MK-7625A Plus Metronidazole Versus Meropenem in Pediatric Participants With Complicated Intra-Abdominal Infection (cIAI) (MK-7625A-035): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for MK-7625A Plus Metronidazole Versus Meropenem in Pediatric Participants With Complicated Intra-Abdominal Infection (cIAI) (MK-7625A-035) (NCT03217136), a randomized phase 2 study. The primary outcome is Number of Participants Experiencing ≥1 Adverse Events (AEs).

2. Clinical Question

3. Trial Design

This was a Phase 2, randomized, active-comparator-controlled, multicenter, double-blind trial. The registry classifies its masking as quadruple and its design as parallel. The study compared ceftolozane/tazobactam plus metronidazole with meropenem; placebo for metronidazole was listed with the meropenem regimen. The registry record does not specify which roles were masked, so the masking classification should not be expanded into assumptions about who knew each assignment.

The record lists an enrollment of 94 and a completed status. The start date was 2018-04-03 and the primary completion date was 2020-03-16. These registry entries describe the study as a whole; the primary analysis population is separately defined as all randomized participants who received any amount of study treatment. The primary outcome groups contain 70 participants in the combination group and 21 in the meropenem group. The reasons those group counts differ from the registered enrollment are not reported in the registry record.

The primary outcome was the number of participants experiencing at least one adverse event, followed for up to approximately 75 days. Secondary outcomes included clinical cure at the end-of-treatment (EOT) and test-of-cure (TOC) visits, and microbiological eradication at those visits. The registry record includes results for these four secondary outcomes. The record does not report the original sample-size justification, the detailed statistical analysis plan, or whether interim analyses were planned or conducted.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All randomized participants who received any amount of study treatment.

5. Baseline Characteristics

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

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants Experiencing ≥1 Adverse Events (AEs), measured over Up to approximately 75 days.

The primary endpoint counts participants who experienced at least one adverse event (AE) during follow-up of up to approximately 75 days. The registry defines an AE as an untoward medical occurrence in a participant administered study treatment; it does not have to be causally related to treatment. The analysis population is all randomized participants who received any amount of study treatment.

This is a participant-level binary outcome: each person is classified according to whether at least one AE occurred, and the posted result is the number of people in that category. A participant with multiple AEs still contributes to the count of participants with an event as a participant, rather than representing multiple participants. The count does not, by itself, describe the total number of events, their duration, severity, or causal relationship to treatment. Serious AEs are reported separately in the safety information.

General statistical context: counting participants with at least one AE gives a simple comparison of the proportion of participants who experienced any such event during the defined observation period. It is relevant to a safety and tolerability objective because it captures whether an event occurred, while not conveying its clinical importance or the full range of harms. The registry record does not report a specific rationale for selecting this endpoint or further detail about how events were assessed.

7. Results Posted in the Registry

• Meropenem: 61.9% (13/21) versus 80.0% (56/70) on control; risk difference -18.1 percentage points (95% CI -40.9 to 4.7), risk ratio 0.77 (0.54–1.10); unadjusted two-proportion z-test p = 0.089.

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.

Percentage of Participants With a Clinical Response of "Cure" at the End of Treatment (EOT) Visit

• 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:
  • Meropenem: 95.2% (20/21) versus 80.0% (56/70) on control; risk difference 15.2 percentage points (95% CI 2.2 to 28.3), risk ratio 1.19 (1.02–1.38); unadjusted two-proportion z-test p = 0.099.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Meropenem and the control. The interval gives the range of effects that remain compatible with the data.

Percentage of Participants With a Clinical Response of "Cure" at the Test of Cure (TOC) Visit

• 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:
  • Meropenem: 100.0% (21/21) versus 80.0% (56/70) on control; risk difference 20.0 percentage points (95% CI 10.6 to 29.4), risk ratio 1.25 (1.11–1.41); unadjusted two-proportion z-test p = 0.026.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for Meropenem than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Percentage of Participants With Microbiological Eradication at the EOT Visit

• 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:
  • Meropenem: 94.7% (18/19) versus 84.1% (53/63) on control; risk difference 10.6 percentage points (95% CI -2.9 to 24.1), risk ratio 1.13 (0.97–1.31); unadjusted two-proportion z-test p = 0.234.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Meropenem and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes cover two domains: clinical response categorized as cure and microbiological eradication. Each is assessed at EOT and TOC, with different follow-up timeframes and, for the microbiological outcomes, smaller analysis denominators than the primary outcome. Across the posted results, the meropenem group has higher observed percentages for these outcomes. The size and precision of the differences vary, and the uncertainty is outcome-specific.

These outcomes complement rather than replace the primary safety result. AEs measure whether participants experienced an untoward medical occurrence, while clinical cure and microbiological eradication describe distinct response outcomes. A pattern across the secondary endpoints can provide context about clinical and microbiological findings, but it cannot turn the safety endpoint into an efficacy endpoint or resolve the uncertainty in the primary comparison.

Unadjusted secondary results carry less weight because the registry reports multiple outcomes and comparisons, with no multiplicity adjustment described. General statistical context: when many hypotheses are examined, the chance of obtaining at least one apparently notable result by chance can increase if the analyses are treated as independent confirmatory tests. Adjustment methods and prespecified testing hierarchies can address this issue, but neither should be assumed when it is not reported. The registry record does not report a multiplicity strategy or identify which secondary outcomes, if any, were intended to support formal claims.

The secondary findings are therefore best read as descriptive and exploratory in the context of the available record. Their interpretation should account for the visit, denominator, confidence interval, and analysis reporting for each endpoint rather than treating them as a single combined result. Reasons for differences in the analysis populations or handling of missing outcome data are not reported in the registry record.

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

• Percentage of Participants With a Clinical Response of "Cure" at the End of Treatment (EOT) Visit
• Percentage of Participants With a Clinical Response of "Cure" at the Test of Cure (TOC) Visit
• Percentage of Participants With Microbiological Eradication at the EOT Visit
• Percentage of Participants With Microbiological Eradication at the TOC Visit

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is a binary participant-level measure: an individual either experienced at least one AE or did not. The posted arm results are counts of participants with an event, with the number at risk in each arm. A comparison of these results can be expressed as a difference in proportions or as a relative measure such as a risk ratio or odds ratio. These measures answer different questions, so their direction and scale need to be read carefully.

Reading the contrast direction

The recalculated primary risk difference is expressed as meropenem minus ceftolozane/tazobactam plus metronidazole. Its estimate is -0.181. A negative value in this direction corresponds to a lower observed event proportion in the meropenem group. The registry’s reported difference in percentage is 18.1, using the listed groups in the opposite apparent direction. A sign change can arise solely from reversing the order of subtraction; it does not change the underlying group results. The registry does not state the analysis method, so the exact definition and calculation details of its reported contrast are not available.

Uncertainty and hypothesis tests

A confidence interval gives a range of estimates compatible with the observed data under the method used to construct it. It is not a range containing a fixed percentage of individual outcomes, and it does not assign a probability that the true effect lies inside that particular interval. The registry reports a 95% confidence interval for its primary difference in percentage. The unadjusted recalculation also has an interval, but the underlying bounds are not repeated in this narrative because the posted values have more than three decimal places. Its interval includes zero, as does the registry-reported interval.

The recalculated unadjusted p-value is 0.089. A p-value measures how unusual data at least as inconsistent with a stated null hypothesis would be under the test’s assumptions; it is not the probability that the null hypothesis is true, nor a measure of clinical importance. The registry record does not report the test used for its own primary comparison, and it does not post a p-value for that comparison. The recalculated p-value should therefore be understood as a simple, unadjusted calculation from the posted summary counts, not as the sponsor’s reported inferential result.

What the estimates do and do not capture

Risk differences describe the absolute separation between event proportions, while relative measures describe their ratio or odds relationship. Neither measure resolves whether an event was caused by treatment. The AE definition explicitly includes events that need not be treatment-related. Nor do participant-level counts capture repeated events: multiple occurrences in one participant are not represented as multiple people in this endpoint.

The primary population includes randomized participants who received any amount of study treatment. This is not the same as a stated all-randomized analysis population, and the registry record does not report additional analysis populations or explain how participants without complete follow-up were handled. The record also does not specify whether the estimates were adjusted, which confidence-interval construction was used, or which hypothesis test generated any sponsor-side inference. No method should be attributed to the trial beyond what is stated in the record.

Planning illustrations

The planning illustrations use the observed effect as a starting point and show per-arm participant counts for detecting the full observed effect or smaller fractions of it. Their stated assumptions are a two-sided significance level of 0.05, equal allocation between the arms, and a normal approximation. They are planning calculations, not a description of the trial’s original design. The original sample-size assumptions and justification are not reported in the registry record. The calculations do not imply that the trial had a particular probability of detecting its observed result.

11. Confidence Intervals and Precision

Precision concerns how much uncertainty surrounds an estimate. The primary comparison is based on 70 participants in the combination group and 21 in the meropenem group, with 56 and 13 participants, respectively, counted as experiencing at least one AE. The registry reports a 95% confidence interval of -2.6 to 41.1 for its difference in percentage. Because this range includes zero and extends in both directions, the posted primary comparison is compatible with a range of possible differences, including no difference.

The interval should be considered alongside the group counts. The smaller meropenem group contributes less information about its event proportion than a similarly sized larger group would generally provide. General statistical context: estimates based on fewer observations tend to be less precise, although the actual interval also depends on the observed data and the method used to calculate it. The registry’s interval is wide enough that the point estimate alone should not be treated as a precise measure of the size or direction of any underlying difference.

The recalculated interval for the risk difference also includes zero. Its estimate is presented in the opposite contrast direction from the registry’s reported positive difference in percentage. The posted intervals are not identical, and the registry record does not report enough method detail to explain the differences in calculation. Both reported and recalculated uncertainty should therefore be kept distinct rather than blended into a single interval.

Secondary outcome intervals are also broad for some measures, particularly where their denominators are smaller. Those intervals describe uncertainty for their specific outcomes and visit times; they do not directly quantify uncertainty in the primary AE comparison. A confidence interval does not account for every source of uncertainty, including limitations in trial conduct, analysis choices, or applicability beyond the enrolled participants.

12. Planning a Similar Trial: Sample Size

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

The planning figures are participants per arm, not total events. They are calculated under the stated assumptions of a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set to the stated fraction of the observed effect. The original trial design assumptions and sample-size justification are not reported in the registry record.

The 80% power column gives the number of participants per arm that the planning calculation estimates would be needed to have an 80% chance of detecting the specified effect under those assumptions, if that effect and the model assumptions were correct. The 90% power column gives the corresponding number per arm for a higher planned chance of detection. These are planning targets, not observed results and not evidence that the trial achieved either power level. This is not observed power.

For the primary AE comparison, the illustrations list 98 participants per arm when planning for 100% of the observed effect, 166 per arm for 75% of the observed effect, and 354 per arm for 50% of the observed effect in the 80% power column. The corresponding 90% power figures are 131, 222, and 474 participants per arm. The same general pattern appears in the other outcomes’ planning illustrations: smaller target effects require larger planned groups to detect them under the stated assumptions.

These calculations are hypothetical illustrations based on observed effects, not a reconstruction of the trial’s protocol. The registry record does not report whether its own planning used these assumptions or effects. A planning figure should not be read as a recommendation for a future study without considering its research question, endpoint, design, and other assumptions.

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 = 0.800; treatment proportion p₁ = 0.619; average p̄ = 0.710.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6420 = 1.2584.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.6291 = 0.5295.
4. n = (1.2584 + 0.5295)² / (-0.1810)² = 97.6, rounded up to 98 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 <- 0.8                          # control proportion
p1 <- 0.619047619047619                          # 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(3217136)
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 = 98 (80% power), 131 (90% power)
 75% of observed effect: n per arm = 166 (80% power), 222 (90% power)
 50% of observed effect: n per arm = 354 (80% power), 474 (90% power)
power.prop.test: 97.6 
Simulated power at n = 98 per arm: 0.803 (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 reported primary comparison is a difference in percentage of 18.1, with a 95% confidence interval from -2.6 to 41.1. No method or p-value is reported for that analysis. The simple recalculation uses the posted group counts and expresses the contrast as meropenem minus ceftolozane/tazobactam plus metronidazole, giving an estimate of -0.181 and an unadjusted p-value of 0.089.

The positive registry estimate and negative recalculated estimate use opposite apparent contrast directions: the combination group had more participants with an AE in the posted counts. Reversing the contrast reverses the sign without changing the observed arm counts. The reported and recalculated confidence intervals are not identical, and the registry record does not state the methods needed to account for that difference. The registry does not report a primary p-value, so the recalculated p-value should not be represented as the sponsor’s test result.

The discrepancy flag is false. The recalculation is an unadjusted reanalysis of summary statistics and is not a substitute for the registry’s own analysis. The appropriate reading is to retain the registry-reported estimate and interval as the reported analysis, while treating the recalculation as a transparent alternative summary with its contrast direction and assumptions stated.

15. Multiplicity, Missing Data and Analysis Populations

The registry record lists six outcome measures and six analyses, while results are posted for the primary outcome and four secondary outcomes. The four secondary results concern clinical cure and microbiological eradication at EOT and TOC. The record does not report a multiplicity adjustment, a prespecified testing hierarchy, or how formal claims across outcomes were controlled. This matters because interpreting several unadjusted comparisons as if each were a single confirmatory test can overstate the strength of the evidence.

The primary analysis population is defined as all randomized participants who received any amount of study treatment. The registry record does not report an all-randomized analysis, a per-protocol population, or additional analysis populations. It also does not describe how missing outcomes, withdrawals, or participants without an assessment at a scheduled visit were handled. The posted denominators differ across outcomes, but the reasons for those differences are not reported and should not be inferred from the counts alone.

The registry record does not report the detailed statistical analysis plan, the original sample-size justification, whether any interim analyses were conducted, or which inferential methods were prespecified. It does not identify the methods used to construct each interval or conduct the reported analyses. Consequently, the summary results do not allow a full assessment of adherence to a prespecified analysis plan, missing-data assumptions, or the handling of multiple outcomes.

These absences do not establish that such procedures were not used; they mean that they are not reported in the registry record. Interpretation should distinguish the posted calculations and results from methodological details that are unavailable.

16. 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: pneumonia (2.9%), constipation (1.4%), faecaloma (1.4%), intestinal obstruction (1.4%), intra-abdominal fluid collection (1.4%).

For serious adverse events, the registry reports 8 participants affected among 70 at risk in the ceftolozane/tazobactam plus metronidazole group, and 0 among 21 at risk in the meropenem group. The record reports no deaths in either group. These are participant counts; they should not be interpreted as a complete account of the number, duration, or clinical consequences of all serious events.

The registry also reports other adverse events affecting 46 participants in the combination group and 10 in the meropenem group. Serious and other adverse-event categories provide additional safety context, but they are not necessarily mutually exclusive descriptions of participants. The primary endpoint is the count with at least one AE, whereas the serious-event figures focus on participants with serious events.

The listed serious-event terms include pneumonia at 2.9%, and constipation, faecaloma, intestinal obstruction, intra-abdominal fluid collection, and abdominal sepsis at 1.4% each. The registry record does not provide further detail in these summary details about event timing, causality assessments, recurrence, or the denominator used for each term percentage. Differences in these observed counts should be read in light of the unequal group sizes and the trial’s limited participant counts, not as definitive evidence about comparative safety.

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

The primary result describes the number of treated randomized participants who experienced at least one AE during follow-up of up to approximately 75 days. The posted counts are 56 of 70 for ceftolozane/tazobactam plus metronidazole and 13 of 21 for meropenem. The registry reports a difference in percentage with a 95% confidence interval that includes zero, while the unadjusted recalculation also has an interval including zero. The estimates are uncertain and should not be reduced to a simple claim of a difference or no difference.

The result does not show that an AE was caused by study treatment; the registry definition explicitly does not require a causal relationship. It also does not describe the number of events per participant, their severity, or their duration. The separate serious-event counts add information about a subset of safety events but do not by themselves characterize the full safety profile.

The secondary clinical and microbiological outcomes provide different kinds of evidence from the primary safety measure. Their observed patterns and uncertainty should be interpreted endpoint by endpoint, with caution about multiple unadjusted comparisons and incomplete reporting of methods. The registry record does not report enough detail about missing data, analysis methods, or multiplicity to support stronger claims about the evidential status of those outcomes.

These results apply to the participants and study conditions represented in this randomized Phase 2 trial. The record does not establish how well the findings extend to other pediatric populations, settings, or treatment practices. The summaries do not justify medical advice or a general conclusion that either regimen works or does not work. They describe observed outcomes and the precision with which the registry reports them.

18. Why This Trial Matters Statistically

This trial illustrates why a safety endpoint needs careful definition. Counting participants with at least one AE offers a direct summary of how many people experienced an untoward medical occurrence, but it does not capture event burden, severity, recurrence, or causal attribution. The registry’s definition specifically allows AEs that are not necessarily related to treatment, so the endpoint should not be mistaken for a count of treatment-caused harms.

It also shows why group size and uncertainty matter. The observed groups are unequal, and the meropenem arm is smaller. A point estimate summarizes the observed contrast, but the confidence interval communicates that a wide range of differences remains compatible with the data. Reading the count, estimate, and interval together is more informative than relying on the direction of the point estimate alone.

The trial’s other outcomes demonstrate the importance of keeping endpoints distinct. Clinical cure, microbiological eradication, and AEs answer different questions. A consistent pattern across outcomes can be informative, but multiple unadjusted comparisons should not be treated as though they were a single prespecified test. The registry record’s missing detail about multiplicity and analysis methods limits how strongly those results can be interpreted.

Finally, the recalculation makes contrast direction visible: the sign of a risk difference depends on the order in which groups are subtracted. Explicitly stating that direction prevents a sign from being mistaken for a contradiction in the underlying counts. The registry-reported analysis and an unadjusted recalculation can be read together while keeping their methods and limitations distinct.

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.

The primary comparison is based on unequal group sizes, with fewer participants in the meropenem group. The resulting estimate is uncertain, and its reported confidence interval includes zero. The trial is registered as Phase 2, and the posted summaries alone do not establish how precisely its results would apply beyond the studied participants.

The registry record does not report the original sample-size justification or the assumptions used to plan enrollment. The sample-size illustrations use the observed effects and stated generic planning assumptions, so they do not reveal the trial’s original design rationale. The record also does not report the detailed statistical analysis plan, interim analyses, adjustment for multiple comparisons, or the specific methods used for the registry’s comparisons and intervals.

The primary analysis population consists of randomized participants who received any study treatment. The record does not report the reasons for the difference between overall enrollment and the primary outcome group counts, nor does it explain differences in denominators among secondary outcomes. Missing-data methods, outcome availability, and the handling of participants without assessments are not reported.

The AE endpoint counts participants with at least one event, not the number or severity of events, and events need not be treatment-related under the registry definition. The reported serious-event terms are limited summary information; details on timing, causality, recurrence, and term-specific denominators are not reported in the registry record. These limitations constrain interpretation of both the comparative estimates and the broader safety pattern.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: MK-7625A Plus Metronidazole Versus Meropenem in Pediatric Participants With Complicated Intra-Abdominal Infection (cIAI) (MK-7625A-035) — NCT03217136.
• Registry record last updated 2023-05-06; status last verified 2023-05.
• Results first posted 2021-12-21.
• 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

NCT03217136 is a completed Phase 2 randomized, active-comparator-controlled, multicenter, double-blind trial of ceftolozane/tazobactam plus metronidazole versus meropenem in pediatric participants with cIAI. The registry lists quadruple masking, parallel groups, and enrollment of 94. The primary outcome counted participants experiencing at least one AE among randomized participants who received any study treatment, over up to approximately 75 days.

The posted primary counts are 56 of 70 in the combination group and 13 of 21 in the meropenem group. The registry-reported difference in percentage is 18.1, with a 95% confidence interval from -2.6 to 41.1. Secondary results cover clinical cure and microbiological eradication at EOT and TOC. The registry record does not report detailed analysis methods, missing-data handling, multiplicity procedures, or the original sample-size justification.