A Study to Evaluate the Efficacy and Safety of CBP-201 in Moderate to Severe Atopic Dermatitis in China: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Evaluate the Efficacy and Safety of CBP-201 in Moderate to Severe Atopic Dermatitis in China (NCT05017480), a randomized phase 2 study. The primary outcome is Investigator Global Assessment (IGA) (0-1).

2. Clinical Question

This is a question about the proportion of participants meeting a defined clinical response criterion over a fixed follow-up interval. It is not a question about average change in IGA or about every aspect of atopic dermatitis. The response definition combines the final IGA category with the amount of decrease from the participant’s prior score.

The comparison in the posted primary result is between Group A and Group B. In Group A, 29.0% met the response criterion, with a 95% confidence interval of 23.0% to 35.0%. In Group B, 5.9% met it, with a 95% confidence interval of 1.4% to 10.4%. These are group-level estimates for the specified endpoint and time frame. They do not describe the response of every participant or establish how results might differ in other populations, at other time points, or under other treatment schedules.

3. Trial Design

The registry describes a randomized, parallel-group, quadruple-masked, multicenter clinical study, with phase 2 listed. Its official title identifies the study as double-blind, while the registry masking classification is quadruple. The record does not explain how those masking descriptions relate to one another. The study is marked completed, and the recorded enrollment is 330.

The primary comparison uses Group A, CBP-201 300mg Q2W by subcutaneous injection, and Group B, placebo Q2W by subcutaneous injection. The primary outcome is measured from baseline to Week16. The primary endpoint denominator is 219 in Group A and 111 in Group B. Those endpoint denominators need not be assumed to describe every analysis or every period of the trial.

The record also names Groups C, D, and E in its safety information: Double-blinded CBP-201 300mg Q2W, Double-blinded CBP-201 300mg Q4W, and Open-Label CBP-201 300mg Q2W. It does not provide enough detail to describe the timing, sequence, or relationship of those groups to the primary comparison. Those details, including whether participants entered more than one group or whether the groups represent later study periods, are not reported in the registry record.

The recorded study start is 2021-08-31, and primary completion is recorded as 2022-12-01. Randomization and masking are design features intended to support a fair treatment comparison and reduce the influence of expectations or knowledge of assignment. The method used to generate the random sequence, allocation concealment procedures, and masking procedures are not reported in the registry record. The trial's original sample-size justification and its planned statistical analysis approach are also not reported in the registry record.

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.

Stage 1 Study

Reasons for not completing this period:

Stage 2 Study

Reasons for not completing this period:

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 Investigator Global Assessment (IGA) (0-1), measured over Baseline to Week16.

The primary endpoint is the percentage of participants whose IGA score is 0-1 and has decreased by at least 2 points from baseline to Week16. The IGA scale described in the registry is a 5-point classification of the overall appearance of skin lesions at a specific time: 0 means clear, 1 almost clear, 2 mild, 3 moderate, and 4 severe. The endpoint therefore requires both a final score in the clear or almost-clear categories and a change of at least 2 points.

A binary response endpoint is useful when the clinical question is whether participants reach a prespecified state, rather than how much their scores change on average. It gives a proportion that can be compared between randomized groups. The resulting proportion depends on the exact response definition and assessment time; it does not capture all possible changes in symptoms or disease severity.

General statistical context: converting a scale into a responder definition makes the outcome easier to interpret as the chance of meeting a stated threshold, but it also discards information about differences among participants who do not meet that threshold and among those who do. The registry record does not report the rationale for choosing this specific threshold, the handling of missing Week16 assessments, or further details about the endpoint analysis population.

7. Results Posted in the Registry

• Group A: CBP-201 300mg Q2W: 29.2% (64/219) versus 6.3% (7/111) on control; risk difference 22.9 percentage points (95% CI 15.4 to 30.4), risk ratio 4.63 (2.20–9.77); unadjusted two-proportion z-test p = <0.001.

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.

Eczema Area and Severity Index (EASI)-75

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Group A: CBP-201 300mg Q2W: 58.4% (128/219) versus 22.5% (25/111) on control; risk difference 35.9 percentage points (95% CI 25.8 to 46.1), risk ratio 2.60 (1.81–3.73); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for Group A: CBP-201 300mg Q2W than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Change in Peak Pruritus Numerical Rating Scale(PP-NRS) (Decreased by ≥ 4 Points)

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Group A: CBP-201 300mg Q2W: 36.1% (78/216) versus 10.9% (12/110) on control; risk difference 25.2 percentage points (95% CI 16.5 to 33.9), risk ratio 3.31 (1.89–5.81); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for Group A: CBP-201 300mg Q2W than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Change in Peak Pruritus Numerical Rating Scale(PP-NRS) (Decreased by ≥ 3 Points)

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Group A: CBP-201 300mg Q2W: 50.0% (109/218) versus 20.7% (23/111) on control; risk difference 29.3 percentage points (95% CI 19.2 to 39.3), risk ratio 2.41 (1.64–3.55); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for Group A: CBP-201 300mg Q2W than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary outcomes include EASI-75, two PP-NRS response thresholds, weekly average PP-NRS change, EASI-90, and percentage change in weekly average PP-NRS. The posted numerical details include Week16 estimates for EASI-75 and the PP-NRS thresholds of at least 4 points and at least 3 points. In each of those comparisons, the response percentage is higher in the CBP-201 group than in the placebo group, and the posted unadjusted p-value is < 0.001.

That broad direction is consistent with the primary IGA result: the posted responder measures tend to show higher response proportions in the CBP-201 group at Week16. These are related but distinct outcomes. EASI and IGA assess different aspects or definitions of disease response, while PP-NRS outcomes concern itch ratings. A consistent direction across several measures can add context, but it does not make their definitions or interpretations interchangeable.

Numerical estimates for weekly average PP-NRS change, EASI-90, and percentage change in weekly average PP-NRS are not reported in the registry record. Their inclusion among named outcomes does not allow the size or precision of those results to be assessed from the available numerical details.

Multiplicity is important because several outcomes and thresholds are considered. General statistical context: when multiple hypotheses are tested, the chance of at least one small p-value arising by chance can increase if each test is interpreted separately without adjustment. The posted secondary p-values are unadjusted, and the registry record does not report a multiplicity-control procedure or a hierarchy of secondary hypotheses. Consequently, the secondary findings are best treated as supportive descriptive evidence, with less inferential weight than a result evaluated under a fully reported prespecified testing strategy. The registry record also does not explain whether these secondary outcomes were prespecified in a statistical analysis plan.

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

• Eczema Area and Severity Index (EASI)-75
• Change in Peak Pruritus Numerical Rating Scale(PP-NRS) (Decreased by ≥ 4 Points)
• Change in Peak Pruritus Numerical Rating Scale(PP-NRS) (Decreased by ≥ 3 Points)
• Change in the Weekly Average Peak Pruritus Numerical Rating Scale(PP-NRS)
• Eczema Area and Severity Index (EASI)-90
• Percentage Change in the Weekly Average Peak Pruritus Numerical Rating Scale(PP-NRS)

9. Statistical Interpretation

10. Statistical Methods Explained

General statistical context: the primary outcome is binary because each participant either meets the IGA response definition at Week16 or does not. A proportion estimates the share of participants who meet that definition in a group. Comparing the group proportions answers the trial’s stated responder question, whereas a comparison of average scores would answer a different question.

What does the risk difference represent?

The posted risk difference is 0.229, with a 95% confidence interval of 0.154 to 0.304. This measure subtracts the comparator response probability from the intervention response probability on the probability scale. A value above zero indicates a higher observed response probability in the intervention group for this comparison. The confidence interval gives a range of values compatible with the observed data under the method used to calculate it. It is not a guarantee that the true value lies within the interval, nor does it describe variation among individual participants.

The record also includes relative measures, including a risk ratio of 4.634 with interval limits 2.198 and 9.772, and an odds ratio of 6.135 with interval limits 2.705 and 13.91. These measures compare the groups on relative rather than absolute scales. Risk ratios and odds ratios are not interchangeable: the odds ratio compares odds, while the risk ratio compares probabilities. When response probabilities are not small, an odds ratio can appear more extreme than a risk ratio. The registry record does not report which measure was prespecified as the principal comparative measure.

What does the p-value tell the reader?

The primary comparison has an unadjusted p-value of < 0.001. General statistical context: a p-value summarizes how unusual data at least as incompatible with a stated null hypothesis would be if that null hypothesis and the test assumptions were correct. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of an effect. The word “unadjusted” matters because it indicates that the posted value has not been adjusted for a family of multiple comparisons. The registry record does not report the precise test, its assumptions, or whether another analysis was used by the study investigators.

The posted recalculated comparisons are simple unadjusted re-calculations from posted summary statistics. They provide a transparent way to describe the group contrast using those summaries, but they are not evidence that the same calculation was the trial’s prespecified analysis. The registry record does not report a full statistical analysis plan or the sponsor’s detailed modeling decisions for the primary endpoint.

Why does the confidence interval matter?

General statistical context: an estimate alone can make a result seem more definite than the data warrant. A confidence interval communicates precision as well as the estimated direction and magnitude. A narrower interval indicates less sampling uncertainty under the method, while a wider interval indicates more. Its width depends on the amount of information available and on the variability and frequency of the outcome. For a binary outcome, the number of participants and the proportion with a response both contribute to precision.

The group-specific intervals and the interval for the risk difference describe related but distinct quantities. Overlap or non-overlap between group-specific intervals is not a replacement for the interval or test for the between-group contrast. The posted risk-difference interval directly addresses that contrast. The registry record does not identify the confidence-interval construction method, so the statistical assumptions behind its limits cannot be fully evaluated from the record alone.

How should the design features be understood?

Random assignment is intended to create groups that are comparable in expectation with respect to both measured and unmeasured factors. Masking is intended to reduce the possibility that knowledge of group assignment influences behavior, assessment, or reporting. These are general principles, not confirmation of how successfully procedures were implemented in this study. The record classifies the study as randomized and quadruple-masked, and its official title calls it double-blind; operational details are not reported in the registry record.

The parallel-group design means the recorded primary comparison is between distinct groups over the stated assessment period. A placebo comparator helps distinguish the outcomes observed with the intervention from outcomes observed under the comparator condition. The posted results do not by themselves establish the reasons for differences between groups or explain the mechanisms that might produce them.

Other important analytical details are not reported in the registry record: the planned hypothesis and test, covariate adjustment, stratification factors, analysis population, handling of protocol deviations, missing-outcome rules, and any interim analyses. The original sample-size justification is also not reported. These gaps mean that the posted summaries permit a focused reading of the numerical outcomes but not a complete audit of the trial’s prespecified statistical methods.

11. Confidence Intervals and Precision

The primary group-specific estimates are 29.0% in Group A, with a 95% confidence interval from 23.0% to 35.0%, and 5.9% in Group B, with a 95% confidence interval from 1.4% to 10.4%. These intervals show that the estimates have uncertainty, especially for the comparator proportion, whose interval spans a broad range of plausible values under the interval method. The trial’s registry record does not identify the method used to construct these intervals.

For the between-group risk difference, the estimate is 0.229 and its 95% confidence interval is 0.154 to 0.304. The interval is entirely on the positive side of zero, indicating that the posted estimate and its interval are consistent with a higher response probability in Group A for this endpoint. The p-value for the unadjusted comparison is < 0.001. Neither the interval nor the p-value describes the probability that a specific participant will respond.

General statistical context: confidence intervals are useful because they convey both the direction of an estimate and its precision. They reflect sampling uncertainty under the assumptions of the calculation, not all sources of uncertainty. They do not account automatically for missing data, measurement limitations, protocol deviations, or choices made after observing results. The registry record does not provide enough analysis detail to evaluate those sources fully.

The participant counts in the primary endpoint are 219 for Group A and 111 for Group B. Unequal group sizes can affect precision, and the smaller group may contribute more uncertainty to its own proportion. The posted interval for the risk difference is the most direct interval for interpreting the comparison; comparing only the two separate group intervals is not a substitute for it.

12. Planning a Similar Trial: Sample Size

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

The sample-size illustrations are stated as participants per arm, not total event counts. They are planning calculations based on the observed effect and are not the original trial’s sample-size justification. For the primary endpoint, planning to detect 100% of the observed effect gives 43 participants per arm for 80% power and 57 participants per arm for 90% power. Planning for 75% of the observed effect gives 67 participants per arm for 80% power and 89 participants per arm for 90% power. Planning for 50% of the observed effect gives 126 participants per arm for 80% power and 168 participants per arm for 90% power.

The stated calculation assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect targeted is the stated fraction of the observed effect. The 80% power column describes the illustrative number per arm for a design with an 80% chance of detecting the assumed effect under those assumptions, if that effect and the assumptions were correct. The 90% power column describes the corresponding planning target with a 90% chance. These are design probabilities under specified assumptions, not probabilities that the study result is true.

Smaller effects are harder to distinguish from random variation, so the illustrations require more participants per arm when the target is a smaller fraction of the observed effect. These calculations are planning illustrations, not observed power. The trial’s own original design assumptions and sample-size 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 = 0.063; treatment proportion p₁ = 0.292; average p̄ = 0.178.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.5405 = 1.0594.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.5157 = 0.4340.
4. n = (1.0594 + 0.4340)² / (0.2292)² = 42.5, rounded up to 43 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 <- 0.0630630630630631                          # control proportion
p1 <- 0.292237442922374                          # 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(5017480)
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 = 43 (80% power), 57 (90% power)
 75% of observed effect: n per arm = 67 (80% power), 89 (90% power)
 50% of observed effect: n per arm = 126 (80% power), 168 (90% power)
power.prop.test: 42.5 
Simulated power at n = 43 per arm: 0.842 (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

Multiplicity arises when a study evaluates more than one outcome, time point, treatment contrast, or statistical hypothesis. Each additional test creates another opportunity to observe a small p-value by chance if no adjustment or testing hierarchy is used. This is a general statistical concern, not evidence that any particular result is false. The registry lists several secondary outcomes, and the posted comparisons are described as unadjusted.

The registry record does not report whether the investigators used a family-wise error procedure, a false-discovery procedure, a sequential testing hierarchy, or another method to address multiplicity. It also does not report whether the primary endpoint was protected from other analyses by a formal prespecified plan. Without those details, the primary and secondary p-values cannot be interpreted as part of a fully documented multiplicity strategy. The secondary results therefore carry less inferential weight than they might under a clearly described confirmatory testing plan.

Missing-data handling is another key issue for a responder endpoint. A participant without an assessable Week16 result may be handled in different ways, and each choice can affect the estimated response proportion. The record does not report how missing assessments were treated, whether participants with missing values were counted as nonresponders, or whether an imputation method was used. The analysis population and the number of participants with missing primary endpoint data are also not reported in the registry record.

The record does not identify whether the primary estimate is based on an intention-to-treat, modified intention-to-treat, per-protocol, or other analysis population. It does not describe exclusions after randomization, protocol deviations, or sensitivity analyses to test the effect of alternative missing-data assumptions. These are not minor technical details: they help readers judge how well the analysis preserves the comparison created by randomization and how dependent the result may be on assumptions about unavailable outcomes.

Further details about the planned statistical analysis, covariate adjustment, interim analyses, and sample-size justification are not reported in the registry record. Their absence limits independent assessment of the analysis strategy and of whether the posted findings were evaluated according to prespecified rules.

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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: cardiac disorders (2.4%), injury,poisoning and procedural complications (1.8%), musculoskeletal and connective tissue disorders (1.2%), infections and infestations (1.2%), endocrine disorders (1.2%).

The registry reports serious adverse events and other adverse events for five named groups. In Group A, 1 of 219 participants had a serious adverse event and 80 of 219 had another adverse event. In Group B, 3 of 111 had a serious adverse event and 34 of 111 had another adverse event. No deaths are recorded in either group. The other named groups have their own reported participant counts: Group C records 1 serious adverse event among 113 participants and 70 with another adverse event; Group D records 3 among 112 and 67, respectively; and Group E records 6 among 85 and 53, respectively. No deaths are recorded in those groups.

These counts are not a direct measure of comparative risk unless the groups, exposure periods, and event-collection methods are understood. The registry record does not explain how Groups C, D, and E relate to Groups A and B or whether participants could contribute to more than one group. It also does not provide event timing, duration of exposure, severity details beyond the serious-event classification, or a detailed account of causality assessment.

The record lists serious-event categories with percentages, including Cardiac disorders at 2.4% and Injury,poisoning and procedural complications at 1.8%. Several other categories are listed at 1.2%. These category percentages are not clearly linked to a particular arm in the registry record. Counts and percentages should therefore be read as registry safety summaries, not as proof of comparative safety or of a causal relationship to treatment.

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

The posted primary result is a comparison of response proportions at a defined time point, using a specific IGA threshold. It shows that 29.0% of participants in Group A met the criterion and 5.9% in Group B did so. The estimated risk difference is 0.229, with a 95% confidence interval of 0.154 to 0.304, and the unadjusted p-value is < 0.001. These statistics describe the observed trial comparison and its sampling uncertainty under the methods used.

The result does not mean that every participant receiving CBP-201 had the response, that no participant receiving placebo had it, or that the same response would be expected for every person with atopic dermatitis. It does not establish the durability of response beyond Week16, because the primary endpoint is defined from baseline to Week16. It also does not answer questions about other doses or schedules beyond the stated comparison, or about populations beyond the Chinese subjects enrolled in this study.

A statistically small p-value does not by itself establish clinical importance, explain the mechanism of a group difference, or capture the balance of benefits and harms. The endpoint is a responder measure based on skin-lesion assessment; it is not a complete summary of symptoms, quality of life, treatment burden, or long-term outcomes. The registry record does not report the rationale for the response threshold or details needed to interpret missing outcomes and the analysis population.

The safety information includes serious adverse events, other adverse events, and deaths across several groups. The registry record does not give enough information about group relationships or exposure periods to support a full comparative safety interpretation. A reader should distinguish what is counted in the record from a causal conclusion about treatment.

Overall, the posted estimates support a precise statement about the recorded Week16 responder comparison, but not an unrestricted conclusion about effectiveness, safety, or outcomes beyond the trial’s defined measures and population. Further interpretation would depend on the full trial report and details not reported in the registry record.

17. Why This Trial Matters Statistically

This trial illustrates how a responder endpoint turns a clinical scale into a probability that participants meet a defined target. The IGA criterion combines a final score of 0-1 with a decrease of at least 2 points. That definition is clinically interpretable as a threshold, while the statistical comparison estimates how frequently each randomized group met it at Week16.

The posted comparison includes both group proportions and a direct risk-difference estimate with a confidence interval. This matters because a p-value alone would not communicate the size or precision of the contrast. The risk-difference interval provides an absolute-scale view of uncertainty, while relative measures such as the risk ratio and odds ratio describe the comparison on different scales. Reading these together helps distinguish evidence against a null difference from the magnitude and precision of the observed estimate.

The secondary outcomes show why trial interpretation must account for a family of related questions. Several responder definitions and symptom measures are listed, and the numerical comparisons available have unadjusted p-values. Without a reported multiplicity strategy, secondary findings can provide context but should not be treated as independent confirmatory evidence.

The record also makes the limits of registry summaries visible. Details about the analysis population, missing data, analysis plan, interim analyses, and sample-size justification are not reported. The safety entries name additional groups without fully explaining their relationship to the primary comparison. Those gaps matter statistically because they influence how confidently readers can assess the analysis choices, the handling of uncertainty, and the comparability of safety information.

Thus, the trial is informative as a randomized placebo comparison with a clearly stated Week16 responder outcome, while the registry summary alone does not answer every question needed for a full appraisal. Distinguishing an observed estimate from its precision, its analysis assumptions, and its scope is central to responsible interpretation.

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.
• Participant counts were reconstructed from posted percentages and arm sizes, so small rounding differences are possible.

Several trial-specific limitations affect interpretation of the registry results. First, the population is described as Chinese subjects with moderate to severe atopic dermatitis. The registry record does not report participant characteristics in enough detail to assess how broadly the result applies across clinical subgroups or to populations outside the study setting.

Second, the primary endpoint is a threshold-based IGA response measured at Week16. This provides a defined responder outcome, but it does not describe changes among participants who do not meet the threshold or establish how long any response lasts. The registry record does not report additional primary endpoint time points or longer-term follow-up results.

Third, the record does not report the statistical analysis plan, the analysis population, the method for handling missing assessments, or sensitivity analyses. These omissions limit assessment of whether the reported comparison follows prespecified procedures and whether conclusions are robust to different assumptions about unavailable data. The original sample-size justification is also not reported, so the design rationale cannot be evaluated from the registry record.

Fourth, the registry includes safety information for Groups C, D, and E in addition to the primary comparison groups, but does not explain their timing or relationship to those groups. This makes it difficult to interpret the safety summaries as a direct comparison between the primary CBP-201 and placebo arms. The record also does not report exposure duration or detailed adverse-event assessment methods.

Finally, multiple secondary outcomes are listed, while a multiplicity-control strategy is not reported. The available numerical secondary results are therefore best viewed as supporting context rather than a fully documented confirmatory set of tests. Together, these limitations do not negate the posted estimates, but they constrain the conclusions that can be drawn from the registry record alone.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: A Study to Evaluate the Efficacy and Safety of CBP-201 in Moderate to Severe Atopic Dermatitis in China — NCT05017480.
• Registry record last updated 2024-05-01; status last verified 2024-04.
• Results first posted 2024-05-01.
• 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

NCT05017480 is a completed phase 2 randomized, parallel-group study of CBP-201 in Chinese subjects with moderate to severe atopic dermatitis. The recorded enrollment is 330. The primary comparison is CBP-201 300mg Q2W by subcutaneous injection versus placebo Q2W, with the primary IGA response measured from baseline to Week16.

The primary response was 29.0% in Group A and 5.9% in Group B. The posted risk difference is 0.229, with a 95% confidence interval of 0.154 to 0.304, and p < 0.001. Numerical secondary results are available for EASI-75 and two PP-NRS response thresholds; the posted comparisons favor a higher response percentage in the CBP-201 group. The record also lists serious and other adverse events across five named groups, with no deaths recorded.

Analysis-population details, missing-data methods, multiplicity procedures, the original sample-size justification, and the relationship among all safety groups are not reported in the registry record. These details limit interpretation beyond the posted endpoint estimates.