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 TRC105 Combined With Standard-dose Bevacizumab for Two Patients With Metastatic And Refractory Choriocarcinoma (NCT02396511), a na phase 2 study. The primary outcome is Progression Free Survival of Two Patients With Metastatic and Refractory Choriocarcinoma.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02396511 |
| Phase | Phase 2 |
| Condition | Choriocarcinoma |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 2 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Tracon Pharmaceuticals Inc. |
| Results posted | Yes |
2. Clinical Question
Population
Two patients with metastatic and refractory choriocarcinoma. The registry record does not report further eligibility criteria or a more detailed description of the participants.
Intervention
TRC105, given by weekly intravenous infusion, in combination with bevacizumab, given by intravenous infusion every 2 weeks.
Comparator
No separate comparator group is described. The registry record identifies a single group receiving TRC105 and bevacizumab, so the study does not provide a like-for-like control comparison.
Primary question
The stated primary question concerns progression-free survival for the two patients receiving the combination. The registry describes assessment every 8 weeks for up to 35 Months, but does not report the observed progression-free survival results.
The study is framed as an assessment of whether the combination is effective for patients with metastatic and refractory choriocarcinoma. Its structure is important to interpreting that question: it is a single-group study with enrollment of 2, not a randomized comparison. There is no separate group receiving another treatment or no study treatment against which the observed course could be compared.
Progression-free survival is a time-to-event outcome, with progression defined using imaging-based criteria and serum β- hCG measurement as described in the registry record. The record also lists frequency and severity of adverse events as a secondary outcome. It does not report the actual primary outcome measurements, individual patient courses, or a statistical analysis of those outcomes. The clinical question can therefore be identified from the registered objective, but the posted record does not permit a conclusion about the observed progression-free survival or a comparative treatment effect.
3. Trial Design
The registry record describes a Phase 2, completed, single-group study sponsored by Tracon Pharmaceuticals Inc. Enrollment was 2. The registered title and brief summary specify two patients with metastatic and refractory choriocarcinoma receiving TRC105 in combination with bevacizumab. The arm description gives TRC105 as a weekly intravenous infusion and bevacizumab as an intravenous infusion every 2 weeks.
The allocation is listed as NA, masking as none, and the model as single group. In practical terms, the record does not describe random assignment, masking, or a concurrent control arm. The listed arm is TRC105 and bevacizumab; the registry does not set out another arm for comparison. Consequently, the design is descriptive rather than a randomized treatment comparison, and it cannot by itself separate outcomes associated with the combination from the natural course of disease or other influences.
The study start is recorded as 2015-01 and primary completion as 2017-12; status is completed. These registry fields describe the study timeline, but do not supply dates of treatment or follow-up for either participant. The primary outcome is progression-free survival, assessed every 8 weeks for up to 35 Months. Frequency and severity of adverse events is the listed secondary outcome. The record indicates 3 outcome measures and 0 analyses, but does not provide analysis results or a statistical analysis plan.
The registry categorizes the study as other and notes that its structure is not reduced to one comparison. For interpretation, the essential feature is the small, single-group design. The study may describe what happened to the enrolled patients, but a control-based estimate of benefit or harm is not available from this design as registered. The status being completed does not itself establish that outcome data or analyses were posted.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | TRC105 and Bevacizumab |
|---|---|
| STARTED | 2 |
| COMPLETED | 2 |
| NOT COMPLETED | 0 |
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: Patients who enrolled in the trial who received at least a portion of a dose were included
| Characteristic | Unit | TRC105 and Bevacizumab |
|---|---|---|
| Participants analysed | 2 | |
| Age, Continuous | Years | 39.5 (37 to 42) |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 0 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 1 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 1 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 1 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 |
| Region of Enrollment: United States | participants | 2 |
| Number of Prior Regimens | prior regimens | 7 (3 to 11) |
6. Primary Endpoint
The registry lists the primary outcome as Progression Free Survival of Two Patients With Metastatic and Refractory Choriocarcinoma, measured over Assessed every 8 weeks for up to 35 Months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Full Range |
| Unit | Months |
| Endpoint classification | not reduced to a single comparison |
The primary outcome is progression-free survival for patients with metastatic and refractory choriocarcinoma, expressed in months. Progression-free survival is a time-to-event measure: it tracks the time until disease progression, according to the specified criteria. The registry states that the measure is assessed every 8 weeks for up to 35 Months and includes measurement of serum β- hCG along with the criteria described for tumor findings.
The record defines progression using Response Evaluation Criteria In Solid Tumors criteria. It describes progression as a 20% increase in the sum of the longest diameter of target lesions, a measurable increase in a non-target lesion, or the appearance of new lesions. It also specifies a 5 mm absolute increase to guard against calling progression when the total sum is very small. The outcome description refers to RECIST 1.1, while the progression definition refers to RECIST v1.0; the registry record does not explain this difference.
Progression-free survival is used in trials because it captures the time until a defined disease-related event, rather than only reporting a measurement at one point. General statistical interpretation: a time-to-event outcome can account for the timing of events and, when appropriate follow-up information is available, the fact that some participants have not experienced the event by the end of observation. However, the registry record does not report event times, censoring information, or a summary estimate for this outcome. It therefore names the endpoint and its assessment approach without supplying the result needed to describe the observed progression-free survival.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the study objective and primary outcome, but does not report a primary outcome result. It provides no progression-free survival estimate, range, event times, or analysis. There are 0 analyses recorded. The completed status indicates the study is listed as completed, but completion is not evidence that a numerical outcome result has been posted.
Interpretation is also constrained by the design. The study has a single group of 2 participants receiving TRC105 with bevacizumab and no separate comparator. Any observed outcome in that group, even if it were reported, would describe those participants under this treatment approach. Without a comparison group, it would not provide a controlled estimate of how outcomes differed from another treatment or from no study treatment. The registry’s stated purpose asks whether the combination is effective, but the design and posted information do not establish a comparative effect.
The planned outcome definition provides some useful context. Progression is based on stated lesion criteria and serum β- hCG measurement, with assessment every 8 weeks for up to 35 Months. Such details indicate what the investigators intended to measure. They do not establish how many assessments occurred, whether either participant experienced progression, when an event occurred, or how missing or incomplete observations were handled. Those details are not reported in the registry record.
The adverse-event fields show that 2 participants were at risk for serious adverse events and 2 were affected in the listed group. The record lists headache, migraine, infusion related reaction, and malaise among the top serious terms, each at 50.0%. It reports 0 deaths. These entries describe the posted safety summary, but do not provide a detailed account of event timing, duration, recurrence, management, or attribution. The percentages do not substitute for participant-level descriptions, and the registry record does not clarify how the listed terms relate to one another for individual participants.
The distinction between a registered outcome and a reported result is central. A protocol-style description can define the endpoint and the intended assessment schedule, while still leaving the observed data unavailable. In this record, the primary outcome is named and defined, but its result and statistical analysis are not reported. No p-value or confidence interval for the primary outcome is available to interpret.
The record also describes 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. Time-to-event calculations are described in terms of total events; other calculations are described in participants per arm. Such illustrations are planning exercises, not observed power and not an analysis of this single-group study. The registry does not report the trial’s own sample-size justification or explain how an observed effect was obtained. With no primary outcome result posted, the planning material cannot fill that evidence gap.
Overall, the record supports a description of the study question, design, scheduled endpoint assessment, and limited safety summary. It does not support an estimate of progression-free survival, a test of the stated efficacy question, or a controlled comparison. The lack of reported outcome analyses should be kept distinct from evidence that an outcome did or did not occur.
9. Statistical Methods Explained
The statistical information in the registry record is limited. It describes the study structure, endpoint definition, and a planning illustration, but it does not report an analysis plan or an analysis of the primary outcome. General statistical concepts can clarify what these methods would mean, but they cannot replace missing study results.
What does a single-group design allow?
A single-group study observes participants receiving the listed intervention without a separate concurrent comparator. In general, this design can describe outcomes among the enrolled participants, but it does not isolate the effect of the intervention from other explanations for those outcomes. A randomized comparison is useful because assignment to different groups supports a structured comparison; this registry record does not describe randomization or a control group. With enrollment of 2, the study is also too limited to characterize a broad range of participant experiences from the registry information alone.
The allocation field is NA, the masking field is none, and the model is single group. These fields should not be read as evidence of a hidden comparison. The record identifies only the group receiving TRC105 and bevacizumab. It does not report a statistical comparison between arms, and the study is not presented as a like-for-like control comparison.
How should a time-to-event endpoint be understood?
Progression-free survival is a time-to-event measure. For each participant, the relevant information would ordinarily include the time from a defined starting point to progression or another specified event, as well as whether follow-up ended before an event was observed. General statistical explanation: participants who have not had an event by the end of observed follow-up may contribute censored information rather than a completed event time. This distinction matters because treating every participant without a recorded event as if progression never occurred would misrepresent follow-up.
The registry names months as the unit and describes assessment every 8 weeks for up to 35 Months. It does not identify the time origin, report event or censoring times, give a summary estimate, or explain how incomplete follow-up was handled. Without those details, a reader cannot reconstruct a time-to-event analysis. The endpoint definition alone is not a result.
The outcome description says progression-free survival is determined according to RECIST 1.1, including serum β- hCG measurement. Its more detailed progression definition references RECIST v1.0. The stated criteria include a 20% increase in the sum of the longest diameter of target lesions, measurable increase in a non-target lesion, or new lesions, as well as a 5 mm absolute increase intended to guard against over calling progression when the total sum is very small. The record does not explain the reference to different RECIST versions, how serum β- hCG was incorporated into event determination, or how disagreements in assessments were resolved.
What do confidence intervals and significance tests ordinarily convey?
General statistical explanation: a confidence interval expresses the uncertainty around an estimated quantity under the assumptions of the analysis. A narrow interval indicates greater precision than a wide interval, while an interval that includes values consistent with different interpretations may leave substantial uncertainty. A p-value, when reported, describes how compatible the observed data are with a specified null hypothesis under the statistical model; it does not by itself measure the size or clinical importance of an effect.
No confidence interval, p-value, or primary outcome estimate is reported in the registry record. There is therefore no inferential result to interpret. A significance threshold mentioned in a planning illustration is not a p-value from an observed study analysis and should not be treated as evidence about the primary outcome.
What is the role of the planning illustration?
The record describes planning calculations using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It states that the effect to detect is a fraction of the observed effect. For time-to-event calculations, the described quantity is the total number of events; for other calculations, it is participants per arm. These are design-planning conventions, not findings about participants.
General statistical explanation: a sample-size calculation depends on assumptions about the target effect and variability, as well as the chosen error rate and design. Changing those assumptions changes the planning requirement. A calculation based on a fraction of an observed effect is an illustration of what a future design might require under the stated assumptions; it is not a measure of the probability that this completed study detected an effect. In particular, a planned sample size must not be interpreted as observed power.
The registry record does not report a trial-specific sample-size justification, the source or estimate of the observed effect used for the illustration, or a protocol rationale. Its planning assumptions do not correspond to the posted design of a single group with 2 participants and no comparator. They cannot be used to infer a trial analysis that is absent from the record.
What does the lack of analyses mean?
The record reports 0 analyses. This means the registry record does not supply a statistical analysis result in the listed analysis field; it does not establish that no analysis was ever conducted outside the registry. The primary outcome result, analysis population, missing-data approach, and statistical methods for endpoint estimation are not reported in the registry record. Careful interpretation should therefore distinguish between an absence of posted analysis and a finding of no effect or no progression.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 3 outcome measures and identifies progression-free survival as the primary outcome. Frequency and severity of adverse events is listed as a secondary outcome. It does not describe how multiple outcomes were handled statistically, whether any multiplicity adjustment was planned, or which analyses were designated as confirmatory. A multiplicity strategy is not reported in the registry record.
General statistical explanation: when a study evaluates multiple outcomes or performs multiple tests, the chance of at least one apparently unusual finding can increase if each test is interpreted independently. Methods for controlling or describing this issue depend on the study objectives and analysis plan. Since that plan is not reported, the registry information does not establish whether such methods were used.
The record does not report the analysis population for the primary outcome, such as whether all enrolled participants were included in an analysis or whether any different population was specified. It also does not explain missing-data handling, censoring rules, withdrawals, or whether all scheduled assessments were completed. For a time-to-event endpoint, these details can affect how the observed follow-up is summarized. The intended assessment schedule—every 8 weeks for up to 35 Months—does not show how much follow-up was actually available.
The registry lists 0 analyses and does not provide participant-level observations or a summary estimate. Consequently, it is not possible to determine whether missing information affected the endpoint or whether any sensitivity analyses were conducted. These items are not reported in the registry record; their absence should not be interpreted as proof that particular methods were or were not used outside the record.
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 |
|---|---|---|---|
| TRC105 and Bevacizumab | 2 | 2 | 100.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| TRC105 and Bevacizumab | 0 of 2 |
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 |
|---|---|
| TRC105 and Bevacizumab | 2 of 2 |
Most frequent serious adverse event terms
| Event term | Organ system | TRC105 and Bevacizumab |
|---|---|---|
| Headache | Nervous system disorders | 1 of 2 |
| Migraine | Nervous system disorders | 1 of 2 |
| Infusion Related Reaction | Injury, poisoning and procedural complications | 1 of 2 |
| Malaise | General disorders | 1 of 2 |
Most frequent non-serious adverse event terms
| Event term | Organ system | TRC105 and Bevacizumab |
|---|---|---|
| Fatigue | General disorders | 2 of 2 |
| Pyrexia | General disorders | 1 of 2 |
| Headache | Nervous system disorders | 1 of 2 |
| Haemoptysis | Respiratory, thoracic and mediastinal disorders | 1 of 2 |
| Hypomagnesaemia | Metabolism and nutrition disorders | 1 of 2 |
| Arthralgia | Musculoskeletal and connective tissue disorders | 1 of 2 |
| Mucosal Inflammation | General disorders | 1 of 2 |
| Palmar-plantar erythrodysaesthesia syndrome | Skin and subcutaneous tissue disorders | 1 of 2 |
| Hypertension | Vascular disorders | 1 of 2 |
| Migraine | Nervous system disorders | 1 of 2 |
Serious events with the highest arm-level rate: headache (50.0%), migraine (50.0%), infusion related reaction (50.0%), malaise (50.0%).
The safety summary concerns the group receiving TRC105 and bevacizumab. The registry lists 2 participants at risk for serious adverse events and 2 affected. It reports 0 deaths. The top serious terms listed are headache, migraine, infusion related reaction, and malaise, each at 50.0%.
These figures should be read as a registry summary, not a complete clinical account. The listed terms do not tell the reader when events began, how long they lasted, whether they recurred, how severe each event was for an individual, or what action was taken. The record does not explain whether the terms occurred in the same or different participants, or specify the denominator used for the term percentages. The percentages should therefore be retained as posted rather than translated into participant counts or event counts.
The secondary outcome is described as frequency and severity of adverse events, but the brief safety fields do not provide the full frequency-and-severity analysis. The record does not report causal attribution or a comparison with another group. In a single-group study with enrollment of 2, these entries describe reported events in the enrolled group; they do not establish how the event pattern would compare under another treatment. The absence of a reported death is not a substitute for a full assessment of other safety outcomes.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed Phase 2, single-group study enrolled 2 patients with metastatic and refractory choriocarcinoma to receive TRC105 with bevacizumab. It specifies the infusion schedules, names progression-free survival as the primary outcome, and describes how progression was to be assessed. It also lists adverse-event frequency and severity as a secondary outcome and provides a limited safety summary.
It does not report the observed progression-free survival result. There is no posted estimate, range, individual follow-up, or analysis of the primary endpoint. Therefore, the registered objective—whether the combination is effective in this setting—cannot be answered from the posted outcome information. This is not evidence that the treatment did or did not affect progression-free survival; it is an absence of a reported result in the registry record.
The single-group design sets another boundary on interpretation. Even if outcome measurements were available, they would describe the enrolled participants receiving the combination. Without a comparator group, an observed course could not be separated from other causes or used as a controlled estimate of how outcomes differ under another treatment. The record does not support a randomized comparison or a broad conclusion about patients beyond the two enrolled participants.
The serious adverse-event summary reports 2 affected participants, lists four top serious terms at 50.0% each, and reports 0 deaths. These entries are informative as a record of what was posted, but lack details about event timing, recurrence, attribution, and participant-level overlap. They should not be treated as a complete account of safety or as a comparative estimate.
The planning illustration is not an outcome finding. Its assumptions describe a calculation for a hypothetical two-arm design, whereas the registered study is single group. Planning numbers, even when derived from an observed effect, are not evidence that this study had a particular probability of detecting an effect. The posted record supports a careful description of the question and design, but not a conclusion about efficacy, comparative benefit, or the overall safety profile.
13. Why This Trial Matters Statistically
This study matters statistically because its design makes the distinction between a clinical question and an estimable treatment comparison especially clear. The registered objective asks whether a combination is effective, while the registered study has a single group and no separate comparator. That structure can describe experience among the enrolled participants, but it does not provide the controlled contrast that would quantify how outcomes differ from another treatment approach.
The sample is also very small: enrollment was 2. This makes the limits of descriptive summaries consequential. Individual events and observations would account for much of the available information, and the posted registry record does not provide the individual progression-free survival data needed to understand either participant’s course. The absence of a primary outcome analysis means readers cannot assess the endpoint estimate or its precision.
Another statistical lesson is that endpoint definitions and results are distinct. The registry describes the progression criteria and the schedule for assessment, yet reports no progression-free survival result. A detailed definition can support consistency in measurement, but it cannot show whether or when an event occurred. The record also references RECIST 1.1 in the outcome description and RECIST v1.0 in the progression definition without explaining the difference, illustrating why clear operational definitions matter.
Finally, the record’s planning illustration should not be conflated with evidence from the completed study. Its assumptions refer to equal allocation between two arms, but the registered model is a single group. This contrast is a reminder that planning calculations depend on design assumptions and do not create a result where none is posted. The distinction between planned information, observed data, and comparative inference is central to reading this trial responsibly.
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 is that the registry record does not report the primary outcome result or a statistical analysis. Although progression-free survival is named and its assessment approach is described, there is no estimate, event-time information, range, confidence interval, or p-value. The record also reports 0 analyses, so the planned endpoint cannot be evaluated from a posted analysis.
The study enrolled 2 participants and used a single group. There is no separate comparator, and the record does not describe random assignment. This prevents a controlled estimate of the difference between the combination and another treatment or comparison condition. The small enrollment also means that the posted group-level safety summary provides only limited information about the range of possible experiences.
The outcome definition has an unresolved detail: progression-free survival is described as determined according to RECIST 1.1, while the progression criteria refer to RECIST v1.0. The record does not clarify how the criteria were reconciled or how serum β- hCG measurement contributed to progression determinations. It also does not report the time origin, event and censoring data, or handling of incomplete follow-up.
For safety, the record gives the number at risk and affected for serious adverse events, top serious terms with percentages, and a death count. It does not give event-level details, participant-level overlap, timing, duration, attribution, or a complete frequency-and-severity analysis. Multiplicity handling, missing-data procedures, analysis populations, and the study’s own sample-size justification are not reported in the registry record. These omissions limit interpretation of both the efficacy question and the safety summary.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: TRC105 Combined With Standard-dose Bevacizumab for Two Patients With Metastatic And Refractory Choriocarcinoma — NCT02396511.
- Registry record last updated 2019-06-11; status last verified 2019-05.
- Results first posted 2019-06-11.
- 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.
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18. Record Summary
NCT02396511 is a completed Phase 2, single-group study sponsored by Tracon Pharmaceuticals Inc. The registry lists 2 participants with metastatic and refractory choriocarcinoma receiving TRC105 weekly by intravenous infusion and bevacizumab by intravenous infusion every 2 weeks. The study start is recorded as 2015-01, and primary completion as 2017-12.
Progression-free survival in months is the primary outcome, with assessment every 8 weeks for up to 35 Months. Frequency and severity of adverse events is listed as a secondary outcome. The registry describes progression criteria but does not report a primary outcome result or statistical analysis. It lists 0 analyses.
The serious adverse-event summary reports 2 participants at risk and 2 affected, with headache, migraine, infusion related reaction, and malaise each listed at 50.0%; deaths are listed as 0. The single-group design has no separate comparator, so the record does not provide a controlled treatment comparison.