Abraxane in Combination With Carboplatin, Erbitux and IMRT for Locally Advanced Squamous Cancer of the Head and Neck: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Abraxane in Combination With Carboplatin, Erbitux and IMRT for Locally Advanced Squamous Cancer of the Head and Neck (NCT00570674), a non-randomized phase 1, phase 2 study. The primary outcome is Dose Limiting Toxicity (DLT) [Phase I].

2. Clinical Question

The question is about tolerability under a specific combined treatment approach, not a randomized estimate of benefit compared with another regimen. The stated DLT definition captures selected treatment-related toxicities and treatment interruptions, using clinical severity grades and duration criteria. Because the regimen varied across Phase I dose levels, the safety question also concerns how toxicity findings informed dose selection.

The registry record does not report the primary DLT count for all treated participants or a Phase II efficacy result. It notes that no DLTs occurred among the first 3 participants at Dose Level 1, followed by expansion of that cohort to 6 because of safety and tolerability concerns. That limited statement does not establish the overall DLT result or resolve how the different dose levels compare. The record also lists secondary outcomes such as overall response rate, 2-year overall survival, duration of PEG therapy, and changes in FACT-H&N scores; their results are not reported in the registry record.

3. Trial Design

This was a Phase I/II, nonrandomized, single-group trial sponsored by Dana-Farber Cancer Institute. The registry lists an enrollment of 29. The recorded start was 2007-11, the primary completion was 2013-10, and the current status is terminated. The reason for termination is not reported in the registry record.

The Phase I portion was a dose-escalation study. Its stated purpose was to determine the safest and most effective Abraxane dose when combined with carboplatin and Erbitux during radiation therapy. The arm descriptions identify several Abraxane dose levels with carboplatin and IMRT. Dose Level 1 also describes Erbitux; the other listed Phase I dose-level descriptions are labeled AC-RT. For the dose levels described as AC-RT, Abraxane doses were 20mg/m2, 30mg/m2, 40mg/m2, and 50mg/m2, with carboplatin AUC 1.5 weekly during radiotherapy for a total of 7 weeks. Their radiation descriptions specify IMRT 5 days per week, with 70 Gy prescribed to the gross tumor volume in 2 Gy fractions. The registry’s Dose Level 1 description is truncated, so its full radiation details are not reported in the registry record.

The Phase II portion was intended to determine treatment effects on head and neck cancers and further study safety. However, a single-group design does not offer a randomized control arm for estimating the treatment’s comparative effect. Changes over time or differences between dose cohorts can be described, but without randomization they cannot by themselves separate treatment effects from other explanations.

The primary endpoint was DLT among treated participants in the dose-escalation cohorts. Adverse-event assessments occurred weekly during treatment, and the DLT observation period incorporated the 7 weeks of treatment. The registry also lists secondary outcomes including response, survival, PEG therapy duration, and patient-reported FACT-H&N score changes at specified follow-up points. Statistical analysis details beyond the outcome descriptions are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Only the first 6 of 7 groups are shown.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The MTD was not reached on this trial but the recommended phase II dose was the highest dose of Abraxane evaluated.

5. Baseline Characteristics

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

Population: The analysis dataset is comprised of all treated patients.

6. Primary Endpoint

The registry lists the primary outcome as Dose Limiting Toxicity (DLT) [Phase I], measured over Adverse event assessments occurred weekly on treatment; The observation period for DLT evaluation incorporated the 7 weeks of treatment..

The primary endpoint is the number of participants with dose-limiting toxicity (DLT) in Phase I. It is a count of people meeting the protocol’s toxicity definition, rather than a continuous measurement or a rate per unit of follow-up. The registry identifies the analysis population as all treated patients in the dose-escalation cohorts.

DLT was defined as selected treatment-related events: grade 3-4 non-hematological toxicity with stated exceptions; grade 3 or greater febrile neutropenia during chemoradiotherapy; grade 4 neutropenia lasting >/= 7 days; grade 3 thrombocytopenia; and grade 4 toxicities causing treatment breaks > 7 days. Dysphagia, esophagitis, mucositis/stomatitis, dermatitis/rash, and untreated nausea, vomiting, and diarrhea are addressed in the definition. The specific criteria make the endpoint a protocol-defined subset of possible harms, not a count of every adverse event.

In dose escalation, DLT is used to help judge whether a dose can be carried forward. It focuses attention on clinically significant toxicity during a defined treatment period, making it relevant to dose selection. It does not, by itself, summarize all safety experience, later events, or treatment effects. The registry reports that assessments occurred weekly on treatment and that the observation window incorporated the 7 weeks of treatment. It does not report the overall DLT count or the result at each dose level, so the endpoint’s observed distribution cannot be reconstructed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a binary primary endpoint: participants with DLT. In general, a binary outcome records whether each participant did or did not meet a defined event criterion during the specified observation period. The endpoint is then summarized as a count of participants with the event. The registry’s endpoint unit is participants with DLT, and its stated analysis population comprises treated patients in the dose-escalation cohorts. The observed count and any corresponding estimate are not reported in the registry record.

What does the DLT definition capture?

The endpoint uses prespecified severity and duration conditions. It includes selected grade 3-4 non-hematological toxicities, with stated exclusions and exceptions; grade 3 or greater febrile neutropenia during chemoradiotherapy; grade 4 neutropenia lasting >/= 7 days; grade 3 thrombocytopenia; and certain grade 4 toxicities that result in treatment breaks > 7 days. This is a composite endpoint because several distinct events can qualify a participant as having DLT. In general, a composite can capture several clinically important ways a regimen may be difficult to tolerate, but its total can conceal which event types contributed most. Event-specific results help interpret that mix, and the registry does not report an overall DLT breakdown by event type.

The registry says adverse-event assessments occurred weekly on treatment, with the DLT observation period incorporating the 7 weeks of treatment. This defines the intended time window for counting DLT, but does not describe follow-up beyond that window for the primary endpoint. In general, a defined window improves consistency by specifying when an event qualifies. It also means that events arising outside the window may not be represented in that endpoint, even if they are recorded elsewhere as adverse events.

How should dose escalation be understood?

The trial’s Phase I component evaluated multiple dose levels rather than assigning participants randomly to a treatment and a control. In general, dose escalation uses accumulating safety information to guide which dose levels are studied next. The record notes that no DLTs were observed in the first 3 participants at Dose Level 1 and that the cohort was expanded to 6 due to safety and tolerability concerns. It also records that, upon further review, it was resolved that the Abraxane dose should not be ...; the registry description is truncated at this point. The full rationale or resulting decision is not reported in the registry record. The note about the initial participants is not a result for the full trial and does not replace the missing DLT counts for all dose cohorts.

In general, comparisons across sequential dose cohorts require caution. Participants in different cohorts may differ for reasons other than dose, and the cohort decisions are part of the dose-escalation process. A nonrandomized cohort comparison is not equivalent to a randomized comparison. The registry does not report a statistical model or adjustment strategy for comparing cohorts.

What do statistical uncertainty and planning calculations mean?

In general, an estimate describes the observed data, while a confidence interval expresses uncertainty about the value that could be expected under a statistical model. An interval is not a guarantee that the true value lies within its limits; it is interpreted through the method used to construct it. For a binary outcome, the precision depends in part on the number of participants and event frequency. The registry does not report a DLT estimate or confidence interval, so the precision of the primary outcome cannot be assessed from the recorded information.

The registry’s sample-size assumptions describe a planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. Such calculations are hypothetical planning scenarios. They do not describe the actual design of this nonrandomized single-group trial, and they are not observed power. The record says that time-to-event planning figures represent total events, while other planning figures represent participants per arm. No planning value is needed to interpret the missing primary endpoint result.

In general, over-dispersion matters when variability in the data is greater than a model assumes. A model that understates variability can produce confidence intervals that are too narrow and tests that are too optimistic. That concept is most relevant to outcomes modeled as counts or rates; this trial’s designated primary endpoint is a participant count. The registry does not report a model for that endpoint, so no model-based adjustment for over-dispersion can be assessed.

What analyses are documented?

The record lists 10 outcome measures and 4 analyses, but does not provide the statistical analysis plan, the definition of each analysis population beyond the primary endpoint population, or the methods used to handle missing observations. It does not report whether analyses were adjusted, which tests were used, or how uncertainty was calculated. Those details should not be inferred from the Phase I/II label or from the endpoint description. The available methods information is therefore sufficient to explain what DLT was intended to measure, but not to reproduce or evaluate a complete statistical analysis.

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.

R code and output

arm    <- c("Phase I Dose Level 1: ACE-RT", "Phase I Dose Level -1: AC-RT", "Phase I Dose Level 2: AC-RT", "Phase I Dose Level 3: AC-RT", "Phase I Dose Level 4: AC-RT")
n      <- c(6, 3, 3, 3, 3)
events <- c(0, 0, 0, 0, 0)
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  Phase I Dose Level 1: ACE-RT  6  0  0.0  0.0  45.9  0.0  39.0  0.4  41.0
ARM  Phase I Dose Level -1: AC-RT  3  0  0.0  0.0  70.8  0.0  56.1  0.6  60.2
ARM  Phase I Dose Level 2: AC-RT  3  0  0.0  0.0  70.8  0.0  56.1  0.6  60.2
ARM  Phase I Dose Level 3: AC-RT  3  0  0.0  0.0  70.8  0.0  56.1  0.6  60.2
ARM  Phase I Dose Level 4: AC-RT  3  0  0.0  0.0  70.8  0.0  56.1  0.6  60.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 10 outcome measures and 4 analyses. These include the Phase I DLT endpoint, overall response rate and 2-year overall survival, duration of PEG therapy, and changes in FACT-H&N score at several follow-up points. When a study assesses multiple outcomes or multiple time points, there are generally more opportunities for a chance finding. Statistical approaches to multiplicity can control error rates, prioritize a primary outcome, or distinguish confirmatory from exploratory analyses. The registry record does not report a multiplicity adjustment, testing hierarchy, or other plan for handling multiple comparisons.

The primary endpoint is identified as DLT in Phase I, but the statistical analysis plan is not reported in the registry record. It is therefore not possible to determine whether the listed outcomes were assigned different inferential roles or whether any results were intended to be confirmatory. No reported statistical significance should be assumed for outcomes whose results are not present.

The endpoint description identifies treated patients in the dose-escalation cohorts as the analysis population. The record does not report the number included in that population, how missing outcome observations were handled, or whether any participants were excluded after treatment began. It also does not report missing-data handling for the listed secondary outcomes. In general, missing observations can affect estimates if the participants with observed data differ systematically from those without observed data. The direction and size of such effects cannot be determined without information about the missingness and analysis methods.

The overall enrollment is 29, while the Phase I adverse-event listing has 28 participants at risk. The reason for that difference is not reported in the registry record. This distinction should be retained rather than assuming the denominators are interchangeable. The registry also does not explain how termination affected outcome follow-up or analysis completeness.

12. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: muco/stomatitis by exam, oral cavity (64.3%), dysphagia (60.7%), chemoradiation dermatitis (28.6%), oral cavity, pain (10.7%), nausea (7.1%).

The registry’s adverse-event summary is labeled All Phase I Participants and records 28 participants at risk for serious adverse events, with 26 affected. For other adverse events, it records 28 participants at risk and 28 affected. These are participant-level counts in the posted summary; they do not indicate how many total events each person experienced. The reason that the serious-event affected count is below the number at risk is not described.

The listed serious-event terms include muco/stomatitis by exam, oral cavity at 64.3%; dysphagia at 60.7%; chemoradiation dermatitis at 28.6%; oral cavity, pain at 10.7%; nausea at 7.1%; and febrile neutropenia at 3.6%. These percentages are reproduced as recorded. The registry does not provide additional event-level detail in the information, such as duration, recurrence, or the number of events per affected participant. The DLT definition and these serious-event listings are also distinct: a serious event is not automatically a DLT unless it meets the specified DLT criteria.

These safety counts are descriptive. Because the trial has no randomized control arm, they do not estimate how the event frequencies compare with another regimen or what would have occurred without this treatment. The registry record does not report a statistical comparison or uncertainty intervals for these figures. The 29-participant enrollment is the overall trial enrollment; the adverse-event denominator is the Phase I group of 28 at risk, and the record does not explain the difference.

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

The registry record establishes that the study was designed to examine an Abraxane-containing chemoradiotherapy regimen in locally advanced squamous cancer of the head and neck. Phase I focused on dose selection and DLT; Phase II was intended to examine treatment effects and further safety. The trial included several Phase I dose-level descriptions, and the registry lists 29 participants overall. These features describe the research question and its structure, not the answer to the efficacy question.

The posted record does not report the overall DLT result, dose-specific DLT counts, or the listed secondary outcome results. It therefore does not establish the frequency of DLT across the dose-escalation cohorts, the precision of that frequency, or the magnitude of response, survival, PEG therapy, or quality-of-life outcomes. The note that the first 3 participants at Dose Level 1 had no observed DLT is limited to that initial group. The same record says the cohort was expanded to 6 due to safety and tolerability concerns, so the initial observation should not be taken as the full cohort result.

The adverse-event summary does provide descriptive participant counts and listed event percentages for Phase I. Those findings indicate which serious-event terms were recorded in that group, but they do not establish comparative risk. A nonrandomized, single-group study cannot separate the regimen’s contribution from other factors using a concurrent randomized comparison. A finding in this study should therefore be interpreted as a report about the observed treated group, not as proof of what would happen under a different treatment or in a broader population.

In general, statistical significance and clinical importance are different questions. A significance test addresses compatibility with a statistical null under specified assumptions; it does not by itself show the size, relevance, or certainty of an effect. The registry record does not report the primary endpoint estimate, inferential test, or confidence interval, and it does not report the Phase II results. The justified conclusion is limited to the trial’s stated aims, design, endpoint definition, and recorded safety summary. No treatment recommendation follows from these data.

14. Why This Trial Matters Statistically

This trial illustrates a common statistical distinction between dose-finding and comparative-effectiveness questions. Phase I aimed to identify an Abraxane dose for a multi-component regimen, with DLT serving as the primary safety endpoint. Phase II was intended to examine treatment effects and safety. Those purposes require different interpretations: dose-escalation information is primarily about tolerability and dose selection, while evidence of comparative benefit generally requires a suitable comparison.

The study’s nonrandomized, single-group design matters because the listed dose cohorts are not randomized arms with a like-for-like control. Describing adverse events or outcomes in these cohorts can be informative, but differences between them do not have the same interpretation as randomized contrasts. The design also makes it important to distinguish a treatment-associated observation from a causal estimate of treatment effect.

The endpoint definition demonstrates how a clinical outcome becomes a statistical variable. DLT is not simply any adverse event; it is a protocol-defined composite using specified toxicity types, severity grades, timing, and treatment-break criteria. Such definitions make counting more consistent, while also limiting the endpoint to the events that qualify. Reading the endpoint alongside broader safety summaries helps avoid conflating a DLT count with all adverse events.

The record also shows why registry completeness matters. It provides the primary endpoint definition and some safety figures, but does not report the overall DLT result, secondary outcome results, or statistical analysis details. Without those elements, readers cannot assess the endpoint estimate or its precision. The status is terminated, but the reason is not reported, so that status alone cannot explain the available results. These distinctions are useful when assessing what a trial record can establish and what remains uncertain.

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 most consequential limitation for interpreting results is that the registry does not report the primary DLT count across the treated dose-escalation cohorts. It gives only a limited statement about the first 3 participants at Dose Level 1 and the subsequent cohort expansion to 6 because of safety and tolerability concerns. Dose-specific results and a complete account of the dose decision are not reported; the relevant arm description is truncated.

The record is nonrandomized and single-group, with no like-for-like randomized control. It therefore cannot provide a randomized estimate of comparative effects. The trial’s overall enrollment is 29, while the Phase I adverse-event listing identifies 28 participants at risk; the reason for this difference is not reported in the registry record. The record also does not explain the reason for termination.

The registry lists secondary outcomes but does not report their results, analysis methods, or uncertainty estimates. The statistical analysis plan, multiplicity approach, missing-data handling, and details of the analysis populations beyond the primary endpoint description are not reported. The adverse-event summary provides participant counts and percentages, but not additional event-level information such as recurrence or duration in the record described.

The arm descriptions are not complete for every regimen detail. In particular, the Dose Level 1 description is truncated, and the record does not fully document the rationale or final outcome of dose escalation. These limitations constrain interpretation to the recorded design, endpoint criteria, and adverse-event summary; they do not justify assumptions about unreported results or methods.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Abraxane in Combination With Carboplatin, Erbitux and IMRT for Locally Advanced Squamous Cancer of the Head and Neck — NCT00570674.
• Registry record last updated 2017-11-13; status last verified 2017-10.
• Results first posted 2016-12-12.
• 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.

19. Record Summary

This is a Phase I/II, nonrandomized, single-group trial sponsored by Dana-Farber Cancer Institute, with 29 participants enrolled. The study examined Abraxane-based treatment with carboplatin and IMRT, with Erbitux included in the described Phase I Dose Level 1 regimen. The registry lists the status as terminated; the reason is not reported.

The Phase I primary endpoint was the number of treated dose-escalation participants with DLT, assessed during a period incorporating the 7 weeks of treatment. The registry reports no DLTs in the first 3 Dose Level 1 participants and says that cohort was expanded to 6 due to safety and tolerability concerns. The full primary endpoint result and the listed secondary outcome results are not reported in the registry record.

The Phase I adverse-event summary lists 28 participants at risk, with 26 affected by serious adverse events and 28 affected by other adverse events. The record provides percentages for several serious-event terms. These are descriptive findings without a randomized comparator.