To Evaluate the Optimal Dose of 68Ga-OPS202 as a PET (Positron Emission Tomography) Imaging Agent in Subjects With Gastroenteropancreatic Neuroendocrine Tumour (GEP-NET): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for To Evaluate the Optimal Dose of 68Ga-OPS202 as a PET (Positron Emission Tomography) Imaging Agent in Subjects With Gastroenteropancreatic Neuroendocrine Tumour (GEP-NET) (NCT03220217), a randomized phase 2 study. The primary outcome is Relative Lesion Counts Presented by Combination of Injected Peptide/Radioactivity Dose Ranges.

2. Clinical Question

3. Trial Design

This was a multicentre, randomised, single-masked, factorial Phase II dose-confirmation study. Its stated purpose was to evaluate the optimal dose of 68Ga-satoreotide trizoxetan as a PET imaging agent for detecting and localising GEP-NETs. The registry lists an enrollment of 29 and a completed status. The study began on 2017-09-26, with primary completion on 2019-07-25.

The factorial structure varied peptide mass and radioactivity dose. The intervention descriptions list peptide-mass ranges of 5-20 μg and 30-45 μg, with radioactivity ranges of 40-80 MBq, 100-140 MBq, and 160-200 MBq represented in the arm descriptions. Subjects received injections at different dose combinations. Some arm descriptions state that a second injection followed after 15 to 21 days; the full details of every arm sequence are not reported in the registry record.

The primary endpoint was assessed at Day 1 and Days 16 to 22. It used lesion counts from 68Ga-satoreotide trizoxetan PET/CT and PET readings, compared with lesions assessed on contrast-enhanced CT at Visit 2 (Day 1) and Visit 3 (Days 16 to 22). The record describes results by dose combination, after the first and second injections, for all organs, the primary GEP-NET site, and individual organs.

The stated primary analysis population was not every enrolled subject: it was a Per Protocol population defined by assessability and the absence of major protocol deviations that affected the primary endpoint. The registry record does not report the rationale for the planned enrollment or further details of the masking procedures.

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.

Before assignment: The Screening Visit (Visit 1) was performed within 2 weeks prior to the first 68Ga-satoreotide trizoxetan administration. Subjects' eligibility was re-checked by the investigator at Visit 2 (Day 1) before randomisation to 1 of 3 study arms (A, B or C) with differing 68Ga-satoreotide trizoxetan peptide mass dose and radioactivity dose range combinations.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Results are presented for the Per Protocol (PP) population which consisted of the first 24 randomised subjects who could be assessed and for whom no major protocol violations/deviations impacting primary endpoint results occurred. Only subjects with data available were included in the analysis.

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: The randomised population included all subjects randomly assigned to a dosing arm/sequence.

6. Primary Endpoint

The registry lists the primary outcome as Relative Lesion Counts Presented by Combination of Injected Peptide/Radioactivity Dose Ranges, measured over Day 1 and Days 16 to 22.

The primary endpoint was relative lesion count, expressed as a ratio: the number of lesions detected by 68Ga-satoreotide trizoxetan PET/CT and PET readings divided by the number of lesions assessed by the standard of truth. The standard of truth was contrast-enhanced CT. The endpoint was reported by peptide-mass and radioactivity-dose combination, following the first and second injections, and across all organs, the primary GEP-NET site, and individual organs. The planned summary statistic was the median, with the full range as the measure of dispersion.

A ratio puts the imaging agent’s lesion count in relation to the reference count, rather than presenting the PET count on its own. This can help describe how closely the imaging count corresponds to the chosen reference under each dose combination. In general, the ratio’s interpretation depends on the numerator and denominator being defined consistently and on understanding the reference method’s role. The endpoint description does not establish that contrast-enhanced CT is error-free; it identifies it as the study’s standard of truth.

The registry record does not report the median ratios or their full ranges. It therefore does not show the observed magnitude or direction of the primary-endpoint results, nor whether the values differed across dose combinations.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registered endpoint is a ratio of two lesion counts: lesions detected using 68Ga-satoreotide trizoxetan PET imaging and lesions assessed using contrast-enhanced CT as the standard of truth. The endpoint is described for PET/CT and PET readings. It is broken down by dose combination, organ grouping, and injection timing. The registry specifies a median and full range as the summary measures. It does not report the actual ratio values or ranges.

What does a ratio convey?

In general, a ratio relates one quantity to a reference quantity. Here, the numerator is the imaging-agent lesion count and the denominator is the count assessed by the study’s reference method. This framing makes the comparison relative to the reference count, rather than treating the PET count as a standalone measure. A ratio does not by itself explain why counts differ. Differences may reflect imaging performance, the reference assessment, or other features of measurement; the registry record does not report an analysis separating such explanations.

Why report a median and full range?

In general, the median is a measure of the centre of a set of observations that is less affected by extreme values than the mean. The full range gives the observed minimum and maximum and therefore indicates how broad the observed values are. A full range can be influenced by extreme observations and does not, by itself, show the distribution between those endpoints. Neither summary provides a confidence interval for the underlying population quantity. The record does not report confidence intervals for the primary endpoint, and the median and range values themselves are not reported.

How should the dose combinations be understood?

The study is described as factorial and varies peptide mass and radioactivity dose. In general, a factorial design can examine combinations of factors and may allow investigators to distinguish the contribution of each factor from the contribution of their combination, if the statistical plan and results support that interpretation. The registry record does not report the statistical model, the planned contrasts, or tests of interaction between peptide mass and radioactivity dose. It is therefore not possible to determine from the record whether effects were analysed separately, jointly, or through a particular factorial model.

The arm descriptions show different dose sequences, and the primary endpoint is specified after the first and second injections. These repeated assessments raise a general analytical consideration: observations from the same subject may be related. A valid analysis of repeated measurements generally needs to account for that relationship when estimating uncertainty. The registry record does not report how within-subject dependence was handled, or whether the same subjects contributed to each comparison.

What can be said about the analysis plan?

The registry identifies the endpoint, its summary statistic, its dispersion measure, its time frame, and the Per Protocol analysis population. It does not report a detailed statistical analysis plan, including the method for estimating uncertainty, hypothesis tests, adjustment variables, or a prespecified hierarchy among the endpoint categories. The registry also lists no analyses. The planned endpoint description should therefore not be mistaken for a complete statistical analysis plan or for a report of the findings.

The record’s sample-size assumptions describe a planning illustration based on an observed effect, using 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. Such illustrations are planning calculations, not observed power and not a substitute for the trial’s original design justification. The registry record does not report the original sample-size justification or identify the design assumptions behind the trial’s enrollment target.

In general, confidence intervals describe a range of values compatible with data and an estimation procedure, subject to that procedure’s assumptions. A narrower interval indicates greater precision under those assumptions; it does not establish that a result is unbiased or clinically important. Because primary-endpoint estimates and their uncertainty are not reported in the registry record, precision cannot be assessed for the lesion-count ratios. No recalculated comparison is available from the record, and there is no sponsor analysis to take precedence over a recalculation.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome is described across several categories and time points: dose combinations, the first and second injections, all organs, the primary site, and individual organs. The registry record does not report a single comparison that reduces those results to one estimate, and it lists no analyses. It also does not report how multiplicity was addressed. In general, examining multiple endpoints or comparisons can increase the chance of finding an apparently notable result by chance; statistical plans may address this through prespecified testing strategies or adjustments. Whether such a strategy was used in this study is not reported in the registry record.

The primary analysis used the Per Protocol population, defined as the first 24 randomised subjects who could be assessed and had no major protocol violations or deviations affecting primary-endpoint results. Only subjects with data available were included. This definition excludes some subjects from the endpoint analysis by design, but the record does not report the number with missing endpoint data, the reasons data were unavailable, or how missingness was handled beyond including only available data. It also does not report an intention-to-treat analysis or a comparison between analysis populations.

In general, missing observations can affect estimates if the availability of data is related to the outcome or to factors associated with it. The direction and extent of any such effect cannot be determined without information about the missing data and the analysis. The registry record does not report sensitivity analyses for missing outcomes.

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 lists serious adverse events and other adverse events separately for the dose groups and overall. For the overall group, 27 were at risk for the serious-adverse-event entry, 0 were affected, and deaths were 0. The corresponding overall entry for other adverse events lists 27 at risk and 18 affected. The arm-specific entries likewise report 0 affected for serious adverse events and 0 deaths; the counts affected for other adverse events vary across the listed dose groups.

These figures are registry counts for the recorded categories. They do not describe the type, timing, duration, severity, or causal attribution of the other adverse events; those details are not reported in the registry record. Nor do the counts establish that the different dose groups had equivalent safety profiles. Group sizes and follow-up may differ, and the record does not report a statistical comparison of safety between regimens.

The absence of recorded serious events in these entries should not be interpreted as proof that serious events cannot occur. These safety counts are descriptive and should be kept distinct from the primary imaging endpoint.

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

This study addresses an imaging-dose question: how lesion counts detected with 68Ga-satoreotide trizoxetan PET/CT and PET compare with lesion counts assessed by contrast-enhanced CT, across peptide-mass and radioactivity-dose combinations. The registry explains the endpoint and identifies the analysis population, but does not report the primary ratio values. The central result about the relative lesion counts therefore cannot be interpreted from the registry record.

The trial’s stated objective was to confirm an optimal dose. That objective does not itself show that an optimal dose was identified. Without reported primary-endpoint summaries, there is no basis in the record to determine which dose combination produced higher or lower relative lesion counts, how large any difference was, or how variable the measurements were. The record also does not provide the inferential results needed to assess uncertainty around dose comparisons.

The record does document a completed randomized, single-masked, factorial Phase II study and lists safety counts. Those details describe the study’s status and structure, not the magnitude or precision of its imaging results. The registry’s safety entries report no serious adverse events or deaths in the listed groups, alongside other adverse-event counts; they do not establish comparative safety or resolve the missing efficacy results.

In general, an endpoint is most informative when its estimate, uncertainty, analysis population, and comparison are all clear. Here, the endpoint definition and Per Protocol population are described, but the numerical estimates and detailed analysis methods are not reported in the registry record. The appropriate interpretation is consequently limited: the registry establishes what was intended to be measured, but not what the primary analysis found.

13. Why This Trial Matters Statistically

This trial is statistically notable for the way its imaging question combines two dose dimensions. Peptide mass and radioactivity dose were varied in a factorial Phase II study, and lesion-count ratios were intended to be examined across dose combinations. Such a design raises questions about the separate and joint contributions of the dose factors. The registry record does not provide the model or contrasts used to answer those questions, so the design description should not be treated as evidence that the effects were separated statistically.

The endpoint also links imaging results to a reference method. Ratios can make counts interpretable in relation to a standard of truth, but interpretation depends on the numerator, denominator, and reference assessment being clearly specified. The registry identifies contrast-enhanced CT as the reference and describes the ratio’s components. It does not report the resulting ratios, leaving the measurement framework visible while the outcome itself remains unavailable.

The endpoint spans organs, injection occasions, and dose combinations. In general, this breadth makes prespecification and multiplicity handling important: many related comparisons can be difficult to interpret as a single dose-confirmation result. The record does not report a single reduced comparison or the multiplicity strategy, so a summary claim about dose selection cannot be supported.

The registry also illustrates why an analysis population needs to be read alongside the endpoint. The primary analysis was restricted to a defined Per Protocol population and included only available data. That population is relevant to interpreting the target of the analysis, but the record does not describe missing-data handling in detail. These design and reporting features matter for understanding what a result would represent; in this case, the absent numerical primary results prevent assessment of either effect size or precision.

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 main limitation for interpretation is that the registry record does not report numerical results for the primary lesion-count ratios. Although it specifies the endpoint, summary statistic, dispersion measure, reference method, time frame, and analysis population, it does not provide the medians or full ranges. No effect estimate, uncertainty interval, or comparison among dose combinations can therefore be assessed from the record.

The primary endpoint covers multiple dose combinations, organs, and injection occasions, but the record does not report a single comparison that reduces those categories to one result. It does not report the statistical analysis plan, the model used, planned contrasts, or the approach to multiplicity. This limits interpretation of how the dose-confirmation question was intended to be answered analytically.

The primary population was the first 24 randomised subjects who could be assessed and had no major protocol violations or deviations affecting primary-endpoint results, and only subjects with data available were included. The registry does not report the number of missing endpoint observations, their reasons, or sensitivity analyses. It also does not report whether results were examined in another analysis population.

The record’s arm descriptions are incomplete, and the full details of every injection sequence are not reported. The sample-size information is described as a planning illustration based on an observed effect; it does not give the original sample-size justification. Finally, safety entries are aggregate counts without reported event details or statistical comparisons between groups. These limitations constrain both efficacy and safety interpretation.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: To Evaluate the Optimal Dose of 68Ga-OPS202 as a PET (Positron Emission Tomography) Imaging Agent in Subjects With Gastroenteropancreatic Neuroendocrine Tumour (GEP-NET) — NCT03220217.
• Registry record last updated 2021-01-14; status last verified 2021-01.
• Results first posted 2021-01-14.
• 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

NCT03220217 is a completed, multicentre, randomised, single-masked, factorial Phase II study of satoreotide trizoxetan PET imaging in GEP-NET. The registry lists enrollment of 29, a start date of 2017-09-26, and primary completion on 2019-07-25.

The primary endpoint was the ratio of lesions detected by PET/CT and PET readings to lesions assessed by contrast-enhanced CT, summarised by median and full range across dose combinations, organs, and injection occasions. The primary analysis population was a defined Per Protocol group, with available data included. Numerical primary-endpoint results and detailed analysis methods are not reported in the registry record. Safety entries report 0 serious adverse events and 0 deaths in the listed groups, with other adverse events also recorded.