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 ABX196 in Combination With Nivolumab in Patients With Hepatocellular Carcinoma (NCT03897543), a na phase 1, phase 2 study. The primary outcome is Incidence and Severity of Adverse Events (AEs).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03897543 |
| Phase | Phase 1, Phase 2 |
| Condition | Carcinoma, Hepatocellular |
| Allocation | Not applicable (single group) |
| Design model | Sequential |
| Masking | None (open label) |
| Enrollment | 10 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Abivax S.A. |
| Results posted | Yes |
2. Clinical Question
Population
Patients with hepatocellular carcinoma. The registry record gives an enrollment of 10 but does not report further participant characteristics in the primary outcome description.
Intervention
ABX196 in combination with nivolumab. ABX196 was administered intramuscularly at 0.1, 0.2, or 0.4 µg after the nivolumab infusion on Day 1 of every other 28-day treatment cycle. Nivolumab was administered intravenously at 240 mg on Days 1 and 15 of each 28-day cycle.
Comparator
There was no control treatment group. The listed groups represent ABX196 dose escalation, and the registry record identifies the study as open-label and uncontrolled. These groups are not a like-for-like control comparison.
Primary question
The primary endpoint was the incidence and severity of adverse events, assessed according to CTC-AE. The endpoint was evaluated from the first day of treatment up to 64 weeks of treatment, with up to 30 days of safety follow-up, for a total of up to 478 days.
The central statistical question is descriptive: what adverse-event counts were recorded in each ABX196 dose group during the stated safety observation period? The posted results report participant counts for serious adverse events, other adverse events, and deaths. They do not establish whether differences between dose groups are attributable to ABX196 dose, to nivolumab, to participant characteristics, or to chance.
The record also names Objective Response Rate (ORR), Progression Free Survival (PFS), Time to Progression (TTP), and change in Alpha Fetoprotein Serum as secondary outcomes. Their results are not reported in the registry record. Consequently, the clinical question that can be addressed from these posted results concerns safety counts, not an estimate of antitumor efficacy or a comparison with another treatment.
3. Trial Design
This was an open-label, uncontrolled Phase 1-2 study sponsored by Abivax S.A. The registry record lists the study as completed. It began on 2020-02-18, with primary completion on 2022-04-14. Enrollment was 10. The stated purpose was to evaluate the safety, tolerability, pharmacodynamic effects, and preliminary efficacy of ABX196 administered with nivolumab in patients with hepatocellular carcinoma.
The study used a sequential model and dose escalation. Its listed ABX196 groups were 0.1 µg, 0.2 µg, and 0.4 µg. ABX196 was given intramuscularly after the nivolumab infusion on Day 1 of every other 28-day treatment cycle. Nivolumab was given intravenously at 240 mg on Days 1 and 15 of each 28-day cycle. The registry record lists no masking and no allocation method.
Sequential dose groups can describe observations made at different dose levels, but they do not provide the protection against confounding that random allocation can offer. In particular, the record does not identify a concurrent control group receiving a different treatment or no ABX196. The groups therefore should not be read as randomized treatment arms, and their observed event counts do not support a direct causal comparison of doses.
Although the record describes a Phase 1-2 study, it does not report the protocol details needed to reconstruct dose-escalation decisions, cohort entry rules, or any transition between phases. The sample-size justification and the statistical plan are not reported in the registry record. The posted record also does not report whether any interim analyses were planned or performed. These omissions limit interpretation of how the study was designed to guide dose escalation or evaluate its stated secondary outcomes.
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 | ABX196 0.1 µg i.m. | ABX196 0.2 µg i.m. | ABX196 0.4 µg i.m. |
|---|---|---|---|
| STARTED | 4 | 3 | 3 |
| COMPLETED | 2 | 1 | 2 |
| NOT COMPLETED | 2 | 2 | 1 |
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 | ABX196 0.1 µg i.m | ABX196 0.2 µg i.m | ABX196 0.4 µg i.m | Total |
|---|---|---|---|---|---|
| Participants analysed | 4 | 3 | 3 | 10 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 | 2 | 1 | 4 |
| Age, Categorical: >=65 years | Participants | 3 | 1 | 2 | 6 |
| Age, Continuous | Years | 65.8 (49 to 76) | 60.3 (53 to 67) | 64 (60 to 67) | 63.6 (49 to 76) |
| Sex: Female, Male: Female | Participants | 0 | 1 | 1 | 2 |
| Sex: Female, Male: Male | Participants | 4 | 2 | 2 | 8 |
| Race/Ethnicity, Customized: Race – Asian | Participants | 1 | 1 | 1 | 3 |
| Race/Ethnicity, Customized: Race – Black or African American | Participants | 0 | 1 | 0 | 1 |
| Race/Ethnicity, Customized: Race – White | Participants | 3 | 1 | 2 | 6 |
| Region of Enrollment: United States | Participants | 4 | 3 | 3 | 10 |
| Hepatocellular Carcinoma | Participants | 4 | 3 | 3 | 10 |
6. Primary Endpoint
The registry lists the primary outcome as Incidence and Severity of Adverse Events (AEs), measured over From first day of treatment (randomization visit) up to 64 weeks of treatment + up to 30 days of safety follow-up (total: up to 478 days).
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint was the incidence and severity of adverse events (AEs), expressed as counts of participants. Events were evaluated according to CTC-AE. The observation window began on the first day of treatment and continued up to 64 weeks of treatment, with up to 30 days of safety follow-up; the record gives the total possible timeframe as up to 478 days.
Safety endpoints are used in early-phase studies to describe the types and frequency of harms observed during treatment and follow-up. Severity grading can help distinguish events of different clinical seriousness, while participant counts indicate how many participants in a group were recorded with an event. These are descriptive measures: without a control group, they cannot isolate the contribution of ABX196 from nivolumab, the underlying disease, or other causes.
The registry record gives serious and other adverse-event participant counts by dose group, but it does not provide a full severity distribution, event-level timing, or exposure-adjusted rates. Nor does it report a formal estimate with a confidence interval for the primary endpoint. The posted counts therefore describe recorded experience in these groups, rather than a precise estimate of event risk in a broader patient population.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted safety counts vary across the listed ABX196 dose groups. For serious adverse events, the record reports 1 of 4 participants in the 0.1 µg group, 0 of 3 in the 0.2 µg group, and 0 of 3 in the 0.4 µg group. For other adverse events, it reports 4 of 4, 2 of 3, and 3 of 3 participants, respectively. Deaths are recorded as 0 for each group. These are descriptive counts, not evidence of a dose-related pattern.
The groups are small, and the study is open-label, uncontrolled, and sequential. A count of zero in a group does not establish that an event cannot occur at that dose; it means only that none was recorded among the participants represented by that count. Likewise, a count in one group that differs from a count in another cannot be interpreted as a treatment effect. The groups were not described as randomized, and the registry record does not give a concurrent control comparison.
The serious-event term list identifies cellulitis at 25.0%. The record does not explain the denominator underlying that percentage or provide enough detail to connect the term percentage to a specific event count with certainty. It should be treated as a registry-reported term summary, not as a rate that can be compared with the group counts without that context.
The primary endpoint concerns adverse events. The registry record lists secondary efficacy outcomes, including ORR, PFS, TTP, and change in Alpha Fetoprotein Serum, but does not report their results. There are no posted analyses in the record for those outcomes, and no comparative efficacy estimate can be drawn from the information recorded. The study's purpose includes preliminary efficacy, but a stated purpose is not itself an efficacy finding.
The record does not report confidence intervals, hypothesis tests, adjusted estimates, or a prespecified statistical analysis plan. Without those details, the precision of the event counts cannot be quantified using posted inferential results. General statistical interpretation is that counts from a small uncontrolled study are most useful for describing what was observed and for identifying questions that may warrant further study; they are not a reliable basis for estimating differences between treatments.
It is also important not to treat dose groups as if they represented a dose-response experiment with otherwise comparable participants. Sequential enrollment can coincide with changes in participant mix, follow-up duration, or treatment exposure. The registry record does not report enough information to assess whether such factors differed across these groups. The observed counts are therefore best read group by group, with the limitations of the design kept in view.
9. Statistical Methods Explained
For an event-count endpoint, the simplest summary is the number of participants recorded with an event within each group. The registry record presents counts with group denominators for serious and other adverse events. A count is directly interpretable as a description of observed participants, but it does not by itself convey uncertainty about the underlying frequency in a wider population. A confidence interval, when reported, expresses statistical uncertainty around an estimate; no confidence intervals for these safety counts are reported in the registry record.
Severity and seriousness are related but distinct ways of characterizing adverse events. Severity refers to the degree of an event under the assessment system, while seriousness is a regulatory classification based on consequences. The primary endpoint refers to incidence and severity assessed according to CTC-AE, and the posted safety breakdown separately identifies serious events and other events. The registry record does not provide the detailed grading distribution needed to examine severity category by category.
When event counts are low, estimates are inherently imprecise. A small change in the observed count can make a group summary look substantially different, even when the underlying event frequency is uncertain. In general, uncertainty intervals help make this imprecision visible. Their absence means the posted counts should not be mistaken for precise population risks. No new interval or event rate can be recovered from the record without making assumptions that are not documented there.
Comparisons across groups need special care. Randomization can help balance measured and unmeasured participant characteristics between treatment groups on average. This study is described as uncontrolled, with sequential dose escalation and allocation listed as NA. The record explicitly cautions that the dose groups are not a like-for-like control comparison. A statistical test comparing their counts would not remove the design limitations, and no such test is reported.
Exposure time also matters when participants have different durations of observation or treatment. A simple participant count does not adjust for differences in time at risk. The endpoint timeframe permits treatment up to 64 weeks and safety follow-up up to 30 days, with a total of up to 478 days, but the record does not give individual observation durations or exposure-adjusted event rates. Therefore, the group counts cannot be interpreted as person-time rates or as directly standardized risks.
The record lists a planning illustration based on a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. Such a planning exercise is not the study's own design, and its assumptions do not convert this sequential uncontrolled trial into a two-arm comparative trial. The registry record does not report the study's sample-size justification. Any sample-size values in a planning illustration should therefore be understood as hypothetical planning outputs, not as observed power or evidence that the trial was adequately powered for a treatment comparison.
In general, power is a design concept describing the probability of detecting a specified effect under stated assumptions. It is not a measure of whether a study found a true effect, and calculating power after observing results does not resolve uncertainty in those results. The planning illustration described in the record is separate from the posted safety counts and should not be interpreted as proof that the study could detect a particular safety or efficacy difference.
The registry record reports no analyses for the named secondary outcomes. It does not give methods for handling repeated measurements, time-to-event censoring, missing observations, or adjustment for prognostic factors. For time-to-event outcomes such as PFS and TTP, general methods account for follow-up time and censoring rather than treating every participant's observation as a simple binary outcome. The record does not establish which methods, if any, were used for those endpoints.
In general, over-dispersion is a concern when variation in event counts exceeds what a chosen statistical model expects. A model that assumes less variability than the data contain can produce uncertainty estimates that are too narrow. The record does not report a count-model analysis or the information needed to assess over-dispersion. No model-based inference should therefore be attributed to the posted counts.
The statistical plan, prespecified analysis populations, definitions of evaluable participants, and treatment of protocol deviations are not reported in the registry record. These details matter because different analysis populations can yield different summaries, particularly when exposure or follow-up is incomplete. The posted group denominators describe the participants included in the recorded safety summaries; they do not establish how the investigators defined all analysis populations or handled missing data elsewhere in the study.
10. Multiplicity, Missing Data and Analysis Populations
The record names several secondary outcomes in addition to the primary safety endpoint: ORR, PFS, TTP, and change in Alpha Fetoprotein Serum. It does not report results or analyses for these outcomes. The number of outcome measures is listed as 5, while the record reports no analyses. The statistical plan and any prespecified hierarchy among outcomes are not reported in the registry record.
Multiplicity arises when several outcomes, groups, time points, or statistical tests are examined. In general, considering many tests can increase the chance of observing an apparently notable result by chance. A prespecified testing strategy or an explicit adjustment can address this issue, but neither is described in the record. Since no inferential results for the secondary outcomes are posted, there is no basis for determining whether or how multiplicity was handled.
Missing-data methods are also not reported in the registry record. The record does not explain whether any participants had incomplete safety follow-up, how incomplete observations were classified, or how missing values were handled for the secondary outcomes. The listed safety denominators indicate the counts used in the posted group summaries, but they do not describe the completeness of every endpoint or the study's rules for missing information.
The record does not describe analysis populations, such as whether summaries included all enrolled participants, only participants who received treatment, or another defined group. It also does not report a protocol or statistical plan that would clarify those choices. As a result, interpretation should stay close to the posted safety counts and should not assume an undocumented missing-data or multiplicity procedure.
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 |
|---|---|---|---|
| ABX196 0.1 µg | 1 | 4 | 25.0% |
| ABX196 0.2 µg | 0 | 3 | 0.0% |
| ABX196 0.4 µg | 0 | 3 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| ABX196 0.1 µg | 0 of 4 |
| ABX196 0.2 µg | 0 of 3 |
| ABX196 0.4 µg | 0 of 3 |
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 |
|---|---|
| ABX196 0.1 µg | 4 of 4 |
| ABX196 0.2 µg | 2 of 3 |
| ABX196 0.4 µg | 3 of 3 |
Most frequent serious adverse event terms
| Event term | Organ system | ABX196 0.1 µg | ABX196 0.2 µg | ABX196 0.4 µg |
|---|---|---|---|---|
| Cellulitis | Infections and infestations | 1 of 4 | n/a of 3 | n/a of 3 |
Most frequent non-serious adverse event terms
| Event term | Organ system | ABX196 0.1 µg | ABX196 0.2 µg | ABX196 0.4 µg |
|---|---|---|---|---|
| Fatigue | General disorders | 2 of 4 | 2 of 3 | 0 of 3 |
| Platelet count decrease | Investigations | 2 of 4 | 2 of 3 | 0 of 3 |
| Diarrhoea | Gastrointestinal disorders | 2 of 4 | 0 of 3 | 1 of 3 |
| Abdominal pain | Gastrointestinal disorders | 1 of 4 | 1 of 3 | 0 of 3 |
| Abdominal pain lower | Gastrointestinal disorders | 2 of 4 | 0 of 3 | 0 of 3 |
| Aspartate aminotransferase increase | Investigations | 1 of 4 | 0 of 3 | 1 of 3 |
| Back pain | Musculoskeletal and connective tissue disorders | 2 of 4 | 0 of 3 | 0 of 3 |
| Corona Virus Infection | Infections and infestations | 0 of 4 | 1 of 3 | 1 of 3 |
| Vaccination complication | Injury, poisoning and procedural complications | 1 of 4 | 1 of 3 | 0 of 3 |
| Hypertension | Vascular disorders | 2 of 4 | 0 of 3 | 0 of 3 |
Serious events with the highest arm-level rate: cellulitis (25.0%).
The serious adverse-event counts are 1 of 4 participants in the ABX196 0.1 µg group, 0 of 3 in the 0.2 µg group, and 0 of 3 in the 0.4 µg group. The other adverse-event counts are 4 of 4, 2 of 3, and 3 of 3, respectively. The death count is 0 in each group. These figures describe participants represented in the registry's safety summaries; they do not establish why an event occurred.
The serious-event term list reports cellulitis at 25.0%. The registry record does not state the denominator for that percentage in the term list, so it should not be treated as a group-specific percentage or combined with the serious-event counts. Nor should the absence of reported deaths or serious events in a group be interpreted as proof that risk is absent. Counts from a small, uncontrolled study are descriptive and have limited precision.
The treatment combines ABX196 and nivolumab, and there is no control group to separate their contributions. These event figures are not comparative estimates of harm, and the record does not provide exposure-adjusted rates or detailed event timing.
12. What the Result Does, and Does Not, Mean
The registry record documents safety observations from an open-label, uncontrolled Phase 1-2 study of ABX196 with nivolumab in hepatocellular carcinoma. It reports participant counts for serious adverse events, other adverse events, and deaths across three ABX196 dose groups. Those data describe what was recorded in the groups and over the stated safety observation period.
The findings do not determine whether ABX196 caused a particular event, whether nivolumab contributed, or whether an event arose from the underlying disease or another cause. The absence of a control group prevents a direct comparison with an alternative treatment or with no ABX196. The sequential dose groups are not randomized comparison groups, so differences between their counts should not be interpreted as evidence that one dose is safer or less safe than another.
The record also does not establish a treatment effect on tumor response, progression, or Alpha Fetoprotein Serum. Although these outcomes are listed as secondary endpoints, their results are not reported in the registry record. No conclusion about efficacy follows from the stated study purpose or from the safety counts alone.
More broadly, these results are a limited description from a small study rather than a precise estimate for a wider population. The record does not report confidence intervals, a statistical analysis plan, detailed participant characteristics, or exposure-adjusted safety estimates. Those omissions restrict evaluation of uncertainty, comparability across dose groups, and generalizability.
The results can inform understanding of what was recorded during this study, but they do not establish a causal relationship or provide a controlled estimate of treatment benefit or harm. Any interpretation should distinguish the observed counts from conclusions that the design and posted analyses cannot support.
13. Why This Trial Matters Statistically
Early-phase studies often have a descriptive role: they record safety and tolerability while treatment is being evaluated and may inform further research. This record illustrates why the design context matters as much as the observed counts. Dose escalation, sequential enrollment, and the absence of a control group mean the group summaries should not be read as a randomized comparison.
The posted safety counts make clear what the registry reports for each ABX196 dose group, while the limits of the record make clear what remains uncertain. The counts do not show whether events were caused by ABX196, nivolumab, or other factors. They also do not provide adjusted comparisons or quantify uncertainty with confidence intervals. This distinction between observation and inference is central to responsible interpretation of small clinical studies.
The record names efficacy outcomes but does not report their results. That gap matters statistically because a trial's stated objectives and its available outcome data are not interchangeable. Readers should distinguish the planned or named questions from the questions that the posted analyses can answer.
Finally, the sample-size planning assumptions described in the record are illustrative rather than evidence of the trial's own design. They presume a two-arm, equal-allocation framework, unlike the recorded sequential dose groups. Recognizing that mismatch helps prevent hypothetical planning calculations from being mistaken for observed power or a formal comparison. Overall, the study is informative as a record of safety observations, while its design and incomplete outcome reporting limit stronger statistical conclusions.
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 study is open-label and uncontrolled, and the registry record lists sequential dose escalation rather than random allocation. The dose groups therefore cannot serve as like-for-like controls. Differences in recorded counts may reflect factors other than dose, and the record does not provide participant characteristics or adjusted analyses that would help assess comparability.
Enrollment was 10, and the posted safety group counts are small. In general, small groups yield imprecise estimates, and a zero count does not rule out an event occurring in a broader population. The registry record does not report confidence intervals or other uncertainty measures for the safety summaries.
The primary endpoint includes incidence and severity assessed according to CTC-AE, but the posted details do not provide a full severity distribution, event-level timing, or exposure-adjusted rates. The maximum observation timeframe is stated, but individual follow-up durations are not reported. The serious-event term percentage is listed without a stated denominator in that term summary.
The secondary outcomes are named but their results are not reported in the registry record. The statistical plan, sample-size justification, interim analyses, analysis populations, and missing-data procedures are also not reported. These gaps prevent assessment of prespecification, multiplicity handling, endpoint-specific methods, and the completeness of follow-up. The posted record consequently supports a narrow descriptive reading of the safety counts, not a comprehensive evaluation of efficacy or comparative safety.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: ABX196 in Combination With Nivolumab in Patients With Hepatocellular Carcinoma — NCT03897543.
- Registry record last updated 2026-09-29; status last verified 2026-08.
- Results first posted 2026-09-29.
- 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.
18. Record Summary
NCT03897543 is a completed, open-label, uncontrolled Phase 1-2 study of ABX196 with nivolumab in patients with hepatocellular carcinoma. The study used sequential dose escalation, with ABX196 groups of 0.1 µg, 0.2 µg, and 0.4 µg. Enrollment was 10.
The primary endpoint was the incidence and severity of adverse events assessed according to CTC-AE, from the first day of treatment up to 64 weeks of treatment plus up to 30 days of safety follow-up, for a total of up to 478 days. The posted results give serious and other adverse-event participant counts and death counts by dose group. They also list cellulitis at 25.0% among serious adverse-event terms.
ORR, PFS, TTP, and change in Alpha Fetoprotein Serum are listed as secondary outcomes, but their results are not reported in the registry record. The study's statistical plan, sample-size justification, missing-data methods, and analysis populations are not reported. Because there is no control group and the dose groups are sequential, the counts are descriptive rather than comparative estimates.