Olaparib in Subjects With Advanced Pancreatic Acinar Cell Carcinoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Olaparib in Subjects With Advanced Pancreatic Acinar Cell Carcinoma (NCT05286827), a na phase 2 study. The primary outcome is Proportion of Participants With Partial Response (PR) or Complete Response (CR) Reported Along With a 95% Two-sided Confidence Interval.

2. Clinical Question

3. Trial Design

This was a phase II, single-group study of olaparib for advanced pancreatic acinar cell carcinoma. The registry lists an enrollment of 5 and identifies the National Cancer Institute as sponsor. The study started on 2023-12-14, had a primary completion date of 2024-12-18, and is marked terminated. The reason for termination is not reported in the registry record.

All participants were intended to receive olaparib; there was no separate control arm. The registry describes oral dosing twice daily in 28-day cycles, with treatment planned for up to 2 years. The protocol description says participants could stop treatment early if their cancer worsened or serious side effects occurred. That description does not establish what happened to individual participants.

Study visits were planned at the beginning of each cycle. The registry describes clinical assessments and CT scans every 8 weeks starting in cycle 2, along with research blood samples and optional tumor biopsies. These are planned procedures, not evidence that every assessment or procedure was completed.

The primary analysis population is reported as 4/5 participants, with one participant excluded as a screen failure. The record does not report the individual response outcomes, the response estimate, or the confidence interval. It also does not report the reason the study was terminated, whether all planned follow-up was completed, or the final follow-up duration.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: 4/5 participants were analyzed because one participant was a screen failure. Due to a small sample size, we are unable to make comparisons that might be interpretable and subject to scientific rigor.

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: Baseline characteristics collected for participants enrolled, not assigned to a Cohort/Arm and not treated are reported.

6. Primary Endpoint

The registry lists the primary outcome as Proportion of Participants With Partial Response (PR) or Complete Response (CR) Reported Along With a 95% Two-sided Confidence Interval, measured over 1-year.

The primary endpoint is the proportion of participants with a complete response or partial response, assessed using RECIST version 1.1, at the 1-year timeframe. It is a binary outcome at the participant level: a participant either meets the response definition or does not. The registry describes partial response as at least a 30% decrease in the sum of target-lesion diameters relative to baseline. Complete response requires disappearance of all target lesions; pathological lymph nodes must have a short axis below 10 mm.

A response proportion provides a direct summary of how many analyzed participants met the stated tumor-response criteria. A confidence interval communicates uncertainty around that estimate, which is especially important when the analysis population is small. It describes a range of values compatible with the data under the statistical method used; it does not guarantee that the true response proportion lies within that particular interval.

The record specifies a two-sided 95% confidence interval but does not report the response count, the estimated proportion, the interval, or the method used to calculate it. Consequently, the endpoint definition is available, but the primary result cannot be interpreted from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a binary response outcome. For each participant in the analysis population, the response assessment classifies the result as complete response, partial response, or neither. The primary measure combines complete and partial responses into one proportion. The registry identifies RECIST version 1.1 as the assessment framework and specifies the response criteria, but does not report the individual classifications or the final proportion.

What does a confidence interval add?

A confidence interval represents uncertainty in an estimate. For a response proportion, the observed data are used to estimate the proportion in the population from which the participants came, and an interval conveys how imprecise that estimate may be. A wider interval generally indicates less precision; a narrow interval generally indicates greater precision. The interpretation depends on the statistical method and its assumptions. The registry calls for a two-sided 95% confidence interval, but the interval and its calculation method are not reported in the registry record.

With a small analysis population, the estimate can be sensitive to the classification of an individual participant. This is a general feature of proportions based on few observations, not a separate finding about any participant in this study. A confidence interval can make that uncertainty more visible, but it cannot compensate for unreported outcomes or create information absent from the data.

Why does the single-group design matter?

A single-group study describes outcomes among participants receiving the intervention. Without a concurrent control group, it cannot directly estimate a comparative treatment effect against another treatment or against no intervention. Differences from external expectations would require assumptions about the comparability of populations, outcome assessment, and follow-up; those assumptions are not described in the registry record. The record itself notes that the small sample size did not allow comparisons that might be interpretable and subject to scientific rigor.

The study has no random allocation, and masking is recorded as none. These design features do not invalidate the descriptive endpoint, but they limit what can be concluded from it. In a non-masked setting, knowledge of treatment and clinical course can potentially affect decisions about assessment or follow-up; the record does not report whether such influences occurred. No adjustment or sensitivity analysis for these concerns is reported in the registry record.

How should the analysis population be read?

The record states that 4/5 participants were analyzed because one participant was a screen failure. This identifies the reported analysis population for the primary outcome. It does not explain whether the analysis was defined in advance, whether additional exclusions occurred for other outcomes, or how missing outcome assessments were handled. Those details are not reported in the registry record.

For a binary endpoint, the denominator and the classification rules are central to interpretation. A participant without an evaluable response assessment cannot simply be assumed to have a response or a nonresponse unless a specified analysis rule says so. The record does not state a rule for unevaluable or missing response assessments. It also does not report the response numerator, so neither the estimate nor its precision can be recovered from the reported analysis population alone.

What does over-dispersion mean in general?

Over-dispersion occurs when the variability in data is greater than a statistical model expects. It can make standard errors and confidence intervals too small if the model assumes less variability than the data contain. It is a general issue for some statistical models, particularly when observations vary more than a simple model permits. The registry record does not report an over-dispersion assessment or indicate that a model requiring such an assessment was used. The primary endpoint is defined as a proportion, but the particular estimation procedure is not reported.

How do the planning illustrations differ from study results?

Sample-size planning calculations are conditional illustrations, not observed outcomes and not observed power. The stated assumptions for the planning illustrations are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect expressed as a stated fraction of the observed effect. Those assumptions describe a hypothetical planning exercise; they do not describe the actual single-group design. A planning illustration cannot be read as the number of participants enrolled, the number analyzed, or evidence about the precision of the missing primary result. The registry record does not report the study’s own sample-size justification or statistical plan.

More broadly, the registry specifies an endpoint and a confidence level but does not report the statistical method used for the primary analysis, any model adjustments, or any interim analyses. These elements are not reported in the registry record and should not be inferred from the endpoint wording or the study’s phase.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 9 outcome measures, including the primary response outcome and secondary measures involving response and disease course, treatment-related serious adverse events, and serum lipase. Multiple outcomes can create multiple opportunities to examine results. In general, a prespecified multiplicity strategy can clarify how such findings should be interpreted, particularly when several outcomes are tested. The multiplicity approach, if any, is not reported in the registry record.

The primary analysis included 4/5 participants because one participant was a screen failure. The record does not report whether this population was prespecified, whether it was the only population used for analysis, or whether other outcomes used different populations. It also does not provide the response numerator or describe how missing, unevaluable, or incomplete assessments were treated. Missing-data methods and sensitivity analyses are not reported in the registry record.

The registry describes follow-up assessments and a 1-year timeframe for the primary endpoint, but it does not report how many participants completed assessment at that timeframe or whether follow-up differed among participants. The study is marked terminated; the reason and its implications for outcome availability are not reported. These omissions prevent assessment of whether missingness could have affected the reported endpoint.

The record identifies one analysis and lists the intended outcomes, but it does not report a detailed statistical analysis plan, interim analyses, or a sample-size justification. These details are not reported in the registry record and cannot be inferred from the number of listed outcomes or the planned confidence level.

11. 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 non-serious adverse event terms

The registry’s adverse-event summary lists 4 participants at risk for other adverse events, with 4 affected, and 4 participants at risk for serious adverse events, with 0 affected. It also records 3 deaths in the group. These are separate summary figures; the registry entries do not establish that the deaths were caused by olaparib or by an adverse event.

The serious-adverse-event count is not the same as the total number of adverse events. The record gives no serious-event terms, and the listed serious-event terms are empty. Although a secondary outcome describes treatment-related serious adverse events by grade and type using CTCAE version 5.0, the numerical grade- and type-specific results are not reported in the registry record. The record also does not supply the timing or circumstances of the deaths or state their relationship to treatment.

These figures should be read as a limited registry summary, not as a complete account of safety. With a small analysis population, the absence of recorded serious adverse events in this summary does not establish that serious harms cannot occur. The registry information does not support conclusions about comparative safety because there is no control group.

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

The record establishes that a phase II, single-group study of olaparib in advanced pancreatic acinar cell carcinoma was conducted, that enrollment was 5, and that 4/5 participants were included in the primary analysis after one screen failure. It also defines the primary endpoint as the proportion with complete or partial response at the 1-year timeframe and specifies a two-sided 95% confidence interval.

The primary response result itself is not reported in the registry record. There is no response count, proportion estimate, or confidence interval in the registry record for this analysis. Therefore, the record does not show how many analyzed participants met the response criteria or how precisely any response estimate was determined. It cannot support a conclusion about the frequency of response in the analyzed group.

Even if a response result were available, the single-group design would make it descriptive rather than a direct comparison with another treatment. The absence of randomization and masking, together with the lack of a concurrent comparator, limits causal interpretation. The registry itself states that the small sample size prevents comparisons that might be interpretable and subject to scientific rigor.

The registry lists several secondary outcomes, but their numerical results are not reported in the registry record. The safety summary records no serious adverse events among 4 at risk, other adverse events affecting 4 participants among 4 at risk, and 3 deaths. The relationship of the deaths to treatment is not reported. These safety counts do not, on their own, establish a treatment effect or a complete safety profile.

The terminated status does not explain why the study ended. Without that reason, outcome completeness, and the primary endpoint results, the registry record supports a description of the design and limited participant counts, but not a conclusion about efficacy or comparative benefit. It also does not establish whether the planned assessments and follow-up were completed.

13. Why This Trial Matters Statistically

This study addresses a rare tumor type identified in the registry as pancreatic acinar cell carcinoma. The registry describes the intended population as adults with disease that had not responded to previous treatments or who were not eligible for surgery. A trial record in this setting can be statistically informative by documenting its eligibility, endpoint definition, analysis population, and uncertainty, even when the study is small and has no control group.

The primary endpoint is clearly framed as a response proportion under RECIST version 1.1, and the record specifies a confidence interval. Those details help readers understand what response was intended to mean and how precision was meant to be presented. But the actual response estimate and interval are not reported in the registry entries available for this analysis. Without them, the central statistical question remains unanswered in the record.

The analysis population of 4/5 also illustrates why denominators matter. A screen failure was excluded from the primary analysis, but the response count is not reported. Even a clearly defined denominator cannot substitute for the numerator and the estimate needed to interpret an endpoint.

The study’s single-group design and small size are central to its statistical scope. It can describe outcomes in the participants studied, but it cannot provide a randomized, concurrent comparison. The registry further notes that comparisons would not be interpretable and subject to scientific rigor given the small sample size. These constraints are not incidental details: they determine what the design can and cannot establish.

For researchers and readers, the record also highlights the distinction between planned outcomes and reported results. Listing a response, survival, or safety outcome does not provide its estimate. Clear reporting of outcome values, confidence intervals, missing-data handling, and reasons for termination would be needed to assess the findings and their limitations more fully.

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 limitation for interpreting this trial record is that the primary response result is not reported. The record provides neither the response count nor the estimated proportion or its specified 95% confidence interval. Without these, the primary endpoint cannot be evaluated quantitatively.

The analysis population was small: 4/5 participants, with one screen failure. A result from such a small group would be sensitive to individual outcomes, and precision would be limited. The registry itself says that the small sample size prevents comparisons that might be interpretable and subject to scientific rigor. There is no concurrent control group, so the design does not support direct comparative treatment-effect estimation.

The study is marked terminated, but the reason is not reported in the registry record. The record also does not establish whether participants completed the planned follow-up or whether the primary endpoint was assessed for all analyzed participants. Missing-data handling, the primary analysis method, multiplicity procedures, interim analyses, and the study’s own sample-size justification are not reported.

Safety information is limited to group counts. Serious adverse-event terms, grades, and types are not reported, and the relationship between the 3 recorded deaths and treatment is not reported. The summary does not provide a basis for comparative safety assessment. Planned procedures and assessments described in the registry should not be assumed to have been completed for every participant.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Olaparib in Subjects With Advanced Pancreatic Acinar Cell Carcinoma — NCT05286827.
• Registry record last updated 2026-08-14; status last verified 2026-07.
• Results first posted 2026-03-11.
• 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.

18. Record Summary

NCT05286827 is a phase II, single-group study of olaparib in advanced pancreatic acinar cell carcinoma, sponsored by the National Cancer Institute. The registry lists enrollment of 5, a start date of 2023-12-14, a primary completion date of 2024-12-18, and a terminated status. The reason for termination is not reported in the registry record.

The primary endpoint was the proportion of participants with complete or partial response under RECIST version 1.1 at the 1-year timeframe, with a specified two-sided 95% confidence interval. The primary analysis included 4/5 participants because one was a screen failure. The response count, estimate, and confidence interval are not reported in the registry record.

The adverse-event summary records 0 serious adverse events among 4 at risk, other adverse events affecting 4 among 4 at risk, and 3 deaths. The deaths’ relationship to treatment is not reported. The study has no control group, and the registry states that the small sample size does not support interpretable comparisons.