A Study to Investigate the Efficacy and Safety of a Single Injection of Corifollitropin Alfa (Organon 36286) for Ovarian Stimulation Using Daily Recombinant Follicle Stimulating Hormone (FSH) as Reference (P05787): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Investigate the Efficacy and Safety of a Single Injection of Corifollitropin Alfa (Organon 36286) for Ovarian Stimulation Using Daily Recombinant Follicle Stimulating Hormone (FSH) as Reference (P05787) (NCT00696800), a randomized phase 3 study. The primary outcome is Percentage of Participants With an Ongoing Pregnancy (Ongoing Pregnancy Rate).

2. Clinical Question

3. Trial Design

This was a phase III, randomized, double-blind, active-controlled, parallel-group clinical trial sponsored by Organon and Co. The registry record reports enrollment of 1509 participants and a completed status. The listed study dates are a start date of 2006-06-27 and a primary completion date of 2007-11-19. The condition is in vitro fertilization.

The intervention of interest was one 150 µg injection of corifollitropin alfa, compared with daily 200 IU recombinant follicle stimulating hormone (recFSH). The arm descriptions indicate that injections were given subcutaneously, with initial treatment on stimulation day 1, described as day 2 or 3 of the menstrual cycle. The corifollitropin alfa arm received placebo-recFSH injections during the initial period, while the comparator arm received recFSH. Both arm descriptions then refer to later daily injections. Those descriptions end mid-sentence, so the complete treatment schedule is not reported in the registry record.

The primary outcome population is described as randomized participants who were treated, grouped according to randomized assignment. The ongoing-pregnancy calculation was per attempt: participants who did not have an embryo transfer were counted as not pregnant. The registry record lists additional outcomes concerning ovarian stimulation, hormone levels, oocytes, fertilization, implantation, and pregnancy. It reports 23 outcome measures, two analyses, and 21 posted secondary outcomes. The original sample-size justification, randomization details beyond the allocation label, and detailed masking procedures are 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.

Before assignment: Of 1509 randomized participants, 1506 received treatment with either Corifollitropin Alfa or recFSH (Intent-to Treat population \[ITT\]).

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent to Treat (ITT) population consisting of all randomized participants who were treated with Corifollitropin Alfa or recFSH, and grouped according to the treatment they were randomized to.

5. Baseline Characteristics

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

Population: The ITT group consisting of randomized participants treated with Corifollitropin Alfa or recFSH

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants With an Ongoing Pregnancy (Ongoing Pregnancy Rate), measured over Assessed at least 10 weeks after embryo transfer (up to 1 year).

The posted primary endpoint is the percentage of participants with an ongoing pregnancy. The registry defines an ongoing pregnancy as a fetus with heart activity at least 10 weeks after embryo transfer, assessed by ultrasound scan or Doppler, or confirmed by live birth. The timeframe is at least 10 weeks after embryo transfer, up to 1 year. The rate uses the total number of participants who started treatment as its denominator; participants without an embryo transfer count as not pregnant.

This endpoint captures a clinical outcome after the ovarian stimulation and embryo-transfer process, rather than measuring ovarian response alone. It is therefore relevant to the overall treatment attempt described in the record, while also being influenced by the sequence of events between stimulation and pregnancy assessment. Counting participants without an embryo transfer as not pregnant makes the endpoint a per-attempt measure, not a pregnancy rate restricted to participants who reached transfer.

The brief summary describes the primary hypothesis as non-inferiority for initiating multifollicular growth, whereas the posted primary outcome is ongoing pregnancy. Those are distinct questions: one concerns ovarian response, and the other concerns pregnancy status following treatment. The registry record does not explain this difference or report the non-inferiority margin. Interpretation of the posted outcome should therefore follow its stated definition and analysis population, rather than treating it as a direct measure of follicular development.

7. Results Posted in the Registry

• 200 IU recFSH: 38.1% (286/750) versus 39.0% (295/756) on control; risk difference -0.9 percentage points (95% CI -5.8 to 4.0), risk ratio 0.98 (0.86–1.11); unadjusted two-proportion z-test p = 0.723.

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 Cumulus-oocyte-complexes

• 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:
  • 200 IU recFSH: mean 12.80 versus 13.60 on control; difference -0.80 (95% CI -2.16 to 0.56), standardized effect d = -0.10; z-test p = 0.249.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between 200 IU recFSH and the control. The interval gives the range of effects that remain compatible with the data.

Percentage of Fertilized Oocytes (Fertilization Rate)

• 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:
  • 200 IU recFSH: mean 67.60 versus 66.00 on control; difference 1.60 (95% CI -0.78 to 3.98), standardized effect d = 0.07; z-test p = 0.187.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between 200 IU recFSH and the control. The interval gives the range of effects that remain compatible with the data.

Percentage of Gestational Sacs (Implantation Rate)

• 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:
  • 200 IU recFSH: mean 32.20 versus 36.20 on control; difference -4.00 (95% CI -8.32 to 0.32), standardized effect d = -0.10; z-test p = 0.070.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between 200 IU recFSH and the control. The interval gives the range of effects that remain compatible with the data.

The posted secondary outcomes span ovarian response and laboratory or pregnancy-related measures. They include the number of cumulus-oocyte complexes, fertilization rate, and implantation rate, alongside listed measures of recombinant FSH use, hormone levels, and follicle counts. Across these types of outcomes, the estimates do not form a single uniform pattern: some group averages are numerically higher in one arm, while others are higher in the other. The confidence intervals and unadjusted comparisons are important context for those observed differences.

These outcomes help describe processes and intermediate results around stimulation and in vitro fertilization, but they do not replace the primary ongoing-pregnancy endpoint. A secondary measure may be biologically or operationally informative without directly answering the primary question about ongoing pregnancy per treatment attempt. The primary endpoint also uses a denominator that counts participants without an embryo transfer as not pregnant, which differs from the populations contributing to some laboratory outcomes.

The registry posts 21 secondary outcomes, and the recalculated analyses shown for selected continuous outcomes are unadjusted. When many outcomes are examined, some apparently notable findings can occur by chance even if there is no underlying difference. Unless a multiplicity plan controls the overall chance of false-positive findings, individual unadjusted results carry less confirmatory weight. A multiplicity strategy and prespecified hierarchy for secondary outcomes are not reported in the registry record.

The secondary results are therefore best used as descriptive context alongside the primary result. They can indicate where the groups’ observed measures differ and how uncertain those comparisons are, but they should not be treated as independent proof that the primary outcome is confirmed or contradicted.

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

• Median Amount of Recombinant FSH Needed to Induce Multifollicular Development Starting at Day 1
• Median Amount of Recombinant FSH Needed to Induce Multifollicular Development Starting at Day 8
• Serum FSH Levels During Stimulation
• Serum Luteinizing Hormone (LH) Levels During Stimulation
• Serum Estradiol (E2) Levels During Stimulation
• Serum Progesterone (P) Levels During Stimulation
• Serum Inhibin-B Levels During Stimulation
• Number of Follicles Categorized by Size on Stimulation Day 1

9. Statistical Interpretation

10. Statistical Methods Explained

The primary endpoint is binary at the participant level: each participant is classified according to whether an ongoing pregnancy was recorded. A percentage summarizes the proportion meeting that outcome in each randomized group. The registry specifies that the denominator is all participants who started treatment and that participants without an embryo transfer count as not pregnant. This definition matters because changing the denominator to participants who reached transfer would answer a different question.

The registry’s own primary analysis reports a risk difference (RD), with a 95% confidence interval. A risk difference compares the event proportions between groups by subtraction, and its sign depends on the order in which groups are compared. The registry reports an estimate of 1.1, with a 95% confidence interval from -3.8 to 5.9. The separate recalculation uses the posted event counts and denominators and reports a risk difference of -0.009, with a confidence interval from -0.058 to 0.040. These are unadjusted summary-statistic calculations; they are not a reconstruction of every part of the sponsor’s analysis.

A confidence interval gives a range of values compatible with the data under the statistical method used. It communicates uncertainty around an estimate, rather than the probability that a particular treatment effect is true. If an interval for a difference includes zero, the data do not resolve the direction of the difference with that interval and method. For non-inferiority, however, the key comparison is generally with a prespecified margin, not simply with zero. The non-inferiority margin and the method used for the sponsor’s reported analysis are not reported in the registry record.

An unadjusted p-value tests a specified null hypothesis without accounting for other comparisons or covariates. The recalculated unadjusted p-value for the primary outcome is 0.723. It should not be interpreted as the probability that the null hypothesis is true, nor as a measure of clinical importance. The registry does not report a p-value for the sponsor’s legacy non-inferiority analysis.

The posted secondary outcomes include continuous measures, reported as means and standard deviations, such as number of cumulus-oocyte complexes, fertilization rate, and implantation rate. A mean describes the group’s average; a standard deviation describes the spread of individual observations around that mean. A mean difference compares group averages, and its confidence interval represents uncertainty in that comparison. The recalculated continuous-outcome comparisons are unadjusted. These summaries do not establish that the underlying distributions are normal, and the registry does not report the methods used for the secondary analyses.

Over-dispersion is a general concern when a statistical model assumes that variation is limited by a particular distribution but the observed data vary more than that model allows. If present and ignored, standard errors can be too small and confidence intervals too narrow. The primary outcome is summarized as a percentage and risk difference, but the registry does not report a model-based analysis or a dispersion assessment. It is therefore not possible to say whether over-dispersion was assessed or relevant to the sponsor’s analysis.

For non-inferiority trials, both the prespecified margin and the analysis population matter. A result can be interpreted as non-inferior only in relation to a justified margin and a method that follows the trial plan. The record identifies the trial as non-inferiority and includes a legacy non-inferiority or equivalence analysis, but the margin, detailed statistical plan, and sample-size justification are not reported in the registry record. The posted primary analysis population is the treated Intent to Treat population, grouped by randomized assignment. How other populations were analyzed is not reported.

The record also lists a recalculated sample-size illustration based on observed effects. It assumes a two-sided significance level of 0.05, equal allocation between the groups, and a normal approximation; it considers the stated fraction of the observed effect. Such calculations are planning illustrations under specified assumptions, not an account of the trial’s original design. The original planning assumptions are not reported in the registry record.

11. Confidence Intervals and Precision

The primary outcome’s posted percentages are 39.0% for 150 µg corifollitropin alfa and 38.1% for 200 IU recFSH. The registry’s own analysis reports a risk difference of 1.1 and a 95% confidence interval from -3.8 to 5.9. The interval spans values below and above zero. This means that the reported data, under that analysis, are compatible with a range of possible differences, including differences in either direction.

The recalculated unadjusted risk difference is -0.009, with a confidence interval from -0.058 to 0.040. This is a separate calculation from posted summary information and should not be conflated with the sponsor’s analysis. The two presentations use different numerical scales, and the registry does not explain the scale convention for the reported legacy analysis. The sponsor’s stated result and the recalculation should therefore be read with their own labels and context rather than treated as interchangeable figures.

Confidence intervals describe statistical uncertainty and precision, not the range of individual participant outcomes. Wider intervals indicate less precision, while narrower intervals indicate more precision, for the estimate and method in question. The interval does not demonstrate equivalence merely because it contains zero. Equivalence or non-inferiority requires a prespecified clinical margin and an analysis showing that the interval meets that criterion. The non-inferiority margin is not reported in the registry record.

The recalculated p-value is unadjusted, and the sponsor analysis does not list a p-value. The record does not report the sponsor’s statistical method, adjustment strategy, or missing-data sensitivity analyses. Those omissions limit how fully the precision of the registry’s reported non-inferiority result can be evaluated.

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 figures are planning illustrations derived from the observed effect, not the trial’s original design calculation. 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 at the stated fraction of the observed effect. For the outcomes in this trial, the figures are participants per arm; the record’s general note says that time-to-event outcomes instead use the total number of events, but the posted outcomes are not time-to-event measures.

The 80% power column estimates how many participants per arm a future study would need, under those assumptions, to have an 80% chance of detecting the specified effect if that effect were the true one. The 90% power column uses a higher chance of detecting that same effect and therefore generally requires a larger planned sample. These are conditional planning quantities, not guarantees about any particular study.

Rows describing 75% or 50% of the observed effect ask what sample size might be needed if a future study aimed to detect a smaller effect than the observed one. Smaller effects are harder to distinguish from random variation, so they require more participants under the same assumptions. The figures are not evidence that the original trial had that power, and they are not observed power.

The trial’s original sample-size justification, target effect, and design assumptions are not reported in the registry record. The planning figures should be read as sensitivity illustrations: their values depend on the selected effect and stated assumptions, and should not be treated as a retrospective evaluation of the trial’s adequacy.

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 = 0.390; treatment proportion p₁ = 0.381; average p̄ = 0.386.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6884 = 1.3493.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.6884 = 0.5794.
4. n = (1.3493 + 0.5794)² / (-0.0089)² = 47,187.5, rounded up to 47,188 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 <- 0.39021164021164                          # control proportion
p1 <- 0.381333333333333                          # 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(696800)
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 = 47,188 (80% power), 63,171 (90% power)
 75% of observed effect: n per arm = 83,980 (80% power), 112,424 (90% power)
 50% of observed effect: n per arm = 189,154 (80% power), 253,223 (90% power)
power.prop.test: 47187.5 
Simulated power at n = 47,188 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. Analyses Reported by the Sponsor

The registry’s own analysis for the ongoing-pregnancy outcome reports a risk difference of 1.1, with a 95% confidence interval from -3.8 to 5.9. The registry also presents an unadjusted recalculation from the posted event counts and denominators: a risk difference of -0.009, with a confidence interval from -0.058 to 0.040 and an unadjusted p-value of 0.723.

The registry identifies the sponsor result as a legacy non-inferiority or equivalence analysis, but does not report the analysis method or non-inferiority margin. The recalculation is an unadjusted comparison of summary statistics, and it is not a reproduction of the sponsor’s full analysis. The reported and recalculated estimates are expressed on different numerical scales in the record; without more detail about the sponsor’s convention, they should not be combined or treated as identical analyses.

The record does not flag a discrepancy between the sponsor analysis and the recalculation. Nevertheless, the sponsor result is the trial’s reported analysis, while the recalculation serves as a transparent secondary check based on posted summaries. Neither should be interpreted as establishing non-inferiority without the margin and planned analysis details. Those details are not reported in the registry record.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists 23 outcome measures, including the primary outcome and 21 posted secondary outcomes, and reports two analyses. Examining multiple outcomes creates a multiplicity issue: even when each individual test uses a conventional threshold, the chance of at least one chance finding across a set of tests can increase. Adjustments, a prespecified hierarchy, or a clear distinction between confirmatory and exploratory outcomes can address this concern. A multiplicity plan is not reported in the registry record.

The secondary continuous-outcome recalculations are identified as unadjusted. They should therefore be interpreted cautiously and not as a collection of confirmatory tests. The record does not report whether the sponsor adjusted for multiple comparisons, selected outcomes according to a hierarchy, or specified which secondary analyses were confirmatory.

The primary analysis population is described as treated randomized participants in the Intent to Treat population, grouped according to randomized assignment. The primary endpoint denominator is all participants who started treatment, with participants without an embryo transfer counted as not pregnant. This definition makes the handling of no-transfer attempts explicit for that endpoint. Other missing-data rules, including how unavailable pregnancy assessments were handled, are not reported in the registry record.

The registry record does not report sensitivity analyses for missing data, details of excluded participants, or the analysis populations used for secondary outcomes. It also does not provide the original statistical analysis plan, the non-inferiority margin, or the sponsor’s analysis method. These omissions limit evaluation of whether the analysis followed prespecified procedures and how robust the results are to alternative assumptions about missing outcomes.

These gaps do not show that a particular procedure was or was not used. They mean only that the relevant details are not reported in the registry record, so the posted results cannot independently resolve those methodological questions.

16. Safety Results

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

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: ovarian hyperstimulation syndrome (1.9%), ectopic pregnancy (0.9%), ovarian torsion (0.5%), ruptured ectopic pregnancy (0.4%), hyperemesis gravidarum (0.3%).

The registry reports serious adverse events among participants at risk in each treatment group. For the 150 µg corifollitropin alfa group, 35 serious adverse events are reported among 755 participants at risk. For the 200 IU recFSH group, 30 are reported among 751 participants at risk. These are counts with their stated denominators, not a complete account of the timing, duration, severity, or causal relationship of events.

The registry lists ovarian hyperstimulation syndrome at 1.9%, ectopic pregnancy at 0.9%, ovarian torsion at 0.5%, ruptured ectopic pregnancy at 0.4%, hyperemesis gravidarum at 0.3%, and haemorrhagic ovarian cyst at 0.3% among the top serious terms. The record does not identify an arm for these listed percentages in the summary, so they should not be interpreted as arm-specific comparative rates.

Other adverse events are reported for 403 of 755 participants in the corifollitropin alfa group and 383 of 751 in the recFSH group. Deaths are not reported in the registry record. These counts alone do not establish that an event was caused by treatment or allow a full comparative safety assessment; event definitions, follow-up details, and the complete event listings matter.

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

The posted results describe a randomized comparison of a single corifollitropin alfa injection with daily recFSH for ovarian stimulation. For the primary ongoing-pregnancy outcome, the observed percentages are 39.0% and 38.1%, respectively. The registry’s reported risk difference and its confidence interval indicate uncertainty around the estimated comparison, while the separate unadjusted recalculation gives a different numerical presentation. Neither result should be reduced to a claim that the treatments are identical.

The trial is identified as non-inferiority, but the registry record does not report the non-inferiority margin or enough detail about the sponsor’s method to verify the formal criterion. A confidence interval that includes zero is not, by itself, evidence of equivalence or non-inferiority. The posted primary outcome is also ongoing pregnancy, whereas the brief summary describes the hypothesis in terms of initiating multifollicular growth. Those outcomes address different stages and the record does not explain their relationship in the trial’s hypothesis testing.

The per-attempt endpoint counts participants without embryo transfer as not pregnant. It therefore reflects the full treatment attempt as defined in the registry, rather than pregnancy among only those who reached transfer. Secondary measures provide additional context about ovarian response and laboratory outcomes, but their unadjusted nature and the absence of a reported multiplicity plan limit their confirmatory interpretation.

The safety counts describe serious and other adverse events in the posted groups, but they do not on their own establish causation or provide a complete comparative safety analysis. Missing-data procedures, detailed analysis methods, and the original sample-size justification are not reported in the registry record.

Overall, the posted statistics support a careful description of observed outcomes and their uncertainty. They do not, without the missing design and analysis details, establish equivalence, non-inferiority, or a clinical recommendation.

18. Why This Trial Matters Statistically

This trial illustrates why the endpoint definition matters as much as the treatment comparison. Ongoing pregnancy is calculated per treatment attempt, with participants who do not reach embryo transfer counted as not pregnant. That choice incorporates events along the treatment pathway and differs from restricting analysis to participants who received an embryo transfer. Readers need the denominator rule to understand what the percentage represents.

It also demonstrates the distinction between a non-inferiority label and evidence that satisfies a non-inferiority criterion. The registry reports a non-inferiority objective, but the margin and original statistical plan are not reported. Without the margin, a reader cannot determine whether the reported confidence interval meets the trial’s intended standard. A result that does not show a clear difference is not automatically proof that treatments are sufficiently similar.

The registry presents both a sponsor-reported analysis and an unadjusted recalculation based on summary statistics. These answer related but not necessarily identical analytic questions. The recalculation can help readers inspect the posted counts, but it cannot reconstruct an unreported analysis method, adjustment, or prespecified plan. Keeping those roles distinct is central to responsible interpretation.

Finally, the breadth of secondary outcomes raises the importance of multiplicity and selective interpretation. Ovarian response, laboratory measures, and pregnancy outcomes illuminate different parts of the process. Without a reported hierarchy or adjustment strategy, secondary findings are more appropriately treated as supporting description than as stand-alone confirmation.

19. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
• Participant counts were reconstructed from posted percentages and arm sizes, so small rounding differences are possible.

Several details needed to fully assess this trial’s statistical conclusions are not reported in the registry record. These include the non-inferiority margin, the original sample-size justification, the sponsor’s detailed analysis method, and the statistical analysis plan. The trial title and brief summary describe non-inferiority for multifollicular development, while the posted primary endpoint is ongoing pregnancy; the record does not explain the relationship between those questions.

The arm descriptions are truncated, so the complete medication schedule cannot be reconstructed from the registry record. Although the registry identifies the trial as double-blind, it does not report detailed masking procedures. The record also does not report how missing outcome data were handled, what sensitivity analyses were conducted, or which analysis populations were used for all secondary outcomes.

The reported primary outcome is a per-attempt measure that counts participants without embryo transfer as not pregnant. This is explicit, but it means the result combines outcomes across treatment and transfer stages. The number of participants contributing to some secondary outcomes differs by measure; interpretation of those outcomes should account for their stated denominators and should not assume they represent the same population as the primary endpoint.

The registry lists multiple outcomes, while a multiplicity plan is not reported. Selected secondary analyses are unadjusted, which limits the evidential weight of isolated findings. Safety summaries provide event counts and selected serious-event terms, but do not give a complete account of event timing, attribution, or arm-specific rates for the listed terms. These limitations constrain interpretation of the posted record and do not establish that unreported procedures were absent.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: A Study to Investigate the Efficacy and Safety of a Single Injection of Corifollitropin Alfa (Organon 36286) for Ovarian Stimulation Using Daily Recombinant Follicle Stimulating Hormone (FSH) as Reference (P05787) — NCT00696800.
• Registry record last updated 2024-06-20; status last verified 2022-02.
• Results first posted 2014-08-21.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

23. Record Summary

The registry describes a completed phase III, randomized, double-blind, active-controlled, parallel trial of ovarian stimulation for in vitro fertilization. It compared a single 150 µg corifollitropin alfa injection with daily 200 IU recFSH and reports enrollment of 1509 participants. The primary posted endpoint was ongoing pregnancy, assessed at least 10 weeks after embryo transfer, with participants without an embryo transfer counted as not pregnant.

Ongoing pregnancy was reported for 39.0% of the corifollitropin alfa group and 38.1% of the recFSH group. The sponsor-reported analysis gives a risk difference of 1.1 with a 95% confidence interval from -3.8 to 5.9; the unadjusted recalculation is reported separately. The registry also posts secondary outcomes and adverse-event summaries. The non-inferiority margin, original sample-size justification, multiplicity plan, and several analysis details are not reported in the registry record.