Open Label Safety/Immunogenicity Study of MYOBLOC (Neurobloc; Botulinum Toxin Type B) in Patients With Cervical Dystonia: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Open Label Safety/Immunogenicity Study of MYOBLOC (Neurobloc; Botulinum Toxin Type B) in Patients With Cervical Dystonia (NCT00702754), a na phase 4 study. The primary outcome is Treatment Assessment Scale (TAS), 4 Wks Post-injection Compared to Baseline (Time 0), Rating of Cervical Dystonia Symptoms.

2. Clinical Question

The study asked whether treatment with MYOBLOC (botulinum toxin type B) could be evaluated for safety and immunogenicity in adults with a clinical diagnosis of cervical dystonia. Its listed primary symptom endpoint was the change on the Treatment Assessment Scale (TAS) four weeks after the first injection compared with baseline. The registry record describes a seven-point scale ranging from -3, significantly worse, through 0, no change, to +3, significantly better.

This is a descriptive question within a treated group, not a randomized comparison of MYOBLOC with another treatment or with no treatment. A change from baseline can describe what happened over time among enrolled participants, but, without a comparison group, it cannot by itself separate treatment effects from other influences on symptoms or their measurement. The registry record does not report a primary endpoint estimate, so the magnitude and precision of the recorded change cannot be assessed from the posted results.

3. Trial Design

The registry identifies this as a Phase 4, completed, open-label, single-group study sponsored by Solstice Neurosciences, LLC, a subsidiary of US WorldMeds, LLC. The recorded study start is 2001-06 and primary completion is 2008-05. Enrollment is listed as 502. The study focused on adults with cervical dystonia and described its purpose as evaluating the safety and immunogenicity of MYOBLOC.

Participants received open-label botulinum toxin type B injections. The arm description specifies 5,000 units up to 25,000 units every 12 weeks. Because there is one treatment group and masking is listed as none, participants and study personnel were not blinded to the assigned study treatment. Allocation is listed as NA, consistent with the absence of a randomized treatment allocation in this single-group record.

The primary outcome is a mean on the Treatment Assessment Scale, comparing the rating four weeks after injection with baseline at the first session. The scale is described as a seven-point rating from -3, significantly worse, to +3, significantly better, with 0 indicating no change. The listed primary population is Safety Population/Intent to Treat. Secondary TAS assessments are specified at approximately weeks 12, 24, 36, 48, 60, 72, and 84, each with assessment four weeks after injection compared with baseline.

The registry lists eight outcome measures and zero analyses. It does not report a separate control group, a masking procedure, a statistical analysis plan, or the criteria used to define the analysis population. Specific details about study visits beyond those in the outcome descriptions, the dose-selection process, and the handling of treatment interruptions are not reported in the registry record. The design therefore supports description of outcomes during open-label treatment, but the record does not establish a controlled estimate of a treatment effect.

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: Subjects had to be Botulinum Toxin Type B naive and could not have received a Botulinum Toxin Type A treatment within 12 weeks of enrollment.

MYOBLOC Treatment Session 1 (Time 0)

MYOBLOC Treatment Session 2 (App 12 Wks)

MYOBLOC Treatment Session 3 (App 24 Wks)

MYOBLOC Treatment Session 4 (App 36 Wks)

Analysis population for the primary outcome, as defined in the registry: Safety Population/Intent to Treat

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.

6. Primary Endpoint

The registry lists the primary outcome as Treatment Assessment Scale (TAS), 4 Wks Post-injection Compared to Baseline (Time 0), Rating of Cervical Dystonia Symptoms, measured over Session 1 - Time 0, 4 weeks post-injection compared to baseline.

The primary endpoint is the mean Treatment Assessment Scale (TAS) rating four weeks after the first injection compared with baseline. Its stated timeframe is Session 1, from Time 0 to four weeks post-injection. The registry describes the TAS as a seven-point scale: -3 means significantly worse, 0 means no change, and +3 means significantly better. The endpoint is expressed in points on a scale, and the planned summary measure is a mean with standard error as its dispersion measure.

The endpoint is intended to capture the direction and average amount of rated cervical dystonia symptom change over the initial assessment period. A mean can summarize the central change across participants, while retaining the scale’s signed interpretation: values toward the positive end indicate ratings of improvement, and values toward the negative end indicate ratings of worsening. The registry does not identify who completed the rating, so the assessor and rating procedure cannot be characterized further.

General statistical context: a mean is useful for summarizing a continuous measure, but it can conceal variation between participants. A standard error describes the uncertainty in an estimated mean; it is not a description of the spread of individual participant ratings. The registry record does not report the endpoint mean, standard error, confidence interval, or participant count contributing to this outcome. Consequently, the posted record does not permit assessment of the observed average change or its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes the primary endpoint as a mean change on a continuous rating scale. It states that the dispersion measure is the standard error. It does not report the fitted statistical model, the exact calculation of change, an estimate, or a confidence interval. The statistical methods used to produce any endpoint result are therefore not reported in the registry record.

What a mean represents

General statistical explanation: a mean combines participant-level measurements into an average. For a change-from-baseline outcome, each participant’s post-baseline value is considered relative to that participant’s baseline value, and the mean summarizes those changes across the analyzed participants. The interpretation depends on the scale and the analysis population. On the TAS as described, positive values indicate ratings toward better symptoms, zero indicates no change, and negative values indicate ratings toward worse symptoms. The registry record does not specify whether the reported mean, if any, was calculated from participant-level changes or from another representation of the endpoint.

A mean is compact, but it does not show how individual responses are distributed. Participants may have similar ratings, or ratings may vary considerably; a single mean cannot distinguish these possibilities. The registry does not report participant-level data or a distributional summary for this endpoint.

Standard error and precision

General statistical explanation: the standard error describes uncertainty in an estimated mean, whereas a standard deviation describes variation among individual observations. A smaller standard error generally indicates a more precisely estimated mean, given the analysis and sample. It does not mean that participant outcomes are less variable. A confidence interval can use the standard error to express a range of plausible values for the mean under specified assumptions. Neither the standard error nor a confidence interval for the primary endpoint is reported in the registry record, so the precision of the endpoint estimate cannot be assessed.

Single-group change and comparison

This study has one open-label treatment group and no separate comparator. General statistical explanation: a pre-post comparison can describe change over time within participants, but the before-and-after contrast does not control for other influences that may also change over time. A randomized concurrent control group can provide a basis for estimating a between-group contrast. No such contrast is part of the design recorded. Accordingly, any within-group result would be descriptive rather than a randomized estimate comparing treatment options.

Repeated assessments

The registry lists a primary assessment four weeks after the first injection and secondary TAS assessments approximately four weeks after injections at weeks 12, 24, 36, 48, 60, 72, and 84. General statistical explanation: measurements repeated in the same participant are related, so analyses that treat them as independent can misrepresent uncertainty. Repeated-measures methods can account for within-participant correlation, but the choice of method depends on the question and data structure. The registry record does not report a repeated-measures model or another method for analyzing follow-up assessments.

Examining several outcomes or time points also raises multiplicity: the more statistical tests considered, the greater the chance of at least one apparently unusual result under a null model. Statistical plans may designate a primary outcome, specify a testing sequence, or adjust for multiple comparisons. The registry identifies a primary endpoint and secondary assessments, but does not report a multiplicity strategy, testing hierarchy, or adjusted results. It is not possible to determine from the record how multiplicity was handled.

Planning assumptions are not observed evidence

The registry includes assumptions for a sample-size planning illustration: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of an observed effect. It describes participant counts as per arm for non-time-to-event outcomes. These are planning assumptions, not results from the study and not observed power. The assumptions describe a two-arm illustration even though this trial is recorded as single group. The registry does not report a trial-specific sample-size justification or the numeric planning results, so those cannot be assessed or treated as properties of the actual trial design.

Safety summaries

The adverse-event information includes counts or affected entries and percentages for listed serious-event terms, but does not identify the at-risk denominators in the relevant fields. General statistical explanation: a proportion requires both a numerator and a clearly defined denominator, with a consistent definition of the population and observation period. The listed percentages can be repeated as registry entries, but their interpretation as risks, incidence rates, or treatment-related events is not supported by the information recorded. No statistical comparison of safety outcomes is reported.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("MYOBLOC Open Label Treatment")
n   <- c(495)
m   <- c(0.9)
sp  <- c(0.1)
sd  <- sp * sqrt(n)      # standard errors converted to SDs
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  MYOBLOC Open Label Treatment  495  0.900  2.225  0.704  1.096

11. Multiplicity, Missing Data and Analysis Populations

The registry identifies one primary TAS endpoint and lists secondary TAS assessments at several later follow-up times. It does not report whether the primary endpoint was tested using a prespecified statistical procedure, whether secondary outcomes were intended to be confirmatory or descriptive, or whether any adjustment for multiple outcomes or time points was used. A multiplicity strategy is not reported in the registry record.

General statistical context: repeated testing across outcomes or time points can increase the chance of a nominally notable result arising by chance. Adjustments, prespecified testing hierarchies, or clear separation of confirmatory and exploratory analyses can help readers interpret such findings. Since no endpoint analyses are listed, and no testing procedure is described, there is no basis for evaluating the effect of multiplicity on the reported evidence.

Missing-data methods are also not reported. The record does not state how many participants had primary endpoint data, how missing visits were handled, whether participants who stopped treatment remained in follow-up, or whether any imputation or sensitivity analysis was used. These details matter for a study with assessments over repeated treatment visits, because the participants observed at later visits may differ from those observed earlier. The record does not establish whether missingness was related to symptoms, adverse events, or other factors.

The primary population is labeled Safety Population/Intent to Treat, but its operational definition is not reported. The registry does not explain how that label was applied to the endpoint analysis or whether the same population was used for safety and symptom outcomes. The enrollment of 502 does not identify the number included in each outcome analysis. The registry also does not report participant flow or endpoint-specific denominators. These omissions limit assessment of the completeness and comparability of the analyses over time.

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

The registry record describes an open-label study of MYOBLOC in adults with cervical dystonia and specifies a symptom-rating endpoint, repeated follow-up assessments, and safety outcomes. It does not report a numerical result for the primary TAS endpoint. As a result, the posted results do not establish the average symptom-rating change, its direction, or its precision. The outcome definition should not be mistaken for an observed finding.

Even if a within-group change estimate were available, the design would not provide a randomized comparison with another treatment or with no treatment. General statistical context: changes observed in a single group may reflect several influences, and a before-and-after result alone cannot isolate the contribution of treatment. The open-label design also means treatment and study participation were not masked, while the registry does not specify who rated symptoms or how the rating was administered.

The safety entries report counts or affected entries and percentages for selected serious-event terms, but the at-risk denominators are null and the deaths field is null. The record therefore does not support calculating event rates from those fields. The listed events should not be treated as proof of treatment causation; the registry entries alone do not establish whether an event was attributed to MYOBLOC.

The record’s planning assumptions are not evidence of observed efficacy, precision, or power. In particular, the planning illustration uses a two-arm framework, while the registered trial has a single group. A planning calculation cannot replace observed results or a trial-specific sample-size rationale. No such rationale is reported in the registry record.

Overall, the record is informative about the study’s stated purpose, design, dosing description, endpoint definitions, and selected safety entries. It is not sufficient to draw conclusions about the size or reliability of symptom change, comparative effects, endpoint missingness, or the statistical handling of repeated outcomes. Those matters are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial illustrates an important distinction between an outcome definition and an outcome result. The registry gives a clear direction for interpreting the TAS scale: -3 indicates significantly worse, 0 no change, and +3 significantly better. It also defines a primary comparison at four weeks after the first injection relative to baseline. However, the endpoint estimate and its uncertainty are not reported. Without them, the scale description cannot answer what change was observed or how precisely it was estimated.

The single-group, open-label structure is also central to statistical interpretation. A change from baseline can describe participants’ recorded course during treatment, but there is no randomized comparator in this record to separate that change from other influences over time. That limitation does not erase the descriptive value of follow-up, but it limits the kind of treatment-effect conclusion the design can support.

Repeated TAS assessments provide a framework for describing symptoms over multiple treatment visits. Their interpretation depends on how within-participant correlation, missing visits, and multiple outcome assessments are handled. The registry does not report those analytic details or any analyses. This makes it impossible to evaluate whether the repeated observations were analyzed as a coherent longitudinal outcome or as separate assessments.

The safety fields likewise show why denominators and definitions matter. Counts and selected percentages are listed, but the at-risk fields are null. Without a defined denominator and analysis period, readers cannot assess event rates from these entries. The record also does not establish causal attribution for the listed events.

For biostatistical review, this record is a useful example of how design features, endpoint reporting, analysis populations, missing data, and safety denominators jointly determine what can be inferred. Here, essential result and method details are not reported, so interpretation must remain limited to the registered design and recorded descriptive entries.

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 primary limitation for interpreting the study is that the registry record does not report the primary TAS estimate or its uncertainty. Although the endpoint scale, direction, population label, and timeframe are stated, there is no reported mean, standard error, confidence interval, or endpoint-specific participant count. The record also lists zero analyses, preventing assessment of the statistical evidence for the primary or secondary outcomes.

The single-group, open-label design has no randomized comparator. Thus, the design cannot estimate a controlled between-group difference. The registry does not report who completed the TAS rating, how ratings were administered, or whether the same assessment procedure was used across visits. The assessor and measurement process therefore cannot be evaluated from the record.

Several features that would support evaluation of a long follow-up are not reported: participant flow, completion at each visit, reasons for missing assessments, missing-data methods, and analyses of sensitivity to missingness. The label Safety Population/Intent to Treat is given for the primary population, but its operational definition and relationship to the outcome analysis are not described. The enrollment figure does not show how many participants contributed data to each outcome.

The registry does not report a trial-specific sample-size justification, statistical analysis plan, multiplicity procedure, or model for repeated measurements. Although planning assumptions are listed, their two-arm framework does not match the single-group design, and numeric planning results are not reported. The safety fields have null at-risk and deaths entries, limiting interpretation of the listed counts and percentages. These omissions restrict evaluation of outcome precision, missingness, safety rates, and the statistical methods used.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Open Label Safety/Immunogenicity Study of MYOBLOC (Neurobloc; Botulinum Toxin Type B) in Patients With Cervical Dystonia — NCT00702754.
• Registry record last updated 2026-05-11; status last verified 2026-04.
• Results first posted 2009-09-23.
• 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.

18. Record Summary

NCT00702754 is listed as a completed Phase 4, open-label, single-group study of MYOBLOC (botulinum toxin type B) in adults with cervical dystonia. Enrollment is 502. The recorded study start is 2001-06, and primary completion is 2008-05. The arm description specifies injections of 5,000 units up to 25,000 units every 12 weeks.

The primary outcome is the mean TAS rating four weeks after the first injection compared with baseline, on a scale from -3 to +3. Secondary TAS assessments are listed at later follow-up visits through approximately week 84. The primary analysis population is labeled Safety Population/Intent to Treat.

The registry lists eight outcome measures and zero analyses. It does not report the primary endpoint result, an analysis plan, missing-data methods, or a trial-specific sample-size justification. Safety entries include 133 serious and 494 other adverse events or affected entries; at-risk fields and the deaths field are null. Selected serious-event terms and percentages are recorded, but the entries do not establish event rates or causation.