PDC-1421 Treatment in Adult Patients With ADHD: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for PDC-1421 Treatment in Adult Patients With ADHD (NCT05202327), a randomized phase 2 study. The primary outcome is Number of Participants With Improvement ≥ 40% in ADHD-RS-IV From Baseline up to 8 Weeks Treatment.

2. Clinical Question

3. Trial Design

This was a phase II, randomized, parallel-group, placebo-controlled study of PDC-1421 Capsule in adults with ADHD. The registry lists quadruple masking. Its brief summary also describes the study as double-blind; the record does not explain the masking roles or reconcile these descriptions. BioLite, Inc. is listed as sponsor.

The three arms were placebo, low-dose PDC-1421, and high-dose PDC-1421. All regimens were scheduled three times daily for 56 days (8 weeks). The placebo arm received two placebo capsules per dose. The low-dose arm received one placebo capsule and one PDC-1421 Capsule per dose, while the high-dose arm received two PDC-1421 Capsules per dose. The primary objective was to determine effective doses and treatment period; the secondary objective was to evaluate safety at various dose levels.

The registry lists 99 participants enrolled, with study start on 2022-04-07, primary completion on 2023-12-06, and status completed. The primary endpoint counts are based on 22 participants in the placebo arm, 23 in the low-dose arm, and 24 in the high-dose arm. These endpoint denominators do not account for the full enrollment, and the reason is not reported in the registry record. The allocation ratio, details of recruitment, and the trial's original sample-size justification are not reported in the registry record.

Outcome timeframes were up to 8 weeks. Although the study objective refers to determining treatment period, the registry record does not report another treatment duration or a comparison of treatment periods. It also does not report a protocol-level statistical analysis plan.

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

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 Number of Participants With Improvement ≥ 40% in ADHD-RS-IV From Baseline up to 8 Weeks Treatment, measured over 8 weeks.

The primary endpoint counts participants with at least 40% improvement in ADHD-RS-IV from baseline up to 8 weeks. The ADHD-RS-IV with Adult Prompts is an 18-item clinician-rated scale based on DSM-IV-TR criteria for ADHD. Its items assess inattentive and hyperactive-impulsive symptoms, with nine items in each group. Each item is scored on a four-point severity scale, and the total score can range from 0 to 54. The adult prompts guide clinicians in exploring symptom extent and severity and impairment. The registry says investigators assessed the scale from Visit 1 to Visit 7.

A threshold-based endpoint turns change in a symptom score into a count of participants meeting a specified improvement criterion. This can make the result easier to interpret as a responder count, but it does not show how far beyond or short of the threshold each participant's change was. It also does not convey the full distribution of score changes. The registry record does not report the rationale for selecting the 40% threshold, the approach to missing endpoint data, or the analysis population used for the primary endpoint.

The posted primary results report 11 participants out of 22 in the placebo arm, 9 out of 23 in the low-dose arm, and 10 out of 24 in the high-dose arm meeting the endpoint. Those counts describe the observed endpoint data; by themselves, they do not establish the precision or interpretation of a difference between groups.

7. Results Posted in the Registry

• Low-dose: 39.1% (9/23) versus 50.0% (11/22) on control; risk difference -10.9 percentage points (95% CI -39.8 to 18.0), risk ratio 0.78 (0.40–1.51); unadjusted two-proportion z-test p = 0.463.
• High-dose: 41.7% (10/24) versus 50.0% (11/22) on control; risk difference -8.3 percentage points (95% CI -37.1 to 20.4), risk ratio 0.83 (0.44–1.57); unadjusted two-proportion z-test p = 0.571.

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.

Number of Participants With a CGI Score of 2 or Lower From Baseline up to 8 Weeks Treatment

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Low-dose: 39.1% (9/23) versus 27.3% (6/22) on control; risk difference 11.9 percentage points (95% CI -15.4 to 39.1), risk ratio 1.43 (0.61–3.36); unadjusted two-proportion z-test p = 0.399.
  • High-dose: 37.5% (9/24) versus 27.3% (6/22) on control; risk difference 10.2 percentage points (95% CI -16.6 to 37.1), risk ratio 1.38 (0.58–3.24); unadjusted two-proportion z-test p = 0.460.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Low-dose and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between High-dose and the control. The interval gives the range of effects that remain compatible with the data.

Change From Baseline up to 8 Weeks in the Sluggish Cognitive Tempo (K-SCT) Score.

• 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:
  • Low-dose: mean -6.04 versus -5.05 on control; difference -0.99 (95% CI -5.83 to 3.85), standardized effect d = -0.12; z-test p = 0.688.
  • High-dose: mean -6.54 versus -5.05 on control; difference -1.49 (95% CI -6.21 to 3.23), standardized effect d = -0.18; z-test p = 0.536.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Low-dose and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between High-dose and the control. The interval gives the range of effects that remain compatible with the data.

Change From Baseline up to 8 Weeks in the ADHD-RS-IV Total Scale.

• 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:
  • Low-dose: mean -13.61 versus -12.14 on control; difference -1.47 (95% CI -7.49 to 4.55), standardized effect d = -0.14; z-test p = 0.632.
  • High-dose: mean -11.75 versus -12.14 on control; difference 0.39 (95% CI -5.62 to 6.40), standardized effect d = 0.04; z-test p = 0.899.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Low-dose and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between High-dose and the control. The interval gives the range of effects that remain compatible with the data.

The posted secondary results span binary responder outcomes and continuous changes in symptom or cognitive-tempo scores. The CGI responder counts are numerically higher in each PDC-1421 group than in placebo, while the group means for the two reported continuous outcomes do not follow one uniform pattern across doses. This mixed pattern does not supply a consistent, precise account that would resolve the uncertainty in the primary endpoint.

The primary result is a threshold-based ADHD-RS-IV responder comparison. The secondary ADHD-RS-IV total-scale change outcome is related to that measure but captures average score change rather than the number meeting the primary responder threshold. The CGI measure offers a separate responder definition, and K-SCT measures a different construct. Outcomes that use different measures or endpoint formats need not move in parallel, and they should not be treated as interchangeable replications of the primary endpoint.

The registry lists five secondary outcomes, but numerical results are posted for only three. The results for ADHD-RS-IV remission and the CAARS:S:S ADHD Index are not reported in the registry record. The comparisons that are posted are unadjusted, and the registry record reports no sponsor analysis records. This limits the ability to assess whether the secondary findings were prespecified, modeled as intended, or adjusted for the number of outcomes examined.

General statistical explanation: examining multiple outcomes increases the chance that some estimates will look noteworthy through random variation alone. Multiplicity procedures can control that risk, but the registry record does not report whether any were planned or used. Accordingly, unadjusted secondary results carry less weight than a prespecified, appropriately analyzed primary result. The secondary outcomes can help describe the breadth of measures collected, but they should not be used to select a favorable result or to override the imprecision of the primary comparison.

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

• Number of Participants With a CGI Score of 2 or Lower From Baseline up to 8 Weeks Treatment
• Change From Baseline up to 8 Weeks in the Sluggish Cognitive Tempo (K-SCT) Score.
• Change From Baseline up to 8 Weeks in the ADHD-RS-IV Total Scale.
• Number of Participants With Symptom Remission in ADHD-RS-IV From Baseline up to 8 Weeks Treatment
• Change From Baseline up to 8 Weeks Treat in the Conners' Adult Attention-Deficit/Hyperactivity Disorder Rating Scale-Self Report: Short Version (CAARS-S:S) ADHD Index of T-score.

9. Statistical Interpretation

10. Statistical Methods Explained

What does a risk difference represent?

For the binary primary endpoint, a risk difference compares the observed proportion meeting the responder criterion in a PDC-1421 group with the corresponding proportion in placebo. A negative estimate means the observed proportion was lower in the named dose group than in placebo; a positive estimate means it was higher. The risk difference is an absolute contrast, rather than a relative comparison. For example, the primary low-dose risk difference is -0.109, and the high-dose risk difference is -0.083. These are unadjusted comparisons based on the posted counts.

General statistical explanation: a risk difference summarizes the separation between two observed proportions, but it does not account automatically for other variables or features of the trial. The registry record does not report an adjusted model for the primary endpoint or describe the method used for a sponsor analysis.

How should the confidence intervals be read?

A confidence interval describes the range of values compatible with the data under the method used to construct it. It communicates uncertainty around an estimate and is not a range containing a fixed proportion of individual participant outcomes. For the primary endpoint, both risk-difference intervals include zero: -0.398 to 0.180 for low-dose versus placebo, and -0.371 to 0.204 for high-dose versus placebo. Zero represents no difference on the risk-difference scale. Because the intervals extend on both sides of zero, the data are compatible with differences in either direction.

General statistical explanation: an interval's width reflects precision, with wider intervals indicating less precision. Interpretation also depends on the endpoint and analysis assumptions. The registry record does not report the sponsor's interval-estimation procedure.

What do the p-values add?

The unadjusted primary p-values are 0.463 for low-dose versus placebo and 0.571 for high-dose versus placebo. General statistical explanation: a p-value measures how unusual data at least as discrepant as those observed would be under a specified null model. It is not the probability that the null hypothesis is true, and it does not measure the probability that the result will be replicated. A p-value also does not express the size or clinical importance of a difference. The registry record does not identify the test used to obtain these posted p-values.

How are continuous outcomes compared?

For the K-SCT score and ADHD-RS-IV total score, the record reports group means, standard deviations, and mean differences versus placebo. A mean difference is an absolute contrast between group averages. For example, the registry lists changes in K-SCT score of -5.05 for placebo, -6.04 for low-dose, and -6.54 for high-dose. For ADHD-RS-IV total score, it lists -12.14 for placebo, -13.61 for low-dose, and -11.75 for high-dose. The listed comparisons are unadjusted mean differences, with confidence intervals and p-values.

General statistical explanation: a mean can summarize a group, while the standard deviation describes variability among observed scores. A mean difference does not describe the full distribution, and its interpretation can depend on the measurement scale and analysis assumptions. The registry does not report an adjusted repeated-measures model or another sponsor analysis for these outcomes.

What does over-dispersion mean in general?

General statistical explanation: over-dispersion occurs when the variability in data is greater than a model assumes. It can make standard errors too small if the model does not allow for the extra variability, which can make confidence intervals too narrow and p-values too small. This concept may matter for some count outcomes, but the primary endpoint is a count of participants meeting a binary criterion, and the record does not report a model for which over-dispersion was assessed. No over-dispersion result is reported in the registry record.

The registry lists six outcome measures in total, including the primary endpoint, and five secondary outcomes. It reports no analysis records. The comparisons should therefore be understood as unadjusted comparisons of the posted group summaries rather than as a reconstruction of a full prespecified analysis. The trial's original statistical methods, model specifications, handling of repeated measurements, covariate adjustments, missing-data procedures, and analysis populations are not reported in the registry record.

11. Confidence Intervals and Precision

The primary risk-difference estimates are imprecise. For low-dose versus placebo, the estimate is -0.109 and its 95% confidence interval runs from -0.398 to 0.180. For high-dose versus placebo, the estimate is -0.083 and its 95% confidence interval runs from -0.371 to 0.204. Both intervals include zero, and each spans values consistent with a difference in either direction. The estimates should not be read as precise measurements of the underlying group differences.

General statistical explanation: a confidence interval conveys uncertainty in an estimated contrast, conditional on the data and the method used to calculate the interval. It is not a guarantee that the true value lies inside the interval, nor does it show the range of individual responses. A broad interval can be compatible with several interpretations, including no difference and differences of varying size. Here, the small endpoint denominators are visible in the group counts, but the registry record does not state why those denominators are below the enrollment figure.

The continuous secondary comparisons are also uncertain. Their reported mean-difference intervals include zero, as do the intervals for the posted CGI comparisons. This does not demonstrate that groups are equivalent. Demonstrating equivalence would require an appropriate design and prespecified margins, which are not reported in the registry record. In addition, confidence intervals and p-values are unadjusted for multiplicity in the posted comparisons, and the record does not report whether a different sponsor analysis was conducted.

Precision is distinct from statistical significance and from clinical importance. Even when a point estimate is close to zero, an interval may remain compatible with effects in either direction; conversely, an estimate's statistical properties alone do not determine whether a difference matters clinically. The record does not give a threshold for a clinically important between-group difference.

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 describe participants per arm for the binary and continuous comparisons in this study. They are not total events. The figures are illustrative calculations based on the observed effect, not the trial's original design justification. The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; each scenario uses the stated fraction of the observed effect as the effect to detect. The trial's own original design assumptions are not reported in the registry record.

For each comparison, the 80% power column gives the estimated number of participants per arm for a future study to have an 80% chance of detecting the specified effect under the planning assumptions, if that effect is real and the assumptions hold. The 90% power column gives the corresponding number per arm for a 90% chance. These are design calculations, not a statement about what happened in this completed study.

Planning for 100% of the observed effect uses the full effect estimate from the posted data. Planning for 75% or 50% of the observed effect considers smaller target effects. Smaller effects are harder to distinguish from random variation, so they require more participants per arm under the same assumptions. The illustrations based on the observed effects can be especially unstable when the original estimates are imprecise, as they are for these comparisons.

These figures are planning scenarios, not observed power. Observed power is not a useful substitute for reading the effect estimate and confidence interval: the trial's results are better understood by considering the estimated differences and their uncertainty. The sample-size calculations do not establish the sample size the completed study should have used, because the original design assumptions and justification are not reported in the registry record.

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, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.500; treatment proportion p₁ = 0.391; average p̄ = 0.446.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.7029 = 1.3777.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.6987 = 0.5880.
4. n = (1.3777 + 0.5880)² / (-0.1087)² = 327.1, rounded up to 328 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
p0 <- 0.5                          # control proportion
p1 <- 0.391304347826087                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^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 (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(5202327)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 328 (80% power), 438 (90% power)
 75% of observed effect: n per arm = 586 (80% power), 784 (90% power)
 50% of observed effect: n per arm = 1,324 (80% power), 1,772 (90% power)
power.prop.test: 327.1 
Simulated power at n = 328 per arm: 0.804 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-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. Multiplicity, Missing Data and Analysis Populations

The registry record lists one primary endpoint and five secondary outcomes, but it reports no analysis records. It therefore does not document how the statistical analyses were prespecified or carried out, whether outcomes were tested in a hierarchy, or whether any adjustment for multiple comparisons was planned. The posted comparisons are unadjusted. With several outcomes and two active-dose comparisons, unadjusted p-values do not by themselves account for the opportunity to observe an apparently unusual result across multiple tests.

General statistical explanation: multiplicity refers to the increased chance of false-positive findings when many hypotheses are assessed. A prespecified testing strategy or adjustment can help control that risk. Without the analysis plan, it is not possible to determine whether the posted secondary comparisons were intended as confirmatory or exploratory, or how the trial's investigators intended to interpret them. The primary endpoint remains the stated primary measure, but its reported comparisons are also unadjusted in the record.

Missing-data methods are not reported in the registry record. The endpoint denominators are 22 for placebo, 23 for low-dose, and 24 for high-dose, while the registry lists 99 participants enrolled. The record does not state why the endpoint denominators are smaller than enrollment, whether these differences reflect missing measurements, exclusions, or another reason, or how any unavailable outcomes were handled. It does not describe imputation, sensitivity analyses, or follow-up completeness.

Analysis populations are also not reported in the registry record. There is no description of whether the results use an intention-to-treat, per-protocol, safety, or other population, and no account of eligibility or exclusions from the posted outcome denominators. The sponsor's analysis methods and any protocol deviations are not described. These omissions limit the ability to judge whether the reported contrasts preserve the randomized comparison and how robust the estimates may be to missing observations or analytic choices.

15. 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 posted serious adverse event figures are zero affected participants in each group: 0 of 22 in placebo, 0 of 23 in low-dose, and 0 of 24 in high-dose. The death count is also 0 in each group. These are observed counts among the participants at risk listed for each arm. They do not establish that the underlying risk is zero, particularly with the limited group sizes represented in the safety record.

General statistical explanation: when no events are observed, the data still allow uncertainty about the event rate; the absence of observed cases is not proof that an event cannot occur. The registry lists no top serious-event terms. It does not report further detail about serious-event definitions, observation duration for safety, relatedness assessments, or a comparative statistical analysis of these outcomes.

The record also lists other adverse events affecting 4 participants in placebo, 6 in low-dose, and 8 in high-dose. Those figures are distinct from the serious-event counts. The serious-event summary alone cannot describe the full safety profile, and these counts should not be interpreted as evidence that one regimen is safer or less safe than another.

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

The posted primary data show that 11 of 22 participants in the placebo group, 9 of 23 in the low-dose group, and 10 of 24 in the high-dose group met the ADHD-RS-IV improvement threshold at 8 weeks. The unadjusted comparisons estimate lower responder proportions in both dose groups than in placebo, but their confidence intervals include zero and extend in both directions. The estimates are imprecise, so the record does not establish the size or direction of a reliable group difference.

This interpretation is specific to the posted endpoint and time frame. It does not summarize every aspect of ADHD symptoms, daily functioning, or treatment experience. The primary outcome reduces a continuous symptom scale to a threshold-based responder count, while the secondary outcomes include different measures and score summaries. Their results are incomplete in the registry record, and the available secondary comparisons are unadjusted.

General statistical explanation: failing to establish a difference is not the same as establishing no difference. These results do not demonstrate equivalence, because an equivalence design and margin are not reported. They also do not establish that an observed difference is clinically important or unimportant; the registry record does not provide a clinical-importance threshold for between-group contrasts.

The safety record reports no serious adverse events or deaths in the listed groups, but those counts do not prove that serious risks are absent. Other adverse events are also listed, and the record does not provide a comprehensive safety interpretation. No treatment recommendation follows from these statistical summaries. The findings describe the posted data, with limitations arising from imprecision, incomplete secondary reporting, and unreported analysis details.

17. Why This Trial Matters Statistically

This trial illustrates why group counts alone are not enough to judge a randomized comparison. The primary responder counts are close in number across groups, but the unadjusted risk-difference estimates have broad confidence intervals that include zero. The point estimates, uncertainty intervals, and analysis context all matter; a count difference by itself cannot indicate how precisely an underlying contrast has been measured.

The study also demonstrates the distinction between a threshold-based binary endpoint and continuous score outcomes. The primary endpoint asks how many participants crossed a specified improvement threshold, whereas secondary measures include average changes and a separate CGI responder outcome. These answer related but different questions. Their patterns need not match, and multiple unadjusted comparisons are harder to interpret than a single prespecified analysis.

For clinical researchers, the record is a reminder that trial registration and posted outcomes do not always provide all the information needed to evaluate methods. The registry reports the enrollment, treatment schedules, endpoint counts, and some secondary results, but it does not report the original sample-size justification, analysis populations, missing-data methods, or multiplicity strategy. It also lists no analysis records and has no numerical results for two secondary outcomes.

The planning illustrations emphasize that a future study designed to detect smaller effects generally requires more participants per arm, under the stated assumptions. They are not a retrospective measure of the completed trial's success or adequacy. Distinguishing such planning calculations from observed evidence helps keep conclusions anchored to what the data estimate and how uncertain those estimates remain.

18. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The primary outcome denominators are smaller than the enrollment listed in the registry, and the reasons are not reported in the registry record. Without information on the analysis population, participant flow, or missing-data handling, it is difficult to determine how the endpoint results relate to all randomized or enrolled participants. The registry record also does not report baseline group characteristics, so the posted summaries cannot describe balance or allow readers to assess the role of baseline differences.

The reported comparisons are unadjusted, and no sponsor analysis records are listed. The record does not identify the statistical tests or models used, whether the analyses followed a prespecified plan, or whether any adjustment was made for multiplicity. The primary results therefore should not be taken as a complete account of the sponsor's intended analysis. The registry does not report an original sample-size rationale, so the posted planning illustrations cannot be used to judge the original design assumptions.

Only three of the five listed secondary outcomes have numerical results in the registry record. The missing numerical results for remission on ADHD-RS-IV and the CAARS:S:S ADHD Index restrict assessment of the breadth and consistency of secondary findings. The posted results also provide limited detail about the timing and completeness of outcome collection beyond the stated 8-week timeframe.

The study is listed as phase II, with a total enrollment of 99, and the observed endpoint groups are small. The confidence intervals reflect substantial uncertainty in the estimated contrasts. The record does not report a clinically important difference threshold, making it difficult to judge the practical importance of values within the intervals. These limitations are specific to the available trial record and should be kept separate from conclusions about unreported analyses or outcomes.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: PDC-1421 Treatment in Adult Patients With ADHD — NCT05202327.
• Registry record last updated 2026-05-06; status last verified 2026-04.
• Results first posted 2026-05-06.
• 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.

22. Record Summary

NCT05202327 is a completed phase II randomized, parallel-group, placebo-controlled study sponsored by BioLite, Inc. It enrolled 99 participants and studied placebo, low-dose PDC-1421 Capsule, and high-dose PDC-1421 Capsule for 56 days (8 weeks). The primary endpoint counted participants with at least 40% improvement in ADHD-RS-IV from baseline.

The posted primary counts were 11 of 22 for placebo, 9 of 23 for low-dose, and 10 of 24 for high-dose. Both unadjusted risk-difference confidence intervals include zero and are broad. Three secondary outcomes have numerical results, while two are not reported in the registry record. The record reports no analysis records, and does not report the original sample-size justification, analysis populations, missing-data methods, or multiplicity approach.

No serious adverse events or deaths were listed in the three groups. The available results describe the recorded outcomes but leave uncertainty about the comparisons, the analysis procedures, and the unreported secondary outcomes.