A Study of Sativex® for 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 Relief of Peripheral Neuropathic Pain Associated With Allodynia. (NCT00711880), a randomized phase 3 study. The primary outcome is Change From Baseline in the Mean Daily Peripheral Neuropathic Pain on a 0-10 Numerical Rating Scale Score During the Last Seven Days of Treatment (End of Treatment).

2. Clinical Question

3. Trial Design

The registry describes a completed phase 3 study with randomized allocation, quadruple masking, and a parallel-group model. Sativex® was compared with placebo for peripheral neuropathic pain associated with allodynia. The sponsor was Jazz Pharmaceuticals. The registry record gives the study start as 2002-05 and primary completion as 2004-03. It reports enrollment of 125 participants.

The primary outcome was a continuous measure: change from baseline in the mean daily pain score during the last seven days of treatment. The score came from a 0 to 10 numerical rating scale completed at bedtime. Participants were asked to rate their pain, or average pain, in the last 24 hours; 0 represented no pain and 10 the worst possible pain. The reported primary timeframe was Day 0 to Day 42.

The primary analysis population was not described as every randomized participant. It comprised randomized participants who received at least one dose of study medication and had on-treatment efficacy data. The posted primary outcome counts were 61 for Sativex and 62 for placebo. The registry record does not report the reasons participants may not have contributed to this analysis, or the original sample-size justification.

Secondary outcomes covered neuropathic pain, sleep quality, pain disability, dynamic and static allodynia, general health, and neuropsychological test scores. The record reports 16 outcome measures and 14 analyses, and 15 secondary outcomes are posted. The details available for the secondary comparisons include changes in neuropathic pain scale score, sleep quality, and pain disability. The registry record does not report the full protocol or a detailed account of how every outcome was analyzed.

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: All randomised subjects who received at least one dose of study medication and had on-treatment efficacy data were included in the analysis

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 the Mean Daily Peripheral Neuropathic Pain on a 0-10 Numerical Rating Scale Score During the Last Seven Days of Treatment (End of Treatment), measured over Day 0 to Day 42.

The primary endpoint measured change from baseline in mean daily peripheral neuropathic pain, using a numerical rating scale from 0 to 10. Participants recorded ratings at bedtime, describing pain or average pain during the previous 24 hours. A negative change means the end-of-treatment score was lower than baseline; it is not a direct measure of the absolute pain score at the end of treatment.

The endpoint summarizes repeated daily ratings over the last seven days of treatment. Averaging ratings can represent the level of pain recorded across that period rather than focusing on a single day. Comparing mean changes between randomized groups addresses whether the observed average change differed between the Sativex and placebo groups. The posted group means were -1.57 for Sativex and -0.59 for placebo, and the unadjusted mean difference was -0.98.

As a general statistical point, continuous outcomes retain information about the magnitude of measured change, rather than reducing each participant’s outcome to a category such as improved or not improved. The interpretation still depends on the scale, the analysis population, and how missing observations were handled. A clinical threshold for meaningful change is not reported in the registry record, so the numerical difference alone cannot establish how important the difference would be to participants.

7. Results Posted in the Registry

• Sativex: mean -1.57 versus -0.59 on control; difference -0.98 (95% CI -1.61 to -0.35), standardized effect d = -0.55; z-test p = 0.002.

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 Mean Neuropathic Pain Scale Score at the End of Treatment

• 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 -9.70 versus -2.00 on control; difference -7.70 (95% CI -13.49 to -1.91), standardized effect d = -0.48; z-test p = 0.009.
• 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 From Baseline in Mean Sleep Quality at the End of Treatment

• 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 -0.82 versus -0.38 on control; difference -0.44 (95% CI -0.69 to -0.19), standardized effect d = -0.61; z-test p = <0.001.
• 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 From Baseline in the Mean Pain Disability Index Score at the End of Treatment

• 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 -5.60 versus 0.30 on control; difference -5.90 (95% CI -9.86 to -1.94), standardized effect d = -0.56; z-test p = 0.004.
• 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.

The posted secondary outcomes cover several related domains, including neuropathic pain, sleep quality, pain disability, allodynia, general health, and neuropsychological test scores. The detailed comparisons available for neuropathic pain scale score, sleep quality, and pain disability show estimates in a direction consistent with more negative mean change for Sativex than placebo. These findings are broadly aligned in direction with the primary endpoint, but they are not substitutes for the primary result.

Each secondary endpoint measures a different aspect of experience or function, and the scales do not necessarily have the same meaning or variability. Their results should not be combined into a single conclusion without a specified method. The registry reports 15 posted secondary outcomes and 14 analyses overall, but the record does not provide a full account of the analysis plan or the relationship between every outcome and analysis.

Unadjusted secondary results carry less weight because testing many outcomes can increase the chance that some appear notable by chance. A multiplicity procedure, such as a prespecified testing order or adjustment, can help address that issue, but one is not reported in the registry record. The secondary comparisons should therefore be treated as supportive descriptive evidence rather than as independent confirmation of the primary finding. The record also does not report a threshold for meaningful change for these secondary measures.

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

• Change From Baseline in Mean Neuropathic Pain Scale Score at the End of Treatment
• Change From Baseline in Mean Sleep Quality at the End of Treatment
• Change From Baseline in the Mean Pain Disability Index Score at the End of Treatment
• Change From Baseline in Mean Dynamic Allodynia Test Score at the End of Treatment
• Change From Baseline in Mean Static Allodynia Test Score at the End of Treatment
• Change From Baseline in Mean Total General Health Questionnaire Score at the End of Treatment
• Change From Baseline in the Mean Brief Repeatable Battery of Neuropsychological Test Score for 'Selective Reminding' at the End of Treatment
• Change From Baseline in the Mean Brief Repeatable Battery of Neuropsychological Test Score for '10/36 Spatial Recall' at the End of Treatment

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is a continuous measure reported as a mean change from baseline. A mean gives the average of the recorded changes among participants included in the analysis. The standard deviations reported for the Sativex and placebo groups describe variation among individual participants’ changes around their respective group means. They are not confidence intervals for the group means and do not indicate that every participant experienced a change close to the average.

The comparison is expressed as a mean difference between Sativex and placebo. For the recalculation, the direction is Sativex minus placebo, so a negative estimate corresponds to a more negative mean change in the Sativex group. The posted means were -1.57 and -0.59, respectively, and the unadjusted mean difference was -0.98. This is a straightforward contrast of the posted group summaries; it does not adjust for other participant characteristics.

As a general statistical concept, a confidence interval gives a range of values compatible with the observed estimate under the analysis assumptions. A 95% confidence interval is not a statement that there is a 95% probability that the specific interval contains the true effect. Rather, the confidence level describes the long-run coverage of intervals constructed by the same procedure under its assumptions. The primary recalculated interval was -1.611 to -0.349. The sponsor’s reported interval was -1.59 to -0.32.

The registry reports the sponsor’s primary analysis as ANCOVA, with an estimated mean treatment difference of -0.96. As a general explanation, analysis of covariance compares outcomes between groups while accounting for specified covariates. The registry record does not report which covariates were included, how they were selected, or the full model specification. The sponsor’s estimate and the unadjusted recalculation therefore arise from different analysis descriptions and should not be treated as identical procedures. The record reports p = 0.004 for the ANCOVA result and p = 0.002 for the unadjusted recalculation.

What does the unadjusted recalculation represent?

The recalculated results are based on the posted summary statistics: group means, standard deviations, and analysis counts. They are simple, unadjusted comparisons and are not a replacement for the sponsor’s prespecified or model-based analysis. The registry record does not report enough detail to reproduce the ANCOVA. The recalculation is useful as a transparent check of the group summaries, but it does not resolve questions about covariate adjustment, missing observations, or the original analysis plan.

The standardized effect size in the recalculation expresses the mean difference relative to a pooled standard deviation. As a general concept, standardization can help describe a contrast relative to the spread of the outcome, but it does not convert the result into a clinical threshold or establish that an effect is important. The registry record reports a standardized effect size of -0.551 for the primary comparison. The scale-based mean difference remains easier to interpret in the original outcome units.

How should the p-values be read?

The unadjusted primary p-value is 0.002, while the sponsor’s ANCOVA p-value is 0.004. Each is tied to its own analysis method and assumptions. A p-value does not quantify the size of the treatment contrast, the precision of the estimate, or the chance that the result will repeat in another study. It should be read alongside the point estimate and confidence interval. The registry record does not report whether a multiplicity adjustment was used for the primary analysis or how the primary test related to other planned tests.

For secondary comparisons, the recalculated p-values are unadjusted. When several outcomes are tested, the chance of finding at least one apparently notable result can increase even if no underlying group differences exist. As a general statistical response, a trial may specify a testing hierarchy or adjustment procedure; the registry record does not report such a procedure. Consequently, secondary p-values should be interpreted more cautiously than a single prespecified primary test.

What does the analysis population tell us?

The stated primary population included randomized participants who received at least one dose of study medication and had on-treatment efficacy data. That definition excludes any randomized participant who did not meet either condition. The posted analysis counts are 61 for Sativex and 62 for placebo. The registry record does not report how many participants were excluded from the primary analysis, why any data were unavailable, or what imputation or other missing-data method was used.

As a general point, an analysis restricted to participants with available on-treatment data can differ from an analysis that includes every randomized participant. If availability of data is related to outcome or group, estimates may be affected. The registry record does not provide the information needed to assess whether that concern arose in this study. The original statistical analysis plan, assumptions for sample-size planning, and details of interim analyses are not reported in the registry record.

11. Confidence Intervals and Precision

The primary unadjusted mean difference was -0.98, with a 95% confidence interval from -1.611 to -0.349. The sponsor’s ANCOVA estimate was -0.96, with a 95% confidence interval from -1.59 to -0.32. Both intervals exclude zero, but they still allow a range of possible differences. The range should be read on the original scale of change in the daily pain rating, rather than as a range of individual participant responses.

As a general explanation, a confidence interval combines the estimated effect with information about its uncertainty under a particular statistical procedure. A narrower interval indicates greater precision for that estimate, while a wider interval indicates less precision. Precision is not the same as clinical importance: even a relatively precise estimate needs to be considered in relation to the measurement scale and a clinically meaningful threshold. Such a threshold is not reported in the registry record.

The two intervals come from distinct analyses. The recalculated interval is based on an unadjusted summary-statistic comparison; the sponsor’s interval is from ANCOVA. The record does not report enough ANCOVA detail to reproduce the sponsor’s estimate or fully explain the difference between the intervals. Neither interval describes uncertainty about all possible study populations, nor does either address missing-data or multiplicity concerns by itself.

The analysis counts were 61 for Sativex and 62 for placebo. The registry record reports enrollment of 125 participants, but does not explain the relationship between enrollment and the primary analysis population in detail. The width of the interval reflects the information available to the reported analysis, not a guarantee of precision for other populations, endpoints, or treatment periods.

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 sample-size figures are planning illustrations based on the observed effect, not the original design justification for the trial. For these continuous outcomes, the figures mean participants per arm. They are not total event counts. The assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The assumed effect to detect is the stated fraction of the observed effect.

The 80% power column gives the planned number of participants per arm for a design with an 80% probability of detecting the specified effect under those assumptions, if that effect is the true one. The 90% power column gives the corresponding planning number for a 90% probability. These are design concepts; they do not say what the probability was that this completed trial would produce a significant result after its outcomes were observed.

For the primary endpoint, planning for 100% of the observed effect gives 52 participants per arm for 80% power and 70 participants per arm for 90% power. Planning for 75% of the observed effect gives 93 participants per arm for 80% power and 124 participants per arm for 90% power. Planning for 50% of the observed effect gives 208 participants per arm for 80% power and 278 participants per arm for 90% power. The smaller-effect scenarios require more participants, because smaller group differences are harder to distinguish from ordinary variation.

This is not observed power. The original trial’s sample-size assumptions and justification are not reported in the registry record, and these illustrations use the observed effect rather than reconstructing the original design.

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 = -0.980; pooled standard deviation σ = 1.780.
2. n = 2 × (1.96 + 0.842)² × 1.780² / -0.980² = 51.8, rounded up to 52 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 <- -0.98                      # observed difference in means
sigma <- 1.77980962859784                     # 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(711880)
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 = 52 (80% power), 70 (90% power)
 75% of observed effect: n per arm = 93 (80% power), 124 (90% power)
 50% of observed effect: n per arm = 208 (80% power), 278 (90% power)
power.t.test: 52.8 
Simulated power at n = 52 per arm: 0.798 (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 sponsor’s reported primary analysis used ANCOVA and estimated a mean treatment difference of -0.96, with a 95% confidence interval from -1.59 to -0.32 and p = 0.004. The registry also reports the unadjusted recalculation from posted group summaries: a mean difference of -0.98, with a 95% confidence interval from -1.611 to -0.349 and p = 0.002.

The two point estimates are close, and both confidence intervals exclude zero. However, the analyses are not the same: the recalculation is unadjusted, while ANCOVA is a model-based analysis. The registry record does not identify the ANCOVA covariates or give enough detail to reproduce that model. The estimates and p-values should therefore be described according to their respective methods rather than substituted for one another.

The registry’s discrepancy indicator is false. The sponsor’s result remains the reported trial analysis, while the recalculation is an additional unadjusted comparison of the posted summaries. Neither result supplies information about the clinical importance threshold, which is not reported in the registry record.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists multiple outcome measures, including the primary pain rating and secondary measures covering pain, sleep, disability, allodynia, general health, and neuropsychological testing. It reports 16 outcome measures, 14 analyses, and 15 posted secondary outcomes. With multiple outcomes, repeated significance testing can increase the chance of apparently notable results even when the underlying effects are absent. This is a general statistical issue, not evidence that a particular posted result is false.

The registry record does not report a multiplicity adjustment, testing hierarchy, or other plan for controlling error across outcomes. It is therefore unclear whether the posted secondary p-values were adjusted, and they should be read as unadjusted results unless the record states otherwise. The registry record does not report enough information to determine how the primary analysis was protected from, or related to, other planned statistical tests.

The primary analysis population included randomized participants who received at least one dose and had on-treatment efficacy data. This is the population specified for the primary endpoint, rather than an explicitly stated analysis of every randomized participant. The posted primary outcome counts were 61 for Sativex and 62 for placebo. The registry record does not report participant-level reasons for lack of efficacy data, the number of missing observations, or how missing outcomes were handled.

Missing-data handling matters because an analysis using observed outcomes may be affected if outcome availability is related to treatment group or pain change. The registry record does not report whether imputation was used, what assumptions were made about missingness, or whether sensitivity analyses assessed alternative assumptions. It also does not report the original sample-size justification, interim analyses, or the detailed statistical analysis plan. These omissions limit how fully the reported analyses can be evaluated.

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: fall (1.6%), myelitis nos (1.6%), bronchopneumonia (1.6%), transient ischaemic attack (1.6%), hypoaesthesia (0.0%).

For serious adverse events, the posted counts are 1 among 63 participants at risk in the Sativex group and 2 among 62 at risk in the placebo group. These are counts, not estimates of comparative safety. The registry also reports other adverse events as affecting 57 of 63 participants at risk in the Sativex group and 48 of 62 in the placebo group.

The listed serious-event terms include Fall, Myelitis NOS, Bronchopneumonia, Transient ischaemic attack, and Hypoaesthesia. The registry reports 1.6% for Fall, 1.6% for Myelitis NOS, 1.6% for Bronchopneumonia, 1.6% for Transient ischaemic attack, and 0.0% for Hypoaesthesia. These entries should be read as reported event terms and percentages; the record does not provide enough detail to establish their timing, duration, or relationship to study medication.

Deaths are not reported in the registry record. The serious-event counts alone do not establish whether the groups differ in safety, particularly without further detail on event definitions, follow-up, and assessment. No medical advice or treatment conclusion follows from these figures.

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

The primary posted results show a negative mean change from baseline in both groups, with a more negative mean change in the Sativex group. The unadjusted mean difference was -0.98, and the sponsor’s ANCOVA estimate was -0.96. Their reported 95% confidence intervals exclude zero. These statistics describe the direction, size, and uncertainty of the group contrast under the respective analyses.

They do not show that every participant’s pain improved, or that an individual participant would experience the group average. A mean summarizes a distribution of individual outcomes. The standard deviations reported for the groups indicate that individual changes varied around those averages. The registry record does not report a threshold for clinically meaningful change, so the estimates cannot be translated into a claim about the importance of the difference to participants.

The result also does not establish the effect beyond the study population, the reported treatment period, or the analysis population. The primary analysis included randomized participants who received at least one dose and had on-treatment efficacy data. How missing data were handled is not reported in the registry record. The primary endpoint timeframe was Day 0 to Day 42, and longer-term outcomes are not reported in the registry record.

Secondary outcomes provide additional measurements, but they should be interpreted with care because multiple outcomes were posted and a multiplicity procedure is not reported. The result is a statistical description of this trial’s posted data, not a guarantee that the same estimate would occur in another study. It does not by itself establish a treatment recommendation or an overall balance of benefits and harms.

18. Why This Trial Matters Statistically

This study illustrates why a treatment comparison should be read through more than a single p-value. The primary mean difference, confidence interval, group means, and analysis population each contribute different information. The direction of the endpoint is especially important: a negative change indicates improvement from baseline, so a negative between-group contrast means the Sativex group had a more negative average change in the posted unadjusted comparison.

The registry also offers a useful distinction between an analysis reported by the sponsor and an unadjusted recalculation from group summaries. The sponsor’s ANCOVA estimate and the recalculated estimate are close, but their methods differ and the ANCOVA details are not reported. Identifying the method behind each estimate helps avoid treating results from distinct analyses as interchangeable.

The study also raises common interpretation questions about analysis populations, missing data, and multiple outcomes. The primary population required at least one dose and on-treatment efficacy data, while the registry record does not describe missing-data handling or multiplicity adjustment. Those details affect how much can be concluded from the numerical results, even when the primary confidence interval excludes zero.

Finally, planning illustrations based on the observed effect can help show how sample requirements change when the target effect is smaller, but they do not reconstruct the trial’s original design. The registry record does not report the original sample-size rationale. Keeping these distinctions clear supports a measured reading of both the primary comparison and the broader set of posted findings.

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 gives limited detail about treatment implementation. It identifies Sativex® and placebo but does not report dose, schedule, adherence, or further information about the treatment arms. Although the study is described as quadruple-masked, the record does not specify which roles were masked or how masking was maintained.

The primary analysis population was restricted to randomized participants who received at least one dose and had on-treatment efficacy data. The record does not report why participants may have lacked data, how missing values were handled, or whether analyses using a different population were conducted. The primary outcome counts were 61 for Sativex and 62 for placebo, while total enrollment was 125; the registry does not explain the difference in detail.

The primary endpoint covers Day 0 to Day 42, and longer-term outcomes are not reported in the registry record. A threshold for meaningful change on the pain scale is also not reported, limiting interpretation of the clinical importance of the numerical contrast. The record does not provide the original sample-size justification, full statistical analysis plan, interim-analysis information, ANCOVA covariates, or a multiplicity strategy.

Safety reporting in the available record is limited to summary counts and selected serious-event terms. Deaths are not reported in the registry record, and the available entries do not describe timing, duration, or event-level context. These reporting limits do not negate the posted estimates, but they constrain how comprehensively the trial’s methods and results can be assessed.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: A Study of Sativex® for Relief of Peripheral Neuropathic Pain Associated With Allodynia. — NCT00711880.
• Registry record last updated 2023-04-12; status last verified 2023-04.
• Results first posted 2012-09-28.
• 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

NCT00711880 is a completed randomized, quadruple-masked, parallel-group phase 3 study comparing Sativex® with placebo for peripheral neuropathic pain associated with allodynia. Enrollment was 125. The primary endpoint was change from baseline in mean daily pain rating during the last seven days of treatment, measured on a 0 to 10 numerical scale over Day 0 to Day 42.

The posted primary means were -1.57 for Sativex and -0.59 for placebo. The unadjusted mean difference was -0.98, with a 95% confidence interval from -1.611 to -0.349 and p = 0.002. The sponsor’s ANCOVA estimate was -0.96, with a 95% confidence interval from -1.59 to -0.32 and p = 0.004.

Secondary outcomes span pain and other health domains, while the record does not report multiplicity procedures or detailed missing-data methods. The primary analysis population required at least one dose and on-treatment efficacy data. The registry record does not report the original sample-size justification, the full statistical plan, or longer-term outcomes.