This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Comparative Study of Ceftaroline vs. Ceftriaxone in Adult Subjects With Community-Acquired Pneumonia (NCT00621504), a randomized phase 3 study. The primary outcome is Clinical Cure Rate at Test-of-Cure (TOC) in the Modified Intent-to-Treat Efficacy (MITTE) Populations.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00621504 |
| Phase | Phase 3 |
| Condition | Bacterial Pneumonia |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 606 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Forest Laboratories |
| Results posted | Yes |
2. Clinical Question
Population
Adults with community-acquired pneumonia were the population of interest. The primary endpoint was defined for the Modified Intent-to-Treat Efficacy population: participants in the Modified Intent-to-Treat population who received any amount of study drug and were in PORT Risk Class III or IV. The full eligibility criteria are not reported in the registry record.
Intervention
The intervention was ceftaroline fosamil for injection. The registry record describes two consecutive 300-mg intravenous infusions over 30 minutes every 12 hours. It also describes adjunctive oral clarithromycin in both treatment groups.
Comparator
The comparator was intravenous ceftriaxone, described as a 1-g infusion over 30 minutes every 24 hours, followed by an intravenous saline placebo infusion. Adjunctive oral clarithromycin was also initiated in the comparator group.
Primary question
The study asked whether clinical cure at Test-of-Cure differed between the treatment groups in the defined efficacy population. Cure meant resolution of all pneumonia signs and symptoms, or improvement sufficient that further antimicrobial therapy was not necessary. The registry record does not report group-level cure results or a comparative estimate.
3. Trial Design
The registry identifies this as a completed phase 3, randomized, parallel-group study. Its official title describes a multicenter, double-blind comparison of ceftaroline and ceftriaxone, with adjunctive clarithromycin, in adults with community-acquired pneumonia. The masking field is recorded as quadruple. Which specific roles were masked is not reported in the registry record.
Enrollment is recorded as 606. The two treatment groups were ceftaroline fosamil for injection and intravenous ceftriaxone. The intervention descriptions include saline placebo with the ceftriaxone infusion and oral clarithromycin as adjunctive therapy in both groups. The registry description says clarithromycin was initiated on Study Day 1, but the available text is incomplete; other details of its administration are not reported in the registry record.
The record lists bacterial pneumonia as the condition and describes the study purpose as assessing the safety and efficacy of ceftaroline in community-acquired pneumonia. The study start is recorded as 2008-01, primary completion as 2008-12, and status as completed. These dates describe the registry record and do not establish when results were made available.
The primary outcome was clinical cure at Test-of-Cure, assessed 8 to 15 days after the last dose of study drug. The primary population was restricted to participants in PORT Risk Class III or IV within the Modified Intent-to-Treat population. The registry record does not report the randomization procedure, allocation concealment, detailed eligibility criteria, or the planned treatment duration.
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: Patients were screened for up to 24 hours
Overall Study
| Stage | Ceftaroline Fosamil for Injection | IV Ceftriaxone |
|---|---|---|
| STARTED | 299 | 307 |
| COMPLETED | 273 | 282 |
| NOT COMPLETED | 26 | 25 |
Reasons for not completing this period:
| Reason | Ceftaroline Fosamil for Injection | IV Ceftriaxone |
|---|---|---|
| Adverse Event | 1 | 3 |
| At the request of sponsor/investigator | 1 | 0 |
| Withdrew consent | 9 | 6 |
| Lost to Follow-up | 8 | 10 |
| Other | 1 | 0 |
| Death | 6 | 6 |
Analysis population for the primary outcome, as defined in the registry: The MITTE Population consisted of all subjects in the MITT Population (all randomized subjects who received any amount of the study drug) in PORT Risk Class III or IV. The Pneumonia Outcomes Research Team (PORT) scale of CAP severity in which Risk Class I is associated with the lowest risk for mortality and Risk Class V represents the highest risk.
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.
| Characteristic | Unit | Ceftaroline Fosamil for Injection | IV Ceftriaxone | Total |
|---|---|---|---|---|
| Participants analysed | 299 | 307 | 606 | |
| Age, Customized: <65 years | participants | 154 | 157 | 311 |
| Age, Customized: >= 65 years | participants | 145 | 150 | 295 |
| Age, Continuous | years | 61.0 (SD 16.6) | 61.0 (SD 16.6) | 61.0 (SD 16.6) |
| Sex: Female, Male: Female | Participants | 108 | 112 | 220 |
| Sex: Female, Male: Male | Participants | 191 | 195 | 386 |
| Race/Ethnicity, Customized: Hispanic | participants | 29 | 27 | 56 |
| Race/Ethnicity, Customized: Non-Hispanic | participants | 270 | 280 | 550 |
6. Primary Endpoint
The registry lists the primary outcome as Clinical Cure Rate at Test-of-Cure (TOC) in the Modified Intent-to-Treat Efficacy (MITTE) Populations, measured over 8 to 15 days after last dose of study drug.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint was clinical cure at Test-of-Cure, assessed 8 to 15 days after the last dose of study drug. Cure was defined as total resolution of pneumonia signs and symptoms, or improvement to an extent that further antimicrobial therapy was not necessary. Failure included persistent, incompletely resolved, or worsening pneumonia requiring alternative antimicrobial therapy; a treatment-limiting adverse event leading to study-drug discontinuation when alternative therapy was needed for pneumonia; or death considered caused by pneumonia. An outcome that could not be determined was classified as indeterminate.
This endpoint captures a clinical assessment after treatment rather than an isolated laboratory finding. In general, a cure endpoint can be useful because it reflects whether the illness has improved enough that additional antimicrobial treatment is unnecessary. The timing also gives the study a defined assessment window after dosing ends. That definition does not, by itself, establish how often cure occurred or whether the groups differed.
The analysis population was the Modified Intent-to-Treat Efficacy population. It included participants in the Modified Intent-to-Treat population who received any amount of study drug and were in PORT Risk Class III or IV. The registry describes the broader Modified Intent-to-Treat population as randomized participants who received any amount of study drug. The primary outcome is recorded as having multiple categories or time points, and the registry record does not provide group-level counts for cure, failure, or indeterminate outcomes. It also does not report a comparative effect estimate or its precision.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies clinical cure at Test-of-Cure as the primary outcome and defines the population and outcome categories. It does not report the number or proportion of participants classified as cured in either treatment group. Nor does it report a between-group difference, a confidence interval, or a significance test for this primary outcome. Consequently, the registry record does not support a numerical estimate of how the groups compared on clinical cure.
This absence matters for interpretation. A defined endpoint tells readers what investigators intended to assess, but it is not itself a result. Without group-level outcome counts or an estimated contrast, readers cannot assess the direction or magnitude of any observed difference, or how precisely it was estimated. The listed enrollment and adverse-event counts do not fill that gap: they concern different information and cannot be used to reconstruct the primary clinical-cure comparison.
The record describes cure, failure, and indeterminate outcomes. These categories are not interchangeable. In general, an indeterminate assessment may arise when the outcome cannot be established, but how such cases were handled in the analysis is not reported in the registry record. The record also does not state whether the primary analysis used a particular treatment of missing or indeterminate assessments, or whether any sensitivity analyses were conducted.
No conclusion about comparative efficacy can be drawn from the endpoint definition alone. This is not evidence that the groups had the same outcomes, nor evidence that one group had better outcomes. It means the primary comparison cannot be quantified from the results recorded in the registry. The sponsor's own analysis takes precedence if a recalculated result conflicts with it, but no sponsor-reported primary comparison is included in the registry information available for this account.
Other registered outcomes include clinical response at End of Therapy, microbiological success and overall clinical and radiographic success at Test-of-Cure, responses by pathogen, relapse and reinfection or recurrence at Late Follow-Up, and safety. Their presence indicates a wider set of questions than the primary cure endpoint. Their group-level results and analysis details are not reported in the registry record. Each outcome would need its own definition, population, time point, and estimate for a complete interpretation.
In general, a confidence interval describes the range of effect values compatible with the data under the analysis assumptions. A narrow interval indicates greater precision than a wide interval, while an interval spanning values in both directions may leave the direction uncertain. No primary-outcome confidence interval is reported in the registry record, so the precision of the primary comparison cannot be assessed. The available information supports a description of the study design and endpoint, but not a numerical claim about comparative cure.
9. Statistical Methods Explained
The registry labels the primary outcome as binary and as a count of participants with an event. A binary outcome places each assessed participant into one of two states for a particular contrast, such as cure versus not cure. In this study, however, the endpoint definition also includes failure and indeterminate categories. The registry notes that the primary outcome has several categories or time points and was not reduced to one comparison. The specific analysis used to address those categories is not reported in the registry record.
What would a treatment comparison estimate?
In general, an unadjusted comparison for a binary endpoint contrasts the outcome frequency between groups without accounting for additional covariates. A difference in frequencies describes an absolute contrast; a relative measure describes the contrast on a ratio scale. Either requires outcome counts and appropriate denominators for both groups. The registry record does not provide the primary cure counts or a comparative effect estimate, so neither form of comparison can be interpreted from the primary results recorded there.
An adjusted analysis can account for prespecified participant characteristics or design factors, depending on the model and analysis plan. Adjustment can change an estimate and its uncertainty. Whether the trial used an adjusted primary analysis, which variables might have been included, and how the model was specified are not reported in the registry record. It would therefore be inappropriate to infer an adjustment strategy from the trial design alone.
How should uncertainty be read?
In general, a confidence interval communicates the precision of an estimated effect. It reflects both the observed data and the assumptions of the statistical method. It does not guarantee that the true effect lies within the interval, and it does not describe the range of individual participant outcomes. A p-value, in general, measures how unusual data at least as incompatible with a specified null hypothesis would be under that hypothesis and the model assumptions. Neither statistic replaces the effect estimate or its clinical context.
No confidence interval or p-value for the primary clinical-cure comparison is reported in the registry record. There is therefore no reported inferential result to interpret for that endpoint. The number of analyses recorded does not supply the missing estimate or explain the analysis procedure.
What do planning calculations mean?
In general, a sample-size calculation is a planning exercise: it estimates the number of participants needed under specified assumptions to detect a chosen effect with a chosen level of power and significance. The planning assumptions recorded for the sample-size illustrations include a two-sided significance level of 0.05, equal allocation, and a normal approximation; the effect to detect is defined as a stated fraction of the observed effect. Such illustrations are not observed power and do not establish what the trial was designed to detect. The registry record does not report the trial's own sample-size justification or the inputs used in its original design.
Planning calculations based on an observed effect are especially dependent on the estimate used as their starting point. In general, an effect estimated from a study can be uncertain, and planning for a smaller fraction of an observed effect explores a different assumed target. These calculations should be read as conditional illustrations, not as evidence that an outcome occurred or as a substitute for a reported treatment-effect estimate. The primary outcome results needed to judge the observed effect are not reported in the registry record.
Why does the analysis population matter?
The primary population excluded participants outside PORT Risk Class III or IV and was drawn from the Modified Intent-to-Treat population, which included randomized participants who received any amount of study drug. This population definition determines whose outcomes would contribute to the primary analysis. In general, results from a restricted efficacy population need not answer the same question as results from all randomized participants. The registry record does not report a separate primary analysis in another population, the handling of participants with missing assessments, or the use of sensitivity analyses.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists several secondary outcomes in addition to the primary clinical-cure endpoint. They span clinical response at End of Therapy, microbiological and combined clinical-radiographic outcomes at Test-of-Cure, pathogen-specific responses, follow-up relapse or recurrence, and safety. Testing multiple outcomes can increase the chance of at least one apparently unusual result if each is assessed separately. In general, a prespecified multiplicity strategy can control or describe that issue; whether this trial used one, and what it involved, are not reported in the registry record.
The registry record does not state whether secondary outcomes were confirmatory or exploratory, how their tests were ordered, or whether any adjustment was made for multiple comparisons. It also does not report an interim-analysis plan, stopping boundaries, or a statistical analysis plan. Those details should not be inferred from the phase, randomization, or masking descriptions.
The primary endpoint permits an indeterminate classification, but the record does not explain how indeterminate or missing assessments were handled in the analysis. It does not report the amount or pattern of missing primary outcome data, reasons for missingness, imputation methods, or sensitivity analyses. In general, missing-outcome methods rely on assumptions about why data are missing; different assumptions can affect an estimate. Without the analysis description and relevant counts, the robustness of the primary comparison to missing data cannot be assessed.
The primary analysis population is described as participants in the Modified Intent-to-Treat population who were in PORT Risk Class III or IV. The broader Modified Intent-to-Treat population is described as randomized participants who received any amount of study drug. Whether additional analysis populations were used, and how deviations from the intended treatment or protocol were handled, are not reported in the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Ceftaroline Fosamil for Injection | 28 | 298 | 9.4% |
| IV Ceftriaxone | 33 | 308 | 10.7% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 2% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Ceftaroline Fosamil for Injection | 65 of 298 |
| IV Ceftriaxone | 53 of 308 |
Most frequent serious adverse event terms
| Event term | Organ system | Ceftaroline Fosamil for Injection | IV Ceftriaxone |
|---|---|---|---|
| Pneumonia | Infections and infestations | 2 of 298 | 5 of 308 |
| Empyema | Infections and infestations | 1 of 298 | 2 of 308 |
| Respiratory failure | Respiratory, thoracic and mediastinal disorders | 2 of 298 | 1 of 308 |
| Sudden death | General disorders | 2 of 298 | 0 of 308 |
| Cholecystitis acute | Hepatobiliary disorders | 0 of 298 | 2 of 308 |
| Gastroenteritis | Infections and infestations | 0 of 298 | 2 of 308 |
| Diabetes mellitus | Metabolism and nutrition disorders | 1 of 298 | 1 of 308 |
| Pleural effusion | Respiratory, thoracic and mediastinal disorders | 1 of 298 | 1 of 308 |
| Pulmonary embolism | Respiratory, thoracic and mediastinal disorders | 1 of 298 | 1 of 308 |
| Asthma | Respiratory, thoracic and mediastinal disorders | 0 of 298 | 2 of 308 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Ceftaroline Fosamil for Injection | IV Ceftriaxone |
|---|---|---|---|
| Diarrhea | Gastrointestinal disorders | 14 of 298 | 7 of 308 |
| Nausea | Gastrointestinal disorders | 8 of 298 | 8 of 308 |
| Insomnia | Psychiatric disorders | 9 of 298 | 6 of 308 |
| Headache | Nervous system disorders | 10 of 298 | 4 of 308 |
| Hypertension | Vascular disorders | 6 of 298 | 8 of 308 |
| Hypokalemia | Metabolism and nutrition disorders | 4 of 298 | 10 of 308 |
| Constipation | Gastrointestinal disorders | 7 of 298 | 5 of 308 |
| Phlebitis | Vascular disorders | 7 of 298 | 5 of 308 |
Serious events with the highest arm-level rate: pneumonia (1.6%), sudden death (0.7%), respiratory failure (0.7%), cholecystitis acute (0.6%), empyema (0.6%).
The safety record reports serious adverse events for the ceftaroline group as 28 affected among 298 at risk, and for the ceftriaxone group as 33 affected among 308 at risk. It separately reports other adverse events as 65 affected among 298 at risk in the ceftaroline group and 53 affected among 308 at risk in the ceftriaxone group. These are counts, not comparative effect estimates. No difference or ratio should be inferred from them without an analysis that accounts for the outcome definition and study population.
The record also lists serious adverse-event terms with percentages: Pneumonia, 1.6%; Sudden death, 0.7%; Respiratory failure, 0.7%; Cholecystitis acute, 0.6%; Empyema, 0.6%; and Gastroenteritis, 0.6%. The record does not specify the denominator or identify these percentages by treatment group. They should therefore not be interpreted as arm-specific rates.
Deaths are not reported in the registry record. The adverse-event counts do not establish causation, and the listed terms do not indicate whether an event was judged related to study treatment. Definitions, follow-up completeness, and comparative safety analyses are not reported in the registry record. Safety counts describe recorded events; by themselves, they do not establish a treatment effect.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, masked, parallel-group phase 3 study was conducted to compare ceftaroline with ceftriaxone, with adjunctive clarithromycin, in adults with community-acquired pneumonia. It identifies clinical cure at Test-of-Cure as the primary endpoint, gives the outcome definitions, and specifies a restricted efficacy population. It also records enrollment and selected adverse-event counts.
Those design details explain what question the study was intended to address, but they do not provide the primary result. Group-level cure counts, an effect estimate, and its uncertainty are not reported in the registry record. As a result, the available information cannot show the direction, size, or precision of a difference in clinical cure between the groups. It also cannot establish that the groups were equivalent or that any observed difference was statistically significant.
The serious and other adverse-event counts offer descriptive safety information, but they are not a complete comparative safety analysis. The registry does not report a safety effect estimate, the attribution of events to treatment, or deaths. The listed serious adverse-event terms lack a stated denominator and group attribution. These limits prevent a full comparison of safety outcomes from the recorded information.
In general, a trial result is most informative when the outcome definition, analysis population, group-level results, effect estimate, and uncertainty can be considered together. Here, the design and endpoint are described, while key primary efficacy results and analysis details are absent. The appropriate interpretation is therefore limited: the registry describes the comparison that was planned and the outcomes it tracked, but it does not supply enough primary outcome information to quantify the treatment comparison.
This limitation concerns the registry record, not necessarily every report or analysis that may exist outside it. Any additional source would need to be assessed on its own methods and results. No treatment recommendation follows from the information recorded.
13. Why This Trial Matters Statistically
This trial illustrates why statistical interpretation requires more than a study title, an endpoint definition, or a sample size. Randomization and masking describe important design features, while the clinical-cure definition explains what investigators intended to classify. Neither tells readers what happened in each group. Without group-level outcomes and an estimated contrast, the primary efficacy question remains unquantified in the registry record.
The specified analysis population also matters. Restricting the primary population to participants in PORT Risk Class III or IV defines the group to which the primary analysis would apply. It is not automatically interchangeable with an analysis of all randomized participants. Clear reporting of the population, missing outcome handling, and analysis method would help readers understand the scope and reliability of a result.
The study also registered multiple outcome domains and safety measures. In general, a collection of outcomes raises questions about prespecification, multiplicity, and which findings are intended to be confirmatory. The registry record does not provide those analysis details. This makes it especially important not to treat an isolated outcome listing as evidence of a statistically reliable treatment difference.
Finally, precision matters alongside the direction of an estimate. A confidence interval can show whether the data are compatible with a broad or narrow range of effects, while a point estimate alone cannot convey that uncertainty. Because the primary comparative estimate and its interval are not reported in the registry record, readers cannot evaluate precision or distinguish an uncertain estimate from a precise one. The trial is therefore a useful example of the difference between a documented design and a fully interpretable posted result.
14. 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 main limitation of the registry information is the absence of group-level results for the primary clinical-cure endpoint. The record defines cure, failure, and indeterminate outcomes and gives the assessment window, but it does not provide counts by category, a treatment contrast, a confidence interval, or a p-value. The size and precision of the primary comparison cannot be assessed.
The primary population is described, but the full eligibility criteria and the complete definition of the PORT classification are not reported in the registry record. The available intervention descriptions are incomplete, including the text on adjunctive therapy. Treatment duration and other protocol details are not reported in the registry record.
Statistical details are also limited. The registry does not report the primary analysis method, an adjustment strategy, handling of missing or indeterminate outcomes, sensitivity analyses, or a multiplicity plan. It does not report interim analyses or the trial's own sample-size justification. These omissions limit assessment of the analysis assumptions and the robustness of any result.
Safety information is partial. Serious and other adverse-event counts are recorded, but a comparative safety estimate, attribution to treatment, death results, and a denominator or group assignment for the listed serious adverse-event percentages are not reported in the registry record. The available safety information should not be treated as a complete account of comparative risk.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Comparative Study of Ceftaroline vs. Ceftriaxone in Adult Subjects With Community-Acquired Pneumonia — NCT00621504.
- Registry record last updated 2017-03-14; status last verified 2017-02.
- Results first posted 2010-11-10.
- 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.
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18. Record Summary
The registry describes a completed, randomized, quadruple-masked, parallel-group phase 3 study of ceftaroline versus ceftriaxone, with adjunctive clarithromycin, in adults with community-acquired pneumonia. Enrollment is recorded as 606. The study start is 2008-01 and primary completion is 2008-12.
The primary endpoint was clinical cure at Test-of-Cure, 8 to 15 days after the last dose of study drug, in the Modified Intent-to-Treat Efficacy population. The endpoint definition includes cure, failure, and indeterminate outcomes. Group-level primary results and a comparative estimate are not reported in the registry record.
The record includes selected serious and other adverse-event counts and lists several secondary outcomes. It does not report the primary analysis method, missing-data handling, multiplicity strategy, or the trial's own sample-size justification.