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Relapsing Multiple Sclerosis Phase 3 Continuous Endpoint NCT02792218

Efficacy and Safety of Ofatumumab Compared to Teriflunomide in Patients With Relapsing Multiple Sclerosis: Complete Statistical Analysis

A randomized, masked phase 3 trial compared ofatumumab with teriflunomide in participants with relapsing multiple sclerosis. The primary analysis assessed annualized relapse rate, with registry results also covering disability, MRI findings, and safety.

Trial start: 2016-09-20  ·  Enrollment: 930  ·  Sponsor: Novartis Pharmaceuticals
Scope of this record

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 and Safety of Ofatumumab Compared to Teriflunomide in Patients With Relapsing Multiple Sclerosis (NCT02792218), a randomized phase 3 study. The primary outcome is Annualized Relapse Rate (ARR).

930
Enrollment
Phase 3
2
Arms
In the primary outcome
n/a
Effect
No re-analysis shown
n/a
95% CI
See limitations
FeatureRegistry value
ClinicalTrials.gov identifierNCT02792218
PhasePhase 3
ConditionRelapsing Multiple Sclerosis
AllocationRandomized
Design modelParallel
MaskingQuadruple
Enrollment930
Arms in the primary outcome2
Lead sponsorNovartis Pharmaceuticals
Results postedYes

2. Clinical Question

Population

Participants with relapsing multiple sclerosis were eligible for the trial. The primary endpoint analysis used the full analysis set. The registry record does not give further eligibility details in the record summarized for these results, so the population should be understood at the level reported rather than extended to other forms of multiple sclerosis or to people outside the trial.

Intervention

The intervention was ofatumumab 20 mg by subcutaneous injection, given on days 1, 7, and 14, at week 4, and every 4 weeks thereafter. Participants also took a teriflunomide-matching placebo capsule once daily. This double-dummy approach meant that the assigned treatment groups followed both an injection schedule and a capsule schedule.

Comparator

The comparator was teriflunomide 14 mg as an oral capsule once daily, together with subcutaneous injections matching placebo ofatumumab on the corresponding schedule. The comparison therefore concerns the assigned treatment regimens, including their matching placebos, rather than a comparison of active treatment with no treatment.

Primary question

The primary question was whether the annualized rate of confirmed relapse differed between the assigned groups from baseline up to 2.5 years. A confirmed relapse required a clinically relevant change on the Expanded Disability Status Scale, assessed by an independent rater, against the previous rating that did not occur during a relapse. The registry reports a negative binomial regression comparison of the relapse rates. The result describes the trial's endpoint and analysis; it is not, by itself, a conclusion about every possible benefit, harm, or outcome.

3. Trial Design

This was a phase 3, randomized, parallel-group trial of ofatumumab versus teriflunomide in participants with relapsing multiple sclerosis. The registry describes the masking as quadruple and the study as double-blind and double-dummy. The registry record does not identify in the results which specific roles were masked, or give further details of the randomization sequence or allocation concealment.

The trial enrolled 930 participants. The primary endpoint was analyzed in the full analysis set, with 454 participants in the ofatumumab group and 451 in the teriflunomide group contributing to the reported arm-level endpoint. The registry record does not explain the accounting between enrollment and these endpoint group sizes, so no reason for that difference should be inferred from the figures alone.

Participants assigned to ofatumumab received 20 mg by subcutaneous injection on days 1, 7, and 14, at week 4, and every 4 weeks thereafter, along with a matching oral placebo capsule once daily. Participants assigned to teriflunomide received a 14 mg oral capsule once daily and matching placebo injections on the corresponding schedule. This design allowed the treatment groups to follow both sets of procedures while maintaining masking.

The study status is completed. Its start date is 2016-09-20, and its primary completion date is 2019-07-05. The registry record describes the comparison and broad design, but details such as the randomization method, treatment adherence, and the operational masking procedures are not reported in the registry record.

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.

Before assignment: A total of 1277 patients were screened, of whom 927 patients were randomized into the study.

Overall Study

StageOMB 20 mgTER 14 mg
STARTED465462
COMPLETED416381
NOT COMPLETED4981

Reasons for not completing this period:

ReasonOMB 20 mgTER 14 mg
Patient/guardian decision1542
Adverse Event1514
Lost to Follow-up105
Lack of Efficacy112
Physician Decision44
Protocol deviation32
New therapy for study indication01
Non-compliance with study treatment01
Pregnancy10

Analysis population for the primary outcome, as defined in the registry: Full analysis set

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.

CharacteristicUnitOMB 20 mgTER 14 mgTotal
Participants analysed465462927
Age, ContinuousYears38.9 (SD 8.77)37.8 (SD 8.95)38.4 (SD 8.87)
Sex: Female, Male: FemaleParticipants318317635
Sex: Female, Male: MaleParticipants147145292
Race/Ethnicity, Customized: AsianParticipants151631
Race/Ethnicity, Customized: Black or African AmericanParticipants152035
Race/Ethnicity, Customized: WhiteParticipants411412823
Race/Ethnicity, Customized: OtherParticipants221436
Race/Ethnicity, Customized: UnknownParticipants202
Number of relapses in the past 12 months prior to screeningNumber of relapses1.2 (SD 0.63)1.3 (SD 0.69)1.2 (SD 0.66)
Expanded Disability Status Scale (EDSS)Score on a scale2.97 (SD 1.357)2.94 (SD 1.355)2.96 (SD 1.356)
Number of Gd-enhancing T1 lesionsT1 lesions1.7 (SD 4.93)1.2 (SD 2.58)1.5 (SD 3.95)

6. Primary Endpoint

The registry lists the primary outcome as Annualized Relapse Rate (ARR), measured over Baseline up to 2.5 years.

ElementRegistry entry
Result typeMean
Measure of spread95% Confidence Interval
Unitnumber of relapses in a year
Endpoint classificationContinuous Endpoint

The primary endpoint was annualized relapse rate, or ARR, from baseline up to 2.5 years. It measures the rate of confirmed relapses per participant-year, rather than simply the proportion of participants who experienced at least one relapse. The registry defines ARR by dividing the total number of confirmed relapses in a treatment group by the total participant-years of time in study.

A relapse counted for this endpoint had to be accompanied by a clinically relevant change on the Expanded Disability Status Scale, assessed by an independent EDSS rater. The required change was an increase of at least 0.5 points on the EDSS, or an increase of 1 point on two functional scores or 2 points on one functional score, excluding changes involving the bowel/bladder or cerebral functional system. The change was assessed against the previous rating that did not occur during a relapse.

Using a rate accounts for the time participants contributed to follow-up. This is useful when participants have different amounts of observation, because the measure relates the relapse count to time under observation. It remains a defined trial outcome: it does not describe every symptom, disability change, or aspect of participants' experience.

7. Why No Re-analysis Is Shown

Reported as posted, not recalculated. Values missing or not estimable for a two-arm comparison (continuous endpoint). A result is recalculated only when the posted data support a clean two-arm comparison, so no result is shown beyond what the sponsor posted.

8. Statistical Interpretation

Clinical Biostats interpretation

The reported ARR was 0.11 in the OMB 20 mg group, with a 95% confidence interval from 0.09 to 0.14. In the TER 14 mg group, the reported ARR was 0.22, with a 95% confidence interval from 0.18 to 0.26. These arm-level estimates describe confirmed relapse rates per year over the stated follow-up period. Their confidence intervals express uncertainty in the estimates; they are not a range of individual participants' relapse counts.

The registry's primary comparison used negative binomial regression and reported a rate ratio of 0.495, with a 95% confidence interval from 0.375 to 0.655 and p < 0.001. A rate ratio compares the modeled rates, with values below 1 indicating a lower modeled rate in the numerator group than in the comparison group. The reported estimate and interval are consistent with a lower modeled ARR for OMB 20 mg relative to TER 14 mg in this trial. The p-value describes how incompatible the observed data are with the model's null comparison, under the assumptions of that analysis; it is not the probability that the null hypothesis is true.

The interval conveys more than the p-value alone: it gives a range of rate-ratio values compatible with the data under the analysis. It does not encompass every source of uncertainty, including questions about generalizability, missing observations, or analysis choices that are not described in the registry record. The arm-level confidence intervals and the rate-ratio confidence interval answer related but distinct questions, so their endpoints should not be compared as if they were the same contrast.

The endpoint's definition matters for interpretation. Only relapses meeting the specified confirmation criteria count toward ARR. The reported estimate therefore concerns confirmed relapses under that definition, not all reported symptoms or every possible measure of disease activity. It also summarizes events over participant-time rather than stating the chance that any one participant will experience a relapse.

The result is one finding from a trial that also listed disability and MRI outcomes. The registry record names those outcome areas, but values for most of the listed secondary measures are not reported in the registry record in the information summarized for these results. The primary endpoint should therefore be read as a focused result rather than as a complete account of every outcome assessed.

9. Statistical Methods Explained

The primary comparison was estimated with a negative binomial regression model. ARR is a count-based rate: the endpoint uses the number of confirmed relapses relative to participant-years of follow-up. A regression model can compare such rates while representing the observed count data. The registry gives the model family and the resulting rate ratio, confidence interval, and p-value, but the model's other specifications are not reported in the registry record. In particular, the registry record does not state which covariates were included or give further details of the model implementation.

Why use a rate ratio?

A rate ratio expresses one modeled event rate relative to another. A value of 1 would indicate equal modeled rates; a value below 1 indicates a lower rate in the numerator group, and a value above 1 indicates a higher rate. This is a general interpretation of the measure, not an additional result. The reported rate ratio of 0.495 compares the OMB 20 mg group with the TER 14 mg group. Its confidence interval, 0.375 to 0.655, describes uncertainty in that relative-rate estimate under the reported analysis.

Why a negative binomial model?

General statistical context: count outcomes can vary more between participants than a simpler count model expects. This is called over-dispersion. A negative binomial model allows greater variability in counts than a Poisson model, and can therefore be useful for count outcomes with over-dispersion. That general rationale does not establish which diagnostics or model checks were performed in this trial. Such details are not reported in the registry record.

Because ARR is defined using participant-years, the time participants contribute to observation is relevant to the rate. The registry defines the endpoint using total relapses divided by total participant-years. It does not report enough model detail to specify how time was represented within the regression or whether any additional adjustments were used. Those elements should not be inferred from the name of the model alone.

What do the confidence intervals express?

A confidence interval describes the precision of an estimate under the statistical method used. In general, a 95% confidence interval is generated by a procedure that would cover the target parameter in 95% of repeated samples if the model assumptions and sampling process held. It is not a statement that there is a 95% probability that this particular interval contains the true value. The arm-level ARR intervals describe uncertainty around each group's rate estimate, while the interval for the rate ratio describes uncertainty around the comparison.

A p-value is a measure of how surprising data at least as incompatible with the null comparison would be under that null and the analysis assumptions. The reported p < 0.001 is not a measure of the size or clinical importance of the difference, and it does not describe the probability that the result arose by chance. The estimated rate ratio and its interval are needed to understand the direction and precision of the comparison.

How to read the secondary comparison and planning illustrations

The registry also reports a secondary binary outcome, the percentage of participants with a confirmed relapse. A binary outcome records whether a participant met the endpoint, rather than counting events relative to participant-time. The recalculated contrast for that outcome is an unadjusted comparison based on posted summary statistics. General statistical context: unadjusted comparisons do not account for covariates or other design features unless those are explicitly incorporated. They should not be treated as interchangeable with the primary negative binomial model.

Planning illustrations use assumed effect sizes and specified statistical assumptions to show how participant counts might relate to power. They are not observed power, do not show what the trial was designed to detect, and do not replace the trial's own analysis. The stated illustration uses a two-sided significance level of 0.05, equal allocation, and a normal approximation, with effects set as fractions of the observed effect. The registry record does not report that these assumptions were the trial's original design assumptions or provide the original sample-size justification.

For the secondary binary comparison, the posted planning values describe participants per arm for 80% power and participants per arm for 90% power at the stated fractions of the observed effect. These are planning illustrations only. They are especially sensitive to the assumed effect: a smaller assumed effect requires a larger planned sample under the illustration's assumptions. No conclusion about the trial's observed power follows from these values.

What is not specified

The registry reports 17 analyses and 30 outcome measures, but the available record does not fully describe the statistical analysis plan. Covariate adjustment, handling of missing outcome data, sensitivity analyses, model diagnostics, and any interim analyses are not reported in the registry record. The absence of those details limits independent assessment of the analysis choices; it does not establish that a particular method was or was not used.

10. Analyses Reported by the Sponsor

MethodEstimate95% CIP-value
negative binomial regression modelrate ratio 0.4950.375 to 0.655< 0.001

The registry reports the primary comparison as a negative binomial regression analysis, with a rate ratio of 0.495, a 95% confidence interval from 0.375 to 0.655, and p < 0.001. The arm-level ARR estimates and confidence intervals are also reported. These are the posted primary results and are the appropriate basis for describing the trial's primary analysis.

No simple unadjusted recalculation of the primary two-group comparison is available in the reported recalculated results. The registry identifies the endpoint as a continuous measure for the recalculation process and records that values were missing or not estimable for a two-arm comparison. This does not contradict the sponsor's reported model analysis: it means a separate, simple recalculation is not available to compare against that model result.

For the secondary percentage-of-participants outcome, an unadjusted recalculation is available, while the registry lists no sponsor-reported analysis for that outcome in the information. That secondary calculation is a different analysis of a different endpoint and should not be used as a replacement for the sponsor's primary regression result. The discrepancy indicator is false. If a discrepancy were present, the sponsor's own analysis would take precedence; there is no such discrepancy indicated for these results.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 30 outcome measures and 17 analyses. When a study examines many outcomes or makes multiple statistical comparisons, multiplicity becomes relevant: the more opportunities there are to find a small p-value, the greater the possibility of a chance finding somewhere among the results. Statistical strategies can address this, for example by adjusting significance thresholds or by specifying a testing sequence. The registry record does not report whether either approach, or another multiplicity procedure, was used.

The reported primary comparison is the principal result for interpreting the trial's stated primary endpoint. The record does not provide enough detail to determine how the primary endpoint was protected from other testing, whether outcomes were hierarchically ordered, or whether the 17 analyses include only planned comparisons. These details are not reported in the registry record. In the absence of a documented multiplicity strategy, secondary p-values should not be treated as if each were an isolated confirmatory test.

The primary analysis population is identified as the full analysis set. The registry record summarized for these results does not give the full analysis-set definition, describe how participants were handled after randomization, or say how missing data were handled. It does not report whether values were imputed, whether participants with incomplete follow-up were included in particular analyses, or whether sensitivity analyses assessed the impact of missingness. Those omissions prevent a complete appraisal of how missing outcomes may have affected estimates.

Details about interim analyses, stopping rules, and the statistical analysis plan are also not reported in the registry record. The absence of those details should be treated as uncertainty about reporting, not as evidence that interim analyses or other procedures did or did not occur. The trial's completion status and posted primary estimate do not resolve these methodological questions.

The sample-size illustrations are calculations based on the observed effect and stated assumptions, not evidence of the original design rationale. The registry record does not report the original sample-size justification. Those illustrations also do not establish observed power; the precision of the actual estimate is better conveyed by its confidence interval. This distinction is important when interpreting secondary outcomes that may have different event frequencies or measurement variability.

12. Safety Results

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

ArmParticipants with serious adverse eventsParticipants at riskPercentage
OMB 20mg5146511.0%
TER 14mg394628.4%
Participants with at least one serious adverse event
Serious adverse events by armOMB 20mg11.0%TER 14mg8.4%% of participants with at least one serious adverse event

Deaths

ArmDeaths (participants affected of at risk)
OMB 20mg0 of 465
TER 14mg0 of 462

Other (non-serious) adverse events

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

ArmParticipants affected of at risk
OMB 20mg282 of 465
TER 14mg308 of 462

Most frequent serious adverse event terms

Event termOrgan systemOMB 20mgTER 14mg
Multiple sclerosis relapseNervous system disorders1 of 4654 of 462
AppendicitisInfections and infestations3 of 4651 of 462
Back painMusculoskeletal and connective tissue disorders2 of 4651 of 462
VertigoEar and labyrinth disorders2 of 4650 of 462
Abdominal pain upperGastrointestinal disorders0 of 4652 of 462
GastroenteritisInfections and infestations2 of 4650 of 462
Injection related reactionInjury, poisoning and procedural complications2 of 4650 of 462
Suicidal ideationPsychiatric disorders2 of 4650 of 462
NephrolithiasisRenal and urinary disorders0 of 4652 of 462
MenorrhagiaReproductive system and breast disorders1 of 4651 of 462

Most frequent non-serious adverse event terms

Event termOrgan systemOMB 20mgTER 14mg
NasopharyngitisInfections and infestations82 of 46569 of 462
Injection related reactionInjury, poisoning and procedural complications74 of 46577 of 462
Upper respiratory tract infectionInfections and infestations47 of 46573 of 462
HeadacheNervous system disorders59 of 46553 of 462
AlopeciaSkin and subcutaneous tissue disorders27 of 46565 of 462
DiarrhoeaGastrointestinal disorders24 of 46564 of 462
FatigueGeneral disorders46 of 46539 of 462
Urinary tract infectionInfections and infestations41 of 46541 of 462
Back painMusculoskeletal and connective tissue disorders35 of 46534 of 462
Injection site reactionGeneral disorders41 of 46526 of 462

Serious events with the highest arm-level rate: multiple sclerosis relapse (0.9%), appendicitis (0.6%), abdominal pain upper (0.4%), nephrolithiasis (0.4%), pulmonary embolism (0.4%).

Do not overextend the safety comparison. Serious-adverse-event counts are safety observations, not efficacy outcomes, and should not be combined with the primary result into a single benefit-risk number.

The registry reports serious adverse events for both groups: 51 among 465 participants at risk in the OMB 20mg group and 39 among 462 at risk in the TER 14mg group. It reports no deaths in either group. These counts describe the posted serious adverse event data; they do not, on their own, establish whether any event was caused by assigned treatment or whether the difference between group counts is statistically meaningful.

The registry also lists 282 participants in the OMB 20mg group and 308 in the TER 14mg group under other adverse events. The record does not provide, in the figures, the definitions needed to interpret the relationship between this category and serious events, or the complete event-level context. The listed serious-event terms include multiple sclerosis relapse at 0.9%, appendicitis at 0.6%, and abdominal pain upper, nephrolithiasis, pulmonary embolism, and vertigo each at 0.4%. The record does not specify the denominator or group attribution for those term percentages in the summarized data, so they should not be assigned to an arm.

Adverse event counts are descriptive. They are not a substitute for assessment of event severity, timing, exposure, attribution, or comparative uncertainty, details of which are not fully reported in the registry record.

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

The primary result describes a lower modeled annualized rate of confirmed relapses in the OMB 20 mg group relative to the TER 14 mg group during the trial's stated follow-up, with the reported rate ratio and confidence interval conveying the estimated relative contrast and its precision. It is evidence about this endpoint, in the participants analyzed under the trial's definition and methods. It should not be expanded into a claim about every clinical outcome.

ARR is a group-level rate based on relapse counts and participant-years. It is not the same as the proportion of participants who experienced at least one relapse, and it does not predict an individual participant's future course. The secondary percentage outcome addresses whether participants experienced a confirmed relapse, while disability and MRI measures represent other outcome domains. Missing results for most named secondary outcomes mean that their relationship to the primary finding cannot be assessed from the registry record.

The confidence interval gives information about statistical precision under the analysis assumptions, but it does not remove uncertainty about the population to which the findings may apply. The registry record does not provide all details about eligibility, missing data, model specifications, or multiplicity. Those limitations matter when assessing robustness and generalizability. A small p-value is not a measure of clinical importance, and statistical evidence for a difference does not settle how that difference should be weighed in a clinical context.

The safety counts are also descriptive and do not establish causation. The registry's posted event totals and selected terms offer a limited account of reported safety outcomes; they do not provide every detail needed to compare risks. Overall, these results describe a randomized trial comparison and its reported estimates. They do not alone establish what will happen for an individual, resolve unreported outcomes, or answer questions beyond the measures and follow-up assessed.

14. Why This Trial Matters Statistically

This trial illustrates why endpoint scale and analysis method need to be read together. The primary outcome is not simply the number of participants with a relapse; it is a rate using relapse counts and participant-years. The negative binomial regression result compares those rates, while a secondary binary outcome addresses the proportion of participants meeting a relapse criterion. Both can be informative, but they answer different questions and should not be conflated.

The distinction between arm-level estimates and a comparative estimate is also central. The ARR values summarize each group, whereas the rate ratio expresses the modeled contrast between groups. Its confidence interval communicates uncertainty about that contrast. Reading the model estimate alongside its interval is more informative than relying on a p-value alone, while the p-value should not be mistaken for effect size, clinical importance, or certainty that a hypothesis is true.

The registry record also demonstrates how interpretation depends on reporting completeness. It names disability and MRI outcomes and records multiple analyses, but the available results do not establish the pattern across those endpoints or describe a multiplicity strategy. A reader can interpret the primary result while still recognizing that the broader outcome picture and some analysis decisions are not available in the record.

Finally, the planning illustrations are distinct from the study's actual design rationale and from observed evidence. They can clarify how assumptions about the effect size and power translate into participant-count planning, but they cannot be used to infer the trial's original target or observed power. Keeping those statistical roles separate helps prevent planning calculations from being mistaken for trial findings.

15. Limitations

The registry record does not report several details needed for a full independent assessment of the primary model, including covariates, diagnostics, and other implementation choices. The negative binomial model is named, but its full specification is not given. The record also does not describe the original sample-size justification, any interim analyses, or the complete statistical analysis plan.

Although the primary population is identified as the full analysis set, the record does not give its operational definition or explain the difference between enrollment and the endpoint group sizes. The handling of missing data, incomplete follow-up, and sensitivity analyses is not reported. Consequently, the degree to which these issues could affect the estimate cannot be judged from the posted details alone.

The registry names multiple secondary outcomes, but values for most of the disability and MRI measures are not reported in the registry record in the information summarized for these results. The multiplicity approach is also not reported. This limits conclusions about whether secondary outcomes align with the primary result and how confidently individual secondary findings should be interpreted.

The trial's reported primary endpoint focuses on confirmed relapses under a specific EDSS-based definition and covers baseline up to 2.5 years. It does not represent all disease manifestations or longer-term outcomes. The summarized safety data provide event counts and selected serious-event terms, but not enough information to establish causality, compare event timing, or fully characterize event-level severity and exposure. These limitations concern the scope and completeness of the available registry reporting; they do not by themselves show that the trial's analysis was invalid.

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19. Record Summary

NCT02792218 is a completed phase 3 randomized, quadruple-masked, parallel-group trial comparing ofatumumab with teriflunomide in participants with relapsing multiple sclerosis. The trial enrolled 930 participants. The primary endpoint was annualized relapse rate from baseline up to 2.5 years, analyzed in the full analysis set with a negative binomial regression model.

The reported primary rate ratio was 0.495, with a 95% confidence interval from 0.375 to 0.655 and p < 0.001. The registry also lists disability, MRI, relapse, and safety outcomes. Results for most named secondary measures and several statistical-plan details are not reported in the registry record, limiting assessment of the full outcome pattern and analysis procedures.

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