AG200-15 Transdermal Contraceptive Delivery System (TCDS) of Levonorgestrel and Ethinyl Estradiol: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for AG200-15 Transdermal Contraceptive Delivery System (TCDS) of Levonorgestrel and Ethinyl Estradiol (NCT01243580), a randomized phase 1 study. The primary outcome is Comparative Evaluation of Ethinyl Estradiol (EE) Cmax Between AG200-15 and Ortho-Cyclen® in Week 1.

2. Clinical Question

This is a pharmacokinetic question, rather than a question about contraceptive effectiveness or a clinical outcome. The record describes a randomized crossover study without masking. In general, a crossover design compares treatments within participants across treatment periods, which can help account for stable differences between participants. The record does not report the treatment sequence, washout details, or the paired participant-level values, so those features cannot be assessed from the posted results.

3. Trial Design

The registry describes NCT01243580 as a completed Phase 1, randomized, open-label crossover study sponsored by Agile Therapeutics. It enrolled 36 healthy volunteers. The study start is recorded as 2009-08, and primary completion as 2009-12. The official title describes an evaluation of the pharmacokinetic profile of Agile TCDS AG200-15 and a comparison of ethinyl estradiol exposure with Ortho-Cyclen® in healthy female volunteers.

The two drug interventions were AG200-15 and Ortho-Cyclen®. AG200-15 is described as an investigational transdermal contraceptive delivery system, while Ortho-Cyclen® is described as the comparator drug intervention. The brief summary says pharmacokinetics and safety were to be evaluated over two consecutive cycles of therapy. The primary outcome description specifies ethinyl estradiol Cmax in week 1 for cycle 2 and cycle 3, with a timeframe of 3 months.

Randomization is recorded, but the allocation sequence, treatment order, and method of generating the sequence are not reported in the registry record. Masking is recorded as none. The registry identifies the model as crossover, but does not report treatment-period details, washout procedures, or how period and sequence effects were handled in the analysis. These omissions matter when assessing how well a crossover analysis accounts for the dependence between measurements from the same participant.

The registry lists 13 outcome measures and 10 analyses. For the primary pharmacokinetic outcome, the group-level results list 29 observations for Ortho-Cyclen® and 33 for AG200-15. These reported outcome counts should not be read as the trial enrollment or as a statement about the number of complete paired observations. The record does not explain the difference between enrollment and the outcome-specific counts.

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: Primary PK population

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 Comparative Evaluation of Ethinyl Estradiol (EE) Cmax Between AG200-15 and Ortho-Cyclen® in Week 1, measured over 3 months.

The primary endpoint is mean ethinyl estradiol Cmax, measured in pg/ml. Cmax is the highest concentration recorded for a drug or measured analyte over the pharmacokinetic sampling period. In this study, the comparison concerns ethinyl estradiol exposure during week 1 of cycle 2 and cycle 3 for AG200-15 and Ortho-Cyclen®. The endpoint description identifies the primary PK population and gives a timeframe of 3 months.

Pharmacokinetic measures are used to characterize how much of a substance reaches the measured concentration profile over time. Cmax focuses on the peak rather than the total exposure across the full sampling period. It is therefore a specific description of the concentration profile, not a direct measure of contraceptive effectiveness, long-term safety, or every aspect of drug exposure.

The posted outcome is continuous and reported as a mean with standard deviation. The registry record gives mean Cmax values of 135.0 pg/ml for Ortho-Cyclen® and 45.5 pg/ml for AG200-15. It also reports a mean difference comparing AG200-15 with Ortho-Cyclen®. The record does not state the full sampling schedule, the precise method for handling repeated measurements across cycles, or whether the reported means combine cycle-specific measurements. Those details limit how precisely the endpoint construction can be reconstructed.

7. Results Posted in the Registry

• AG200-15: mean 45.50 versus 135.00 on control; difference -89.50 (95% CI -109.69 to -69.31), standardized effect d = -2.31; z-test p = <0.001.

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: ethinyl estradiol Cmax is summarized as a mean, with standard deviation as the measure of dispersion. A mean describes the arithmetic center of observed values. A standard deviation describes how dispersed individual observations are around that mean. It is not interchangeable with a standard error or a confidence interval, which address uncertainty in an estimate.

What does the mean difference represent?

The reported comparison is oriented as AG200-15 relative to Ortho-Cyclen®. Its estimated mean difference is -89.5 pg/ml. The negative sign indicates that the AG200-15 group mean is lower than the Ortho-Cyclen® group mean under this orientation. The interval reported for the difference ranges from -109.7 to -69.31 pg/ml. The recalculation is an unadjusted re-analysis of the posted summary statistics, not a replacement for the sponsor's analysis.

In general, a mean difference keeps the outcome in its original units, which makes it possible to relate the estimate to the measurement scale. The comparison does not by itself establish whether a difference is clinically important. That judgment would require a relevant clinical interpretation or a prespecified threshold, neither of which is reported for this pharmacokinetic endpoint.

How should the p-values be read?

A p-value describes how compatible data are with a specified statistical null hypothesis under the model and assumptions used. It is not the probability that a treatment works, nor does it measure the probability that the null hypothesis is true. The recalculated unadjusted result is p < 0.001. The registry's reported ANOVA result is p < 0.001 and is classified as an equivalence analysis. The record does not report the full null and alternative hypotheses, the equivalence margin, or the confidence interval used for that analysis. Therefore, the reported p-value cannot independently establish whether equivalence criteria were met.

In general, equivalence testing asks whether a difference is sufficiently small to lie within a prespecified range considered acceptable for the purpose of the study. The range must be defined before results are interpreted. A small p-value from an equivalence procedure is not interpreted in the same way as a small p-value from a conventional test for any difference. Since the margin and full test details are not reported in the registry record, the ANOVA result is best described as the sponsor's reported equivalence analysis rather than given a stronger interpretation.

What does crossover mean for analysis?

In general, a crossover study exposes participants to more than one intervention in a sequence, with comparisons potentially made within the same participant. Measurements from the same participant are often correlated. Accounting for this pairing can improve precision and can affect the standard error of a treatment contrast. A simple comparison of independent group summaries may not preserve that within-participant information.

The registry identifies the study as crossover, but the posted summary comparison does not provide paired values, a within-participant correlation, or enough detail to reconstruct a paired analysis. The recalculation uses posted summary statistics and is unadjusted. It should therefore be understood as a summary-statistic comparison, not as a reconstruction of the complete crossover model. Treatment sequence, period effects, carryover assessment, and any adjustment for these features are not reported in the registry record.

The group standard deviations are 50.7 pg/ml and 24.0 pg/ml. In general, unequal variability can affect how a comparison is modeled and how much influence each group contributes to its uncertainty. In a crossover design, however, the variability of the paired differences is also important. Marginal group standard deviations alone do not reveal that paired variability.

What can the interval tell us?

In general, a confidence interval gives a range of values compatible with the data and the analysis assumptions at a specified confidence level. A narrower interval indicates greater precision for the estimated quantity, while a wider interval indicates less precision. The posted interval for the mean difference is -109.7 to -69.31 pg/ml. Its confidence level and calculation method are not reported in the registry record. The interval should therefore be reported as posted, without assigning it a confidence level not stated in the record.

Statistical precision is distinct from clinical importance. An interval may indicate that the estimated difference is measured with some degree of precision, but it does not determine the meaning of that difference for a clinical decision. For this study, the endpoint is pharmacokinetic, and no clinical threshold for interpreting the difference is reported.

What remains unknown?

The registry record does not report a detailed statistical analysis plan, treatment sequence, crossover model specification, multiplicity procedure, or missing-data method. It also does not report the equivalence margin. Without these details, readers cannot determine whether all planned analyses were followed, how repeated-cycle information entered the primary estimate, or how incomplete records affected the result.

These limits do not erase the posted group means or comparison. They define what can be concluded from the summary: the record gives descriptive Cmax results, an unadjusted recalculation, and a sponsor-reported ANOVA equivalence p-value, but not the full analysis details needed to reproduce the sponsor's procedure or fully assess its assumptions.

10. Confidence Intervals and Precision

The mean difference is reported as -89.5 pg/ml, with an interval from -109.7 to -69.31 pg/ml. The interval represents uncertainty around the estimated comparison under the method used to produce it. The interval's confidence level and exact calculation method are not reported in the registry record. Those details should not be inferred from the endpoints.

The interval lies on the negative side of zero, consistent with the reported direction of the comparison: the AG200-15 mean is lower than the Ortho-Cyclen® mean. Its range gives a sense of the estimates compatible with the posted comparison under its assumptions. It does not show the range of individual participants' Cmax values. The standard deviations of 24.0 pg/ml for AG200-15 and 50.7 pg/ml for Ortho-Cyclen® describe dispersion in the outcome observations, a different feature from uncertainty in the mean difference.

Precision depends on the amount and structure of information used in the analysis. Although the outcome summaries list 33 observations for AG200-15 and 29 for Ortho-Cyclen®, the record does not report the number of complete paired observations or the within-participant correlation. Because this is a crossover study, that missing information makes it difficult to assess whether the unadjusted summary-statistic interval reflects the dependence between measurements.

The reported interval also does not establish whether the difference is clinically important. The registry record does not report a clinical interpretation threshold or an equivalence margin. Precision and clinical meaning are separate: an estimate can be described statistically without claiming that it is meaningful for a clinical decision.

11. Planning a Similar Trial: Sample Size

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

The sample-size figures are planning illustrations expressed as participants per arm, not total events. They use a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set as a stated fraction of the observed effect. The listed scenarios are planning for 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect.

For each scenario, the 80% power column gives the illustrated participants per arm under the assumptions for a design with an 80% chance of detecting an effect of that size if the assumed effect and model are correct. The 90% power column gives the corresponding planning figure for a 90% chance. These are design calculations, not evidence about the probability that the observed result is true or that the study achieved a particular probability of success.

The figures are based on the observed effect in this trial. Smaller target effects require more participants to detect under otherwise comparable assumptions, which is why the planning figures rise as the assumed fraction of the observed effect becomes smaller. These are planning illustrations, not observed power.

The registry record does not report the original trial's sample-size justification or design assumptions. The displayed calculations therefore should not be read as evidence that the actual enrollment was chosen using these assumptions, or that they reproduce the study's original planning process. They are useful for understanding how an assumed effect size and target power relate to illustrative per-arm enrollment needs, not for reconstructing the trial's protocol.

12. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -89.500; pooled standard deviation σ = 38.817.
2. n = 2 × (1.96 + 0.842)² × 38.817² / -89.500² = 3.0, rounded up to 3 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -89.5                      # observed difference in means
sigma <- 38.8170323440626                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(1243580)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 3 (80% power), 4 (90% power)
 75% of observed effect: n per arm = 6 (80% power), 8 (90% power)
 50% of observed effect: n per arm = 12 (80% power), 16 (90% power)
power.t.test: 4.2 
Simulated power at n = 3 per arm: 0.572 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

13. Analyses Reported by the Sponsor

The sponsor's reported analysis is an ANOVA identified as an equivalence analysis, with p < 0.001. The posted record does not give the equivalence margin, full model specification, confidence interval, or detailed hypotheses for that test. Its result should therefore be attributed to the sponsor's analysis and interpreted within the limits of the information recorded.

A separate unadjusted recalculation from the posted summary statistics reports a mean difference of -89.5 pg/ml, with an interval from -109.7 to -69.31 pg/ml and p < 0.001. This recalculation describes a direct comparison of the posted summary values; it does not reproduce the sponsor's equivalence procedure. The two p-values come from analyses with different stated roles, so they should not be treated as interchangeable tests of the same question.

The registry record does not flag a discrepancy between the sponsor result and the recalculation. The sponsor result remains the reported analysis for the sponsor's equivalence question, while the recalculation offers a transparent, unadjusted summary-statistic comparison. Because the detailed sponsor model and equivalence margin are not reported, the sponsor result cannot be independently reconstructed from the registry information alone.

14. Multiplicity, Missing Data and Analysis Populations

The registry lists 13 outcome measures and 10 analyses, but a detailed statistical analysis plan is not reported in the registry record. The record does not identify a multiplicity adjustment, a hierarchy of outcomes, or a rule for selecting which analyses would be considered confirmatory. Without this information, it is not possible to determine how the reported p-values should be interpreted in light of the full set of outcomes and analyses.

In general, when several outcomes or comparisons are tested, the chance of obtaining at least one small p-value by chance can increase. Procedures for multiplicity control can address that issue, but their appropriateness depends on the study's planned questions and analysis strategy. No such procedure is reported for this study, so no adjustment should be assumed for the unadjusted recalculation or the sponsor's reported equivalence result.

The record also does not report how missing observations were handled, whether any imputation was used, or whether the analysis included all randomized participants or only participants with evaluable pharmacokinetic data. The primary endpoint is described for the primary PK population, and outcome-specific counts are listed for the two interventions. The record does not define the population's inclusion rules or explain the relationship between those counts and the enrolled population.

Missing data can affect both the estimate and its uncertainty, especially if the probability of missingness is related to the measured outcome or treatment experience. In general, complete-case analysis and imputation rely on different assumptions. Because the registry record does not describe the handling of missing outcome data, it is not possible to evaluate those assumptions or quantify their influence.

For a crossover study, analysis populations and incomplete treatment periods can be particularly relevant because a within-participant comparison may require measurements under both interventions. The record does not state how participants with incomplete periods or unavailable measurements were treated, nor does it report sensitivity analyses. These are uncertainties about the analysis record, not evidence that a particular method was or was not used.

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 2.5% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports serious adverse events for the two interventions. For Ortho-Cyclen®, 0 serious adverse events are listed among 34 at risk. For AG200-15, 0 serious adverse events are listed among 36 at risk. Deaths are reported as 0 for both interventions. The record lists other adverse events for 3 participants at risk under Ortho-Cyclen® and 23 participants at risk under AG200-15.

These counts are descriptive registry figures. They do not by themselves establish whether an intervention is safer, and they should not be interpreted as proof that serious events cannot occur. The record does not provide event-level details for serious adverse events because no serious terms are listed. It also does not provide severity, timing, duration, attribution, or the definitions used for the other adverse-event category in the information.

The at-risk counts differ between the intervention entries and should not be added together or treated as the number of unique participants in a crossover trial. A participant may contribute information under more than one intervention. The registry record does not explain the event-counting or attribution rules in detail. Safety interpretation is therefore limited to the recorded counts and the stated at-risk groups.

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

The results describe a pharmacokinetic comparison of ethinyl estradiol peak concentration between AG200-15 and Ortho-Cyclen® in healthy female volunteers. The recorded mean Cmax values are 45.5 pg/ml for AG200-15 and 135.0 pg/ml for Ortho-Cyclen®. The reported mean difference, comparing AG200-15 with Ortho-Cyclen®, is -89.5 pg/ml, and the recalculated interval ranges from -109.7 to -69.31 pg/ml.

These numbers address a particular laboratory pharmacokinetic measure. They do not directly answer whether either intervention prevents pregnancy, how participants would experience treatment, or how the interventions compare for outcomes beyond those recorded. The registry record describes evaluation of pharmacokinetics and safety, not a clinical effectiveness endpoint in the comparison at issue. No claim about clinical benefit or lack of benefit follows from the Cmax difference alone.

The sponsor's ANOVA analysis is marked as an equivalence analysis and has p < 0.001. Equivalence depends on a prespecified margin and the relevant model. Since the margin and detailed analysis specifications are not reported in the registry record, the p-value should not be taken alone as a complete account of the equivalence question. The unadjusted recalculation is informative as a comparison of the posted summary statistics but does not substitute for the sponsor's analysis.

The study was Phase 1, open-label, and conducted in healthy volunteers. The registry record does not provide enough detail to assess treatment sequence, paired data, missing observations, or the full analysis plan. Its findings should be understood within that study population, design, endpoint, and reporting context. They do not establish how the pharmacokinetic comparison would translate to different populations, longer-term use, or other outcomes.

The safety counts are also limited. Zero serious adverse events are recorded for both interventions, but the record's safety summaries do not establish that serious events are impossible or characterize the full safety profile. The available results are observations from this study, not medical advice or a basis for an individual treatment decision.

17. Why This Trial Matters Statistically

This study illustrates how a pharmacokinetic comparison can produce a clear difference in a measured concentration while leaving important interpretation questions open. The mean Cmax values and mean difference describe the scale and direction of the observed comparison. The interval describes uncertainty around the unadjusted estimate, but the record does not state its confidence level or calculation method.

The crossover design also highlights a common statistical issue: repeated treatment measurements from the same participant may be related. In general, that within-participant association can affect the precision of the treatment comparison. The registry identifies the crossover structure, yet the posted aggregate values do not reveal paired measurements or the correlation between them. Readers therefore cannot reconstruct the complete within-participant analysis from the summaries.

The sponsor labels its ANOVA as an equivalence analysis. This matters because equivalence is not established simply by observing a difference or by reading a p-value without its testing framework. The equivalence margin and detailed analysis specification are not reported in the registry record. The distinction between that sponsor analysis and the unadjusted recalculation is important when explaining what each result does and does not address.

Finally, the sample-size illustrations show how planning depends on the effect size one aims to detect and the desired power. Smaller target effects require more participants under otherwise comparable assumptions. Because the illustrations use the observed effect and do not reproduce the original design assumptions, they should be kept separate from the trial's actual enrollment and from any claim about the study's power.

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 registry record provides limited detail about the crossover conduct and analysis. It does not report treatment sequence, washout procedures, period effects, or how carryover was assessed. It also does not provide paired participant-level results or the within-participant correlation. These gaps limit independent assessment of whether the summary-statistic recalculation reflects the study's crossover structure.

The primary endpoint is described as Cmax in week 1 for cycle 2 and cycle 3, with a timeframe of 3 months, but the record does not explain whether cycle-specific results were combined or exactly how repeated measurements informed the reported means. The detailed sampling schedule and endpoint derivation are not reported in the registry record.

The reported sponsor analysis is identified as an ANOVA equivalence analysis, but the equivalence margin, model specification, and associated interval are not reported. The statistical analysis plan, multiplicity approach, and missing-data method are also not reported. Consequently, readers cannot fully evaluate the sponsor's inferential framework or determine how incomplete outcome information was handled.

The primary outcome summaries list 29 observations for Ortho-Cyclen® and 33 for AG200-15, while enrollment is 36. The record does not explain the outcome-specific counts or establish how many complete paired comparisons contributed to the analysis. Those figures should not be interpreted as a complete description of participant flow.

The study concerns healthy female volunteers and a pharmacokinetic endpoint. The registry record does not report results that would directly establish clinical effectiveness or characterize outcomes beyond the listed measures. Safety counts are also limited to the reported categories and do not give detailed event descriptions, timing, or attribution.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: AG200-15 Transdermal Contraceptive Delivery System (TCDS) of Levonorgestrel and Ethinyl Estradiol — NCT01243580.
• Registry record last updated 2018-01-23; status last verified 2017-12.
• Results first posted 2017-12-19.
• 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

NCT01243580 is recorded as a completed, randomized, open-label, Phase 1 crossover study sponsored by Agile Therapeutics. It enrolled 36 healthy female volunteers and compared AG200-15, an investigational transdermal contraceptive delivery system, with Ortho-Cyclen®.

The primary pharmacokinetic outcome was mean ethinyl estradiol Cmax in week 1 of cycle 2 and cycle 3, measured in pg/ml. The posted means were 135.0 pg/ml for Ortho-Cyclen® and 45.5 pg/ml for AG200-15. The reported mean difference for AG200-15 relative to Ortho-Cyclen® was -89.5 pg/ml, with an interval from -109.7 to -69.31 pg/ml. A sponsor-reported ANOVA equivalence analysis had p < 0.001; the unadjusted recalculation had p < 0.001.

The registry lists 13 outcome measures and 10 analyses. It reports 0 serious adverse events and 0 deaths for both intervention entries. Details needed to reconstruct the crossover analysis, equivalence criteria, multiplicity handling, and missing-data approach are not reported in the registry record.