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 Safety and Efficacy of SNX-5422 in Human Epidermal Growth Factor Receptor 2 (HER2) Positive Cancers (NCT01848756), a na phase 1, phase 2 study. The primary outcome is Objective Response Rate.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01848756 |
| Phase | Phase 1, Phase 2 |
| Condition | Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 15 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Esanex Inc. |
| Results posted | Yes |
2. Clinical Question
The study concerned SNX-5422, an experimental drug described in the registry as blocking Hsp90, in subjects with selected HER2-positive cancers. The clinical question was whether treatment was associated with objective tumor responses, measured using RECIST, and whether participants experienced safety events during treatment. The record also describes clinical benefit as complete remission, partial remission, or stable disease at six months.
Population
Subjects with selected HER2-positive cancers. The registry lists the condition as cancer and describes the primary analysis population as the per-protocol population, including all enrolled evaluable subjects. Further eligibility details are not reported in the registry record.
Intervention
SNX-5422 capsules, administered open-label. The planned schedule was a total of 100 mg/m2 every other day for 21 days, for a total of 11 doses, within a 28-day treatment cycle. Further treatment on a 28-day cycle was at the principal investigator’s discretion based on safety.
Comparator
There was no comparison group. The registry describes a single-group study with no allocation to different treatment arms, so the study does not provide a like-for-like control comparison.
Primary question
The primary outcome was objective response rate, based on complete and partial remissions assessed using RECIST. The registry gives an assessment timeframe of up to 24 months from last patient entry, but notes that no patient completed six months on study before termination, the first analysis time point for the endpoint.
Because the study ended before that first assessment point was reached by any participant, the posted record cannot answer the primary response question with observed six-month outcome data. The safety information describes events among participants at risk, but without a comparator it cannot establish how those events compare with another treatment or with no study treatment.
3. Trial Design
The registry describes a single-arm phase 1/2 study of SNX-5422 in subjects with selected HER2-positive cancers. It lists the study as open-label, with a single-group model and no allocation to comparison arms. The sponsor was Esanex Inc. Enrollment was 15. The recorded study start was 2013-04, and primary completion was 2015-02. The study status is terminated.
Participants received SNX-5422 capsules on the planned schedule of 100 mg/m2 every other day for 21 days, totaling 11 doses in a 28-day treatment cycle. The description says participants could continue on a 28-day cycle at the principal investigator’s discretion based on safety. The registry does not report how many participants continued treatment or how long any individual received it.
An open-label design means treatment assignment and treatment identity were not masked in the way they would be in a blinded study. In a single-arm design, outcomes are observed in the treated group without a concurrent control group. This can describe what happened among participants in the study, but it cannot by itself separate treatment-associated outcomes from the course of the underlying disease, other care, or other influences.
The primary outcome was objective response rate, with tumor measurements made using RECIST. The registry gives a timeframe of up to 24 months from last patient entry. However, it also states that no patient completed six months on study, the first analysis time point for this endpoint, when the study terminated. The termination is attributed to business reasons related to slow recruitment and the availability of newer targeted treatments. Those statements explain why the endpoint was not assessed at its first planned time point; they do not establish what the response result would have been with longer follow-up.
Details such as the full eligibility criteria, dose modification rules, study sites, recruitment dates beyond the recorded start and primary completion, and a complete statistical analysis plan are not reported in the registry record. The available design information therefore supports a description of the study structure and dosing schedule, but not a reconstruction of all operational or analysis decisions.
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 | SNX-5422 |
|---|---|
| STARTED | 15 |
| COMPLETED | 12 |
| NOT COMPLETED | 3 |
Reasons for not completing this period:
| Reason | SNX-5422 |
|---|---|
| Adverse Event | 1 |
| Withdrawal by Subject | 1 |
| Enrolled in Error | 1 |
Analysis population for the primary outcome, as defined in the registry: Per protocol population including all enrolled evaluable subjects.Due to slow recruitment and availability newer targeted treatments the study was terminated for business reasons. No patient completed 6 months on study, the first analysis time point for this endpoint, at the time of study termination
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 | SNX-5422 |
|---|---|---|
| Participants analysed | 15 | |
| Age, Continuous | years | 58 (SD 12.9) |
| Gender: Female | Participants | 9 |
| Gender: Male | Participants | 6 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 1 |
| 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 | 13 |
| Race (NIH/OMB): More than one race | Participants | 1 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Objective Response Rate, measured over Up to 24 months from last patient entry.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was objective response rate. The registry describes objective tumor responses as complete remissions plus partial remissions, with tumor measurements made using Response Evaluation Criteria in Solid Tumors (RECIST). In general, response criteria provide a defined framework for classifying changes in measured tumors, so that assessments use consistent rules rather than an informal judgment alone.
The endpoint is intended to summarize the proportion of the evaluated population who meet the specified response categories. In this study, the registry says the responses would be listed by subject. It also identifies clinical benefit as a separate measure comprising complete remissions, partial remissions, and stable disease at six months. Stable disease is not included in the stated definition of objective response rate.
The registry’s stated timeframe was up to 24 months from last patient entry, but it identifies six months as the first analysis time point and reports that no patient completed six months on study before termination. Consequently, the posted record does not give an observed primary response result at that assessment point. The endpoint’s definition and purpose can be described, but its value, precision, and distribution among participants cannot be determined from the posted results. The registry’s description of a per-protocol population including all enrolled evaluable subjects does not give the number evaluable for this endpoint.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a study intended to assess the safety and antitumor activity of SNX-5422 in selected HER2-positive cancers. The primary outcome was objective response rate using RECIST. The decisive limitation for interpreting that outcome is stated directly in the record: no patient completed six months on study, which was the first analysis time point for the endpoint, before the study terminated. No observed primary response estimate is reported in the registry record.
The study ended for business reasons, attributed to slow recruitment and the availability of newer targeted treatments. This reason does not imply either a positive or a negative tumor response result. It means that the planned first assessment point was not reached by any participant, so the primary outcome cannot be interpreted as evidence for or against an observed response rate at that point. The assessment window of up to 24 months from last patient entry does not replace the missing six-month assessment.
Enrollment was 15, and the design was single-group and open-label. These characteristics matter when reading any descriptive outcomes. Without a concurrent comparison arm, there is no within-trial estimate of how outcomes would have differed under another treatment or no study treatment. Open-label treatment can also affect measurements or reporting in ways that blinding is intended to limit, although the registry does not report whether such effects occurred in this study.
The safety record reports 8 participants with serious adverse events among 15 at risk and 15 participants with other adverse events among 15 at risk. The listed serious event terms include Renal Failure Acute at 13.3%, and Abdominal Pain Upper, Atrial Fibrillation, Diarrhoea, Haematemesis, and Nausea at 6.7% each. These entries describe reported events in this study group. They do not, by themselves, establish that SNX-5422 caused an event, quantify a comparative excess, or identify a risk relative to another treatment. The registry does not report deaths for this group.
Confidence intervals and formal hypothesis tests would ordinarily help show the statistical uncertainty around an estimate or assess a specified comparison. The registry record lists no analyses and provides no primary response estimate, interval, or test result. Therefore, the precision of an efficacy estimate cannot be assessed from the posted results. A lack of an observed primary result is not equivalent to a finding of no response; it is an absence of an evaluable result at the first specified time point.
General interpretation: a small, uncontrolled study can provide descriptive observations, but its results should not be treated as a causal comparison. In this record, the early termination and lack of six-month endpoint assessments place a more fundamental limit on efficacy interpretation: the principal endpoint result is unavailable, rather than merely imprecise.
9. Statistical Methods Explained
The study design and the statistical interpretation are closely linked. This was a single-group, open-label study, rather than a randomized comparison. In general, random allocation helps balance measured and unmeasured characteristics between treatment groups, while a concurrent control group supplies a reference for comparing outcomes over the same period. Neither feature is present in the registry description. The study can therefore describe observations among participants who received SNX-5422, but cannot provide a controlled estimate of the treatment’s effect relative to another group.
What does an objective response measure?
The primary endpoint was objective response rate, based on complete and partial remissions assessed using RECIST. In general, an endpoint definition specifies what outcome counts and the rules used to classify it. A response rate then summarizes the frequency of participants meeting those criteria in the defined analysis population. The registry says responses would be listed by subject and identifies the per-protocol population as including all enrolled evaluable subjects. It does not report the number evaluable or any participant-level response classifications in the posted results.
The registry also describes clinical benefit as complete remission, partial remission, or stable disease at six months. That measure differs from objective response because it includes stable disease. The record states that no patient completed six months on study before termination, which was the first analysis time point for the endpoint. This prevents interpretation of the intended six-month response and clinical-benefit assessments from the posted results.
Why does a confidence interval matter?
General explanation: a confidence interval expresses the statistical uncertainty around an estimate under a specified method. A narrow interval indicates greater precision than a wide interval, while an interval that spans a broad range can leave substantial uncertainty about the underlying value. An interval does not correct weaknesses in the design, create a control group, or resolve missing outcome assessments.
No primary response estimate or confidence interval is reported in the registry record. Accordingly, it is not possible to describe the precision of a primary efficacy estimate. Even if an estimate were available, its interpretation would need to account for the single-arm design, the evaluable population, and the fact that the study ended before any participant completed the first endpoint assessment time point.
What can significance testing establish?
General explanation: a hypothesis test evaluates how compatible the observed data are with a specified statistical model and null hypothesis. A p-value is not the probability that a treatment works, and it does not measure the size or clinical importance of an effect. A test also cannot answer a comparative question if the study lacks a suitable comparison group.
The registry lists no analyses. It does not report a primary endpoint test, p-value, or inferential comparison. The full statistical analysis plan, including any intended estimation methods, hypothesis tests, adjustment procedures, or interim analyses, is not reported in the registry record. No test should be inferred from the endpoint name or the existence of a planned assessment timeframe.
How should safety counts be read?
General explanation: safety summaries commonly distinguish participants who experienced at least one event from the number of events themselves. A participant can experience more than one event or event type, so counts of affected participants and counts of individual events are not interchangeable. The registry reports numbers of participants at risk and affected for serious and other adverse events. The listed serious event terms and percentages are descriptive entries; the registry information does not establish that each event was treatment-related.
General explanation: over-dispersion matters when variation in count data exceeds what a simple statistical model assumes. It can affect standard errors and uncertainty estimates for analyses of event counts. The registry does not report an event-count model or an analysis that would allow over-dispersion to be evaluated. In any case, the reported safety summaries do not constitute a controlled comparison, and the small enrolled group limits how broadly the descriptive observations can be generalized.
What is the role of sample-size planning?
General explanation: a sample-size calculation is a planning exercise based on assumptions about the outcome, target effect, variability, significance level, power, and allocation. It is not an observed result and does not show that a study had a particular probability of finding an effect after the data are collected. The registry record does not report the study’s own sample-size justification or the assumptions used to determine enrollment. The posted record’s absence of primary endpoint analyses also means there is no basis for interpreting a calculated planning illustration as evidence about the study’s observed efficacy.
Overall, the statistical record supports a clear account of the design, endpoint definition, and safety summaries, but not an efficacy estimate. The missing first endpoint assessment is distinct from statistical imprecision: without the required observed endpoint data, neither an estimate nor its uncertainty can be assessed.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists seven outcome measures and identifies objective response rate as the primary outcome. It also lists safety outcomes concerning adverse events, changes in vital signs, physical examination or clinical laboratory findings, ophthalmologic changes, and adverse events by severity and relationship to treatment. The record does not report a multiplicity strategy for handling statistical tests across these outcomes. Since no analyses are listed, it is not possible to determine whether any formal testing was performed or how any testing across outcomes would have been interpreted.
Missing outcome information is especially consequential for the primary endpoint. The registry states that no patient completed six months on study, the first analysis time point for the endpoint, before termination. The primary result is therefore not reported in the registry record. The record does not give a participant-level accounting of missing measurements, reasons for missingness by participant, or a method for handling missing endpoint data.
The stated primary analysis population is the per-protocol population, described as including all enrolled evaluable subjects. The registry does not report the number evaluable, detailed analysis-population definitions, or how participants who discontinued or lacked assessments would be handled. It also does not report whether analyses were planned for all enrolled participants or for other populations.
In general, multiplicity concerns arise when several outcomes or hypotheses are tested: the chance of a false-positive conclusion can increase if testing is not accounted for. Missing data can also affect estimates if the participants with observed measurements differ systematically from those without them. These are general statistical concerns; the registry does not provide enough detail to establish which methods, if any, were used for this study. No specific adjustment, imputation method, sensitivity analysis, or interim analysis is reported in the registry 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 |
|---|---|---|---|
| SNX-5422 | 8 | 15 | 53.3% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| SNX-5422 | 15 of 15 |
Most frequent serious adverse event terms
| Event term | Organ system | SNX-5422 |
|---|---|---|
| Renal Failure Acute | Renal and urinary disorders | 2 of 15 |
| Abdominal Pain Upper | Gastrointestinal disorders | 1 of 15 |
| Atrial Fibrillation | Cardiac disorders | 1 of 15 |
| Diarrhoea | Gastrointestinal disorders | 1 of 15 |
| Haematemesis | Gastrointestinal disorders | 1 of 15 |
| Nausea | Gastrointestinal disorders | 1 of 15 |
| Vomiting | Gastrointestinal disorders | 1 of 15 |
| Cardiac Tamponade | Cardiac disorders | 1 of 15 |
| Pericardial Effusion | Cardiac disorders | 1 of 15 |
| Pneumonia | Infections and infestations | 1 of 15 |
Most frequent non-serious adverse event terms
| Event term | Organ system | SNX-5422 |
|---|---|---|
| Diarrhoea | Gastrointestinal disorders | 13 of 15 |
| Nausea | Gastrointestinal disorders | 8 of 15 |
| Vomiting | Gastrointestinal disorders | 8 of 15 |
| Fatigue | General disorders | 6 of 15 |
| Aspartate Aminotransferase increased | Investigations | 5 of 15 |
| Anaemia | Blood and lymphatic system disorders | 4 of 15 |
| Abdominal Pain | Gastrointestinal disorders | 3 of 15 |
| Decreased Appetite | Metabolism and nutrition disorders | 3 of 15 |
| Alanine Aminotransferase Increased | Investigations | 3 of 15 |
| Constipation | Gastrointestinal disorders | 2 of 15 |
Serious events with the highest arm-level rate: renal failure acute (13.3%), abdominal pain upper (6.7%), atrial fibrillation (6.7%), diarrhoea (6.7%), haematemesis (6.7%).
The registry reports serious adverse events for the SNX-5422 group among 15 participants at risk. Eight participants were affected. For other adverse events, 15 participants were at risk and 15 were affected. These figures describe participants recorded as having events; they should not be read as a count of all individual event episodes.
The listed serious event terms and percentages are Renal Failure Acute, 13.3%; Abdominal Pain Upper, 6.7%; Atrial Fibrillation, 6.7%; Diarrhoea, 6.7%; Haematemesis, 6.7%; and Nausea, 6.7%. The percentages are registry entries for the listed terms. A participant may have experienced more than one event or term, so the listed percentages should not be added together to obtain a total affected proportion.
These are descriptive safety observations in a single study group. They do not establish whether an event was caused by SNX-5422, and there is no control group for comparison. The registry does not report deaths for this group. Detailed event narratives, timing, duration, outcomes, or participant-level overlap among event terms are not reported in the registry record. The entries therefore describe what was reported, but do not support a comparative estimate of treatment-related risk.
12. What the Result Does, and Does Not, Mean
The record documents a single-arm, open-label phase 1/2 study of SNX-5422 in selected HER2-positive cancers, with enrollment of 15. It specifies the intended dosing schedule, names objective response rate as the primary outcome, and provides descriptive safety figures. These features make the record informative about the study’s design and the kinds of outcomes collected or intended to be collected.
It does not provide an observed primary response rate. The registry states that no patient completed six months on study before termination, and six months was the first analysis time point for the endpoint. Therefore, the posted information cannot show how many participants had complete or partial remissions at that assessment, or estimate the response rate at that point. This is an unavailable efficacy result, not a result showing that there were no responses.
The study also cannot provide a direct comparison with another treatment or a no-treatment group. Its single-group design means that the safety figures are descriptive and that any observed outcome cannot be contrasted against a concurrent control. The open-label design adds a further reason to interpret subjective aspects of measurement or reporting cautiously, although the registry does not state that bias occurred.
The serious adverse event figures identify 8 affected participants among 15 at risk, and the other adverse event figures identify 15 affected participants among 15 at risk. These counts and the listed serious event terms are not by themselves evidence of causation. No comparative risk estimate is reported, and deaths are not reported for the group.
General interpretation: a study’s information value depends both on what it measures and on whether the necessary observations are available. Here, the endpoint is defined, but its first assessment point was not reached by any participant before termination. The available record can describe the design and safety reporting, but it cannot establish an efficacy estimate or a comparative treatment effect.
13. Why This Trial Matters Statistically
This trial is statistically notable because the primary endpoint was defined, but the registry states that no participant reached its first assessment time point before the study ended. That distinction is important: an endpoint can be specified in advance without an observed result being available. Readers should not confuse a planned measure with evidence about the measure’s value.
The single-arm, open-label design also shapes what the data could establish even if outcome observations were available. A single group allows descriptive reporting of participant outcomes, while a concurrent comparison is needed to estimate how outcomes differ between treatments within the study. Without that comparator, observed changes cannot be cleanly attributed to the study treatment rather than other influences. This is a design limitation, not a statistical adjustment that can be removed after the fact.
The study enrolled 15 participants and was terminated for business reasons related to slow recruitment and the availability of newer targeted treatments. Early termination limited the opportunity to reach the primary endpoint’s first assessment point. This illustrates why recruitment and follow-up are part of the statistical context: an intended analysis depends on obtaining the outcome observations needed for it.
The record also illustrates the difference between safety description and safety comparison. It reports affected participants and serious event terms, but no control group is available to anchor a comparative estimate. The number of participants at risk is stated, while details needed to interpret event timing, duration, relationship, and overlap are not reported in the registry record.
For biostatistical interpretation, the central issue is therefore not a subtle choice among models or tests. The registry has no listed analyses and lacks an observed primary endpoint result at the first assessment time point. The main lesson is to distinguish a protocol-defined estimand from an estimable result, and to distinguish descriptive safety reporting from evidence of comparative risk.
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 most direct limitation is that no patient completed six months on study, the first analysis time point for the primary endpoint, when the study terminated. As a result, the registry does not report an observed primary response result at that point. The stated timeframe of up to 24 months from last patient entry does not supply missing assessments.
Enrollment was 15, and the study had no comparison group. The resulting observations are limited to the participants in the SNX-5422 group and cannot establish a difference from another treatment or from no treatment. Open-label conduct also means the study was not masked; the registry does not report whether this affected assessment or reporting.
The record attributes termination to business reasons, specifically slow recruitment and availability of newer targeted treatments. It does not give further details about the recruitment process, participant follow-up after treatment stopped, or the circumstances of each participant’s discontinuation. Those details are not reported in the registry record.
For efficacy, the registry describes a per-protocol population of all enrolled evaluable subjects, but does not give the number evaluable or participant-level outcomes. It does not report a primary endpoint estimate, confidence interval, hypothesis test, or analysis method. The full statistical plan, sample-size justification, missing-data approach, and any interim analyses are not reported in the registry record.
For safety, affected-participant counts and serious event terms are available, but the registry does not provide event narratives, timing, duration, outcomes, or participant-level overlap among terms. The listed terms do not establish causality, and the lack of a control group prevents a direct comparative assessment. Deaths are not reported for the group. These limits mean the safety information is descriptive rather than a complete comparative risk analysis.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Efficacy of SNX-5422 in Human Epidermal Growth Factor Receptor 2 (HER2) Positive Cancers — NCT01848756.
- Registry record last updated 2017-02-09; status last verified 2016-12.
- Results first posted 2016-11-21.
- 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
The registry record describes a phase 1/2, single-group, open-label study of SNX-5422 in selected HER2-positive cancers, sponsored by Esanex Inc. Enrollment was 15. The study began in 2013-04, had primary completion in 2015-02, and is listed as terminated.
The planned treatment was SNX-5422 capsules at 100 mg/m2 every other day for 21 days, totaling 11 doses in a 28-day cycle, with further cycles at the principal investigator’s discretion based on safety. The primary outcome was objective response rate assessed using RECIST, with an assessment timeframe of up to 24 months from last patient entry. The record states that no patient completed six months on study, the first endpoint analysis time point, before termination.
The record reports 8 participants with serious adverse events among 15 at risk and 15 with other adverse events among 15 at risk. It lists serious event terms and percentages but gives no deaths for the group. No analyses are listed, and no primary efficacy result is reported in the registry record.