A Study of Sativex® for Pain Relief of Peripheral Neuropathic Pain, Associated With Allodynia: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Sativex® for Pain Relief of Peripheral Neuropathic Pain, Associated With Allodynia (NCT00710554), a randomized phase 3 study. The primary outcome is Change From Baseline in Mean Peripheral Neuropathic Pain on a 0-10 Numerical Rating Scale (NRS) Score at the End of Treatment (15 Weeks).

2. Clinical Question

The study is registered as NCT00710554 and is marked completed. It concerns pain related to peripheral neuropathy and allodynia, and its stated purpose was to evaluate Sativex compared with placebo for pain relief. The registry lists the study as Phase 3. These details define the clinical comparison, but they do not by themselves establish what the results mean for every person with these conditions or for care outside this trial.

3. Trial Design

The registry describes a randomized, parallel-group comparison of Sativex and placebo. Allocation is listed as randomized, and masking is listed as quadruple. The official title describes the study as double blind, while the registry's masking field says quadruple; the record does not define which study roles were masked or explain this wording. The available arm descriptions contain no additional information about treatment procedures.

Enrollment was 246. The primary efficacy analysis was not described as including every randomized participant: its stated population comprised participants who were randomized, received at least one dose of study medication, and yielded on-treatment efficacy data. For the primary endpoint, the reported arm summaries use 77 participants for Sativex and 92 for placebo. The registry does not report the reasons that participants may not have contributed to that endpoint analysis.

The primary outcome was assessed at the end of treatment, identified as 15 weeks in its title, with the timeframe also stated as Day 7 to Day 98. The study is marked completed. The registry gives a start date of 2005-08 and a primary completion date of 2006-10, but the original design assumptions and a fuller account of study conduct are not reported in the registry record. In particular, details about dosing, adherence, and any protocol changes are not reported there.

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: The efficacy analyses were conducted on data from all subjects who were randomised, received at least one dose of study medication and yielded on-treatment efficacy data.

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 Change From Baseline in Mean Peripheral Neuropathic Pain on a 0-10 Numerical Rating Scale (NRS) Score at the End of Treatment (15 Weeks), measured over Day 7 to Day 98.

The primary endpoint is change from baseline in mean peripheral neuropathic pain on a 0-10 numerical rating scale. Participants were asked to rate their pain, or average pain over the last 24 hours, at bedtime each day. The scale anchors are 0 for no pain and 10 for pain as bad as the participant can imagine. A negative change from baseline indicates improvement in the pain score.

The reported outcome is a mean, a summary of the average change among participants included in each arm's analysis. Comparing mean changes provides a way to describe the average difference between the Sativex and placebo groups, while the arm-level standard deviations indicate how variable individual changes were. This endpoint is relevant to the stated study question because it records pain intensity over time using a consistent numerical scale.

The primary timepoint is described as the end of treatment at 15 weeks, and the recorded timeframe is Day 7 to Day 98. The registry does not give a more detailed explanation of why this measure or timepoint was selected. An average group change does not show the full range of individual responses, and it should not be read as a description of what happened to every participant.

7. Results Posted in the Registry

• Sativex: mean -1.36 versus -0.84 on control; difference -0.52 (95% CI -1.11 to 0.07), standardized effect d = -0.27; z-test p = 0.084.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Change From Baseline in Neuropathic Pain Scale Score at the End of Treatment (15 Weeks)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Sativex: mean -11.57 versus -7.19 on control; difference -4.38 (95% CI -9.75 to 0.99), standardized effect d = -0.24; z-test p = 0.110.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Sativex and the control. The interval gives the range of effects that remain compatible with the data.

Change From Baseline in Sleep Quality 0-10 Numerical Rating Scale Scores at the End of Treatment (15 Weeks)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Sativex: mean -2.00 versus -1.20 on control; difference -0.80 (95% CI -1.57 to -0.03), standardized effect d = -0.31; z-test p = 0.043.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Sativex than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Change in Baseline Mean Dynamic Allodynia Test Score at the End of Treatment (15 Weeks)

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Sativex: mean -1.10 versus -1.00 on control; difference -0.10 (95% CI -0.73 to 0.53), standardized effect d = -0.04; z-test p = 0.755.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Sativex and the control. The interval gives the range of effects that remain compatible with the data.

The registry record lists secondary outcomes spanning neuropathic pain, sleep quality, dynamic and punctate allodynia, global impression, brief pain inventory, and quality-of-life measures. The posted secondary results cover distinct dimensions of participants' experience rather than repeated versions of a single endpoint. Their overall pattern is mixed: the registry's ANCOVA result for sleep quality differs from those reported for the other posted comparisons, while the results across the other outcomes do not give a consistent signal of group differences.

These outcomes add context to the primary pain measure, but they do not overturn or replace the primary result. Measures may differ in scale, variability, analysis population, and sensitivity to change. An outcome that is more favorable on one measure does not establish a general effect across all aspects of pain or functioning. The record does not report a prespecified hierarchy among secondary outcomes or explain how their results were intended to support the primary question.

Multiplicity matters because assessing many outcomes creates more opportunities for nominally unusual results even when no underlying differences exist. General statistical explanation: when many hypotheses are tested, interpreting each unadjusted p-value as if it were the only test can make chance findings seem more compelling. The registry record does not report a multiplicity adjustment or a strategy for controlling the overall error rate. Therefore, unadjusted secondary results should be treated as exploratory or supportive evidence rather than definitive standalone findings. This caution is especially relevant when a secondary result is considered apart from the overall pattern and the primary endpoint.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Change From Baseline in Neuropathic Pain Scale Score at the End of Treatment (15 Weeks)
• Change From Baseline in Sleep Quality 0-10 Numerical Rating Scale Scores at the End of Treatment (15 Weeks)
• Change in Baseline Mean Dynamic Allodynia Test Score at the End of Treatment (15 Weeks)
• Change in Baseline Mean Punctate Allodynia Test Scores at the End of Treatment (15 Weeks)
• Subject Global Impression of Change
• Change From Baseline in Brief Pain Inventory (Short Form) Scores at the End of Treatment
• Change From Baseline in Quality of Life EuroQol 5-D (Health Status Index) Score at the End of Treatment (15 Weeks)
• Change From Baseline in Quality of Life EuroQol 5-D (Health Status Visual Analogue Scale) Score at the End of Treatment (15 Weeks)

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: it is a numerical pain score, and the registry reports change as a mean with a standard deviation. A mean difference expresses the contrast between the average changes in the two arms. In the unadjusted re-calculation, the comparison is Sativex minus placebo. Because negative change means improvement, a negative difference corresponds to a larger average decrease in the Sativex group. This direction is a matter of the endpoint's coding; it is not, by itself, a conclusion about clinical importance.

What does the unadjusted re-calculation represent?

The re-calculation uses the posted arm-level sample sizes, means, and standard deviations to form a simple, unadjusted comparison. It is useful as a transparent check on the numerical summaries, but it does not reproduce an analysis that adjusts for other variables. The registry reports an ANCOVA estimated mean treatment difference as its trial analysis. The record does not describe the covariates, model specification, or other details of that ANCOVA, so those cannot be reconstructed from the registry information. The ANCOVA estimate and the summary-based estimate should therefore be presented as distinct analyses, not interchangeable versions of one result.

How should a confidence interval be read?

General statistical explanation: a confidence interval expresses the range of effect estimates compatible with the data and the method used, at the stated confidence level. It is not a range that contains a fixed proportion of individual participants' outcomes, and it is not a probability statement about the true effect after observing the interval. For the registry's primary ANCOVA estimate, the 95% interval runs from -0.79 to 0.11 and includes zero. That means the analysis is compatible with a range of group differences that includes no average difference as well as values on either side of zero. The interval is more informative about precision than the point estimate alone.

What does a p-value contribute?

General statistical explanation: a p-value describes how unusual data at least as incompatible with a specified null hypothesis would be under the assumptions of the statistical test. It does not give the probability that the null hypothesis is true, and it does not measure the size or practical importance of a difference. The reported primary p-value is 0.139; the unadjusted re-calculation gives 0.084. Those numbers refer to different analyses, so they should not be treated as conflicting readings of one identical test. Neither replaces consideration of the estimate, its interval, the analysis population, and the study's limitations.

Why can standard deviations matter?

General statistical explanation: the standard deviation describes the spread of observed values around the mean. Greater variation among participants can make an average contrast less precise, while a smaller standard deviation can make an average easier to estimate, all else being equal. The primary arm standard deviations are 2.02 for Sativex and 1.86 for placebo. These summarize variability in the analyzed scores; they are not confidence intervals and do not describe the uncertainty in the treatment contrast on their own.

Why does analysis population matter?

The registry says the efficacy analyses included randomized participants who received at least one dose and yielded on-treatment efficacy data. This definition differs from a population that necessarily includes every randomized participant regardless of whether outcome data were available. General statistical explanation: restricting analysis to participants with observed on-treatment data can affect interpretation if the reasons data are unavailable are related to outcomes or treatment. The record does not report how many participants lacked relevant data, why data were missing, or what methods were used to address missingness. It is not possible to assess those issues from the stated analysis population alone.

Why can over-dispersion matter?

General statistical explanation: over-dispersion arises when observed variability is greater than a statistical model assumes. If a model understates variability, uncertainty can be understated and tests can appear more decisive than warranted. The primary endpoint is continuous, and the registry reports standard deviations rather than a count outcome model. The record does not report an over-dispersion assessment for the primary analysis; this concept is a general modeling consideration, not a finding about this trial.

11. Confidence Intervals and Precision

Precision concerns how narrowly the data locate the estimated difference, rather than whether a result crosses a chosen significance threshold. The registry's primary ANCOVA estimate is -0.34, with a 95% confidence interval from -0.79 to 0.11. The interval includes zero and extends to values on either side of it. Thus, the point estimate alone gives a more definite impression than the range of values compatible with the analysis.

The unadjusted re-calculation gives an estimate of -0.52 and a confidence interval from -1.11 to 0.070. This interval also includes zero. Its upper endpoint is recorded with more than three decimal places; because values in explanatory text should not exceed three decimal places, the endpoint is not repeated. The central interpretation remains that this unadjusted interval spans zero. It should not be conflated with the ANCOVA interval, which comes from the registry's reported analysis.

General statistical explanation: a confidence interval is influenced by both the amount of information and the variability in the outcome. A wider interval indicates less precision about the average contrast, while a narrower interval indicates greater precision under the analysis assumptions. Neither interval gives a complete account of the data, individual variation, missingness, or the suitability of the model.

The primary intervals leave uncertainty about the direction and magnitude of the group contrast. They do not establish equivalence, because no equivalence margin is reported in the registry record. Nor does an interval that includes zero prove that there is no difference. The registry record does not report a clinically important difference threshold, so the clinical importance of values within either interval cannot be determined from these estimates alone.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are expressed as participants per arm because the outcomes in this study are continuous. They are not total event counts. The planning illustration assumes a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It uses the observed effect as its starting point and considers the stated fractions of that effect. The trial's original sample-size assumptions and justification are not reported in the registry record.

The 80% power column gives the estimated participants per arm for a future planning scenario to have 80% power to detect the specified effect under those assumptions. The 90% power column gives the corresponding number for 90% power. Power is a property of a planned study under assumed conditions; it is not a probability that the observed result is true, nor is it a measure of the quality of this completed trial. Smaller effects require more participants to detect under otherwise unchanged assumptions. The larger planning counts for smaller fractions of the observed effect illustrate that relationship.

These are planning illustrations based on the observed effect, not the trial's design calculations. They do not show the power the completed trial actually had, and this is not observed power. Their values depend on the assumed effect and other planning conditions; a future study using different assumptions could require different sample sizes. The figures should therefore be read as conditional planning guidance rather than as a retrospective judgment of the trial's adequacy.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -0.520; pooled standard deviation σ = 1.934.
2. n = 2 × (1.96 + 0.842)² × 1.934² / -0.520² = 217.2, rounded up to 218 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -0.52                      # observed difference in means
sigma <- 1.93445593397189                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(710554)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 218 (80% power), 291 (90% power)
 75% of observed effect: n per arm = 387 (80% power), 518 (90% power)
 50% of observed effect: n per arm = 869 (80% power), 1,164 (90% power)
power.t.test: 218.2 
Simulated power at n = 218 per arm: 0.799 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The registry reports the trial's primary comparison using ANCOVA: an estimated mean treatment difference of -0.34, with a 95% confidence interval from -0.79 to 0.11 and p = 0.139. This is the sponsor-reported analysis recorded for the primary endpoint. The registry does not give enough detail about the model to reconstruct its adjustment or verify every analytical choice.

The unadjusted re-calculation from the posted arm summaries yields a mean difference of -0.52 and p = 0.084. It uses the arm means, standard deviations, and analysis counts, rather than the ANCOVA model. The estimates and p-values differ, which is possible when methods differ; the registry does not explain the numerical difference. The discrepancy flag is false, so the record does not identify a discrepancy requiring the sponsor's result to be displaced. The two results should still be labeled by method, with the registry's ANCOVA treated as the trial's own reported analysis and the simple re-calculation as a separate descriptive check.

Neither p-value should be interpreted alone. The ANCOVA interval includes zero, as does the interval from the unadjusted re-calculation. The registry's own reported analysis is the primary reference for what the trial reported; the re-calculation adds a transparent unadjusted perspective, not a correction to the sponsor's analysis.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists 10 secondary results and reports multiple outcomes in addition to the primary pain endpoint. Each outcome comparison creates another opportunity for a result to appear notable by chance. General statistical explanation: multiplicity procedures address the increased chance of false-positive findings when several hypotheses are assessed. The registry record does not report whether a correction was applied, whether outcomes were tested in a planned hierarchy, or how secondary analyses were used to support conclusions. In the absence of that information, secondary p-values should be read as individual, unadjusted results unless the record explicitly states otherwise.

The primary analysis population is described as participants who were randomized, received at least one dose of study medication, and yielded on-treatment efficacy data. This is the population used for the stated efficacy analyses, not necessarily all randomized participants. The registry does not report the number excluded from this population or the reasons they did not contribute on-treatment efficacy data.

Details about missing outcome data are not reported in the registry record. In particular, the record does not describe the amount or pattern of missingness, imputation, sensitivity analyses, or whether participants who discontinued treatment continued to provide outcomes. These omissions limit assessment of how missing data might affect the estimates. General statistical explanation: missing data can influence an estimate if the availability of an outcome is related to the outcome itself or to treatment group; the direction and size of any such influence cannot be inferred without relevant information.

The registry does not report the original sample-size justification, planned interim analyses, or a fuller statistical analysis plan. Those omissions mean it is not possible to assess from the record whether the achieved analysis population matched the original planning assumptions or whether all reported analyses followed a prespecified plan. No conclusion about undocumented procedures should be inferred from their absence.

16. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 3% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: coma (0.8%), dizziness (0.8%), loss of consciousness (0.8%), enterovesical fistula (0.8%), head injury (0.8%).

The registry reports serious adverse events in 10 of 128 participants at risk in the Sativex group and 6 of 118 at risk in the placebo group. It also reports other adverse events affecting 109 of 128 participants at risk in the Sativex group and 83 of 118 at risk in the placebo group. These are counts of participants affected and the corresponding groups at risk, not measures of the primary efficacy endpoint. The safety populations differ from the primary efficacy analysis counts.

The serious-event terms listed include Coma, Dizziness, Loss of Consciousness, Enterovesical Fistula, Head Injury, and Joint Dislocation, each recorded as 0.8%. These are term-specific registry entries; they should not be added or treated as a complete description of all safety outcomes. Death counts are not reported in the registry record.

These figures describe what the registry reports, not the cause of an event or the comparative risk after accounting for follow-up time and other factors. The record does not provide enough detail to evaluate event timing, severity beyond the serious-event classification, or the relationship of each event to study medication. The counts should therefore be interpreted descriptively.

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

The primary result is an estimate of the average change in pain score between randomized groups in the stated efficacy population. The arm means were -1.36 for Sativex and -0.84 for placebo, and the registry's ANCOVA estimate of the treatment difference was -0.34. Its 95% confidence interval includes zero, and the reported p-value is 0.139. The unadjusted re-calculation also has an interval that includes zero. These results indicate uncertainty about the size and direction of the average group contrast in the analyses recorded.

This does not mean that every participant experienced the group average, or that individual outcomes can be predicted from the mean. It also does not establish that the groups are equivalent: the registry does not report an equivalence or non-inferiority margin. Conversely, the estimates do not establish a clinically meaningful difference. A clinical importance threshold is not reported in the registry record.

The reported evidence is bounded by the study's population, endpoint, time frame, and analysis. It concerns peripheral neuropathic pain associated with allodynia, a daily numerical pain measure, and the end-of-treatment assessment described in the registry. The stated efficacy analysis excludes randomized participants who did not receive at least one dose or did not yield on-treatment efficacy data. Missing-data handling is not reported, which further limits interpretation.

The secondary outcomes and adverse-event counts offer additional descriptions, but they do not resolve uncertainty in the primary comparison. The registry information does not support claims about unreported doses, long-term outcomes, other populations, or effects outside the measured outcomes. These statistics describe the posted trial results; they are not medical advice or a recommendation about treatment.

18. Why This Trial Matters Statistically

This trial illustrates why a point estimate and a significance test are not enough to characterize a clinical comparison. The primary means and the estimated difference point in one direction, while the confidence interval spans zero. Reading the estimate together with its interval makes the uncertainty visible instead of reducing the result to a yes-or-no judgment based on a p-value.

It also demonstrates why the analysis method matters. The registry's ANCOVA estimate is not the same as the simple unadjusted re-calculation from arm-level summaries. Both are useful to identify, but they answer the comparison through different methods. Keeping the registry's reported analysis distinct from the re-calculation prevents a derived summary comparison from being mistaken for the trial's own model-based result.

The stated efficacy population is another important statistical detail. Randomization is a design feature, but the primary analysis is described as limited to participants with at least one dose and on-treatment efficacy data. Without details about missing outcomes and exclusions, readers cannot fully assess how the analyzed group relates to everyone randomized.

Finally, the secondary outcomes and planning illustrations show two common interpretive challenges. Many outcome comparisons can make isolated unadjusted findings less persuasive, while sample-size planning values are conditional scenarios rather than retrospective evidence of power. Together, these considerations show how careful interpretation depends on the endpoint, estimand, analysis population, uncertainty, and reporting completeness—not merely on whether a p-value crosses a threshold.

19. 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 registry record does not report the original sample-size calculation or its assumptions, so the planning illustrations based on the observed effect cannot be treated as the trial's design rationale. The reported primary analysis population requires receipt of at least one dose and on-treatment efficacy data. The record does not state how many randomized participants failed to meet those criteria or why.

Missing-data methods are not reported. There is no registry description of imputation, sensitivity analyses, or outcomes after treatment discontinuation. This prevents a full assessment of whether the primary estimate could be affected by incomplete outcome data. The record also does not report the covariates or detailed specification used in the ANCOVA analysis, limiting independent evaluation of that model.

The registry does not describe a multiplicity strategy for the secondary outcomes, so individual secondary p-values should be interpreted cautiously. The available record also does not report a clinically important difference threshold, an equivalence margin, or detailed dosing and treatment-adherence information. These gaps constrain interpretation of clinical importance and of the precise treatment contrast.

Safety findings are reported as counts, with no death counts reported in the registry record. The available information does not describe event timing or provide enough context to attribute events to treatment. These limitations are specific to the information recorded for this trial and do not establish that the unreported procedures or data were absent from the study itself.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: A Study of Sativex® for Pain Relief of Peripheral Neuropathic Pain, Associated With Allodynia — NCT00710554.
• Registry record last updated 2023-05-03; status last verified 2023-04.
• Results first posted 2012-09-14.
• 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.

23. Record Summary

NCT00710554 is a completed Phase 3 randomized, placebo-controlled, parallel-group study of Sativex for peripheral neuropathic pain associated with allodynia. The registry reports enrollment of 246 and quadruple masking; the official title describes the study as double blind. The primary endpoint was change in mean pain score on a 0-10 numerical rating scale, with negative change indicating improvement.

The primary efficacy summaries were -1.36 for Sativex and -0.84 for placebo. The registry's ANCOVA estimate was -0.34, with a 95% confidence interval from -0.79 to 0.11 and p = 0.139. The interval includes zero. A separate unadjusted re-calculation gives a mean difference of -0.52 and p = 0.084; it should not be confused with the registry's reported analysis.

Secondary findings are mixed, multiplicity handling and missing-data methods are not reported in the registry record, and safety counts are descriptive. Interpretation is limited to the posted outcomes and analysis information.