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 Induction and Maintenance of Castration After Subcutaneous Injections of Triptorelin Pamoate in Patients With Prostate Cancer (NCT01715129), a na phase 3 study. The primary outcome is Percentage of Subjects Demonstrating Castration at Day 29 and Maintaining Castration at Day 183.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01715129 |
| Phase | Phase 3 |
| Condition | Prostate Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 126 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Ipsen |
| Results posted | Yes |
2. Clinical Question
Population
The study enrolled 126 patients with locally advanced or metastatic prostate cancer. The primary endpoint describes an intention-to-treat population at Day 29 and a separate population of subjects initially castrated at Day 183. The registry defines the visit population as the number of subjects attending that visit.
Intervention
Participants received triptorelin pamoate 11.25 mg by subcutaneous injection. The arm description specifies administration on Day 1 and Day 92. The study evaluated the efficacy, safety, and local tolerability of this three-month formulation.
Comparator
There was no separate comparator group. The study is recorded as single-group, with allocation marked not applicable and masking listed as none. Consequently, the registry record does not establish a randomized, like-for-like comparison against another treatment or a control condition.
Primary question
The primary question was what percentage of subjects demonstrated castration at Day 29 and, among those initially castrated, what percentage maintained castration at Day 183. Castration was defined using a serum testosterone threshold of <50 ng/dL or 1.735 nmol/L. The registry record does not report the observed percentages or their confidence intervals.
The endpoint therefore concerns both an early status and a later status conditional on early castration. The early measure describes the proportion meeting the testosterone definition at Day 29 in the stated intention-to-treat population. The later measure addresses maintenance through Day 183 in the initially castrated population, after two subcutaneous administrations three months apart. These are related but distinct summaries: the second does not use the same population denominator as the first.
The registry lists additional outcomes concerning castration, testosterone, time to castration, triptorelin levels, PSA, and clinically apparent tumor progression. Their presence identifies other questions considered by the study, but their numerical results are not reported in the registry record.
3. Trial Design
This was a Phase III, single-group study sponsored by Ipsen. It evaluated subcutaneous triptorelin pamoate 11.25 mg in patients with locally advanced or metastatic prostate cancer. The record lists enrollment of 126 and a completed study, with a start in 2013-01 and primary completion in 2013-10. The arm description specifies injections on Day 1 and Day 92.
Allocation is marked not applicable, masking is listed as none, and the model is single-group. In practical statistical terms, the study has no concurrent randomized control group in the registry record. Its primary endpoint is therefore a description of the observed castration proportions under the study regimen, rather than an estimate of a randomized treatment contrast. Any comparison with an external benchmark would require information and assumptions not reported in the registry record.
The primary endpoint is measured at two time points and uses two analysis populations. At Day 29, the stated population is the intention-to-treat population. At Day 183, the stated population consists of subjects initially castrated. The registry describes the latter measure as maintenance of castration after two administrations. This distinction matters because the Day 183 percentage is conditional on having met the earlier castration status, rather than being a continuation of the same denominator used at Day 29.
The registry lists 14 outcome measures and zero analyses. This does not establish that no analyses were performed; it means analysis details and numerical results are not reported in the registry record. The protocol, a detailed statistical analysis plan, the rationale for the enrollment target, and any interim analysis procedures are not reported in the registry record.
The study also listed safety and local tolerability among its aims. Safety figures include subjects affected by serious adverse events and other adverse events, along with selected serious-event terms. Because there is no control group, those counts describe events observed among participants in the treatment group; they do not by themselves estimate excess risk attributable to treatment.
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: A total of 139 subjects were screened and 13 subjects were screen failures.
Overall Study
| Stage | Triptorelin Pamoate |
|---|---|
| STARTED | 126 |
| COMPLETED | 117 |
| NOT COMPLETED | 9 |
Reasons for not completing this period:
| Reason | Triptorelin Pamoate |
|---|---|
| Adverse Event, fatal | 1 |
| Lack of Efficacy | 3 |
| Protocol Violation | 1 |
| Consent Withdrawn | 2 |
| Lost to Follow-up | 1 |
| Other | 1 |
Analysis population for the primary outcome, as defined in the registry: N=Number of subjects attending the visit
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 | Triptorelin Pamoate |
|---|---|---|
| Participants analysed | 126 | |
| Age, Continuous | years | 70.4 (SD 7.3) |
| Sex/Gender, Customized: Male | participants | 126 |
| Race/Ethnicity, Customized: Caucasian / White | participants | 120 |
| Race/Ethnicity, Customized: Missing | participants | 6 |
| Height | cm | 172.2 (SD 6.7) |
| Weight | kg | 80.6 (SD 12.8) |
| Body Mass Index (BMI) | kg/m² | 27.16 (SD 3.96) |
| Prostate Specific Antigen (PSA) | ng/mL | 133.53 (SD 385.60) |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Subjects Demonstrating Castration at Day 29 and Maintaining Castration at Day 183, measured over At Day 29 and 183.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | Percentage of subjects |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of subjects demonstrating castration at Day 29 and maintaining castration at Day 183. Castration is defined as serum testosterone <50 ng/dL or 1.735 nmol/L, measured using the LC-MS/MS method, with specified imputation from immunoassay results when LC-MS/MS data were planned to be available only at particular time points. The registry says each percentage was calculated with a respective 95% confidence interval using exact methods.
The endpoint uses Day 29 to assess whether subjects meet the biochemical threshold after the first administration. The Day 183 measure asks whether castration was maintained among subjects initially castrated, after the two subcutaneous administrations three months apart. That conditional definition is important: it does not describe the percentage of the entire enrolled population who remained castrated at Day 183.
A percentage is useful for expressing how common a defined status was within a specified analysis population. The confidence interval conveys uncertainty around that estimated proportion; in general, it indicates a range of values reasonably compatible with the observed data under the method’s assumptions. Exact methods are commonly used for proportions when a normal approximation may be unsuitable, particularly when counts are limited or proportions are near a boundary. The actual endpoint percentages, counts, and confidence limits are not reported in the registry record, so their magnitude and precision cannot be assessed.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes the question and method for the primary endpoint but does not report the endpoint’s observed percentages, counts, or 95% confidence intervals. It is therefore not possible to characterize the numerical level of castration at Day 29, or the numerical proportion maintaining castration at Day 183, from the registry record. The absence of those results also prevents an assessment of how precise either estimate was.
The Day 29 estimate is specified for the intention-to-treat population, while the Day 183 maintenance estimate is for subjects initially castrated. The two estimates answer different questions and use different populations. In general, a conditional estimate among subjects meeting an earlier criterion should not be interpreted as though it were the proportion of all enrolled participants meeting that criterion at the later visit. The registry does not provide the counts needed to examine the size of either analysis population or the movement of participants between populations.
The study’s single-group design further limits interpretation. An observed percentage can describe what was recorded among participants receiving the study regimen, but without a concurrent control group it cannot isolate a treatment effect from other explanations. There is no randomized comparison in the registry record from which to estimate a difference between treatment groups. The record also does not report an external comparator or a prespecified benchmark for judging the observed percentages.
The primary endpoint is based on a laboratory threshold, not a direct measure of symptoms, quality of life, or clinical progression. Other outcomes listed in the registry include PSA measures and clinically apparent tumor progression, but their results are not reported in the registry record. Thus, the primary endpoint alone cannot establish what happened on those other outcomes.
For safety, the record lists 6 of 126 subjects affected by serious adverse events and 45 of 126 affected by other adverse events. It also lists selected serious-event terms with percentages. These are descriptive counts in a single treatment group, not comparative safety estimates. The registry does not report a comparison that would quantify how those figures differ from a control condition, and the listed event terms should not be treated as a complete account of all possible safety information.
Overall, the posted record identifies the study population, regimen, endpoint definitions, and some safety summaries, but its lack of numerical primary efficacy results leaves the central endpoint question unanswered quantitatively. Detailed analysis methods beyond the stated exact confidence intervals and imputation rule are not reported in the registry record.
9. Statistical Methods Explained
The statistical information in the registry record is limited. It specifies a percentage endpoint, the analysis populations at the two primary time points, an exact confidence-interval method, and a particular approach to some missing laboratory measurements. It does not report the full statistical analysis plan or the numerical endpoint results. The explanations below distinguish those stated methods from general statistical concepts.
What does a percentage estimate?
A percentage for a binary outcome describes the share of a defined population that meets a criterion. Here, the criterion is serum testosterone below the stated threshold for castration. The denominator must be interpreted in light of the analysis population: the Day 29 population is described as intention-to-treat, while the Day 183 population consists of subjects initially castrated. A percentage without its population definition and numerator and denominator can be difficult to interpret. The registry states that the visit population is the number of subjects attending the visit, but the actual endpoint counts and percentages are not reported in the registry record.
In general, a proportion is an estimate based on observed participants, and a different set of participants or outcomes could yield a different estimate. Its confidence interval expresses statistical uncertainty under the assumptions of the calculation. A narrower interval generally indicates greater precision, while a wider interval indicates less precision. A confidence interval does not remove limitations from study design, measurement, missing data, or selection into an analysis population.
Why use an exact confidence interval?
The registry states that the 95% confidence intervals for the primary percentages were calculated using exact methods. In general, exact methods for a proportion use the discrete probability model for the observed count rather than relying on a normal approximation. This can be useful when the sample is limited, the observed proportion is close to zero or one, or the approximation may not represent the uncertainty well. Exact intervals can be asymmetric around the estimate. Their width depends on the observed data and the analysis population.
The record does not specify the exact interval procedure by name, nor does it provide the numerical interval limits. It is therefore not possible to reproduce or evaluate the primary confidence intervals from the registry record. The method label alone also does not make an estimate precise: precision depends on the number of observations and the observed result, neither of which is reported for the endpoint.
How should the two time points be understood?
At Day 29, the endpoint assesses castration in the intention-to-treat population. At Day 183, the endpoint assesses maintenance among subjects initially castrated. In general, conditioning a later analysis on an earlier response changes the population being described. The later estimate is a maintenance measure for that selected group, not an estimate for all enrolled subjects. The selection definition is stated, but the registry does not report how many subjects were initially castrated or included in the Day 183 analysis.
The study regimen included administration on Day 1 and Day 92, and the primary endpoint refers to Day 29 and Day 183. The registry describes Day 183 as after two administrations three months apart. It does not report details beyond that description about visit windows, the handling of missed visits, or additional analysis rules.
What is the role of the laboratory threshold?
The endpoint classifies a subject according to whether serum testosterone is below <50 ng/dL or 1.735 nmol/L. Such a threshold converts a continuous laboratory measurement into a binary status. In general, this can make an endpoint easier to summarize as a proportion, but it also means that measurements close to the threshold may be classified differently after small measurement variations. The registry specifies LC-MS/MS as the measurement method for the primary definition. It also describes an imputation rule for particular time points, rather than reporting that every value was measured using one method.
What does the imputation rule say?
For missing data at time points when LC-MS/MS data were planned to be available only, the registry says missing data were imputed by the immunoassay method. This is a specific rule for the endpoint measurement. In general, imputation substitutes an available or estimated value for a missing observation so that the analysis can include a result under a stated rule. The interpretation depends on how the substitute relates to the missing value and on the circumstances causing missingness. The registry does not report how many observations were imputed, the values involved, or sensitivity analyses assessing alternative assumptions.
The record does not describe a broader missing-data strategy for other outcomes, nor does it explain the treatment of participants without a usable measurement or visit. These details are not reported in the registry record and should not be inferred from the stated imputation rule.
What can a single-group design estimate?
In general, a single-group study can summarize outcomes observed in participants who received a regimen. It cannot create a randomized comparison when no comparator group is present. Without a concurrent control, changes or outcomes cannot be attributed to the intervention alone on the basis of the study design. Other factors, including the natural course of disease, participant characteristics, measurement procedures, and follow-up, may also be relevant to interpretation. The registry record does not report a comparator or an adjustment strategy that would address those issues.
The record includes a planning illustration based on an observed effect, with 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 fraction of the observed effect. Such illustrations are not observed power and do not establish the trial’s original design assumptions. The record explicitly frames them as planning illustrations rather than the trial’s own design. The underlying sample-size justification and protocol are not reported in the registry record.
What is not available for assessment?
The registry lists 14 outcome measures and zero analyses, but it does not provide the numerical primary outcome results in the record. It also does not report the detailed statistical analysis plan, interim analyses, multiplicity procedure, or justification for enrollment. These omissions mean that the specified endpoint method can be described, but the actual efficacy estimates, their precision, and the full analysis decisions cannot be independently assessed from the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 14 outcome measures, including the primary castration endpoint and additional outcomes concerning testosterone, castration timing, drug levels, PSA, and clinically apparent tumor progression. It does not report a multiplicity adjustment or a prespecified hierarchy for interpreting several outcomes. When multiple outcomes or repeated tests are considered, general statistical practice recognizes that the chance of at least one apparently notable result can rise if each is interpreted separately. Whether or how that issue was addressed in this study is not reported in the registry record.
The primary endpoint uses two time points and different analysis populations: the intention-to-treat population at Day 29 and subjects initially castrated at Day 183. The registry states that each percentage had a respective 95% confidence interval calculated using exact methods. It does not explain whether the two estimates were treated as co-primary, how success was defined across them, or how any repeated testing was handled. Those details are not reported in the registry record.
For missing primary laboratory data, the record specifies imputation by immunoassay at time points when LC-MS/MS data were planned to be available only. It does not provide the number of missing or imputed observations, the distribution of missing visits, or sensitivity analyses. The record’s statement about this rule should not be taken to mean that all missing data for all outcomes were handled in the same way.
The endpoint description identifies an intention-to-treat population at Day 29 and an initially castrated population at Day 183, but further analysis-population rules are not reported in the registry record. The record says the visit population is the number attending the visit; it does not specify additional procedures for participants who discontinued, missed an assessment, or lacked a usable laboratory value. These omissions limit assessment of how missingness or participant availability may have affected the percentages.
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 |
|---|---|---|---|
| Triptorelin Pamoate 11.25 mg | 6 | 126 | 4.8% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Triptorelin Pamoate 11.25 mg | 45 of 126 |
Most frequent serious adverse event terms
| Event term | Organ system | Triptorelin Pamoate 11.25 mg |
|---|---|---|
| Pneumonia | Infections and infestations | 2 of 126 |
| Fibula Fracture | Injury, poisoning and procedural complications | 1 of 126 |
| Cardiac Failure | Cardiac disorders | 1 of 126 |
| Myocardial infarction | Cardiac disorders | 1 of 126 |
| Chronic Obstructive Pulmonary Disease | Respiratory, thoracic and mediastinal disorders | 1 of 126 |
| Anaemia | Blood and lymphatic system disorders | 1 of 126 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Triptorelin Pamoate 11.25 mg |
|---|---|---|
| Hot Flush | Vascular disorders | 13 of 126 |
| Weight Increased | Investigations | 12 of 126 |
| Weight Decreased | Investigations | 7 of 126 |
| Hypertension | Vascular disorders | 6 of 126 |
| Headache | Nervous system disorders | 4 of 126 |
| Erectile Dysfunction | Reproductive system and breast disorders | 3 of 126 |
| Hyperhidrosis | Skin and subcutaneous tissue disorders | 3 of 126 |
| Oedema Peripheral | General disorders | 2 of 126 |
| Breast Pain | Reproductive system and breast disorders | 2 of 126 |
| Fall | Injury, poisoning and procedural complications | 2 of 126 |
Serious events with the highest arm-level rate: pneumonia (1.6%), fibula fracture (0.8%), cardiac failure (0.8%), myocardial infarction (0.8%), chronic obstructive pulmonary disease (0.8%).
The registry lists 6 of 126 subjects affected by serious adverse events in the triptorelin pamoate 11.25 mg group. It also lists 45 of 126 subjects affected by other adverse events. These figures describe the numbers of subjects recorded in the respective categories; they are not treatment-versus-control comparisons. Deaths are not reported in the registry record.
Selected serious adverse-event terms are listed with percentages: Pneumonia, 1.6%; Fibula Fracture, 0.8%; Cardiac Failure, 0.8%; Myocardial infarction, 0.8%; Chronic Obstructive Pulmonary Disease, 0.8%; and Anaemia, 0.8%. These listed terms are a selection, not necessarily a complete inventory of every event or every safety outcome. The registry record does not provide further event-level detail in the information.
In general, safety figures in a single-group study are descriptive. They can indicate what was recorded among participants during the study, but without a concurrent comparator they cannot show how those figures compare with what would have occurred under another condition. A serious event occurring during a study does not, by itself, establish that the study regimen caused it. The registry record does not report a comparative safety analysis or details needed to assess causal attribution.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a Phase III, single-group study evaluated subcutaneous triptorelin pamoate 11.25 mg in patients with locally advanced or metastatic prostate cancer. It defines a primary endpoint based on serum testosterone at Day 29 and maintenance of castration at Day 183 among subjects initially castrated. It also specifies an exact confidence-interval method and a limited imputation rule for some laboratory measurements.
However, the numerical primary endpoint results are not reported in the registry record. No observed percentage, count, or confidence interval is available for either time point. As a result, the record does not allow a quantitative statement about the proportion meeting the castration definition or the precision of either estimate. The listed secondary outcomes likewise do not come with numerical results in the record.
Even if the primary percentages were available, the single-group design would support a description of outcomes among participants receiving the regimen, not a randomized estimate of comparative efficacy. The record has no concurrent comparator. It therefore cannot establish how outcomes would differ under another treatment or control condition. This is a design limitation, not a question that can be resolved by interpreting a percentage in isolation.
The safety figures indicate that 6 of 126 subjects were recorded as affected by serious adverse events and 45 of 126 by other adverse events, with selected serious-event terms and percentages also listed. These data describe recorded events in the study group. They do not estimate comparative risk or establish that an event was caused by the intervention. The deaths field is not reported in the registry record.
The record also does not report the detailed statistical analysis plan, the enrollment rationale, interim analysis procedures, multiplicity handling, or broader missing-data analyses. Consequently, the endpoint definition and some methods can be described, but the full analytic context and numerical evidence needed for a more complete assessment are unavailable in the registry record.
13. Why This Trial Matters Statistically
This study is statistically notable because its primary endpoint combines a laboratory threshold with a time-specific maintenance question. The early assessment describes castration at Day 29, while the later assessment concerns maintenance at Day 183 among subjects initially castrated. Those populations are not interchangeable. Clear interpretation depends on keeping the denominator and conditioning rule attached to each estimate.
The endpoint also illustrates how a continuous measurement can be converted into a binary outcome using a threshold. This permits a proportion-based summary, but the interpretation is tied to the chosen threshold and laboratory method. The registry identifies serum testosterone <50 ng/dL or 1.735 nmol/L and names LC-MS/MS, with a stated imputation rule for some missing measurements. Those methodological details matter because they define how subjects are classified.
The study’s single-group design makes the distinction between observed outcomes and comparative treatment effects especially important. A single-group percentage can describe the study participants, but it cannot provide a randomized contrast against a control group. That distinction prevents descriptive results from being mistaken for evidence of a comparative effect.
The record’s incomplete numerical reporting is also consequential. It describes the primary endpoint and exact confidence-interval method, yet does not report the estimates or their intervals. Readers therefore cannot judge the magnitude or precision of the endpoint results from the registry record. The number of outcome measures and absence of reported analysis details also leave multiplicity decisions unclear.
Finally, the safety figures demonstrate why event counts need context. They summarize affected subjects in the treatment group, but without a comparison group they do not quantify relative safety. Together, these features make the study useful for discussing endpoint definitions, conditional populations, precision, and the limits of descriptive single-group evidence.
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 trial-specific limitation is the single-group design. The registry lists no comparator group, and allocation is marked not applicable. Outcomes observed in the treatment group therefore cannot be contrasted with a concurrent control to estimate a randomized treatment difference. No external benchmark or comparative adjustment is reported in the registry record.
The registry record does not report the primary endpoint’s observed percentages, counts, or 95% confidence intervals. This prevents assessment of the central endpoint’s magnitude and statistical precision. It also does not report numerical results for the secondary outcomes listed, despite identifying 14 outcome measures.
The primary endpoint uses different analysis populations at its two time points. Day 29 is described for the intention-to-treat population, whereas Day 183 is evaluated among subjects initially castrated. The record does not give the number included in either endpoint calculation or the number initially castrated. This limits assessment of the denominator and the extent to which the later result reflects a selected subgroup.
The registry describes imputation by immunoassay for missing values at time points when LC-MS/MS data were planned to be available only. It does not report how many values were missing or imputed, whether missingness varied over follow-up, or whether sensitivity analyses were conducted. Handling of missing data for other outcomes is not reported in the registry record.
Other limitations of the available record include the absence of a reported statistical analysis plan, multiplicity procedures, interim analysis details, and enrollment justification. Safety summaries are descriptive, and deaths are not reported in the registry record. The study is listed as completed, but the available record does not provide the numerical efficacy results needed for a full statistical interpretation.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Induction and Maintenance of Castration After Subcutaneous Injections of Triptorelin Pamoate in Patients With Prostate Cancer — NCT01715129.
- Registry record last updated 2019-12-09; status last verified 2019-11.
- Results first posted 2015-10-28.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT01715129 is a completed Phase III, single-group study sponsored by Ipsen. It enrolled 126 patients with prostate cancer, described as locally advanced or metastatic in the official title. The study evaluated triptorelin pamoate 11.25 mg administered subcutaneously on Day 1 and Day 92. The record lists a start in 2013-01 and primary completion in 2013-10.
The primary endpoint was the percentage of subjects demonstrating castration at Day 29 and maintaining castration at Day 183. Castration was defined by serum testosterone <50 ng/dL or 1.735 nmol/L. The registry describes exact 95% confidence intervals and a specific immunoassay imputation rule for some missing measurements. Numerical primary endpoint results are not reported in the registry record.
The record lists 14 outcome measures and zero analyses. It reports 6 of 126 subjects affected by serious adverse events and 45 of 126 affected by other adverse events, along with selected serious-event terms and percentages. A comparator, detailed analysis plan, multiplicity procedure, enrollment justification, and deaths are not reported in the registry record.