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 Zalutumumab With or Without Irinotecan Chemotherapy in Cetuximab-Refractory Colorectal Cancer (NCT00677924), a randomized phase 1, phase 2 study. The primary outcome is Number of Participants With Adverse Events (AEs).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00677924 |
| Phase | Phase 1, Phase 2 |
| Condition | Colorectal Cancer |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 9 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Genmab |
| Results posted | Yes |
2. Clinical Question
Population
Participants with colorectal cancer who had failed standard chemotherapy and progressed during or within 3 months of stopping cetuximab-based therapy. The registry describes the primary-outcome population as all participants exposed to zalutumumab or irinotecan, irrespective of compliance with the planned treatment course.
Intervention
Zalutumumab, including the 8 mg/kg and 16 mg/kg dose arms. The registry’s arm descriptions characterize both dose arms as zalutumumab in combination with irinotecan, although the trial title describes treatment with or without irinotecan.
Comparator
The posted arms are the 8 mg/kg and 16 mg/kg zalutumumab groups. The record does not identify a separate untreated or standard-care comparator among these arms. It describes the study as randomized and parallel, with no masking.
Primary question
How many exposed participants experienced adverse events, and what safety information was recorded for the two dose groups? The registry also lists best overall tumour response as a secondary outcome, but does not post an analysis of that outcome.
The trial’s stated purpose was to assess safety and efficacy of zalutumumab alone or with irinotecan in colorectal cancer. Its specific primary outcome was the number of participants with adverse events, measured from first dose through follow-up, up to approximately 1 year. An adverse event was defined as an untoward medical occurrence temporally associated with use of the investigational product, whether or not it was considered related to treatment.
The registry reports 3 participants in the 8 mg/kg group, with adverse events recorded for 3, and 6 participants in the 16 mg/kg group, with adverse events recorded for 5. These are descriptive counts from small groups, not evidence of a statistically established difference between doses. The record contains no posted analysis comparing the groups, and does not report results for the listed secondary outcome. The reason the trial was terminated is not reported in the registry record.
3. Trial Design
The registry describes a randomized, parallel-group phase I/II trial with no masking. It lists an enrollment of 9 participants and the condition as colorectal cancer. The trial began in 2008-04, had primary completion in 2009-04, and is marked terminated. The reason for termination is not reported in the registry record.
The record identifies two dose groups: Zalatumumab 8 mg/kg and Zalutumumab 16 mg/kg. It describes the first as zalutumumab in combination with irinotecan, and describes the second in the same way. The trial title and brief summary refer to zalutumumab with or without irinotecan, but the arm descriptions do not set out a separate irinotecan-free group. A fuller account of how irinotecan was assigned or administered is not reported in the registry record.
The primary outcome was the number of participants with adverse events. Its stated assessment period ran from the first dose through follow-up, up to approximately 1 year. The outcome population included all participants exposed to zalutumumab or irinotecan, regardless of compliance with the planned course of treatment. The registry also lists number of participants with best overall tumour response as a secondary outcome. It reports 2 outcome measures but only 1 posted secondary outcome.
Randomization is intended to support a fair comparison by assigning participants to groups according to a chance-based process. In general, randomization can reduce systematic differences in known and unknown participant characteristics, but it does not ensure balance in a trial with few participants. The method used to generate the random sequence, any allocation-concealment procedure, and the detailed dose-escalation process are not reported in the registry record. The planned sample size, its justification, and any protocol-level statistical plan are also not reported.
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
| Stage | Zalatumumab 8 mg/kg | Zalutumumab 16 mg/kg |
|---|---|---|
| STARTED | 3 | 6 |
| COMPLETED | 3 | 6 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: All participants who had been exposed to zalutumumab or irinotecan, irrespective of their compliance to the planned course of 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.
| Characteristic | Unit | Zalatumumab 8 mg/kg | Zalutumumab 16 mg/kg | Total |
|---|---|---|---|---|
| Participants analysed | 3 | 6 | 9 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 2 | 5 | 7 |
| Age, Categorical: >=65 years | Participants | 1 | 1 | 2 |
| Age, Continuous | years | 61 (57 to 66) | 61 (33 to 76) | 61 (33 to 76) |
| Sex: Female, Male: Female | Participants | 1 | 5 | 6 |
| Sex: Female, Male: Male | Participants | 2 | 1 | 3 |
| Region of Enrollment: Belgium | participants | 3 | 6 | 9 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Adverse Events (AEs), measured over From first dose up to follow-up (up to approximately 1 year).
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint counts participants who experienced at least one adverse event during the stated observation period. The registry defines an adverse event broadly: an unfavourable or unintended sign, symptom, disease, or abnormal laboratory finding temporally associated with use of an investigational product, whether or not it is judged to have a causal relationship to that product. The endpoint is therefore a count of participants with events, not a count of every event occurrence or a measure of event severity.
Safety outcomes are used in clinical trials to describe the kinds of unwanted medical occurrences reported during exposure and to identify issues that may warrant further assessment. Counting participants with at least one event gives a simple summary of how many exposed participants had an event recorded. The registry’s primary-outcome population includes all participants exposed to zalutumumab or irinotecan, irrespective of compliance with planned treatment.
The posted counts are 3 participants with adverse events among 3 in the 8 mg/kg group, and 5 among 6 in the 16 mg/kg group. The registry does not post uncertainty intervals or a statistical comparison for this endpoint. Because the endpoint is broad and does not itself establish causation, these counts should be read as adverse events recorded during the specified period, not as events necessarily caused by study treatment. Serious adverse events are reported separately in the safety information.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary outcome is reported as a participant count in each dose group. In the 8 mg/kg group, the registry reports 3 participants and adverse events for 3. In the 16 mg/kg group, it reports 6 participants and adverse events for 5. These are the posted descriptive results for the primary endpoint; they do not, by themselves, quantify a reliable difference between dose groups.
The groups are very small, and the record reports no confidence intervals, p-values, or other inferential analysis. Without those analyses, the precision of any estimated difference cannot be assessed from the posted results. Even if the raw counts appear different, small groups can yield unstable estimates: a change in the outcome for one participant would have a noticeable influence on the group summary. This is a general limitation of interpreting event counts from small samples, not a separate finding about these participants.
The registry reports 2 participants with serious adverse events among 3 at risk in the 8 mg/kg group, and 3 among 6 at risk in the 16 mg/kg group. It also reports other adverse events for 3 of 3 and 5 of 6, respectively. These are separate descriptive safety summaries. They should not be combined into a new total, because the record does not say whether participants appear in more than one category or provide enough detail to determine overlap.
The registry lists serious-event terms with percentages: pulmonary embolism, 66.7%; disease progression, 33.3%; colonic obstruction, 16.7%; and bile duct obstruction, 16.7%. The record does not state the denominator used for each displayed percentage or whether the terms overlap within participants. These entries therefore describe the posted serious-event terms, but should not be treated as mutually exclusive categories or as a complete account of event timing, recurrence, or attribution.
No analysis is posted for best overall tumour response, the listed secondary outcome. The number of analyses in the record is 0, and the record indicates that values for a two-arm binary comparison are missing or not estimable. Consequently, there is no posted treatment-effect estimate for a between-group comparison to interpret. The primary counts can describe what was recorded among these participants, but they do not establish comparative safety or efficacy.
The study is marked terminated. That status alone does not explain why the trial ended, whether termination was planned, or whether it was related to safety, recruitment, or another issue; the reason is not reported in the registry record. No conclusion about the cause of termination or the balance of benefits and harms can be drawn from the status label alone.
9. Statistical Methods Explained
The primary outcome is binary at the participant level: each exposed participant either had at least one adverse event recorded or did not. The posted results are counts of participants with events and the group sizes. This form of outcome summary is different from a count of all event episodes, because one participant with several events still contributes once to a participant-level count. The registry does not post a breakdown of the number of event episodes for the primary endpoint.
In general, a binary outcome can be summarized using the number of participants with an event and the number assessed. A comparison between groups may be expressed as a difference or ratio of event probabilities, with a confidence interval to convey uncertainty. Those methods require a defined comparison and usable outcome information. The registry does not post an effect estimate or confidence interval for the two arms. It indicates that values for a two-arm binary comparison are missing or not estimable, so no recalculated comparison is available to interpret.
In general, a confidence interval describes a range of values compatible with the observed data under the statistical model used. A wide interval signals limited precision; a narrow interval signals greater precision, conditional on the model and data. Confidence intervals are especially important when samples are small, because a single participant can materially change an estimate. No confidence interval is reported for the primary outcome in this record, so the degree of uncertainty cannot be quantified from an interval posted by the registry.
In general, a significance test evaluates how compatible the observed data are with a specified null hypothesis under its assumptions. A p-value is not the probability that a treatment has no effect, and it does not measure the size or clinical importance of an effect. The registry posts no analysis for this endpoint and no p-value for a comparison between dose groups. The absence of a posted test is not evidence that the groups are equivalent; equivalence would require a prespecified question and an analysis suited to it.
Random allocation can help make groups comparable in expectation, but chance imbalance remains possible, particularly when group sizes are small. The registry says the study was randomized but does not report the sequence-generation method, allocation concealment, or stratification factors. Those details matter when assessing how assignment was implemented and whether other design features may have influenced comparability. They are not reported in the registry record.
The posted sample-size assumptions describe a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. For non-time-to-event outcomes, such planning figures are expressed as participants per arm. These assumptions describe an illustration, not the trial’s original design. The registry does not report the trial’s own sample-size justification. A planning calculation based on an observed effect is not observed power and does not establish that a study was adequately powered.
In general, power is the probability that a planned statistical test will reject a specified null hypothesis if a particular effect is true, under the assumptions used for the calculation. It depends on the effect size, variability, significance threshold, allocation, and sample size. It cannot be read as the probability that a result is true, nor does a post hoc calculation repair the uncertainty caused by a small dataset. No such interpretation should be attached to planning illustrations.
The description of the outcome as a count of participants with an event means that methods for continuous outcomes, such as comparing means and standard deviations, do not fit this primary endpoint. In general, count-data models may be considered when the outcome is the number of event episodes, especially if the data vary more than a simple model expects; this extra variability is called over-dispersion. Here the primary endpoint is participant-level occurrence, and the registry does not post event-episode counts or a model for them. Over-dispersion therefore cannot be evaluated from the posted primary outcome.
The primary endpoint has a stated observation period from first dose through follow-up, up to approximately 1 year. For a fair comparison, follow-up and outcome ascertainment should be sufficiently comparable between groups. Details about visit schedules, censoring, adjudication, and the completeness of follow-up are not reported in the registry record. The endpoint population is defined by exposure rather than by compliance, but the registry does not describe additional analysis populations or how participants with incomplete outcome information were handled.
The registry’s analysis count is 0. This means no statistical analyses are posted in the record; it does not establish what analyses may have been planned in a protocol or conducted outside the registry entry. Any protocol-based analysis plan, adjustment model, interim analysis, or stopping rule is not reported in the registry record. The available numerical interpretation should therefore remain descriptive.
10. Exact Estimates for Each Arm
No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.
| Arm | Participants | Events | Observed % | Clopper-Pearson 95% CI | Wilson 95% CI | Bayesian 95% credible interval |
|---|---|---|---|---|---|---|
| Zalatumumab 8 mg/kg | 3 | 3 | 100.0% | 29.2% to 100.0% | 43.9% to 100.0% | 39.8% to 99.4% |
| Zalutumumab 16 mg/kg | 6 | 5 | 83.3% | 35.9% to 99.6% | 43.6% to 97.0% | 42.1% to 96.3% |
R code and output
arm <- c("Zalatumumab 8 mg/kg", "Zalutumumab 16 mg/kg")
n <- c(3, 6)
events <- c(3, 5)
for (i in seq_along(n)) {
ci <- binom.test(events[i], n[i])$conf.int # Clopper-Pearson exact interval
cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i]) # Bayesian, uniform Beta(1,1) prior
wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}
ARM Zalatumumab 8 mg/kg 3 3 100.0 29.2 100.0 43.9 100.0 39.8 99.4
ARM Zalutumumab 16 mg/kg 6 5 83.3 35.9 99.6 43.6 97.0 42.1 96.311. Multiplicity, Missing Data and Analysis Populations
The registry lists 2 outcome measures and posts 1 secondary outcome: number of participants with best overall tumour response. The primary outcome is the number of participants with adverse events. No statistical analyses are posted, and no result for the listed secondary outcome is provided. The registry does not report a multiplicity strategy, such as a prespecified hierarchy or an adjustment for testing several outcomes. Without such information, the intended confirmatory status of the outcome measures cannot be determined from the record.
Multiplicity matters in general when several outcomes or comparisons are tested, because interpreting many tests without a plan can increase the chance of a misleading positive finding. This is a general statistical concern, not a claim that a particular error occurred in this trial. Since no analyses are posted, there are no reported tests to interpret for multiplicity.
The primary-outcome population is defined as all participants exposed to zalutumumab or irinotecan, regardless of compliance with the planned course. The record does not describe an intention-to-treat population, a per-protocol population, or other analysis sets. It also does not report how missing outcome information was handled, whether imputation was used, or whether all participants completed the planned follow-up. These details are not reported in the registry record.
For safety, the group-specific at-risk counts are posted alongside the counts with serious and other adverse events. The record gives no death counts; these are not reported in the registry record. It also does not explain whether any participants lacked safety follow-up or how incomplete exposure information was addressed. Therefore, the posted group counts should be read with the limits of the reported population definition and follow-up details in mind.
12. 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 |
|---|---|---|---|
| Zalatumumab 8 mg/kg | 2 | 3 | 66.7% |
| Zalutumumab 16 mg/kg | 3 | 6 | 50.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Zalatumumab 8 mg/kg | 3 of 3 |
| Zalutumumab 16 mg/kg | 5 of 6 |
Most frequent serious adverse event terms
| Event term | Organ system | Zalatumumab 8 mg/kg | Zalutumumab 16 mg/kg |
|---|---|---|---|
| Disease progression | General disorders | 1 of 3 | 1 of 6 |
| Pulmonary embolism | Respiratory, thoracic and mediastinal disorders | 2 of 3 | 0 of 6 |
| Colonic obstruction | Gastrointestinal disorders | 0 of 3 | 1 of 6 |
| Bile duct obstruction | Hepatobiliary disorders | 0 of 3 | 1 of 6 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Zalatumumab 8 mg/kg | Zalutumumab 16 mg/kg |
|---|---|---|---|
| Nausea | Gastrointestinal disorders | 3 of 3 | 4 of 6 |
| Dry skin | Skin and subcutaneous tissue disorders | 2 of 3 | 5 of 6 |
| Fatigue | General disorders | 3 of 3 | 4 of 6 |
| Diarrhoea | Gastrointestinal disorders | 3 of 3 | 3 of 6 |
| Rash | Skin and subcutaneous tissue disorders | 2 of 3 | 4 of 6 |
| Anorexia | Metabolism and nutrition disorders | 2 of 3 | 2 of 6 |
| Vomiting | Gastrointestinal disorders | 2 of 3 | 1 of 6 |
| Dyspnoea | Respiratory, thoracic and mediastinal disorders | 0 of 3 | 3 of 6 |
| Neutropenia | Blood and lymphatic system disorders | 0 of 3 | 2 of 6 |
| Abdominal pain | Gastrointestinal disorders | 0 of 3 | 2 of 6 |
Serious events with the highest arm-level rate: pulmonary embolism (66.7%), disease progression (33.3%), colonic obstruction (16.7%), bile duct obstruction (16.7%).
The registry reports serious adverse events for 2 of 3 participants at risk in the Zalatumumab 8 mg/kg group and 3 of 6 at risk in the Zalutumumab 16 mg/kg group. Other adverse events are reported for 3 of 3 and 5 of 6 participants, respectively. These are participant counts, not counts of every event episode. A participant may have experienced more than one event, and the registry does not clarify whether the serious-event and other-event summaries overlap.
The listed serious-event terms are pulmonary embolism, 66.7%; disease progression, 33.3%; colonic obstruction, 16.7%; and bile duct obstruction, 16.7%. The record does not report the denominator for each percentage or explain whether one participant could contribute to multiple terms. These percentages should not be added together or interpreted as mutually exclusive categories.
The registry’s definition of an adverse event does not require the event to be caused by treatment. The serious-event counts should therefore be read as safety reports during the study, not as proof of treatment causation. Death counts are not reported in the registry record. The posted results also do not give event-level timing, duration, outcome, or attribution detail sufficient for a fuller assessment.
13. What the Result Does, and Does Not, Mean
The posted safety results describe adverse events among the participants recorded in two zalutumumab dose groups. The primary endpoint count is 3 of 3 participants in the 8 mg/kg group and 5 of 6 in the 16 mg/kg group. Serious adverse events are reported for 2 of 3 and 3 of 6 at risk, respectively. These findings describe the registry entries for this small trial; they are not a statistical demonstration that one dose is safer or less safe than the other.
No confidence intervals, p-values, adjusted analyses, or estimable two-arm comparison are posted. As a result, the precision of any comparative estimate cannot be assessed from the registry results. In general, limited sample sizes make estimates less stable and can leave substantial uncertainty about the range of outcomes that might be seen in a larger study. The record does not provide an analysis that resolves that uncertainty.
The primary endpoint concerns adverse events, not tumour response. Although best overall tumour response is listed as a secondary outcome, the record does not post its results or a statistical analysis. The available results therefore do not establish an efficacy effect, and the adverse-event counts should not be used to infer one.
Nor do the results establish that reported events were caused by zalutumumab or irinotecan. The endpoint definition explicitly includes occurrences whether or not they have a causal relationship to the investigational product. The registry does not provide enough event-level attribution information to determine causality.
The record’s terminated status does not reveal why the trial ended. It cannot be used on its own to infer a safety concern, lack of efficacy, recruitment difficulty, or any other explanation. The reason is not reported in the registry record. Overall, the posted information supports a narrow descriptive account of reported events in the enrolled participants, not a definitive comparison between dose levels or a conclusion about treatment effects.
14. Why This Trial Matters Statistically
This trial illustrates the difference between reporting observed counts and estimating a comparative effect. The registry gives group sizes and participant counts for adverse events, but no inferential analysis. Readers can identify what was recorded in each group, yet cannot use the entry to assess a confidence interval or statistical evidence for a difference between doses.
That distinction is important in a randomized trial with few participants. Randomization is valuable because it aims to reduce systematic differences between groups, but it does not eliminate chance imbalance, and small groups provide limited information about uncommon outcomes. In general, these features make careful attention to uncertainty essential. A count is informative as a description of the observed sample, but it does not alone describe the range of plausible results beyond that sample.
The trial also highlights the need to distinguish broad adverse-event reporting from causal attribution. The primary definition includes medical occurrences whether or not they are considered related to treatment. Serious-event terms and counts are useful safety descriptions, but without more detail they do not identify which events were treatment-related or how events overlapped across participants.
Finally, the registry separates a stated study purpose from posted statistical evidence. It describes safety and efficacy as aims and lists best overall tumour response as a secondary outcome, but no analysis is posted and the response result is absent. This makes transparent outcome reporting and a documented analysis plan especially important for interpretation. The statistical value of the record lies in showing the limited descriptive information available, while making clear that a comparative treatment conclusion is not supported by the posted analyses.
15. 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 enrollment was 9, with 3 participants in the 8 mg/kg group and 6 in the 16 mg/kg group. These small groups limit how precisely the reported event counts can characterize outcomes, particularly for serious events or less common event types. The registry does not post confidence intervals or a comparative analysis to quantify uncertainty.
The registry record is marked terminated, but does not report the reason. It also does not provide the planned enrollment target or a sample-size justification, so it is not possible to determine from the record whether the enrollment was completed as intended. The planning assumptions described in the record are an illustration based on an observed effect, not documentation of the trial’s original design.
The trial title describes zalutumumab with or without irinotecan, while both arm descriptions characterize their dose groups as receiving zalutumumab in combination with irinotecan. The listed intervention is zalutumumab. The record does not clarify whether an irinotecan-free group was planned, enrolled, or analyzed, or provide sufficient detail about treatment administration to resolve this wording.
Safety reporting is limited to participant counts and listed serious-event terms. The registry does not report event timing, duration, outcomes, attribution, or whether individual participants contributed to multiple terms or categories. Death counts are not reported in the registry record. The stated primary-outcome follow-up extends from first dose through follow-up, up to approximately 1 year, but completeness of follow-up and missing-data handling are not described.
Only 1 secondary outcome is posted, and its result is absent. No statistical analyses are posted, and details of the randomization procedure, allocation concealment, multiplicity handling, interim analyses, and statistical analysis plan are not reported in the registry record. These omissions constrain interpretation of both design and results.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: Zalutumumab With or Without Irinotecan Chemotherapy in Cetuximab-Refractory Colorectal Cancer — NCT00677924.
- Registry record last updated 2023-07-18; status last verified 2023-07.
- Results first posted 2011-12-23.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
19. Record Summary
The registry describes a randomized, parallel-group, unmasked phase I/II trial of zalutumumab in colorectal cancer among participants whose disease had progressed during or within 3 months of stopping cetuximab-based therapy after standard chemotherapy. It lists 9 participants and two dose groups: 8 mg/kg and 16 mg/kg. Both arm descriptions state that zalutumumab was combined with irinotecan.
The primary outcome was the number of participants with adverse events from first dose through follow-up, up to approximately 1 year. The registry reports adverse events for 3 of 3 participants in the 8 mg/kg group and 5 of 6 in the 16 mg/kg group. It also posts serious-event counts and selected serious-event terms. Best overall tumour response is listed as a secondary outcome, but no result is posted.
The trial is marked terminated. No statistical analyses are posted, and a two-arm binary comparison is not estimable from the registry entry. The reason for termination, the trial’s own sample-size justification, and details of the analysis plan are not reported in the registry record.