Patients With Intermittent Claudication Injected With ALDH Bright Cells: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Patients With Intermittent Claudication Injected With ALDH Bright Cells (NCT01774097), a randomized phase 2 study. The primary outcome is Peak Walking Time (PWT).

2. Clinical Question

3. Trial Design

This completed phase 2 study was randomized, quadruple-masked, and used a parallel-group model. The registry reports enrollment of 82. Participants were assigned to ALD-301 or placebo (vehicle), both administered by intramuscular injection. The sponsor was The University of Texas Health Science Center, Houston. The recorded study start was 2013-06, and primary completion was 2016-08.

The condition records identify peripheral artery disease and intermittent claudication. The study description focuses on whether cells taken from a participant’s bone marrow could be injected into affected calf and lower thigh muscles and whether this approach could be administered safely and improve blood flow or peak walking time. The registry does not report additional details about the cell preparation or the injection procedure.

The primary outcome was peak walking time, assessed at baseline and 6 months. Its description defines the measure as the placebo-adjusted average change over time in the maximum duration a participant could walk on a treadmill under standardized conditions before claudication symptoms prevented continuing. The primary analysis population is described as participants with available analyzable baseline and 6-month treadmill test results.

The registry lists ankle-brachial index before and after exercise, claudication onset time, peak walking time, and patient-reported measures of walking and peripheral artery disease-related function among the outcomes. The registry record does not report the original sample-size justification, the detailed allocation procedure, or the operational details of masking.

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: Participants who had available analyzable baseline and 6 month treadmill test results.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: Information for 4 participants is not available due to patient withdrawal from the study.

6. Primary Endpoint

The registry lists the primary outcome as Peak Walking Time (PWT), measured over Assessed at baseline and 6 months.

Peak walking time measures how long a participant can continue walking on a treadmill under standardized conditions before claudication symptoms make walking intolerable. It is a functional measure: it captures walking performance during a defined exercise test rather than asking participants to estimate their usual walking in daily life. The registry describes the primary outcome as the placebo-adjusted average change over time, assessed from baseline to 6 months.

The measure is relevant to this trial because intermittent claudication is associated with pain during walking, and the study’s stated purpose included assessing whether the intervention could improve peak walking time. A change in duration can summarize a participant’s performance on the test, while comparing changes between randomized groups helps separate the difference associated with assignment to ALD-301 from changes also seen in the placebo group. That comparison does not by itself establish why any change occurred.

In the posted arm summaries, the mean values are 2.2 minutes for ALDHbr and 1.2 minutes for placebo, with standard deviations of 3.9 and 2.7, respectively. The primary outcome description identifies the analysis population as participants with analyzable treadmill results at both baseline and 6 months. The registry record does not report further detail about how unavailable or non-analyzable treadmill results were handled in the primary analysis.

7. Results Posted in the Registry

• ALDHbr: mean 2.20 versus 1.20 on control; difference 1.00 (95% CI -0.52 to 2.52), standardized effect d = 0.30; z-test p = 0.196.

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.

Pre-exercise Ankle-Brachial Index (ABI)

• 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:
  • ALDHbr: mean 0.61 versus 0.64 on control; difference -0.03 (95% CI -0.10 to 0.04), standardized effect d = -0.19; z-test p = 0.406.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between ALDHbr and the control. The interval gives the range of effects that remain compatible with the data.

Post-exercise Ankle-Brachial Index (ABI)

• 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:
  • ALDHbr: mean 0.30 versus 0.34 on control; difference -0.04 (95% CI -0.12 to 0.04), standardized effect d = -0.23; z-test p = 0.310.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between ALDHbr and the control. The interval gives the range of effects that remain compatible with the data.

Claudication Onset Time (COT)

• 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:
  • ALDHbr: mean 2.80 versus 2.50 on control; difference 0.30 (95% CI -0.55 to 1.15), standardized effect d = 0.17; z-test p = 0.490.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between ALDHbr and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes extend the assessment beyond treadmill peak walking time. They include ankle-brachial index measured before and after exercise, claudication onset time, and patient-reported measures of peripheral artery disease and walking ability. Together, these outcomes address physiological measurements, when symptoms begin during walking, and participants’ reported functional limitations. They can add context to the primary result, but they address different aspects of the condition and are not substitutes for the primary endpoint.

In the detailed secondary analyses, the reported estimates do not form a consistent pattern of clear between-group separation. The confidence intervals include zero, and the registry reports linear-regression interaction terms for the ankle-brachial index and claudication onset time outcomes. Those model-based results concern the pattern over the assessed trajectory rather than simply repeating the primary endpoint’s comparison. The registry record does not report detailed results for every listed patient-reported measure.

Secondary findings generally carry less confirmatory weight when many outcomes are examined and the analysis plan does not report how multiplicity was handled. With multiple comparisons, the chance of an apparently notable result arising by chance can increase. The registry record does not report a multiplicity adjustment plan. Accordingly, secondary outcomes are best read as supportive or exploratory evidence, and individual results should not be treated as independent confirmation of the primary finding.

The overall secondary pattern does not resolve the primary analysis’s uncertainty. It also does not establish that no changes occurred. Interpretation depends on the specific outcome, the model, the completeness of measurements, and whether the analysis was prespecified; those details are not all reported in the registry record.

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

• Pre-exercise Ankle-Brachial Index (ABI)
• Post-exercise Ankle-Brachial Index (ABI)
• Claudication Onset Time (COT)
• Peak Walking Time (PWT)
• Peripheral Artery Questionnaire (PAQ)
• Walking Impairment Questionnaire (WIQ)-Walking Distance Score
• Walking Impairment Questionnaire (WIQ)- Walking Speed Score
• Walking Impairment Questionnaire (WIQ)-Ability to Climb Stairs Score

9. Statistical Interpretation

10. Statistical Methods Explained

What does a mean difference represent?

Peak walking time is continuous, so it can be summarized with a mean. A mean difference compares the average outcome in the ALDHbr group with the average in the placebo group. A positive estimate in the posted comparison indicates a higher mean for ALDHbr; a negative estimate would indicate a higher mean for placebo. The primary registry analysis calls its result a net mean difference. The separate unadjusted re-calculation uses the posted arm-level summaries and is not a substitute for the sponsor’s analysis.

The arm summaries also report standard deviations. A standard deviation describes how spread out individual measurements are around their group mean. It is not a confidence interval and does not describe the uncertainty in the group mean itself. In the primary outcome summaries, the reported standard deviations are 3.9 minutes for ALDHbr and 2.7 minutes for placebo. Variation among participants is relevant because greater variability generally makes a group comparison less precise when other features are similar.

How should the confidence interval be read?

A confidence interval gives a range of values reasonably compatible with the data and the statistical model used to calculate it. The sponsor reports a 95% confidence interval for the primary mean difference, from -0.6 to 2.5 minutes. Because this range includes zero, it is compatible with no mean difference as well as with differences favoring either group. The interval does not assign a probability to each possible effect, and it is not a guarantee that the true effect lies inside the observed limits.

The width of an interval is a practical indication of precision: a narrower interval leaves fewer effect sizes compatible with the analysis, while a wider interval leaves more. Precision depends on factors including the amount of outcome variability, the number of analyzable observations, and the analysis method. An interval that includes zero should not be interpreted as proof of no effect. Conversely, a positive point estimate alone does not establish a difference when uncertainty remains substantial.

What does the p-value add?

The registry reports a two-sided t-test for the primary comparison and a p-value of 0.238. In general, a p-value describes how unusual a test statistic at least as incompatible with the null hypothesis would be if the null hypothesis and test assumptions held. It is not the probability that the null hypothesis is true, and it is not a measure of clinical importance. The p-value should be considered alongside the effect estimate, its confidence interval, and the design and completeness of the data.

The unadjusted re-calculation reports p = 0.196. This is a separate calculation based on posted summary statistics, rather than the trial’s own analysis. The values need not match because the registry’s analysis and the simple re-calculation may not use identical inputs or methods. The registry record does not report enough detail to reconstruct every feature of the sponsor’s analysis. The primary reported result remains the sponsor’s analysis.

Why can variability and over-dispersion matter?

For a continuous outcome, variation in participant measurements affects how precisely a group mean and a between-group difference can be estimated. If observations are more variable than a model anticipates, standard errors may be underestimated and confidence intervals may be too narrow. This issue is often described as over-dispersion when the observed variability exceeds what a model assumes. It is a general statistical concern; the registry record does not report that over-dispersion was identified or that a correction for it was used in this trial.

The displayed standardized effect in the re-calculation is based on the mean difference relative to a pooled standard deviation. Such a standardized measure can help describe the size of a continuous-outcome difference relative to variability, but it does not replace the difference in minutes, which is directly interpretable for peak walking time. The registry record does not report a clinically meaningful threshold for peak walking time, so the clinical importance of a given difference cannot be assessed from a threshold defined in the record.

How do the secondary analyses differ?

The registry reports linear-regression interaction terms for the detailed ankle-brachial index and claudication onset time analyses. An interaction term in a repeated-time analysis can represent whether the pattern of change over time differs between groups. That is not the same estimand as a simple comparison of one mean at one visit. The reported estimates, confidence intervals, and p-values should therefore be understood in the context of the model description rather than treated as interchangeable with the primary t-test.

The detailed secondary analyses include pre-exercise ankle-brachial index, post-exercise ankle-brachial index, and claudication onset time. Their reported confidence intervals include zero. The registry also lists patient-reported outcomes, but the registry record does not report detailed results for every listed secondary measure in the registry record for interpretation. It does not report a multiplicity adjustment plan, so individual secondary p-values should be viewed as exploratory rather than as confirmatory evidence.

These methods explain how estimates can be interpreted; they do not identify the original analysis plan. The registry record does not report the trial’s full statistical analysis plan, the handling of missing data, or whether any interim analyses were conducted.

11. Confidence Intervals and Precision

The primary estimate is 0.9 minutes, with a reported 95% confidence interval from -0.6 to 2.5 minutes. This range is wide enough to include zero, a modest difference in the direction of placebo, and a larger difference in the direction of ALDHbr. The point estimate is therefore only one part of the result; the interval shows that the data do not pin down the magnitude or direction with high precision.

The interval’s inclusion of zero does not establish that the groups have the same mean change. It means the analysis does not rule out no difference at the confidence level reported. Nor does the upper limit prove that an effect of that size is present. Confidence limits represent uncertainty under the analysis, rather than a set of outcomes guaranteed to contain the true effect.

The reported analyzable primary outcome groups include 37 participants assigned to ALDHbr and 39 assigned to placebo. The arm-level standard deviations, 3.9 and 2.7 minutes, indicate substantial variation in observed peak walking time relative to the estimated group means. Variation and the available analyzable observations both contribute to uncertainty. The registry record does not report a clinically meaningful threshold for interpreting the interval, so statistical uncertainty cannot be translated into a judgment about whether particular differences would matter to participants.

The secondary confidence intervals also include zero in the detailed analyses. That pattern is consistent with uncertainty about the direction and size of those between-group differences. It should not be treated as evidence of equivalence, especially because the record does not report equivalence margins or a design intended to test equivalence.

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 illustrations express sample sizes as participants per arm, not as total events. They are calculations based on the observed effect, rather than the trial’s original design. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each planning scenario asks what sample size would be needed to detect a specified fraction of the observed effect.

The 80% power column represents the planned chance of detecting the stated effect under the calculation’s assumptions if that effect were the true effect. The 90% power column uses a higher target chance of detection under the same kind of assumptions. Neither column describes the probability that the trial’s conclusion is correct. These are planning illustrations, not observed power.

The rows for 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect show how the assumed target effect changes the planning estimate. Smaller effects are harder to distinguish from random variation, so they require more participants for a given power target. The posted planning values are not a recommendation for a future study by themselves: they rely on an effect estimated from this trial, and that estimate is uncertain. The original protocol’s sample-size justification and design assumptions are not reported in the registry record.

For the continuous outcomes in this study, the listed quantities refer to participants per arm. The registry record’s planning description distinguishes these from time-to-event calculations, which would be expressed as total events; no time-to-event planning results are described for these continuous outcomes.

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 = 1.000; pooled standard deviation σ = 3.338.
2. n = 2 × (1.96 + 0.842)² × 3.338² / 1.000² = 174.9, rounded up to 175 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 <- 1                      # observed difference in means
sigma <- 3.33810919128973                     # 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(1774097)
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 = 175 (80% power), 235 (90% power)
 75% of observed effect: n per arm = 311 (80% power), 417 (90% power)
 50% of observed effect: n per arm = 700 (80% power), 937 (90% power)
power.t.test: 175.9 
Simulated power at n = 175 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 sponsor’s reported primary analysis is a two-sided t-test. It gives a net mean difference of 0.9 minutes, a 95% confidence interval from -0.6 to 2.5 minutes, and p = 0.238. The simple unadjusted re-calculation from the posted arm summaries gives a mean difference of 1.0 minutes and p = 0.196. Both analyses place the point estimate in the direction of a higher mean peak walking time for ALDHbr, and both leave substantial uncertainty about the difference.

The re-calculation is useful as a check based on summary statistics, but it is not the sponsor’s analysis and may not reproduce its exact analytic choices. The sponsor’s result is the trial’s own reported analysis. The registry record does not flag a discrepancy between the sponsor’s result and the re-calculation. The slightly different estimates and p-values should therefore be presented as distinct analyses, not combined or treated as interchangeable.

The sponsor’s confidence interval includes zero, as does the interval from the unadjusted re-calculation. Neither result establishes a clear difference, and neither demonstrates equivalence. Details of any covariate adjustment or other analytic features beyond the reported t-test are not reported in the registry record.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists 12 outcome measures and 11 analyses. It identifies the primary endpoint as peak walking time and lists several secondary outcomes, including ankle-brachial index, claudication onset time, and patient-reported walking and peripheral artery disease measures. The registry record does not report a comprehensive statistical analysis plan or whether a hierarchy of secondary hypotheses was prespecified.

The registry record does not report whether p-values were adjusted for multiple comparisons. When several outcomes or analyses are examined, unadjusted p-values can overstate the strength of evidence if each is interpreted as a separate confirmatory test. This general concern is especially relevant for secondary outcomes. Without a reported adjustment strategy or prespecified testing hierarchy, those results are more appropriately treated as exploratory and interpreted in conjunction with their estimates and confidence intervals.

The primary analysis population is described as participants with available analyzable baseline and 6-month treadmill test results. This gives a definition of who contributed to the primary outcome analysis, but the registry record does not report how unavailable or non-analyzable results were handled, why they were unavailable, or whether any imputation was used. The registry record also does not report a detailed missing-data analysis or sensitivity analyses addressing missing outcomes.

Reported sample sizes vary across outcome summaries. The registry record does not provide enough information to determine the reasons for those differences or their implications for possible bias. The original sample-size justification, interim-analysis plan, and complete analysis-population definitions are not reported in the registry record. These omissions limit assessment of whether all planned analyses were reported and how robust the results are to alternative assumptions.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: coronary artery disease (2.5%), escherichia urinary tract infection (2.5%), copd exacerbation (2.5%), ischemic limb pain (2.5%), acute anemia (2.4%).

The registry reports serious adverse events among 4 of 40 participants at risk in the ALDHbr group and 8 of 42 participants at risk in the placebo group. Other adverse events are reported for 1 of 40 participants at risk in the ALDHbr group and 6 of 42 participants at risk in the placebo group. These are descriptive counts within the reported at-risk groups; they do not establish that an event was caused by the assigned intervention.

The serious-event terms listed include coronary artery disease, Escherichia urinary tract infection, COPD exacerbation, ischemic limb pain, acute anemia, and anginal discomfort (symptomatic). The registry gives percentages for these terms but does not identify their group-specific distribution in the record. The categories and counts should not be combined into a total, because the record does not clarify whether participants could contribute to more than one event category.

Death counts are not reported in the registry record. Adverse-event counts alone do not determine comparative safety: interpretation also depends on event definitions, timing, severity, attribution, follow-up, and completeness of reporting. Those details are not reported in the registry record.

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

The primary result describes the difference in peak walking time observed between randomized groups in the registry’s analysis. The sponsor reports a mean difference of 0.9 minutes, with a 95% confidence interval from -0.6 to 2.5 minutes and p = 0.238. The result does not establish a clear between-group difference, but it also does not prove that the groups are equivalent or that no effect exists. The interval retains uncertainty about both direction and size.

Because the study was randomized and quadruple-masked, its design was intended to compare assigned groups while limiting some sources of bias. Those design features do not remove uncertainty caused by outcome variability, incomplete outcome availability, or limitations in reported methods. The primary result applies to the registry-defined analysis population with analyzable baseline and 6-month treadmill results; it should not automatically be generalized beyond the studied population and setting.

The outcome is a standardized treadmill measure of walking duration before claudication symptoms prevent continued walking. It does not directly measure all aspects of daily mobility, quality of life, blood flow, or long-term outcomes. Other listed outcomes may provide complementary information, but the secondary results do not convert an uncertain primary result into a definitive conclusion.

The adverse-event summaries describe events reported in the registry, but they do not establish causality or settle comparative safety. The registry record does not report death counts, complete event-attribution details, or the original sample-size rationale. The results should therefore be understood as the posted clinical and statistical findings, with the reported uncertainty and limitations, rather than as a general claim that the intervention is effective, ineffective, safe, or unsafe.

18. Why This Trial Matters Statistically

This trial illustrates why a point estimate should be read together with its uncertainty. The primary estimate favors a higher mean peak walking time in the ALDHbr group, but the sponsor’s confidence interval includes zero and extends in both directions. A positive estimate alone does not establish a reliable difference. The interval indicates that the data are compatible with a range of possible effects, including no difference.

The study also shows why the sponsor’s analysis and an unadjusted re-calculation need to be distinguished. The re-calculation from posted summaries offers a transparent comparison based on group means and variability, while the sponsor’s reported t-test is the trial’s own analysis. Their estimates and p-values are close in direction but not identical. Treating them as the same result would obscure that methodological distinction.

Secondary measures can help explore whether an outcome pattern extends beyond the primary endpoint, but multiple outcomes also create multiplicity concerns. The registry does not report a multiplicity adjustment plan, so secondary findings warrant restraint. This is a general statistical lesson: a larger set of analyses can generate useful questions, while making isolated results less persuasive unless the analysis strategy is clear.

Finally, the sample-size illustrations demonstrate the dependence of planning on the effect one hopes to detect. A smaller target effect requires more participants under the stated planning assumptions. Such illustrations are not evidence of the trial’s achieved power and cannot replace the original design justification, which is not reported in the registry record.

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 a primary analysis population defined by available analyzable treadmill tests at baseline and 6 months, but does not explain the handling or reasons for unavailable or non-analyzable results. It also does not report imputation methods or sensitivity analyses for missing data. As a result, the possible influence of missing outcome information cannot be assessed from the record.

The record does not report the original sample-size justification, detailed allocation procedures, or a full statistical analysis plan. It also does not report whether there were interim analyses, how multiplicity was handled, or whether the primary analysis included adjustments beyond the stated t-test. These gaps limit assessment of prespecification and of the analysis choices behind the posted result.

The primary outcome is a treadmill-based measure, so it captures performance under standardized test conditions rather than every aspect of walking in daily life. The registry does not report a clinically meaningful threshold for interpreting peak walking time. Although several secondary outcomes are listed, detailed results are not reported in the registry record for every listed measure. Their absence from the detailed record means they cannot be used to corroborate or qualify the primary estimate.

The safety information is also limited. The registry reports serious and other adverse-event counts, but the record does not provide the full context needed to assess attribution, timing, recurrence, or completeness. Death counts are not reported in the registry record. These limitations do not invalidate the posted results, but they constrain how broadly and confidently they can be interpreted.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Patients With Intermittent Claudication Injected With ALDH Bright Cells — NCT01774097.
• Registry record last updated 2017-04-21; status last verified 2017-03.
• Results first posted 2017-04-21.
• 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

The registry identifies a completed, randomized, quadruple-masked, parallel-group phase 2 trial comparing intramuscular ALD-301 with placebo (vehicle) in participants with peripheral artery disease and intermittent claudication. Enrollment was 82. The primary endpoint was peak walking time assessed at baseline and 6 months, in participants with analyzable treadmill results at both assessments.

The sponsor’s primary analysis reported a net mean difference of 0.9 minutes, with a 95% confidence interval from -0.6 to 2.5 minutes and p = 0.238. The interval includes zero, leaving uncertainty about the direction and size of the difference. The registry also reports secondary physiological and patient-reported outcomes and adverse-event counts, but important details about multiplicity, missing data, the original sample-size rationale, and some outcome analyses are not reported in the registry record.