This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record.
1. Trial at a Glance
AXEPT was a randomized phase 3 treatment trial comparing two second-line chemotherapy strategies for metastatic colorectal cancer.
| Feature | AXEPT |
|---|---|
| NCT ID | NCT01996306 |
| Title | A Phase III Study of 2nd-line XELIRI ± Bevacizumab vs. FOLFIRI ± Bevacizumab in mCRC |
| Status | COMPLETED |
| Allocation | RANDOMIZED |
| Design model | PARALLEL |
| Masking | NONE |
| Primary purpose | TREATMENT |
2. Clinical Question
Population
Patients with colorectal neoplasms and related metastatic gastrointestinal malignancies enrolled in the AXEPT study.
Intervention
XELIRI ± bevacizumab, including irinotecan and capecitabine-based therapy.
Comparator
FOLFIRI ± bevacizumab, including irinotecan, 5-FU, leucovorin, and bevacizumab-based therapy.
Primary question
Comparison of overall survival between randomized treatment groups.
3. Trial Design
Randomized parallel-group phase 3 design.
Two treatment arms.
650 participants.
Epidemiological and Clinical Research Information Network.
4. Endpoints
| Endpoint | Definition | Time Frame |
|---|---|---|
| Overall survival | Time from the date of enrollment to death from any cause. | Assessed until 1.5 years after the last patient enrolment. |
5. Planned Analysis
The ClinicalTrials.gov record identifies overall survival as the primary endpoint but does not report posted statistical analyses or outcome estimates.
For an endpoint defined as time from enrollment to death from any cause, a typical analysis would use time-to-event methods. These methods account for patients whose event time is not observed during follow-up through censoring and allow comparison of survival distributions between randomized groups.
No formal statistical analyses were posted to ClinicalTrials.gov.
6. Statistical Methodology
Time-to-event analysis
Overall survival is a time-to-event endpoint. Statistical methods for this endpoint generally focus on the distribution of survival times rather than simply comparing proportions at a single time point.
Censoring
When follow-up ends before an event occurs, survival methods allow available follow-up information to contribute without treating those observations as failures.
Randomized comparison
Randomization creates the framework for comparing treatment groups while reducing the influence of measured and unmeasured baseline differences.
7. Statistical Methods Explained
Why is overall survival a time-to-event endpoint?
Overall survival measures the time until death from any cause, making the timing of events important rather than only whether an event occurred.
Why are survival methods used?
Patients may have different follow-up durations. Survival methods incorporate incomplete follow-up through censoring.
What does a hazard ratio represent?
If reported, a hazard ratio would compare estimated instantaneous event rates between treatment groups under a statistical model. It would not represent the percentage of patients who survive.
Why does randomization matter?
Randomization supports a fair comparison by assigning treatment groups without investigator choice.
Why are confidence intervals important?
Confidence intervals describe uncertainty around an estimate and help distinguish precise estimates from estimates with substantial uncertainty.
8. Limitations
- The ClinicalTrials.gov record does not report statistical analysis results for the primary endpoint.
- Only the registered primary endpoint information is available in the record.
- Additional endpoint analyses, subgroup analyses, safety comparisons, and long-term outcomes are not reported in the registry information.
9. Why This Trial Matters Statistically
| Concept | How it appears in AXEPT |
|---|---|
| Randomization | Parallel randomized treatment comparison. |
| Phase 3 design | Confirmatory clinical trial framework. |
| Overall survival | Primary time-to-event endpoint. |
| Censoring | Important consideration for survival follow-up. |
| Comparative effectiveness | Two chemotherapy strategies evaluated. |
10. Related Tutorials
11. Related Calculators
12. Sources
- ClinicalTrials.gov record: NCT01996306
- PubMed: 29555258
- PubMed: 28007025