estimates from groups of this size can be imprecise, particularly when the outcome is common. The point estimates should therefore be read alongside their confidence intervals, not as exact descriptions of the underlying event probabilities.

For the 0.5 mg comparison with placebo, the risk-difference confidence interval lies above zero. That interval indicates uncertainty remains about the size of the difference even though its range does not include no difference. For the 1 mg comparison with placebo, the confidence interval includes zero and allows for effects in either direction. This does not demonstrate equivalence; an equivalence conclusion would require an appropriate design and specified margin, neither of which is reported in the registry record.

The relative risk intervals also indicate uncertainty. The 0.5 mg relative risk interval is close to the null value at its lower end, while the 1 mg interval spans values below and above the null. Because interval endpoints for these estimates are not repeated here, the key interpretation is their relationship to the relevant null value, not a false sense of precision from a single point estimate.

Confidence intervals describe statistical uncertainty under an analysis method. They do not account automatically for every limitation, including the small safety population, potential missing outcome information, or unreported multiplicity procedures. The registry record does not report how missing safety data were handled. Precision should be interpreted in light of those limits as well as the interval width.

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists three outcome measures, but no secondary outcome results are posted. It also lists no analyses. The posted primary outcome counts and the unadjusted comparisons are available, but a full statistical analysis plan, including the prespecified comparison hierarchy, is not reported in the registry record. It is therefore not possible to determine from the record whether the two comparisons were planned as confirmatory tests or how multiplicity was considered.

Multiplicity arises when several hypotheses are tested: the more tests conducted, the greater the chance that at least one result appears noteworthy by chance. The two unadjusted p-values should consequently be interpreted as individual comparisons, not as evidence adjusted across a family of tests. No adjustment method is reported.

The analysis population was the safety analysis set: randomized participants who received at least 1 dose. Treatment was classified according to treatment actually received, regardless of assigned treatment. The registry record does not report an intention-to-treat analysis for this endpoint, the number of participants excluded from the safety set, or whether any participants had missing primary outcome data.

Missing-data handling is not reported in the registry record. The available counts do not establish whether all participants had complete follow-up through Week 16 or how incomplete observation, if any, affected the endpoint. The record also does not describe imputation, sensitivity analyses, or procedures for handling treatment discontinuation. These omissions limit assessment of whether the observed counts could be affected by missing outcome information.

These reporting gaps do not invalidate the posted counts, but they restrict what can be concluded about their robustness and their role in the original analysis. In particular, they make it inappropriate to treat the unadjusted p-values as a complete account of the trial’s statistical evidence.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: diverticulitis (3.6%), pleurisy (3.6%), vertigo (3.4%), pneumonia mycoplasmal (3.4%), tonsillitis (3.4%).

The serious adverse event counts were 0 among 25 participants receiving placebo, 4 among 29 receiving Laquinimod 0.5 mg, and 2 among 28 receiving Laquinimod 1 mg. The registry defines a serious adverse event as an adverse event resulting in outcomes such as death, initial or prolonged inpatient hospitalization, a life-threatening experience, persistent or significant disability or incapacity, or congenital anomaly, or otherwise deemed significant for another reason.

These figures count participants with serious adverse events, not the total number of separate serious events. The registry also reports zero deaths in each group. Serious-event counts from groups of this size are descriptive and do not provide a precise comparison of underlying risks. A count of zero in a group does not establish that the risk is zero.

The reported top serious-event terms include Diverticulitis and Pleurisy at 3.6% each, and Vertigo, Pneumonia Mycoplasmal, Tonsillitis, and Depression at 3.4% each. The record’s primary adverse-event endpoint includes both serious and non-serious events and does not require a causal relationship. The serious-event figures should therefore be read separately from the overall primary endpoint counts.

13. What the Result Does, and Does Not, Mean

The registry results describe how many participants in each safety group experienced at least one adverse event over the stated timeframe. They show 21 of 25 participants in the placebo group, 29 of 29 in the Laquinimod 0.5 mg group, and 25 of 28 in the Laquinimod 1 mg group. The unadjusted comparison with placebo shows a higher observed event proportion for the 0.5 mg group, while the 1 mg comparison has a confidence interval that includes no difference.

These findings do not establish whether any individual event was caused by laquinimod. The endpoint includes events without regard to the possibility of a causal relationship, and it combines serious and non-serious adverse events. The event count alone does not describe severity, duration, recurrence, or the clinical importance of each event.

The results also do not establish that the treatment groups are equivalent, or that a difference is absent when a comparison is not statistically significant. The limited group sizes and the uncertainty in the estimates matter. No multiplicity adjustment, missing-data strategy, or detailed analysis plan is reported in the registry record.

Finally, the primary endpoint is a safety outcome. It does not answer whether laquinimod changes lupus arthritis activity or provides clinical benefit. Although the study aimed to evaluate clinical effect as well as safety, no secondary outcome results are posted in the registry record. Conclusions should therefore remain confined to the posted safety counts and their uncertainty.

14. Why This Trial Matters Statistically

This trial illustrates why the endpoint and analysis population must be considered before interpreting a treatment comparison. The primary outcome counts participants with adverse events, a broad safety measure that includes both serious and non-serious events. It does not measure disease activity, and it does not require events to be attributed to study treatment.

The registry also makes an important population distinction. Although participants were randomized, the safety analysis set included those who received at least 1 dose and assigned them to groups according to treatment actually received. That definition is relevant when interpreting the comparisons: the posted counts are not described as an all-randomized analysis by assigned group.

The results demonstrate how a point estimate and its uncertainty can lead to different readings across comparisons. The 0.5 mg comparison has an unadjusted p-value of 0.025 and an interval excluding zero, while the 1 mg comparison has an unadjusted p-value of 0.57 and an interval including zero. Neither observation should be detached from the small group sizes, the lack of reported multiplicity procedures, or the absence of a detailed analysis plan.

The planning illustrations also show why sample-size calculations need careful labeling. They are based on observed effects and stated assumptions, and are not the original design justification or observed power. Keeping these distinctions clear helps prevent descriptive safety data from being overinterpreted as definitive evidence about treatment effects.

15. 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 safety groups were small: 25 participants received placebo, 29 received Laquinimod 0.5 mg, and 28 received Laquinimod 1 mg. The resulting estimates have limited precision, as reflected by confidence intervals that remain broad. A small observed group count, including zero serious adverse events in the placebo group, cannot establish that an underlying event risk is absent.

The primary endpoint combines serious and non-serious events and counts participants rather than event episodes. It does not convey the severity or duration of all events, and it includes events regardless of possible causal relationship. The serious-event counts are separately reported, but they too are based on small groups.

The safety analysis set includes randomized participants who received at least 1 dose and classifies them by treatment actually received. The registry record does not report an intention-to-treat analysis for the endpoint or explain whether assigned and received treatment differed for any participant. Details of missing outcome data and their handling are also not reported.

Only unadjusted comparisons are posted, with no reported multiplicity adjustment or complete statistical analysis plan. No secondary outcomes are posted, so these results do not answer the study’s clinical-effect question. The planning illustrations are based on observed effects and are not a substitute for the unreported original sample-size justification.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study of Laquinimod in Participants With Systemic Lupus Erythematosus (SLE) Active Lupus Arthritis — NCT01085084.
• Registry record last updated 2022-07-07; status last verified 2022-06.
• Results first posted 2022-07-07.
• 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.

19. Record Summary

NCT01085084 is a completed Phase IIa randomized, parallel-group, placebo-controlled study of laquinimod in participants with systemic lupus erythematosus and active lupus arthritis. The study enrolled 82 participants and compared placebo with Laquinimod 0.5 mg and Laquinimod 1 mg, taken orally once daily for 12 weeks.

The primary endpoint was the number of participants with adverse events from baseline up to Week 16. The posted safety counts were 21 of 25 for placebo, 29 of 29 for Laquinimod 0.5 mg, and 25 of 28 for Laquinimod 1 mg. Unadjusted comparisons with placebo are reported; the registry record does not report secondary outcome results, a detailed analysis plan, or missing-data handling.