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 HepaSphere™ Microspheres Prospective Registry (NCT04866290), a registered phase not stated study. The primary outcome is Overall Survival.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04866290 |
| Phase | Phase not stated |
| Condition | Metastatic Colorectal Cancer |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 105 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Merit Medical Systems, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The registry enrolled people with metastatic colorectal cancer to the liver. The record reports enrollment of 105. For the primary endpoint, it specifies that all enrolled subjects who received one or more TACE cycles were included in the calculation of median overall survival. The record does not describe additional eligibility details in the information available for this analysis.
Intervention
The intervention was transarterial chemoembolization using HepaSphere™ Microspheres loaded with irinotecan. The registry identifies HepaSphere Microspheres as a device intervention and describes the treatment as intended for colorectal liver metastasis. The record does not report the number of cycles received by each participant or other treatment details.
Comparator
No concurrent comparison group is described. This is a prospective registry, and the allocation method is not stated. Accordingly, it is not a randomized comparison, and the registry does not support treating its participants as a like-for-like control group against another treatment. Comparisons with outcomes from other populations would require evidence that is not reported in the registry record.
Primary question
The primary question was the median overall survival among treated subjects, measured in months, with a 95% confidence interval. The outcome timeframe was 24 months. The registry description says analysis would occur after all enrolled subjects had been followed for survival for 24 months, were considered lost to follow-up, or had died, whichever came first. The numerical median and interval are not reported in the registry record.
3. Trial Design
This was a prospective registry of transarterial chemoembolization for metastatic colorectal cancer in the liver, using HepaSphere™ Microspheres loaded with irinotecan. The registry record identifies Merit Medical Systems, Inc. as the sponsor and reports enrollment of 105. Its status is completed. The recorded start date is 2016-09-22, and the primary completion date is 2021-06.
The record describes the aim as documenting safety and efficacy in real-life usage conditions and adding to understanding of the treatment’s use and value. It also notes that the microspheres loaded with irinotecan received CE mark for the specified indication in 2015. These statements describe the registry’s context and purpose; they are not clinical outcome findings.
No randomized allocation or concurrent control arm is described, and allocation is not stated. The registry should therefore be read as an observational treatment registry rather than a randomized comparison. Without a like-for-like control group, the record cannot isolate the effect of treatment from other factors that may influence survival or adverse events.
The primary endpoint population is described as all enrolled subjects who received one or more TACE cycles. The primary endpoint was median overall survival, with a 24-month timeframe and a planned 95% confidence interval. The registry also lists objective response rate, best tumor response, liver progression-free survival, and time to progression as secondary outcomes. Numerical results for these outcomes are not reported in the registry record. The registry record does not describe the full protocol, treatment schedule, eligibility criteria, or statistical analysis plan.
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.
Enrolled and Completion of TACE Cycle 1
| Stage | Patients With Metastatic Colorectal Cancer to the Liver |
|---|---|
| STARTED | 105 |
| COMPLETED | 105 |
| NOT COMPLETED | 0 |
Completion of TACE Cycle 2
| Stage | Patients With Metastatic Colorectal Cancer to the Liver |
|---|---|
| STARTED | 105 |
| COMPLETED | 58 |
| NOT COMPLETED | 47 |
Analysis population for the primary outcome, as defined in the registry: All enrolled subjects received one or more TACE Cycles and therefore were included in the calculation of the primary endpoint, Median Overall Survival.
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 | Patients With Metastatic Colorectal Cancer to the Liver |
|---|---|---|
| Participants analysed | 105 | |
| Age, Continuous | years | 66 (SD 10.2) |
| Sex: Female, Male: Female | Participants | 22 |
| Sex: Female, Male: Male | Participants | 83 |
| Race and Ethnicity Not Collected | Participants | — |
| Region of Enrollment: Greece | Participants | 100 |
| Region of Enrollment: France | Participants | 5 |
| Baseline Disease Status: Tumor Location: Unilobar Liver Disease/Tumor Location | Participants | 65 |
| Baseline Disease Status: Tumor Location: Bilobar Liver Disease/ Tumor Location | Participants | 40 |
6. Primary Endpoint
The registry lists the primary outcome as Overall Survival, measured over 24 months.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | 95% Confidence Interval |
| Unit | months |
| Endpoint classification | Time-to-Event Analysis |
Overall survival is the time from a defined starting point until death from any cause. The registry’s primary endpoint is the median overall survival, expressed in months. The median is the time by which half of the analyzed population has experienced the event and half has not, subject to the handling of follow-up and censoring. It is a time-to-event summary, not an average survival time.
In general, a median can be useful when follow-up durations differ or when the distribution of event times is not well represented by a mean. A 95% confidence interval expresses uncertainty around the estimated median under the analysis method; it does not describe the range of survival times among individual participants. Its width is informative about precision: a wider interval indicates less precision than a narrower one.
The registry gives a timeframe of 24 months and describes analysis after subjects had been followed for survival for 24 months, were considered lost to follow-up, or had died, whichever came first. The stated primary population includes all enrolled subjects who received one or more TACE cycles. The numerical median and 95% confidence interval are not reported in the registry record, so the endpoint’s observed value and precision cannot be assessed from the reported information.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies median overall survival as its primary endpoint, but the numerical median and its 95% confidence interval are not reported in the registry record. Consequently, the posted information does not establish the observed survival time or how precisely it was estimated. The endpoint’s planned timeframe was 24 months; that timeframe is not itself an outcome result.
The record lists 105 enrolled participants and states that all enrolled subjects who received one or more TACE cycles were included in the primary-endpoint calculation. It does not report a numerical survival estimate, the number of participants included in a final survival analysis, or a follow-up summary. The record’s status of completed does not replace those missing outcome details.
The registry lists objective response rate, best tumor response, liver progression-free survival, and time to progression as secondary outcomes. Their numerical results are not reported in the registry record. It therefore is not possible to judge tumor response or progression outcomes from these details. The registry lists 5 outcome measures, but outcome names alone do not show what was observed.
For safety, the record lists 1 participant affected by a serious adverse event among 105 at risk, and 97 affected by other adverse events among 105 at risk. It also records 79 deaths. These are descriptive counts in the registry; the information does not establish that deaths or adverse events were caused by treatment. The serious adverse event term listed is tumor rupture, reported as 1.0%. The record does not provide the detail needed to interpret timing, duration, severity beyond the serious classification, or attribution.
Because no randomized comparison is described and allocation is not stated, the registry does not provide a controlled estimate of treatment effect. The safety and survival figures should be read as observations within a treated registry population, not as evidence that treatment caused a particular outcome or changed outcomes relative to an alternative. Any conclusion about comparative benefit or harm would require information and analyses not reported in the registry record.
9. Statistical Methods Explained
The primary endpoint is a time-to-event outcome. In general, time-to-event analyses use both the time until an event and information from participants whose event time is not observed during follow-up. When follow-up ends before an event is observed, the participant may be censored at the last time known to be event-free. Censoring is not the same as experiencing the event. The registry describes a follow-up rule involving 24 months, loss to follow-up, or death, whichever came first, but the analysis details for censoring are not reported in the registry record.
What does a median survival estimate convey?
The median is a location summary of the survival-time distribution: it marks the time at which the estimated survival probability reaches the midpoint. In general, it can be easier to interpret than a mean when follow-up is incomplete or survival times are skewed. It does not describe the experience of every participant, nor does it indicate whether the treatment caused the observed survival pattern. For this registry, no numerical median is reported, so its magnitude cannot be interpreted.
How should the confidence interval be read?
A 95% confidence interval gives an interval of plausible values for the endpoint under the assumptions of the statistical method. In general, narrower intervals indicate more precise estimates, while wider intervals indicate greater uncertainty. The interval is not a range expected to contain the survival time of most individuals. The registry names a 95% confidence interval for the median, but its endpoints are not reported in the registry record. Precision therefore cannot be evaluated.
What is the role of a hazard ratio?
In general, a hazard ratio compares the instantaneous event rates between groups over follow-up, subject to modeling assumptions. It is not the same as a ratio of median survival times and does not by itself give an absolute survival difference. A hazard ratio requires a defined comparison. No randomized comparison is described, and the numerical primary result is a median rather than a reported hazard ratio. A sponsor-reported hazard ratio is not reported in the registry record, so there is no such estimate to interpret.
What do the planning assumptions mean?
Any sample-size illustrations associated with this record are planning exercises, not observed trial results or retrospective proof of power. The stated assumptions use a two-sided significance level of 0.05, equal allocation between two hypothetical arms, and a normal approximation; the target effect is framed as a fraction of the observed effect. For time-to-event outcomes, the stated illustration concerns a total number of events using the Schoenfeld approach; other outcomes are framed as participants per arm. Those assumptions describe hypothetical planning and do not change the registry’s single-group design. No sample-size justification from the original study design is reported in the registry record. In general, planning calculations depend on their assumptions and should not be interpreted as the probability that a completed study detected a true effect.
Which analysis methods are documented?
The registry identifies the primary endpoint, its unit, its timeframe, and a confidence interval, but a detailed statistical analysis plan is not reported in the registry record. The record does not specify the estimator used for median survival, the confidence-interval construction, covariate adjustment, subgroup analyses, or interim analyses. Those details should not be inferred from the endpoint definition alone. No analyses are listed in the record’s analysis information.
Why does the design matter for interpretation?
In general, an uncontrolled registry can describe outcomes among people receiving a treatment under recorded practice conditions. It cannot by itself separate treatment effects from patient characteristics, disease course, additional care, or selection into treatment. A randomized control group is not described, and allocation is not stated. Consequently, statistical summaries of this registry would be descriptive rather than a randomized estimate of comparative treatment effect. Even a precise estimate within the treated group would not, on its own, establish what would have happened to comparable people under another treatment or no treatment.
10. Multiplicity, Missing Data and Analysis Populations
The registry names one primary outcome, overall survival, and lists secondary outcomes of objective response rate, best tumor response, liver progression-free survival, and time to progression. Considering several outcomes raises a general multiplicity issue: the more statistical claims tested, the greater the chance that at least one appears notable by chance if each is interpreted without accounting for the group of tests. The registry record does not report a multiplicity adjustment, a hierarchy for testing secondary outcomes, or a complete analysis plan. Numerical secondary-outcome findings are not reported in the registry record, so the impact of multiplicity on any claims cannot be assessed.
The primary endpoint description defines a follow-up window through 24 months, loss to follow-up, or death, whichever came first. It does not report how many participants had complete follow-up, how many were censored, or how missing observations were handled. The registry record also does not describe procedures for recovering missing information or sensitivity analyses. In general, incomplete follow-up can affect precision and interpretation in survival analysis; the consequences depend on why follow-up ended and on the analytic handling of those observations.
The stated primary population comprises all enrolled subjects who received one or more TACE cycles. This is a treatment-exposed population definition, but the record does not give a participant flow or explain whether any enrolled subjects did not meet that description. It also does not report analysis populations for the secondary outcomes. The missing details limit assessment of how the enrolled population relates to each reported endpoint.
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 |
|---|---|---|---|
| Patients With Metastatic Colorectal Cancer to the Liver | 1 | 105 | 1.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Patients With Metastatic Colorectal Cancer to the Liver | 79 of 105 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Patients With Metastatic Colorectal Cancer to the Liver | 97 of 105 |
Most frequent serious adverse event terms
| Event term | Organ system | Patients With Metastatic Colorectal Cancer to the Liver |
|---|---|---|
| Tumor rupture | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1 of 105 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Patients With Metastatic Colorectal Cancer to the Liver |
|---|---|---|
| Abdominal pain upper | Gastrointestinal disorders | 89 of 105 |
| Nausea | Gastrointestinal disorders | 28 of 105 |
| Vomiting | Gastrointestinal disorders | 19 of 105 |
| Fatigue | General disorders | 17 of 105 |
| Blood bilirubin increased | Investigations | 12 of 105 |
| Transaminases increased | Investigations | 10 of 105 |
| Pyrexia | General disorders | 4 of 105 |
| Abscess | Infections and infestations | 1 of 105 |
| Liver abscess | Infections and infestations | 1 of 105 |
| Overdose | Injury, poisoning and procedural complications | 1 of 105 |
Serious events with the highest arm-level rate: tumor rupture (1.0%).
The registry lists a group of patients with metastatic colorectal cancer to the liver and records 105 at risk for serious adverse events and 105 at risk for other adverse events. It reports 1 participant affected by a serious adverse event and 97 affected by other adverse events. These are descriptive safety counts; they do not establish that an event was caused by the microspheres or by irinotecan.
The serious adverse event term listed is tumor rupture, reported as 1.0%. That term and percentage describe what is recorded, not a comparative safety rate. The record does not provide event timing, duration, individual clinical context, or further details about attribution. The registry also lists 79 deaths. Deaths are important clinical outcomes, but the available information does not identify their causes or establish a relationship to treatment.
In general, safety counts need context such as the definition of each event category, the observation period, event severity, recurrence, and whether events were judged treatment-related. These details are not reported in the registry record. The counts should therefore be read as registry observations rather than as causal evidence or as a comparison with another therapy.
12. What the Result Does, and Does Not, Mean
The registry record describes prospective observation of a treatment used for colorectal cancer metastatic to the liver. It identifies median overall survival as the primary endpoint, reports enrollment of 105, and describes the primary population as enrolled subjects who received one or more TACE cycles. It also records safety information and names several secondary outcomes. These elements show what the registry set out to monitor, but they do not establish the size or direction of a treatment effect.
The numerical median overall survival and its 95% confidence interval are not reported in the registry record. Numerical results for the listed secondary outcomes are also not reported. Thus, the posted information does not permit assessment of the observed survival estimate, response, or progression outcomes, nor the precision of an estimated treatment effect. The record’s completion status is not a substitute for numerical outcome results.
The safety information records 1 participant affected by a serious adverse event and 97 affected by other adverse events, with 79 deaths. The serious adverse event term listed is tumor rupture at 1.0%. These registry entries are descriptive. They do not show whether events were attributed to treatment, how they occurred over time, or how outcomes would compare under a different treatment.
Because no randomized comparison is described, the registry cannot establish that treatment caused an outcome or was better or worse than an alternative. General statistical reasoning also cautions that a registry population may differ from people receiving other care in ways that influence observed outcomes. The record can contribute observational information about treatment use, but comparative conclusions require a suitable comparison and adequate outcome reporting, neither of which is described in the available record.
13. Why This Trial Matters Statistically
Prospective registries can capture experience in real-life usage conditions, a purpose stated for this study. Such records may be useful for describing treatment use, observed outcomes, and safety events in a defined clinical setting. Their statistical value depends on clear outcome definitions, complete follow-up information, and transparent reporting of estimates and uncertainty. This registry identifies its primary endpoint and several secondary outcomes, but their numerical results are not reported in the registry record.
The study also illustrates the distinction between describing outcomes and estimating comparative effects. Without a randomized comparison group, observed survival or adverse-event counts describe the registry population. They do not by themselves show what outcomes would have been under another treatment. This distinction is essential when readers encounter a treatment-focused registry or planning illustrations based on hypothetical comparisons.
Precision matters alongside an outcome estimate. The primary endpoint specifies a 95% confidence interval, but the interval and median are not reported. Without them, readers cannot judge the uncertainty of the primary estimate. Likewise, the listed secondary outcomes cannot be evaluated from outcome names alone. Clear reporting of estimates, uncertainty, follow-up, and analysis populations is needed for a fuller statistical interpretation.
The record’s stated objective—to add to understanding of treatment use and value—makes the difference between registry description and causal inference especially relevant. Observational data can contribute context, but the design and reporting determine which questions can be answered. Here, the available record supports description of the study’s aims, endpoint definitions, enrollment, and selected safety counts, while leaving the primary clinical estimate unreported.
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 for interpreting efficacy is that the numerical primary endpoint result is not reported in the registry record. The median overall survival and its 95% confidence interval are absent, so neither the estimated survival time nor its precision can be evaluated. Numerical findings for objective response rate, best tumor response, liver progression-free survival, and time to progression are also not reported.
The design is a prospective registry, with no randomized comparison described and allocation not stated. It therefore does not provide a like-for-like control comparison. Differences between registry participants and people receiving other care could influence outcomes, and the available record does not describe methods to address such differences. It also does not report the detailed statistical analysis plan, interim analyses, or sample-size justification.
Follow-up and missing-data details are limited. The endpoint description gives a 24-month timeframe and mentions loss to follow-up as a stopping condition, but the record does not report follow-up completeness, censoring counts, or the handling of missing observations. It does not provide a participant flow for the primary or secondary analyses.
Safety interpretation is also constrained. The record gives counts of participants affected by serious and other adverse events, a serious event term, and deaths, but does not report event timing, recurrence, attribution, causes of death, or a comparative safety group. These omissions limit causal interpretation and assessment of how completely the events were captured.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: HepaSphere™ Microspheres Prospective Registry — NCT04866290.
- Registry record last updated 2023-04-03; status last verified 2023-03.
- Results first posted 2022-10-12.
- 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.
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18. Record Summary
This completed prospective registry studied transarterial chemoembolization using HepaSphere™ Microspheres loaded with irinotecan for metastatic colorectal cancer to the liver. The sponsor was Merit Medical Systems, Inc. The record reports enrollment of 105, a start date of 2016-09-22, and a primary completion date of 2021-06.
The primary endpoint was median overall survival in months, with a 95% confidence interval and a 24-month timeframe. The primary population included enrolled subjects who received one or more TACE cycles. Secondary outcomes included objective response rate, best tumor response, liver progression-free survival, and time to progression.
The numerical primary and secondary outcome results are not reported in the registry record. Safety information includes 1 participant affected by a serious adverse event, 97 affected by other adverse events, and 79 deaths; tumor rupture is listed as a serious adverse event term at 1.0%. No randomized comparison is described.