A Phase 2 Clinical Trial of the Safety and Effects of IRX-2 in Treating Patients With Operable Head and Neck Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Phase 2 Clinical Trial of the Safety and Effects of IRX-2 in Treating Patients With Operable Head and Neck Cancer (NCT00210470), a na phase 2 study. The primary outcome is Number of Participants With Adverse Events and Serious Adverse Events.

2. Clinical Question

3. Trial Design

This was a Phase 2 trial, described in the brief summary as Phase 2a, investigating safety and biological activity of the IRX-2 regimen in patients with untreated, resectable squamous cell cancer of the head and neck. The official title describes it as open-label and identifies the treatment as subcutaneous IRX-2 with cyclophosphamide, indomethacin, and zinc. The regimen description also includes omeprazole.

The study is listed as single-group, with allocation recorded as not applicable and masking as none. There is no randomized control group in the registry record. The treatment group is named IRX-2 Regimen. Accordingly, the posted safety counts characterize participants receiving that regimen; they cannot establish how those outcomes compare with a separate treatment or usual care.

The registry records an enrollment of 27. The primary outcome population description says 27 participants entered the study and were treated, and that all participants were included in the safety analysis. The outcome timeframe is enrollment through 30 days post-surgery. The study status is completed. Its start is listed as 2005-07 and its primary completion as 2010-12.

The listed secondary outcomes include clinical and histological tumor responses, tolerance of surgery and post-operative adjuvant therapy, skin-test reactivity as a measure of immune competence, disease-free survival, overall survival, lymphocyte infiltration, and a relationship between overall survival and immune competence. The registry record does not report results for these outcomes in the registry record for this analysis. Nor does it report a detailed protocol or the methods used to analyze these outcomes.

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: Pathologically confirmed (by histology) squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx. No prior surgery, radiation therapy, or chemotherapy of this tumor other than biopsy or emergency procedure required for supportive care. No medical contraindications to surgical resection and reconstruction required.

Overall Study

Analysis population for the primary outcome, as defined in the registry: 27 participants were entered into study and treated. All participants were included in the safety analysis.

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 With Adverse Events and Serious Adverse Events, measured over Enrollment through 30 days post-surgery.

The primary outcome is the number of participants with adverse events and serious adverse events. It is a participant-count outcome: it describes how many participants experienced an event, rather than the total number of event episodes. The registry specifies a timeframe from enrollment through 30 days post-surgery. It states that the frequency of adverse events greater than 5% is reported and that all serious adverse events are described.

Safety outcomes are used in a trial such as this to characterize unwanted events observed during treatment and the specified follow-up period. Counts can make clear how many participants were recorded as affected, while descriptions of serious events identify the kinds of events recorded. Those summaries are important for understanding the safety experience in the studied group, but a count alone does not show whether an event was caused by treatment, how long it lasted, or how severe it was beyond its serious-event classification.

The registry does not report a comparative safety endpoint, a prespecified statistical test, or an estimate of uncertainty for these counts. Because this is a single-group study, the outcome is descriptive rather than a randomized estimate of relative safety. The registry record also does not provide the criteria used to classify an event as serious or the method used to determine treatment relatedness.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count represent?

The primary outcome is a count of participants with adverse events and serious adverse events. A participant count differs from an event count: a participant can experience more than one event, but a participant-based summary counts that person as affected rather than adding each episode. The record reports 7 participants affected by serious adverse events and 23 participants with other adverse events, with 27 at risk in each category. The available information does not state whether participants could appear in both categories, so the counts should not be added together or treated as mutually exclusive groups.

Why does the observation window matter?

The registry defines the primary outcome timeframe as enrollment through 30 days post-surgery. A timeframe identifies which period the outcome is intended to cover; it does not by itself show that every participant had the same length of observation. The record does not describe individual follow-up duration or explain how events outside that stated window were handled. The death count is reported separately, and its relationship to the primary outcome window is not reported in the registry record.

What does the reporting threshold mean?

The outcome description says the frequency of all adverse events greater than 5% is reported, while all serious adverse events are described. This threshold indicates that the registry’s account of non-serious adverse events is selective according to frequency. It does not mean that less frequent events did not occur. Serious adverse events are described separately, but the record does not give full case narratives or detailed event-level data. The listed percentages for serious-event terms should be kept distinct from the participant counts unless the reporting denominator is explicitly defined.

Why are confidence intervals and tests useful?

General statistical context: a confidence interval expresses uncertainty around an estimate. For a participant count or event proportion, it can help readers judge how much the observed value might vary because the study included a limited group rather than every patient who could receive the regimen. A statistical test addresses a specified hypothesis, often by comparing observed data with a model under that hypothesis. Neither an interval nor a test can answer a causal question when the design lacks a suitable comparison group. The registry record does not report confidence intervals, a hypothesis test, or a formal statistical analysis for the primary safety outcome.

What can a single-group design establish?

General statistical context: a single-group study can describe what was observed among people who received an intervention. Without a concurrent control group, it cannot separate the intervention’s possible effects from background risks, the underlying condition, surgery, or other care. Randomization, when used in a controlled trial, helps balance known and unknown prognostic factors across groups; this study is not listed as randomized and has no like-for-like control comparison. The results therefore remain descriptive, even if event counts are reported precisely.

How should planning calculations be understood?

General statistical context: sample-size planning illustrations explore how a future study might be designed under specified assumptions. They are not observations from the trial, and they are not observed power. The planning assumptions associated with this record describe a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. Those assumptions do not describe the single-group design used in this trial. They also do not supply evidence that a particular effect was observed or that a future study would reproduce it. The registry record does not report the trial’s own sample-size justification or a statistical plan explaining how its enrollment was chosen.

General statistical context: over-dispersion can matter when variability in event counts exceeds what a simple count model expects. In that setting, uncertainty estimates from a model that assumes less variability may be too narrow. The available outcome is a participant count, however, and the registry record does not report a count model, an over-dispersion assessment, or model-based uncertainty estimates. No such method can be attributed to this trial.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists several secondary outcomes, including tumor response, tolerance of surgery and post-operative adjuvant therapy, immune competence measured by skin-test reactivity, disease-free survival, overall survival, lymphocyte infiltration, and a relationship between overall survival and immune competence. Considering multiple outcomes can raise a multiplicity issue: when many hypotheses are tested, the chance of at least one apparently unusual result can increase. General statistical context: researchers may address this through a prespecified hierarchy, adjustment, or by treating analyses as exploratory. The registry record does not report a multiplicity strategy, and it does not report inferential results for the listed secondary outcomes.

The information available identifies 27 participants entered and treated, all included in the safety analysis. It does not report how missing observations were handled, whether any participants had incomplete safety follow-up, or how missing data were handled for secondary outcomes. The registry record does not state whether analysis populations other than the safety population were defined or used. Consequently, the available information does not support conclusions about exclusions, missingness patterns, or sensitivity analyses.

The safety analysis population is described as all participants in the study who were entered and treated. That description is useful, but the record does not provide further detail about the exact analysis procedures or event-coding rules. It also does not report a statistical analysis plan, interim analyses, or a sample-size justification. These omissions limit assessment of whether outcomes and analyses were prespecified and how incomplete information may have affected the reported results.

11. 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: aspiration pneumonia (11.1%), respiratory infection (3.7%), neck abscess (3.7%), postoperative infection (3.7%), alcohol withdrawal (3.7%).

The registry reports 7 participants with serious adverse events among 27 at risk and 23 participants with other adverse events among 27 at risk. These are participant counts within the IRX-2 Regimen group. They are not numbers of event episodes, and the record does not establish whether the two participant categories overlap. No combined total should be inferred.

The serious-event terms include ASPIRATION PNEUMONIA, listed at 11.1%, and RESPIRATORY INFECTION, NECK ABSCESS, POSTOPERATIVE INFECTION, and ALCOHOL WITHDRAWAL, each listed at 3.7%. The registry does not provide term-specific counts or clarify the denominator for these percentages in the information available. It also records 10 deaths, but timing, cause, and relationship to the regimen are not reported in the registry record.

These figures describe events recorded in the study; they do not establish that the regimen caused them. The record does not report attribution assessments, event-level details, or a comparison group. Its stated safety reporting window is enrollment through 30 days post-surgery, but the timing of the death count is not specified. The adverse-event description reports events greater than 5%, so absence of a lower-frequency non-serious event from the listed results should not be interpreted as evidence that it did not occur.

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

The primary outcome provides a descriptive account of adverse events recorded in participants treated with the IRX-2 regimen. It reports serious adverse events for 7 participants and other adverse events for 23 participants, with 27 at risk in each category. The registry also lists selected serious-event terms and records 10 deaths. These values communicate what was recorded in this group, but the information does not include uncertainty estimates or detailed event-level context.

The design limits what can be inferred. The trial is open-label and single-group, with allocation listed as not applicable and no control arm described. As a result, the counts cannot quantify how the safety experience differs from another treatment or from a control condition. They also cannot establish which events were caused by the regimen. The registry record does not report causality assessments, the timing or causes of deaths, or the relationship of deaths to treatment.

The study was also intended to investigate biological activity, and the registry lists tumor-response, immune, and survival outcomes. Their results are not reported in the information available for this analysis. No claim about tumor response, survival benefit, or lack of benefit follows from the safety counts. Similarly, a listed outcome is not itself evidence that an outcome improved or worsened.

General statistical context: an observed count is a summary of the enrolled study group, not a guarantee of the frequency in other settings. Its interpretation depends on how outcomes were defined, how completely participants were followed, and how events were collected and classified. Details about missing data, event attribution, and the statistical analysis are not reported in the registry record. The findings therefore support a limited description of the recorded safety experience, not a causal or comparative conclusion.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of how safety outcomes are presented in an open-label, single-group study. The primary outcome is participant-based, and the registry provides counts for serious and other adverse events. It also identifies serious-event terms and a death count. Distinguishing participant counts from event episodes matters because the two summaries answer different questions and cannot be substituted for one another.

The design also illustrates the boundary between description and comparison. A single-group account can show which events were recorded among treated participants, but there is no control group against which to estimate a relative difference. Without randomization and a comparator, background risks and other care cannot be separated from any possible treatment contribution. The open-label design is another reason to read the reported outcome as a descriptive safety record rather than a blinded comparison.

The registry’s reporting threshold for non-serious adverse events is statistically relevant as well. Reporting events greater than 5% does not guarantee that less frequent events were absent; it defines which frequencies are described in that outcome statement. The serious-event descriptions are presented separately, and the available information does not give event-level detail or explain the percentages’ denominator.

Finally, the record lists multiple secondary outcomes but does not report their results or a multiplicity strategy. That distinction is important: an outcome’s presence in a registry is not a finding. Clear separation of recorded results, unreported analyses, and limitations of a single-group design helps readers avoid treating descriptive safety counts as comparative or efficacy evidence.

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 principal limitation is the absence of a control group. The study is listed as single-group, open-label, and not randomized. Thus, the adverse-event counts cannot be compared with an equivalent group receiving another treatment, and they cannot isolate the regimen’s contribution from disease, surgery, or other care.

The registry gives participant counts but does not provide confidence intervals, formal tests, or a detailed statistical analysis for the primary outcome. It does not report event-level data, severity grading beyond the serious-event designation, or treatment-relatedness assessments. The serious-event term percentages are listed without a denominator or corresponding term-specific counts in the information available. The registry also does not explain whether participants could be represented in both the serious and other adverse-event counts.

The outcome window is stated as enrollment through 30 days post-surgery, but individual follow-up details are not reported. Although 10 deaths are recorded, their causes, timing, and relationship to the outcome window or regimen are not reported in the registry record. The handling of missing observations and any incomplete follow-up is also not described.

Finally, the registry lists secondary outcomes concerning tumor response, immune measures, and survival, but their results are not reported in the information available. A multiplicity plan, interim analyses, and the trial’s sample-size justification are not reported in the registry record. These gaps limit interpretation of both the safety summary and the broader biological aims.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Phase 2 Clinical Trial of the Safety and Effects of IRX-2 in Treating Patients With Operable Head and Neck Cancer — NCT00210470.
• Registry record last updated 2020-12-11; status last verified 2020-12.
• Results first posted 2012-02-08.
• 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.

18. Record Summary

The registry identifies NCT00210470 as a completed Phase 2 study, described in its brief summary as Phase 2a. It evaluated the safety and biological activity of the IRX-2 regimen in patients with untreated, resectable squamous cell cancer of the head and neck. The regimen included IRX-2, cyclophosphamide, indomethacin, zinc, and omeprazole.

The study was open-label and single-group, with no control group described. The registry records enrollment of 27 and states that all 27 participants entered and treated were included in the safety analysis. The primary outcome counted participants with adverse events and serious adverse events from enrollment through 30 days post-surgery. The reported safety figures include 7 participants with serious adverse events, 23 with other adverse events, and 10 deaths. The record lists serious-event terms with percentages, but does not report a comparative analysis or the results of the listed secondary tumor-response, immune, and survival outcomes.