9-ING-41 Plus Retifanlimab and Gemcitabine/Nab-Paclitaxel in Patients With Advanced Pancreatic Adenocarcinoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for 9-ING-41 Plus Retifanlimab and Gemcitabine/Nab-Paclitaxel in Patients With Advanced Pancreatic Adenocarcinoma (NCT05239182), a na phase 2 study. The primary outcome is Disease Control Rate (DCR).

2. Clinical Question

3. Trial Design

This was a phase 2, single-group study of a combination regimen for advanced pancreatic adenocarcinoma. The registry describes the regimen as frontline therapy and lists 9-ING-41, retifanlimab, gemcitabine, and Abraxane, the brand name used in the record for nab-paclitaxel. The study was unmasked, and allocation is listed as not applicable. There was no randomized control arm, so the design does not support a direct concurrent comparison of the combination with a separate treatment group.

The record lists seven enrolled participants. It gives a start date of 2022-01-26 and a primary completion date of 2022-12-20, and lists the study status as terminated. These record details describe enrollment and study status; they do not establish why the study was terminated or what outcomes were observed. The reason for termination is not reported in the registry record.

The recorded chemotherapy schedule specifies intravenous nab-paclitaxel at 125 mg per square meter followed by gemcitabine at 1000 mg per square meter on days 1, 8, and 15 of a 28-day cycle. Retifanlimab is listed at 500 mg intravenously on day 1 of a 28-day cycle. The description available for the 9-ING-41 schedule is incomplete, so its dose and administration schedule are not reported in the registry record.

The primary endpoint was disease control rate, defined for treated patients who were radiologically evaluable. Other listed outcomes include best response, overall response rate, adverse events and serious adverse events, duration of response, progression-free survival, and overall survival. The registry record does not report statistical analysis results for these outcomes. The protocol’s planned analysis methods, planned enrollment target, and reason for study termination 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.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Treated patients who were radiologically evaluable.

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.

6. Primary Endpoint

The registry lists the primary outcome as Disease Control Rate (DCR), measured over Up to approximately 11 months from baseline.

Disease control rate is the percentage of patients whose disease meets a specified response or stability criterion over a defined assessment period. In this study, the endpoint included complete response, partial response, or stable disease lasting at least 16 weeks during treatment. The endpoint description identifies RECIST v1.1 as the response framework. Under that framework, complete response concerns disappearance of target lesions, partial response requires a specified decrease in their summed diameters, and stable disease falls between the criteria for response and progressive disease.

The endpoint combines tumor shrinkage with maintained disease status. That can be useful in a study where the question is whether patients experience response or sustained stability, rather than whether shrinkage alone occurs. The duration requirement means a response or stable status must persist through the stated period to count toward disease control. This makes the endpoint a categorical measure tied to imaging assessments and time on treatment, not a direct measure of survival or symptom improvement.

The denominator is defined as treated patients who were radiologically evaluable. The number of patients meeting that definition and the number meeting the disease-control definition are not reported in the registry record. Consequently, the recorded information does not establish the observed percentage or its precision. The endpoint also does not, by itself, establish that any observed disease status was caused by the regimen; interpretation depends on the study design and the quality and completeness of outcome assessment.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record describes the primary outcome as a percentage and defines the analysis population as treated patients who were radiologically evaluable. It does not include an efficacy result or statistical analysis entry. The methods below explain how such results are ordinarily interpreted; they do not claim that these methods were used in this study. The statistical analysis plan is not reported in the registry record.

What does a percentage endpoint represent?

In general, a percentage endpoint expresses the number of participants meeting a prespecified outcome definition relative to the relevant analysis population. Here, the endpoint definition combines response categories with a duration condition. A participant would need to meet the specified RECIST category and the stated duration criterion to count as having disease control. The meaning of the percentage depends on both the numerator and the denominator, so the population definition matters as much as the response criteria.

The endpoint population is not automatically identical to the enrollment population. The record specifies treated, radiologically evaluable patients, while it separately lists seven enrolled participants. Without the endpoint denominator and outcome count, the percentage cannot be reconstructed. It would be inappropriate to assume that every enrolled participant was treated, evaluable, or assessed at the required time.

What does a confidence interval convey?

In general, a confidence interval describes the statistical uncertainty around an estimated quantity under the assumptions of the method used. For a percentage, the interval reflects that the observed proportion is based on a finite group and may differ from the underlying proportion in a broader population. A narrower interval generally indicates greater precision, while a wider interval indicates greater uncertainty. An interval does not resolve limitations in study design, measurement, or representativeness.

No confidence interval for disease control rate is reported in the registry record. With no endpoint estimate, its precision cannot be assessed from the recorded efficacy results. The confidence level and interval method planned for the primary outcome are also not reported in the registry record.

How does the single-group design affect inference?

In general, a single-group study can describe outcomes among participants receiving a regimen, but it does not provide a concurrent randomized estimate of what would have happened under a comparator regimen. Differences between observed outcomes and expectations from other populations can reflect differences in patient characteristics, assessment procedures, follow-up, or other influences. A nonrandomized external comparison would require additional data and assumptions; such a comparison is not reported in the registry record.

The record lists allocation as not applicable and the model as single-group. Thus there is no like-for-like control arm in the recorded design. This is not a matter of choosing a different statistical test: without a concurrent comparison group, a comparative effect cannot be estimated from randomized between-group data.

Why can a small denominator create uncertainty?

In general, proportions based on limited observations can change substantially when the outcome status of a participant changes. Their uncertainty is therefore important to report alongside the point estimate. The registry lists seven enrolled participants, but it does not report the primary endpoint denominator or numerator. No new percentage or uncertainty measure can be calculated from the enrollment entry alone.

Methods for binary outcomes may also differ in how they estimate uncertainty, particularly when the observed percentage is near an endpoint of its possible range. Which interval method, if any, was planned or used is not reported in the registry record. No hypothesis test or p-value for the primary endpoint is reported.

What is over-dispersion, and is it relevant?

In general, over-dispersion means observed variability exceeds what a statistical model assumes. It can arise when outcomes are more heterogeneous or clustered than the model allows, and can make standard errors and confidence intervals too optimistic if ignored. This is a general statistical consideration rather than a reported feature of this trial. The registry record does not describe a model for the primary endpoint, a dispersion assessment, or an adjustment for over-dispersion.

How should planning illustrations be read?

In general, a sample-size calculation illustrates the amount of information a future study might need under stated assumptions. It is not an observed result and does not measure the probability that this completed study found a real effect. The planning assumptions associated with the displayed calculations specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. For time-to-event calculations, the assumptions refer to a total number of events, while other calculations are expressed as participants per arm.

Those assumptions describe a planning illustration, not the design of this single-group study. The record does not report a statistical rationale for the trial’s actual enrollment, and the planning illustration should not be interpreted as observed power. Since no primary efficacy estimate is recorded, the underlying observed effect used for such an illustration cannot be assessed from the efficacy entries. The study’s planned sample size and statistical power are not reported in the registry record.

What is not known about the analysis?

The registry record does not state how missing imaging assessments were handled, which analysis populations were used beyond the primary endpoint population definition, or whether any sensitivity analyses were planned. It does not report interim analyses, covariate adjustment, multiplicity procedures, or the planned statistical test. These details should not be inferred from the phase, endpoint label, or study status. Without a recorded analysis plan and outcome results, the statistical interpretation must remain descriptive and limited to the entries that are available.

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("9-ING-41 Plus Retifanlimab Plus Gem/Abraxane")
n      <- c(6)
events <- c(6)
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  9-ING-41 Plus Retifanlimab Plus Gem/Abraxane  6  6  100.0  54.1  100.0  61.0  100.0  59.0  99.6

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary endpoint and several secondary outcomes, including best response, overall response rate, adverse events and serious adverse events, duration of response, progression-free survival, and overall survival. When a study assesses multiple outcomes or performs repeated statistical tests, multiplicity can increase the chance of at least one apparently notable result arising by chance. In general, a prespecified testing hierarchy or adjustment can address that issue. The registry record does not report whether any multiplicity procedure or testing hierarchy was planned.

There are no statistical analysis results recorded for the listed efficacy outcomes. The record therefore does not provide a basis for determining whether outcomes were analyzed, whether tests were performed, or how any multiple comparisons were handled. It would be inappropriate to infer a correction method or testing order.

The primary endpoint population is described as treated patients who were radiologically evaluable, but the record does not report its size or explain how participants without evaluable imaging were handled. The handling of missing outcome assessments, withdrawals, protocol deviations, and incomplete follow-up is not reported in the registry record. It is also not reported whether an intention-to-treat population or another analysis population was used for secondary outcomes.

In general, missing outcome data can affect both the denominator and the estimated outcome rate, especially when the availability of an assessment is related to a participant’s health or study discontinuation. Sensitivity analyses can examine how conclusions change under different assumptions about missing observations. Whether such analyses were planned or performed is not reported in the registry record. These uncertainties limit interpretation independently of the single-group design and the absence of efficacy results.

12. Safety Results

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

Deaths

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: sepsis (28.6%), blood bilirubin increased (14.3%), anemia (14.3%), colitis (14.3%), thromboembolic event (14.3%).

The safety listing is for the 9-ING-41 plus retifanlimab plus Gem/Abraxane group. It reports serious adverse events affecting four of seven participants at risk, other adverse events affecting seven of seven at risk, and four deaths. The registry also lists sepsis at 28.6%, with blood bilirubin increased, anemia, colitis, and thromboembolic event each listed at 14.3% among the top serious-event terms.

These are descriptive registry entries. The term “serious” is a safety classification and should not be treated as synonymous with severe intensity. The listed terms and percentages do not establish that events were caused by a study drug, and the record does not report event narratives, timing, duration, or attribution. The top-term list does not indicate whether events occurred in the same or different participants, so its entries should not be added together. The cause and timing of the recorded deaths are not reported in the registry record.

The at-risk group counts are not an efficacy denominator and should not be used to infer the number of radiologically evaluable patients. Because this was a single-group study without a concurrent control, the safety entries do not provide a comparative estimate of excess risk. They describe what the registry records for this group, with no causal or comparative conclusion established by these counts alone.

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

The registry record establishes that a phase 2, single-group study of 9-ING-41, retifanlimab, gemcitabine, and nab-paclitaxel was conducted in advanced pancreatic adenocarcinoma and was later listed as terminated. It records seven enrolled participants and defines disease control rate as the primary endpoint. It also records safety counts and serious-event terms for the treatment group.

What the record does not establish is the observed disease control rate. It contains no endpoint numerator, no endpoint denominator, and no efficacy analysis result. It therefore cannot show from the recorded data how many treated, radiologically evaluable participants met the response-or-stability definition, nor how precise any resulting estimate would be. The absence of a reported estimate should not be mistaken for evidence that no participant experienced disease control.

Even a reported outcome rate from this design would be descriptive of the study group rather than a randomized comparison with another treatment. Without a control group, observed outcomes cannot isolate the effect of the combination from other influences. The record does not provide an external comparator, comparative treatment-effect estimate, or adjustment that would change that design limitation.

The safety figures indicate recorded events in the treatment group, but they do not establish causation, comparative safety, or the circumstances of the deaths. The reason for termination and the explanation for the missing efficacy analysis are not reported in the registry record. Overall, the record supports a limited account of study design, the intended primary endpoint, and some safety entries; it does not support a quantitative conclusion about efficacy or a causal conclusion about treatment effects.

14. Why This Trial Matters Statistically

This study illustrates why a registry record needs to be read at the level of both design and available results. The record identifies a clinically relevant endpoint, a defined imaging-based response framework, and a time requirement for disease control. Those definitions make clear what the intended measure represents. Yet without the endpoint count and denominator, the endpoint cannot be translated into an observed rate or an uncertainty estimate.

The single-group design also illustrates a distinction between describing outcomes and estimating comparative effects. A response percentage, if reported, would characterize the assessed participants in the regimen group. It would not provide the randomized contrast needed to separate treatment-associated outcomes from other explanations. This limitation remains even when an endpoint is clearly defined and the assessment criteria are standardized.

The safety entries highlight another statistical distinction: counts and percentages are useful descriptions, but they do not establish causation or comparative risk. Serious-event terms can overlap within participants, and their registry listing does not reveal event timing or attribution. Interpretation requires keeping the recorded descriptive information separate from causal claims.

Finally, the terminated status and lack of recorded efficacy analyses make transparency about missing results especially important. The registry record does not explain the termination or provide an analysis plan that would clarify how the intended outcomes were to be handled. For researchers and clinical statisticians, this is a reminder to distinguish planned endpoints, observed data, and analyzed results. A well-specified endpoint is not a substitute for a reported estimate, and enrollment is not an outcome.

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.

Several trial-specific limitations constrain interpretation. The design is single-group and unmasked, with allocation listed as not applicable. There is no concurrent control group for a randomized comparison, so the record cannot provide a treatment contrast against another regimen. The small enrollment listed in the record also means that any descriptive estimate, if available, would need to be interpreted in light of its precision; the registry does not report a primary endpoint estimate or confidence interval.

The study is listed as terminated, but the reason for termination is not reported in the registry record. The record gives a primary completion date, but does not report why the study stopped, whether follow-up continued after that date, or whether planned assessments were completed. The complete 9-ING-41 dosing schedule is not reported in the registry record, limiting the regimen details available in this entry.

The primary analysis population is defined as treated, radiologically evaluable patients, but its size and outcome count are not reported. The handling of missing imaging, withdrawals, and incomplete follow-up is not reported in the registry record. No efficacy analysis results, confidence intervals, or statistical tests are recorded for the primary endpoint or listed secondary outcomes. The analysis plan, multiplicity approach, and planned enrollment target are also not reported.

Safety information is presented as group-level counts and selected serious-event terms. Event timing, severity grading beyond the serious classification, relationship to study treatment, participant-level overlap, and causes of death are not reported in the registry record. Without a comparator, the listed safety counts cannot quantify comparative risk. Together, these limitations leave the available record informative about intended design and selected safety entries, but insufficient for an efficacy estimate or a causal treatment-effect conclusion.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: 9-ING-41 Plus Retifanlimab and Gemcitabine/Nab-Paclitaxel in Patients With Advanced Pancreatic Adenocarcinoma — NCT05239182.
• Registry record last updated 2025-07-17; status last verified 2025-06.
• Results first posted 2025-07-17.
• 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

NCT05239182 is listed as a phase 2, unmasked, single-group study of 9-ING-41 plus retifanlimab and gemcitabine/nab-paclitaxel for advanced pancreatic adenocarcinoma. The record lists seven enrolled participants, a start date of 2022-01-26, a primary completion date of 2022-12-20, and a terminated status.

The primary endpoint was disease control rate among treated, radiologically evaluable patients, based on complete response, partial response, or stable disease lasting at least 16 weeks. No efficacy analysis results are reported. The safety entries list serious adverse events affecting four of seven at risk, other adverse events affecting seven of seven at risk, and four deaths. The reason for termination, primary endpoint result, and statistical analysis plan are not reported in the registry record.