University of California, San Diego (UCSD) Suramin Autism Treatment-1 (SAT1) Trial: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for University of California, San Diego (UCSD) Suramin Autism Treatment-1 (SAT1) Trial (NCT02508259), a randomized phase 1, phase 2 study. The primary outcome is Autism Diagnostic Observation Schedule, 2nd Edition (ADOS2).

2. Clinical Question

In statistical terms, the trial asks whether the primary ADOS2 result differs in the context of the randomized comparison of suramin and saline. The score ranges from 0-10, and higher scores are described as indicating more severe core autism spectrum disorder symptoms. Scores of 6 and below are described as off the ASD spectrum, while a score of 7-10 was required for enrollment. Those score descriptions help explain the measure and the enrolled range; they do not themselves establish the meaning of a change over time. The registry record reports the timeframe as 6 weeks compared with baseline, but further details about measurement procedures, analysis populations, and missing observations are not reported in the registry record.

3. Trial Design

This was the University of California, San Diego (UCSD) Suramin Autism Treatment-1 (SAT1) Trial, registered as NCT02508259. The record lists Phase 1 and Phase 2, randomized allocation, quadruple masking, and a parallel model. The study status is completed. The sponsor was the University of California, San Diego. The start is listed as 2015-05 and primary completion as 2016-03.

The registry lists 10 participants enrolled. The Suramin arm had 5 participants and the Saline (Placebo) arm had 5 participants. The intervention descriptions specify a single infusion over 30 minutes: 20 mg/kg suramin in 50 ml of saline for the suramin arm, and 50 ml of saline for the comparator arm. The summary describes the study as designed to test safety and efficacy of a single intravenous dose of suramin in autism spectrum disorders.

Randomized allocation is intended to support a comparison between assigned groups, while masking is intended to limit influences from knowledge of assignment. The registry record identifies the design features but does not report the method used to generate the allocation sequence, how masking was implemented, or whether masking was assessed. Further design details, including a protocol account of the planned statistical analyses, are not reported in the registry record.

The primary endpoint is ADOS2 at 6 weeks compared with baseline. The record lists six outcome measures and six analyses. Four named secondary outcomes are the Aberrant Behavior Checklist (ABC), Autism Treatment Evaluation Checklist (ATEC), The Clinical Global Impression - Improvement Scale (CGI-I), and Repetitive Behavior Questionnaire. Results for additional measures or details about their timing and analysis are not reported in the registry record. The record does not report a sample-size justification or other information establishing how enrollment was planned.

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

Analysis population for the primary outcome, as defined in the registry: Patients receiving either suramin or saline.

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: Male subjects with autism spectrum disorder (ASD), ages 4-17 years

6. Primary Endpoint

The registry lists the primary outcome as Autism Diagnostic Observation Schedule, 2nd Edition (ADOS2), measured over 6 weeks compared to baseline.

The primary endpoint is the Autism Diagnostic Observation Schedule, 2nd Edition (ADOS2), reported as a mean on a scale of 0-10. The registry describes the primary timeframe as 6 weeks compared with baseline. It also describes the score direction: higher values indicate more severe core symptoms of autism spectrum disorder. Scores of 7-10 were required for enrollment and are described as diagnostic for autism spectrum disorder; scores of 6 and below are described as off the ASD spectrum.

ADOS2 is used in this trial as a measure of core autism-related symptoms. A continuous scale retains gradations in scores rather than reducing the result to a simple diagnostic category. That makes it possible to describe mean scores and changes on the scale, while interpretation still depends on what was measured, when it was measured, and how the analysis was conducted. The registry gives a 6-week comparison with baseline, but does not report further detail about the scoring procedure or any threshold for a meaningful change.

The arm summaries list a mean value of -1.6 for Suramin and -0.4 for Saline (Placebo), with a standard deviation of 0.55 in each arm. These values are in the posted results for the primary endpoint. The registry's sponsor analysis is separately labeled “Mean Difference (Net),” and reports an estimate with a confidence interval and p-value. The record does not provide enough additional analytic detail to treat the arm summaries and sponsor analysis as interchangeable estimates of the same contrast.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: ADOS2 scores are reported as means, with standard deviations. For a continuous measure, a mean describes the center of a set of observations, while a standard deviation describes how dispersed those observations are around the mean. The arm summaries report the means and standard deviations for each group. They are descriptive statistics; alone, they do not show the uncertainty in a treatment contrast or explain how the sponsor's analysis was constructed.

What does the reported t-test describe?

The registry lists a two-sided t-test for the sponsor analysis. In general, a t-test evaluates a specified contrast in means in relation to the variation in the data, under assumptions about the observations and the analysis. A two-sided test considers departures in either direction from its null value. The registry reports the test result as p = 0.003 and gives a 95% confidence interval. It labels the estimate “Mean Difference (Net)” and lists it for the Suramin group, but does not report sufficient detail to identify the exact construction of that net difference or fully define the contrast. The test name alone does not fill in those missing details.

How should the confidence interval be read?

In general, a confidence interval gives a range of values compatible with the observed data and the method's assumptions at the stated confidence level. It conveys precision as well as direction for the quantity being estimated. The sponsor result reports a 95% interval from -2.3 to -0.9 around an estimate of -1.6. Its interpretation depends on what “Mean Difference (Net)” means in the analysis. The registry does not report a threshold that would define a clinically important difference, so the interval cannot by itself distinguish clinically important from unimportant values.

A p-value is not the probability that a treatment effect is real, nor is it a measure of the effect's size. In general, it describes how unusual data at least as incompatible with the specified null would be under that null and the model assumptions. Its meaning depends on the hypothesis tested, the analysis population, and the analysis method. The posted p-value is tied to the sponsor analysis as it is recorded; since the contrast is not fully explained, the number should not be assigned a broader meaning than the record supports.

Why does the two-arm recalculation matter?

A recalculation of a two-arm comparison would require a clearly defined estimand and adequate summary information for that comparison. The registry indicates that values were missing or not estimable for a two-arm comparison of this continuous endpoint. The listed arm means and standard deviations do not remove the need to know how the outcome values relate to baseline and how the sponsor defined the net difference. The sponsor analysis is therefore distinct from a separately recalculated two-arm result. The registry does not flag a discrepancy between the sponsor's result and a recalculation.

What do the planning illustrations mean?

In general, sample-size planning estimates how many participants may be needed under a stated statistical model and a chosen effect to detect. The record describes its planning illustrations as based on the observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The illustrations use stated fractions of the observed effect. These are planning assumptions, not the trial's reported design justification, and the registry does not report the trial's own sample-size justification.

Sample-size planning values are not observed power. Observed power is not a useful substitute for reading the effect estimate and its uncertainty after a trial. Planning calculations are conditional on the assumed effect, variability, allocation, and statistical approach; assumptions that differ from the trial's actual data can change what those calculations imply. The record's planning description should therefore be understood as illustrative rather than evidence that the trial was adequately powered for a particular effect.

Why can over-dispersion matter?

In general, over-dispersion means that the observed variability exceeds what a particular statistical model expects. When a model assumes less variability than is present, standard errors and uncertainty intervals may be too small, and tests may appear more decisive than warranted. That issue is most directly relevant when a model specifies a variance structure; a mean and standard deviation alone do not establish whether over-dispersion is present. The registry record does not report an over-dispersion assessment or a model-based adjustment for it. With a continuous endpoint and a small sample, the appropriate concern is to understand the assumptions and the underlying observations, details that are not reported in the registry record.

The registry's choice to list a t-test gives some information about the sponsor's method, but not a complete statistical analysis plan. Further details such as assumptions checks, covariate adjustment, handling of baseline values, and methods for missing observations are not reported in the registry record. The test result should be read alongside these limitations rather than as a complete account of the analysis.

10. Confidence Intervals for Each Arm

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

R code and output

arm <- c("Suramin", "Saline (Placebo)")
n   <- c(5, 5)
m   <- c(-1.6, -0.4)
sp  <- c(0.55, 0.55)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Suramin  5  -1.600  0.550  -2.283  -0.917
CARM  Saline (Placebo)  5  -0.400  0.550  -1.083  0.283

11. Analyses Reported by the Sponsor

The registry reports a sponsor analysis for the Suramin group, with the method listed as a two-sided t-test. The estimate is labeled “Mean Difference (Net)” and is -1.6, with a 95% confidence interval from -2.3 to -0.9 and p = 0.003. The analysis is classified as an equivalence analysis in the record. However, an equivalence margin and further detail about the precise contrast are not reported in the registry record. The reported label and statistics should therefore be retained without assuming a different hypothesis or analysis definition.

The posted arm summaries report means of -1.6 for Suramin and -0.4 for Saline (Placebo), with standard deviations of 0.55 in both groups. The registry indicates that a two-arm recalculation for the continuous endpoint was not estimable because values were missing or not estimable for that comparison. A distinct recalculated between-arm estimate is consequently not available to compare directly with the sponsor result. The registry does not flag a discrepancy, but that does not resolve the missing detail about the sponsor contrast. In reading the result, the sponsor's reported analysis is the inferential result available in the registry, and its interpretation remains bounded by the analysis description recorded there.

12. Multiplicity, Missing Data and Analysis Populations

The registry lists six outcome measures and six analyses, and it names four secondary outcomes: the Aberrant Behavior Checklist (ABC), Autism Treatment Evaluation Checklist (ATEC), The Clinical Global Impression - Improvement Scale (CGI-I), and Repetitive Behavior Questionnaire. The primary outcome is ADOS2. Considering several outcomes or analyses raises the general issue of multiplicity: when many hypotheses are tested, the chance of seeing at least one result that appears unusual under its null can increase. Statistical approaches can address multiplicity, but the registry record does not report whether any adjustment was planned or applied.

The status of the six analyses and their relationship to the outcome measures are not explained in enough detail to reconstruct a complete testing strategy. The record does not report which analyses were confirmatory, whether a hierarchy or gatekeeping procedure was used, or whether the sponsor designated a single primary analysis in a protocol. The listed primary endpoint identifies the principal outcome in the registry, but it does not substitute for a full analysis plan.

Missing-data handling is also not reported in the registry record. The record does not say whether all randomized participants contributed to the primary analysis, how missing follow-up measurements were handled, or whether any imputation or sensitivity analysis was used. Those details matter because the analysis can depend on which observations are available and on assumptions about missingness. No analysis population definition, such as an intention-to-treat or per-protocol population, is reported in the registry record.

Further information about interim analyses, stopping rules, and prespecified analysis decisions is not reported in the registry record. These are not details that can be inferred from the randomized, masked design or from the reported p-value. Without them, readers cannot fully assess the extent to which the reported analysis follows a prespecified testing strategy. These omissions do not negate the posted statistics, but they limit the assessment of their role among the trial's outcomes and analyses.

13. Safety Results

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

Deaths

Other (non-serious) adverse events

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

Most frequent non-serious adverse event terms

The registry reports serious adverse events for both arms. Among 5 participants at risk in the Suramin group, 0 were affected by a serious adverse event; among 5 participants at risk in the Saline (Placebo) group, 0 were affected. The record lists 0 deaths in each arm. No serious adverse event terms are listed in the registry record.

For other adverse events, the registry reports 5 affected participants among 5 at risk in the Suramin group and 4 affected participants among 5 at risk in the Saline (Placebo) group. These are participant counts, not counts of every event, and the record does not give further details about event types, severity, timing, or attribution. The serious-event counts should not be conflated with the counts for other adverse events.

With 5 participants in each arm, these safety observations describe only the small trial population. The absence of reported serious adverse events or deaths in this sample does not establish that such events cannot occur, and the other-event counts do not by themselves establish a causal difference between groups. More detailed safety methods and follow-up information are not reported in the registry record.

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

The posted results describe a randomized comparison of a single suramin infusion with saline in 10 participants with autism spectrum disorders. The primary outcome was ADOS2 at 6 weeks compared with baseline. The arm summaries report a mean value of -1.6 for Suramin and -0.4 for Saline (Placebo), with a standard deviation of 0.55 in each arm. The sponsor analysis reports a “Mean Difference (Net)” of -1.6, a 95% confidence interval from -2.3 to -0.9, and p = 0.003. The analysis description does not fully specify the contrast, and a separate two-arm recalculation is not estimable in the registry record.

These results do not establish a broader conclusion about the effect of suramin. The registry does not report a clinically meaningful threshold for ADOS2 change, so statistical evidence cannot by itself indicate the importance of the score difference. Nor does the reported result address whether a change persists beyond the recorded 6-week timeframe. Further information about the participants, analysis population, missing observations, and testing strategy is not reported in the registry record.

The trial's small enrollment means that the estimates are based on a limited number of observations. A narrow-looking interval or a small p-value cannot eliminate uncertainty about how representative this sample is or whether the analysis was sensitive to individual observations. Interpretation also depends on the exact outcome contrast and analysis assumptions. The record contains no protocol-level account sufficient to answer all of those questions.

Safety results are likewise limited to the recorded counts: no serious adverse events or deaths are reported among the participants at risk, while other adverse events are reported in both groups. These figures should be read as observations from this trial rather than as definitive evidence of safety in a wider population.

The result is best understood as a registry-reported statistical finding in a small, completed, randomized, masked trial, accompanied by important gaps in analytic detail. It does not establish treatment efficacy, lack of efficacy, or a clinical recommendation. Such conclusions would require context and evidence beyond the statistics reported in this record.

15. Why This Trial Matters Statistically

This trial is statistically notable because it combines randomization and quadruple masking with a very small total enrollment: 10 participants, divided evenly between Suramin and Saline (Placebo). Random allocation and masking are valuable design features, but neither removes the imprecision and generalizability concerns that come with a small sample. The arm-level summaries and sponsor result therefore need to be read with close attention to what each estimate represents.

The primary measure is continuous and has a stated direction: higher ADOS2 scores indicate more severe core symptoms. The registry describes the outcome at 6 weeks compared with baseline. This makes the result dependent not only on the scale but also on the definition of the change or contrast being analyzed. The sponsor analysis is labeled “Mean Difference (Net),” yet further details about its construction are not reported in the registry record. That distinction is a useful reminder that a statistical method name and a numerical result do not, by themselves, fully define the estimand.

The record also illustrates the difference between a sponsor-reported inferential result and an independent recalculation. The sponsor reports a two-sided t-test, confidence interval, and p-value, while the registry indicates a two-arm recalculation is not estimable. Without a clearly defined contrast and the required information for a recalculation, the analysis cannot be reconstructed from the record alone.

Finally, the record lists multiple outcomes and analyses, but does not report a multiplicity strategy, missing-data approach, or analysis population. These gaps affect how confidently readers can place the primary result among the other planned or reported analyses. The trial matters statistically as an example of why design strengths, numerical results, and reporting completeness must be considered together rather than treated as interchangeable evidence.

16. 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 trial enrolled 10 participants, with 5 in each arm. The small sample limits the precision and breadth of what can be learned from the observed results. The registry record does not report a sample-size justification, so the intended detectable effect and the rationale for the enrollment target cannot be assessed. The planning illustrations described in the record are not the trial's own design justification.

The primary endpoint is described at 6 weeks compared with baseline. A longer-term outcome timeframe is not reported in the registry record. Consequently, the record does not support conclusions about persistence of the observed scores beyond the stated primary timeframe. It also does not provide additional participant characteristics needed to assess how closely the enrolled group represents other people with autism spectrum disorders.

The sponsor analysis is reported as a two-sided t-test, but the exact contrast represented by “Mean Difference (Net)” is not fully defined. The registry indicates that a separate two-arm recalculation is not estimable. This limits independent checking and makes it important not to treat the sponsor estimate as a clearly documented between-arm comparison without further information.

Other important analytic details are not reported in the registry record, including the analysis population, handling of missing observations, baseline adjustment, assumptions checks, multiplicity procedures, and whether interim analyses or stopping rules were used. The record lists six outcome measures and six analyses, but does not explain their full relationship or the prespecified testing strategy. For safety, the registry provides counts but not detailed descriptions of other adverse events, timing, or attribution. These limitations narrow the interpretation of both efficacy-related and safety-related results.

17. Related Tutorials

18. Related Statistical Calculators

19. Sources

• ClinicalTrials.gov: University of California, San Diego (UCSD) Suramin Autism Treatment-1 (SAT1) Trial — NCT02508259.
• Registry record last updated 2019-07-16; status last verified 2019-06.
• Results first posted 2019-07-16.
• 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.

20. Record Summary

NCT02508259, the UCSD Suramin Autism Treatment-1 (SAT1) Trial, is listed as a completed Phase 1 and Phase 2 randomized, quadruple-masked, parallel-group study sponsored by the University of California, San Diego. The record lists a start of 2015-05 and primary completion of 2016-03, with 10 participants enrolled.

Participants were assigned to a single intravenous infusion of 20 mg/kg suramin in 50 ml saline over 30 minutes or 50 ml saline over 30 minutes. The primary outcome was ADOS2 at 6 weeks compared with baseline. The sponsor analysis reports an estimate of -1.6, a 95% confidence interval from -2.3 to -0.9, and p = 0.003, with the estimate labeled “Mean Difference (Net).” The registry does not fully describe the contrast, and a two-arm recalculation is not estimable from the record. Serious adverse events and deaths are reported as 0 in both arms. Further analytic and follow-up details are not reported in the registry record.