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 An Efficacy Study Comparing ZD6474 to Placebo in Medullary Thyroid Cancer (NCT00410761), a randomized phase 3 study. The primary outcome is Progression-Free Survival(PFS).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00410761 |
| Phase | Phase 3 |
| Condition | Thyroid Cancer |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 331 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Genzyme, a Sanofi Company |
| Results posted | Yes |
2. Clinical Question
Population
People with hereditary or sporadic medullary thyroid cancer that was unresectable, locally advanced, or metastatic. The registry lists thyroid cancer as the condition and does not give further eligibility details in the posted record.
Intervention
Vandetanib, identified in the registry as ZD6474, at a dose of 300 mg in the randomized treatment period.
Comparator
Placebo. The trial was randomized, placebo-controlled, double-blinded, and parallel-group, with quadruple masking listed in the registry.
Primary question
How did the estimated median time from randomization to objective disease progression or death compare between the vandetanib and placebo groups? The registry posts estimated medians for progression-free survival, but no sponsor-reported hazard ratio or direct statistical test for this comparison.
The primary endpoint was progression-free survival (PFS), defined from randomization until objective progression determined by RECIST assessment, or death from any cause in the absence of documented progression, subject to the registry’s stated timing condition for death. The medians were not met during the reported analysis, so the posted values are estimates from a Weibull model rather than observed points at which half of a group had experienced the endpoint.
The registry also lists objective response, disease control, duration of response, overall survival, biochemical responses, and time to worsening of pain as secondary outcomes. Counts are posted for some of these outcomes, but sponsor-reported analyses are not reported in the registry record. The central statistical question is therefore not simply which posted values are numerically larger. It is how the endpoint definitions, model-based estimates, uncertainty, and missing analysis details affect the strength of conclusions that can be drawn from the record.
3. Trial Design
This was an international, phase III, randomized, double-blinded, placebo-controlled, multicenter, parallel-group study. The registry lists quadruple masking. The stated enrollment was 331, and the record is marked completed. The study began on 2006-11-23, with primary completion on 2009-07-31.
The randomized treatment groups were vandetanib 300 mg and placebo. For the primary endpoint, the posted group sizes are 231 for vandetanib and 100 for placebo. The registry describes the study as involving people with unresectable locally advanced or metastatic medullary thyroid cancer; its brief summary refers to hereditary or sporadic disease. More detailed eligibility criteria and the methods used to maintain masking are not reported in the registry record.
RECIST tumor assessments were scheduled at screening, within 3 weeks before randomization, and then once every 12 weeks up to discontinuation of blinded treatment, unless a participant withdrew consent. The objective response outcome also specifies a confirmatory scan at least 4 weeks after the first response. The secondary biochemical calcitonin outcome used blood samples at screening baseline and then every 4 weeks until discontinuation and 60-day follow-up. These schedules describe when assessments were planned; the registry does not provide a complete account of attendance, missing assessments, or the analysis populations used for each endpoint.
The adverse-event record separates the randomized treatment period from open-label treatment. These periods should be read separately: the open-label groups are not the same comparison as the blinded randomized groups, and the registry’s posted counts do not establish that the groups are comparable for safety assessment. Details of treatment switching, exposure duration, and the rules for attributing events 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.
Randomized Treatment Period
| Stage | Vandetanib 300 mg/Vandetanib 300 mg | Placebo/Vandetanib 300 mg |
|---|---|---|
| STARTED | 231 | 100 |
| Received Randomized Treatment | 231 | 99 |
| COMPLETED | 14 | 1 |
| NOT COMPLETED | 217 | 99 |
Reasons for not completing this period:
| Reason | Vandetanib 300 mg/Vandetanib 300 mg | Placebo/Vandetanib 300 mg |
|---|---|---|
| Adverse Event | 34 | 3 |
| Objective Disease Progression | 103 | 68 |
| Withdrawal by Subject | 11 | 6 |
| Other | 69 | 21 |
| Randomized but did not Receive Treatment | 0 | 1 |
Open-Label Treatment Period
| Stage | Vandetanib 300 mg/Vandetanib 300 mg | Placebo/Vandetanib 300 mg |
|---|---|---|
| STARTED | 109 | 79 |
| COMPLETED | 28 | 21 |
| NOT COMPLETED | 81 | 58 |
Reasons for not completing this period:
| Reason | Vandetanib 300 mg/Vandetanib 300 mg | Placebo/Vandetanib 300 mg |
|---|---|---|
| Adverse Event | 13 | 15 |
| Objective Disease Progression | 42 | 27 |
| Withdrawal by Subject | 8 | 7 |
| Other | 18 | 9 |
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 full analysis set included all randomized participants.
| Characteristic | Unit | Vandetanib 300 mg | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 231 | 100 | 331 | |
| Age, Continuous | years | 50.7 (18 to 83) | 53.4 (26 to 84) | 52 (18 to 84) |
| Sex: Female, Male: Female | Participants | 97 | 44 | 141 |
| Sex: Female, Male: Male | Participants | 134 | 56 | 190 |
6. Primary Endpoint
The registry lists the primary outcome as Progression-Free Survival(PFS), measured over RECIST tumour assessments were performed at screening (within 3 weeks before date of randomisation), then once every 12 weeks up to and including discontinuation of blinded study treatment, unless patients had withdrawn consent..
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | 95% Confidence Interval |
| Unit | Months |
| Endpoint classification | Time-to-Event Analysis |
The primary endpoint, PFS, measures time from randomization until objective disease progression or death under the definition stated in the registry. Progression was determined by RECIST assessments. A death without previously documented objective progression counted only when it occurred within 3 months of the last evaluable RECIST assessment. This combines disease progression and death into a time-to-event outcome, so the result concerns the timing of either event rather than tumor response alone.
Time-to-event endpoints are useful when the timing of an event matters and participants may have different follow-up durations. In general, they can use information about when events occur, rather than reducing follow-up to a yes-or-no outcome at a single fixed time. Interpretation also depends on follow-up, event ascertainment, and how participants without an observed event are handled. Those analysis details are not reported in the registry record.
RECIST assessments were scheduled at screening, within 3 weeks before randomization, and every 12 weeks during blinded treatment unless consent was withdrawn. The record says the PFS medians were not met and that the posted values were estimated from a Weibull model. Thus, the values should be understood as model-based median estimates, not as observed times at which half of each group had reached progression or death. The registry does not post a confidence interval for either median or a sponsor-reported hazard ratio for the comparison.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry reports estimated median PFS of 30.5 months for vandetanib 300 mg and 19.2 months for placebo. Both values are identified as Weibull-model estimates because the medians were not met. They describe the fitted time-to-event distributions under that model; they are not direct observations of a point at which half of each group had an event. The record does not provide confidence intervals for these medians, a sponsor-reported hazard ratio, or a sponsor-reported statistical test for the primary comparison.
Without those comparative estimates and their uncertainty, the numerical separation between the posted medians should not be treated as a complete inferential result. A median alone does not describe the full pattern of event times, and the record does not show whether the relative event rate changed over follow-up. The registry’s primary endpoint description is specific about the event definition and assessment schedule, but does not report the analysis population, censoring details, or other time-to-event analysis methods needed to assess the estimate fully.
For three posted binary secondary outcomes, the registry gives participant counts by group, while sponsor-reported analyses are not reported in the registry record. Simple unadjusted recalculations from those counts show higher proportions in the vandetanib group for objective response, disease control, and biochemical calcitonin response. The risk-difference estimates are 0.320 for objective response, 0.156 for disease control, and 0.663 for calcitonin response. Their respective 95% confidence intervals are 0.228 to 0.412, 0.057 to 0.255, and 0.594 to 0.731. The unadjusted p-values for each are <0.001.
These recalculations are not substitutes for the sponsor’s analysis. They use posted summary counts and are unadjusted; they do not account for any analysis choices or multiplicity procedures that may have been used. The registry does not report sponsor analyses for these outcomes, so the calculations should be read as descriptive, unadjusted comparisons rather than as the trial’s complete inferential record. The listed secondary outcomes also include duration of response, overall survival, CEA response, and time to worsening of pain, but results for those outcomes are not reported in the record used for this analysis.
9. Statistical Methods Explained
Progression-free survival is a time-to-event endpoint. In general, this means that the outcome records the time until a defined event, while participants who have not had an event by the end of their observed follow-up may contribute information up to that point. The registry defines the event as objective RECIST progression or death under a stated timing condition. It does not report the detailed censoring rules, the analysis population, or the number of events used in the primary analysis. Those omissions limit independent assessment of how the time-to-event estimates were obtained.
What does an estimated median represent?
A median time-to-event value is the time at which the estimated event-free proportion reaches the halfway point. In this trial, the registry says the medians were not met and that the posted values were estimated using a Weibull model. A model can estimate features of a time-to-event distribution even when the observed follow-up has not reached the point at which the median is directly observed. Such an estimate depends on the model’s fit and assumptions, so it is not identical to a directly observed median. The record does not post confidence intervals for the two estimates or additional information about model checking.
The posted medians are 30.5 months for vandetanib 300 mg and 19.2 months for placebo. Those numbers alone do not quantify the relative rate of progression or death throughout follow-up. A hazard ratio, if reported, would describe a relative event rate under its model and interpretation; the registry record does not report one for PFS. Nor does it provide a sponsor-reported test of the treatment comparison. No comparative PFS statistic should be inferred from the two medians alone.
How should the binary outcomes be read?
For the posted binary outcomes, a risk difference is the difference between the observed proportions in the two groups. It is expressed on the probability scale. The unadjusted recalculations use the posted counts: objective response was recorded for 104 of 231 participants in the vandetanib group and 13 of 100 in the placebo group; disease control for 200 of 231 and 71 of 100; and calcitonin response for 160 of 231 and 3 of 100. The estimated risk differences and confidence intervals are reported with those outcomes. These recalculations are simple comparisons of the posted summaries, not sponsor-reported analyses.
A confidence interval describes a range of values compatible with the data under the method used. It communicates uncertainty in an estimate; it does not guarantee that the true value lies within the interval, nor does it address every source of bias or uncertainty. The intervals for the three recalculated risk differences are unadjusted. The record does not report whether the sponsor used a different method, adjusted for other variables, or prespecified a particular multiplicity procedure. The unadjusted p-values likewise do not account for testing several outcomes.
The record also lists relative risks and odds ratios for these recalculations. Those measures express contrasts on different scales from a risk difference. Their interpretation can be less direct when the outcome is common, and they should not be mistaken for absolute changes in probability. None of these unadjusted calculations establishes why the groups’ observed counts differ, and they do not replace the trial’s planned analysis.
What do the planning illustrations mean?
The sample-size illustrations use a two-sided significance level of 0.05, equal allocation between groups, and a normal approximation. They show participants per arm for 80% or 90% power when planning to detect a stated fraction of the observed effect. These are planning illustrations computed from observed effects, not the trial’s original design justification and not observed power. In general, power is a design-stage probability under specified assumptions; calculating it after observing results does not measure the strength or reliability of the findings. The sample-size assumptions for the original trial are not reported in the registry record.
For binary outcomes, the illustrations use participants per arm. The registry notes that time-to-event illustrations, where present, use a total number of events, but no such PFS planning comparison is posted in this record. The illustrations depend on the selected effect size and assumptions; they are not evidence that the trial was designed around the observed effect. They should not be used to infer the original recruitment target or to judge the primary endpoint’s certainty.
Finally, the registry’s adverse-event summaries are counts within treatment periods and are distinct from efficacy analyses. General comparisons of adverse-event counts require attention to time at risk, exposure, follow-up, and attribution rules. The record lists counts at risk and counts affected, but does not provide enough detail to make adjusted safety comparisons. The open-label period is especially distinct from the randomized, blinded period and should not be treated as a continuation of the original randomized comparison without additional design and analysis information.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one primary endpoint, PFS, and multiple secondary outcomes. It does not report a statistical analysis plan, a hierarchy for testing endpoints, a multiplicity adjustment, or whether any outcomes were considered exploratory. When several outcomes are tested, unadjusted p-values do not control the overall chance of false-positive findings across the set. The posted p-values for the recalculated binary comparisons are unadjusted, so they should not be read as accounting for the full collection of outcomes.
Missing-data handling is also not reported in the registry record. The assessment schedule states that RECIST evaluations occurred at screening and every 12 weeks during blinded treatment unless consent was withdrawn, but it does not give the number of missed or unevaluable assessments or explain how missing assessments were handled. The record does not report the analysis populations used for PFS or the secondary outcomes, such as whether analyses followed the randomized assignment for all participants or used another population definition. It also does not provide detailed censoring rules for PFS.
These omissions matter because endpoint interpretation depends on which participants and assessments contribute to an analysis. For time-to-event outcomes, censoring and follow-up affect the estimated event-time distribution. For binary outcomes, incomplete outcome ascertainment can affect the observed proportions. The registry record does not provide enough information to assess these issues or determine whether missingness could have differed between groups.
These are gaps in the registry record, not evidence that a particular procedure was or was not used in the full trial. The registered design and posted outcome values do not establish the protocol’s analysis methods, interim analyses, sample-size justification, or missing-data strategy. Those details 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 |
|---|---|---|---|
| Randomized Treatment Period: Vandetanib 300 mg | 92 | 231 | 39.8% |
| Randomized Treatment Period: Placebo | 16 | 99 | 16.2% |
| Open-Label Treatment Period: Vandetanib 300 mg/Vandetanib 300 mg | 53 | 109 | 48.6% |
| Open-Label Treatment Period: Placebo/Vandetanib 300 mg | 36 | 79 | 45.6% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Randomized Treatment Period: Vandetanib 300 mg | 66 of 231 |
| Randomized Treatment Period: Placebo | 10 of 100 |
| Open-Label Treatment Period: Vandetanib 300 mg/Vandetanib 300 mg | 52 of 109 |
| Open-Label Treatment Period: Placebo/Vandetanib 300 mg | 41 of 79 |
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 |
|---|---|
| Randomized Treatment Period: Vandetanib 300 mg | 226 of 231 |
| Randomized Treatment Period: Placebo | 87 of 99 |
| Open-Label Treatment Period: Vandetanib 300 mg/Vandetanib 300 mg | 32 of 109 |
| Open-Label Treatment Period: Placebo/Vandetanib 300 mg | 70 of 79 |
Most frequent serious adverse event terms
| Event term | Organ system | Randomized Treatment Period: Vandetanib 300 mg | Randomized Treatment Period: Placebo | Open-Label Treatment Period: Vandetanib 300 mg/Vandetanib 300 mg | Open-Label Treatment Period: Placebo/Vandetanib 300 mg |
|---|---|---|---|---|---|
| Pneumonia | Infections and infestations | 7 of 231 | 0 of 99 | 3 of 109 | 1 of 79 |
| Diarrhoea | Gastrointestinal disorders | 6 of 231 | 0 of 99 | 1 of 109 | 2 of 79 |
| Appendicitis | Infections and infestations | 3 of 231 | 0 of 99 | 3 of 109 | 2 of 79 |
| Dehydration | Metabolism and nutrition disorders | 3 of 231 | 0 of 99 | 0 of 109 | 3 of 79 |
| Nephrolithiasis | Renal and urinary disorders | 3 of 231 | 0 of 99 | 0 of 109 | 3 of 79 |
| Vomiting | Gastrointestinal disorders | 2 of 231 | 0 of 99 | 1 of 109 | 2 of 79 |
| Sepsis | Infections and infestations | 4 of 231 | 0 of 99 | 1 of 109 | 0 of 79 |
| Urinary Tract Infection | Infections and infestations | 3 of 231 | 0 of 99 | 2 of 109 | 0 of 79 |
| Decreased Appetite | Metabolism and nutrition disorders | 4 of 231 | 0 of 99 | 0 of 109 | 1 of 79 |
| Cerebrovascular Accident | Nervous system disorders | 0 of 231 | 0 of 99 | 3 of 109 | 2 of 79 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Randomized Treatment Period: Vandetanib 300 mg | Randomized Treatment Period: Placebo | Open-Label Treatment Period: Vandetanib 300 mg/Vandetanib 300 mg | Open-Label Treatment Period: Placebo/Vandetanib 300 mg |
|---|---|---|---|---|---|
| Diarrhoea | Gastrointestinal disorders | 123 of 231 | 27 of 99 | 4 of 109 | 32 of 79 |
| Rash | Skin and subcutaneous tissue disorders | 105 of 231 | 11 of 99 | 4 of 109 | 25 of 79 |
| Nausea | Gastrointestinal disorders | 74 of 231 | 16 of 99 | 5 of 109 | 18 of 79 |
| Hypertension | Vascular disorders | 71 of 231 | 6 of 99 | 2 of 109 | 15 of 79 |
| Fatigue | General disorders | 54 of 231 | 23 of 99 | 3 of 109 | 13 of 79 |
| Headache | Nervous system disorders | 62 of 231 | 9 of 99 | 4 of 109 | 5 of 79 |
| Decreased Appetite | Metabolism and nutrition disorders | 42 of 231 | 13 of 99 | 2 of 109 | 17 of 79 |
| Acne | Skin and subcutaneous tissue disorders | 47 of 231 | 5 of 99 | 0 of 109 | 21 of 79 |
| Asthenia | General disorders | 34 of 231 | 12 of 99 | 0 of 109 | 12 of 79 |
| Vomiting | Gastrointestinal disorders | 33 of 231 | 7 of 99 | 3 of 109 | 9 of 79 |
Serious events with the highest arm-level rate: dehydration (3.8%), nephrolithiasis (3.8%), acute myocardial infarction (3.7%), pneumonia (3.0%), pancreatitis acute (2.8%).
During the randomized treatment period, the registry reports serious adverse events affecting 92 of 231 participants assigned to vandetanib 300 mg and 16 of 99 participants in the placebo group. It reports other adverse events affecting 226 of 231 and 87 of 99, respectively. Death counts in the randomized treatment period are listed as 66 and 10. These are counts for the stated period, not adjusted estimates of comparative risk, and the record does not supply a statistical comparison or exposure-adjusted analysis.
The registry separately lists open-label treatment-period counts: serious adverse events affected 53 of 109 in the vandetanib-to-vandetanib group and 36 of 79 in the placebo-to-vandetanib group. Other adverse events affected 32 of 109 and 70 of 79, and deaths are listed as 52 and 41. These open-label counts should not be combined with or directly compared as if they were the randomized blinded groups. Treatment exposure, follow-up, and group composition may differ; details needed to assess those factors are not reported in the registry record.
The listed serious-event terms include dehydration and nephrolithiasis at 3.8% each, acute myocardial infarction at 3.7%, pneumonia at 3.0%, and pancreatitis acute and appendicitis at 2.8% each. The record does not provide additional context about event timing, duration, attribution, or how these terms were selected.
12. What the Result Does, and Does Not, Mean
The posted results describe a randomized comparison of vandetanib 300 mg with placebo and report Weibull-model estimates of median PFS. The estimated median is 30.5 months in the vandetanib group and 19.2 months in the placebo group. The registry says the medians were not met, and it does not provide confidence intervals for these estimates or a sponsor-reported hazard ratio or test of the primary comparison. The figures therefore summarize the posted model-based estimates but do not, by themselves, establish the size or precision of a comparative treatment effect.
The posted counts for objective response, disease control, and calcitonin response are higher in the vandetanib group, and unadjusted calculations give risk differences with confidence intervals and p-values. These analyses are based on summary counts and are not reported as sponsor analyses. They do not address multiplicity, missing outcome data, or other analysis choices that may affect interpretation. They also concern secondary outcomes and do not replace the primary time-to-event analysis.
In general, randomized allocation can support a comparison between assigned groups when the trial is conducted and analyzed appropriately. The registry record alone does not provide all information needed to assess that condition, including analysis populations, missing-data methods, detailed censoring rules, or the statistical plan. The posted outcome values should therefore be understood within the limits of the record, rather than as a complete account of the trial’s efficacy or safety evidence.
These results do not establish an individual prognosis, and they are not medical advice. They describe group-level outcomes recorded in this trial. They do not show that every participant had the same experience, explain the mechanism behind group differences, or answer questions about outcomes not reported in the registry record.
13. Why This Trial Matters Statistically
This trial is statistically notable for the contrast between a time-to-event primary endpoint and several binary secondary outcomes. PFS depends on when progression or death occurs, while response and disease-control counts record whether a defined outcome was observed. Those endpoints answer related but distinct questions, so agreement in direction can be informative without making them equivalent evidence.
The PFS values are model-based median estimates because the medians were not met. That makes it especially important to distinguish a fitted estimate from a directly observed median and to consider the uncertainty around it. The registry record does not post confidence intervals for the medians or a sponsor-reported hazard ratio or comparison test. Without those quantities and relevant analysis details, readers cannot assess the primary contrast’s precision from the registry record alone.
The binary secondary outcomes illustrate how unadjusted recalculations can add a descriptive comparison when sponsor analyses are absent. Their confidence intervals and p-values quantify uncertainty under the recalculation methods, but do not resolve questions about multiplicity, missingness, or the trial’s prespecified analysis. The separate open-label safety summaries also illustrate why treatment period and study design matter when reading event counts.
More broadly, the record shows why statistical interpretation needs more than a numerical contrast. Endpoint definitions, assessment schedules, model assumptions, analysis populations, uncertainty, and the distinction between randomized and open-label periods all shape what can be concluded. The record is useful for identifying posted estimates and counts, while its unreported analysis details limit a fuller evaluation.
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 primary result is presented as estimated median PFS values from a Weibull model, with no confidence intervals for the medians and no sponsor-reported hazard ratio or test of the group comparison in the registry record. The record does not provide the number of PFS events, detailed censoring methods, model diagnostics, or the analysis population. These gaps restrict assessment of the estimate’s precision and of the assumptions behind it.
For the posted secondary outcomes, sponsor-reported analyses are not reported. The recalculated comparisons use summary counts and are unadjusted. The registry does not report how multiplicity was addressed, whether the outcomes were prespecified in a hierarchy, or how missing observations were handled. Results for several listed secondary outcomes are not reported in the record used for this analysis.
The record gives assessment schedules but not completeness of follow-up or the extent of missing and unevaluable assessments. It does not supply the full eligibility criteria, baseline group characteristics, detailed treatment exposure, or information needed to interpret all adverse-event counts in relation to time at risk. Randomized-period and open-label-period safety summaries are separate, and the latter are not a randomized comparison of the same form.
These limitations describe information not reported in the registry record; they do not establish that the full trial report lacked those methods or data. They mean that conclusions based on this record should remain limited to the posted estimates, counts, and their stated definitions.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: An Efficacy Study Comparing ZD6474 to Placebo in Medullary Thyroid Cancer — NCT00410761.
- Registry record last updated 2025-09-24; status last verified 2025-09.
- Results first posted 2012-03-26.
- 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
NCT00410761 is a completed, international phase III randomized, double-blinded, placebo-controlled, parallel-group study of ZD6474, identified as vandetanib, in medullary thyroid cancer. The registry lists quadruple masking and enrollment of 331. The study began on 2006-11-23, and primary completion was 2009-07-31.
The primary outcome was PFS, defined as time from randomization to RECIST progression or death under the registry’s stated timing condition. Estimated medians were 30.5 months for vandetanib 300 mg and 19.2 months for placebo; the registry states that these were Weibull-model estimates because the medians were not met. A sponsor-reported comparative hazard ratio, confidence intervals for these medians, and a primary comparison test are not reported in the registry record.
Counts are posted for selected secondary outcomes and adverse events. Sponsor-reported analyses for the secondary outcomes, the statistical analysis plan, multiplicity procedures, and missing-data methods are not reported in the registry record.