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 Multiple Rising Does Study (Subcutaneous Doses) of BI 655064 in Male and Female Patients With Chronic Primary Immune Thrombocytopenic Purpura (ITP). (NCT02009761), a na phase 1 study. The primary outcome is Number of Patients With Response in Platelet Count.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02009761 |
| Phase | Phase 1 |
| Condition | Purpura, Thrombocytopenic, Idiopathic |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 6 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Boehringer Ingelheim |
| Results posted | Yes |
2. Clinical Question
Population
Patients with chronic primary immune thrombocytopenic purpura (ITP). The primary outcome population is the Treated Set: patients dispensed trial medication and documented to have taken at least one dose.
Intervention
BI 655064, administered as a subcutaneous injection once a week. The brief summary describes treatment for up to 12 weeks. The named arm is BI 655064 120 mg / 180 mg.
Comparator
There was no separate comparator group. The registry record describes a single-group study without masking.
Primary question
How many treated patients met the registry’s platelet-count response definition during the period up to 12 weeks? That definition required both a rise from baseline and a platelet count above the specified threshold, with no rescue therapy.
This is a descriptive question in a small, open-label study, not a comparison of BI 655064 against another treatment. The registry record lists an enrollment of 6, but does not report the number who met the primary response definition. It therefore does not provide the central outcome count needed to describe how often the defined response occurred.
The response definition combines a change from baseline with an absolute platelet-count threshold. Baseline was the platelet count at Visit 2 before BI 655064 administration. A participant was considered a non-responder if only one of the two platelet-count conditions was met. The no-rescue-therapy condition is also part of the outcome definition, so a platelet count meeting the thresholds alone was insufficient.
The study also lists drug-related adverse events and reaching an ITP cut-off point among its secondary outcomes. Those outcomes do not replace the primary response measure, and the registry record does not report their detailed results in the registry record for this analysis.
3. Trial Design
This was a Phase 1 study of BI 655064 in patients with chronic primary immune thrombocytopenic purpura. The registry describes it as open label, with no masking, and as a single-group study. Allocation is listed as not applicable. There was no separate control arm, so the design does not provide a like-for-like comparison against another treatment or against placebo.
The registry names the arm BI 655064 120 mg / 180 mg and describes subcutaneous administration once a week. Its arm description states that patients received 120 mg once weekly for 4 weeks, but the available description ends before the full dosing schedule is given. The brief summary says treatment was planned for up to 12 weeks. The complete escalation schedule and the circumstances governing dose changes are not reported in the registry record.
The record lists enrollment of 6. The primary outcome applies to the Treated Set, defined as patients who were dispensed trial medication and documented to have taken at least one dose. The registry’s safety figures list 6 participants at risk for the reported serious and other adverse-event counts. Enrollment and the treated-set definition describe different aspects of the record and should not be treated as interchangeable without a reported participant flow.
The study started on 2013-12-18, and primary completion is recorded as 2016-04-26. Its status is terminated. The reason for termination, the timing of termination relative to the planned treatment period, and any effects on outcome collection are not reported in the registry record. The record does not describe a randomized comparison or masking that could reduce the influence of expectations on outcome assessment.
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: All subjects were screened for eligibility prior to participation in the trial. Subjects attended a specialist site which ensured that they (the subjects) strictly met all inclusion and none of the exclusion criteria. Subjects were not to be allocated to a treatment group if any of the entry criteria were violated.
Overall Study
| Stage | BI 655064 120 mg / 180 mg |
|---|---|
| STARTED | 6 |
| COMPLETED | 2 |
| NOT COMPLETED | 4 |
Reasons for not completing this period:
| Reason | BI 655064 120 mg / 180 mg |
|---|---|
| Adverse Event | 4 |
Analysis population for the primary outcome, as defined in the registry: Treated Set (TS): Included all patients who were dispensed trial medication and were documented to have taken at least one dose of trial medication.
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: Treated Set (TS): Included all patients who were dispensed trial medication and were documented to have taken at least one dose of trial medication.
| Characteristic | Unit | BI 655064 120 mg / 180 mg |
|---|---|---|
| Participants analysed | 6 | |
| Age, Continuous | Years | 66.0 (SD 9.5) |
| Sex: Female, Male: Female | Participants | 3 |
| Sex: Female, Male: Male | Participants | 3 |
| 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 | 1 |
| Race (NIH/OMB): White | Participants | 5 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Patients With Response in Platelet Count, measured over Up to 12 weeks..
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with a response in platelet count, assessed up to 12 weeks. The registry defines response using two platelet-count conditions: an increase greater than 20 x 10^9/L from baseline at any time from Week 1 through Week 12, and a platelet count above 50 x 10^9/L at any time in that period with no rescue therapy. Baseline is the platelet count at Visit 2 before BI 655064 administration. A participant meeting only one condition was classified as a non-responder.
This combined definition makes the outcome more specific than either criterion alone. In general, requiring both a change from baseline and an absolute threshold distinguishes a relative rise from reaching a stated platelet-count level. The no-rescue condition further defines the circumstances under which the response counts. These are properties of the registry’s operational definition; they do not establish how meaningful a response is for a participant’s health or experience.
The endpoint is reported as a count of participants, rather than as a continuous summary of platelet counts. Counts can be straightforward to interpret when the number assessed and the number meeting the definition are both reported. In this record, the primary response count is not reported in the registry record, so the frequency of response and its precision cannot be described from the posted results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the trial as a single-group, open-label Phase 1 study, and lists enrollment of 6. It provides the definition of the primary platelet-count response but does not report how many participants met that definition. Without the response count and the corresponding number assessed for that endpoint, the main efficacy result cannot be quantified. No estimate of the response frequency or its uncertainty can be drawn from the posted primary outcome information.
The definition requires both a rise greater than 20 x 10^9/L from baseline and a platelet count above 50 x 10^9/L, with no rescue therapy, during the stated period. Meeting one condition alone is explicitly classified as non-response. This matters when interpreting any response count: it would represent participants satisfying the full composite rule, not everyone with any platelet-count increase. The registry record does not report participant-level platelet values or the timing of responses.
Because there is no separate comparator group, the design cannot estimate a treatment contrast against another arm. In general, a change observed during treatment in a single group can reflect multiple influences, including the underlying condition and events occurring over time; the design cannot isolate those influences from a treatment effect in the way a suitable controlled comparison can. Open-label conduct also means masking was absent, although the record does not state how outcome assessment was conducted.
The listed safety counts are descriptive. The record lists 0 serious adverse events among 6 at risk, 6 participants with other adverse events among 6 at risk, and 0 deaths. These counts do not establish whether events were caused by treatment. With a small number of participants, counts describe what was recorded in this study but cannot characterize uncommon events reliably. The registry lists no serious adverse-event terms.
The sample-size material is a planning illustration based on an observed effect, with two-sided significance level 0.05, equal allocation between two arms, and a normal approximation. It is not a description of this single-group study’s original design, and it is not observed power. The registry does not report the effect value needed to interpret those planning illustrations in this account. The sponsor’s analysis results are not reported in the registry record, so no sponsor estimate or statistical test can be discussed.
Overall, the posted information supports a description of the design, response rule, and recorded safety counts, but not a numerical conclusion about the primary response outcome. The reason for termination and the handling of incomplete outcome data are not reported in the registry record, which further limits interpretation of the study’s conduct and results.
9. Statistical Methods Explained
Statistical interpretation depends first on the design and the outcome definition. This study is recorded as a single-group, open-label Phase 1 study, with no separate comparator. Its primary endpoint is a count: the number of participants meeting the specified platelet-count response rule. The registry lists no analyses. It does not report a primary response count, an estimate of response frequency, a confidence interval, or a statistical test for that outcome.
What does a participant count represent?
For a binary outcome such as responder versus non-responder, each participant is classified into one of two categories under the stated rule. A count tells how many participants were classified as responders. To interpret that count as a frequency, a reader also needs to know how many participants were assessed for the outcome and how missing or unevaluable observations were treated. The primary outcome’s count and assessed denominator are not reported in the registry record.
In general, a confidence interval describes the range of values reasonably compatible with the observed data under a statistical method and its assumptions. It helps convey precision, which is distinct from whether an estimate is large or small. No confidence interval for the primary endpoint is reported in the registry record. With a small study population, estimates for binary outcomes can be imprecise; the actual precision cannot be assessed without the outcome count and an uncertainty interval.
Why does the response rule require both criteria?
The endpoint is a composite classification based on two platelet-count conditions and the absence of rescue therapy. The first condition is a rise greater than 20 x 10^9/L from baseline, while the second is a platelet count above 50 x 10^9/L during the outcome period without rescue therapy. The registry states that satisfying only one platelet-count condition results in classification as a non-responder. This rule prevents the endpoint from counting a participant solely because of one of those two platelet-count features. It does not, by itself, show how often each condition occurred separately.
The time window is up to 12 weeks, with the platelet-count conditions assessed at any time between Week 1 and Week 12. Baseline is defined as the platelet count at Visit 2 before the first administration described in the endpoint definition. A response count would therefore summarize whether the full rule was met at any qualifying time in that window; it would not describe the duration of response or the platelet-count trajectory. Those details are not reported in the registry record.
What can a single-group design establish?
In general, a single-group study describes outcomes observed among participants receiving the study intervention. Without a concurrent comparison group, it does not estimate the difference in outcomes between treatment strategies. A before-and-after interpretation also requires appropriate outcome data at both time points and assumptions about what would have happened without treatment. The registry record does not supply a controlled contrast or a causal estimate.
Open-label means masking was not used, according to the record. As a general statistical consideration, knowledge of treatment can influence care, reporting, or assessment, depending on how outcomes are collected. The platelet-count definition includes measured laboratory values and a rescue-therapy condition, but the registry record does not describe assessor masking, laboratory procedures, or rescue-treatment decision rules. Their influence therefore cannot be evaluated from the record.
How should the planning calculations be read?
The sample-size material is described as a planning illustration computed from an observed effect, not as the trial’s own design. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. In general, such calculations ask how many participants per arm would be needed under assumed conditions to detect a specified effect with a chosen power. They depend on the assumed effect, outcome variability, design, and analysis method.
These assumptions do not match the recorded single-group design, which has no equal allocation between two arms. The illustration is not evidence that the study had a particular probability of finding an effect, and sample-size calculations should not be called observed power. The exact planning values and the observed effect are not reported in the registry record, so they cannot be interpreted as estimates of this study’s response or precision.
Why does over-dispersion matter in general?
For count outcomes, a statistical model may assume a particular relationship between the mean and variability. Over-dispersion means the observed variability is greater than the model assumes. If not accounted for, standard errors can be too small and confidence intervals or tests can appear more precise than the data warrant. This is a general consideration for count modeling, not a reported feature or analysis of this trial. The primary endpoint is a participant count, and the registry record does not report a model for it.
More broadly, no inferential method, adjustment strategy, or statistical analysis plan is reported in the registry record. The available data therefore support descriptive statements about the listed design and safety counts, but not reconstruction of an unreported efficacy analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary outcome and two secondary outcomes: the number of subjects with drug-related adverse events and the number of patients reaching the ITP cut-off point. It does not report a multiplicity procedure, such as an adjustment for assessing several outcomes, in the registry record. Without a reported analysis plan, it is not possible to determine whether any statistical tests were planned, how they would have been prioritized, or whether multiplicity was addressed in another way.
The record does not report the primary response count or a statistical analysis for the outcome. It also does not describe missing-data rules, imputation, handling of participants who stopped treatment, or whether observations were excluded from the endpoint. These details are important because the primary response requires information over a defined period and includes a no-rescue condition. The outcome population is the Treated Set, defined as participants dispensed medication and documented to have taken at least one dose, but that definition alone does not explain how incomplete outcome data were treated.
The registry records enrollment of 6 and lists 6 at risk for the safety counts. It does not provide a participant flow connecting enrollment, treatment exposure, endpoint availability, and analysis populations. The reason for termination and whether termination affected the planned outcome collection are not reported in the registry record. Consequently, the potential effect of missing or incomplete data on the primary result cannot be assessed.
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 |
|---|---|---|---|
| BI 655064 120 mg / 180 mg | 0 | 6 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| BI 655064 120 mg / 180 mg | 0 of 6 |
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 |
|---|---|
| BI 655064 120 mg / 180 mg | 6 of 6 |
Most frequent non-serious adverse event terms
| Event term | Organ system | BI 655064 120 mg / 180 mg |
|---|---|---|
| Platelet count decreased | Investigations | 3 of 6 |
| Upper respiratory tract infection | Infections and infestations | 2 of 6 |
| Headache | Nervous system disorders | 2 of 6 |
| Petechiae | Skin and subcutaneous tissue disorders | 2 of 6 |
| Conjunctival haemorrhage | Eye disorders | 1 of 6 |
| Flatulence | Gastrointestinal disorders | 1 of 6 |
| Mouth haemorrhage | Gastrointestinal disorders | 1 of 6 |
| Hernia | General disorders | 1 of 6 |
| Contusion | Injury, poisoning and procedural complications | 1 of 6 |
| Hypokalaemia | Metabolism and nutrition disorders | 1 of 6 |
The registry’s safety figures list 0 serious adverse events among 6 participants at risk, 6 participants with other adverse events among 6 at risk, and 0 deaths. The record does not list any serious adverse-event terms. These are counts from the safety record; they should not be read as proof that treatment caused or prevented an event.
Serious adverse events and other adverse events are distinct categories in the record. The count for other adverse events does not establish their severity, duration, or relationship to BI 655064. Although a secondary outcome is described as drug-related adverse events, the safety figures summarized in the record do not provide event descriptions that would support attributing the counts to treatment. Such attribution is not reported in the registry record.
In general, a safety count describes events recorded in the participants observed, while the number at risk gives context for that count. The figures do not characterize the risk of uncommon events with precision, especially in a small study. They also do not replace a detailed account of event timing, exposure, seriousness, or causality, which is not reported in the registry record.
12. What the Result Does, and Does Not, Mean
The posted results establish several features of the study: it was a Phase 1, open-label, single-group investigation of BI 655064 in patients with chronic primary immune thrombocytopenic purpura; the brief summary describes weekly subcutaneous dosing for up to 12 weeks; and the primary outcome used a defined platelet-count response rule. The registry also lists safety counts, including 0 serious adverse events and 0 deaths among the recorded at-risk group.
The primary response count is not reported in the registry record. Therefore, the central efficacy outcome cannot be summarized as a response frequency, and its statistical precision cannot be evaluated. The response rule itself should not be mistaken for a result: it explains how responders would be classified, not how many participants met the definition.
The study’s single-group, open-label design does not provide a comparison against another treatment. In general, outcomes observed in one group cannot by themselves separate treatment effects from other influences over time. The record also does not report the reason for termination, complete dose-escalation details, missing-data handling, or an analysis plan. These gaps restrict what can be concluded from the registry entry.
The safety counts are similarly descriptive. Zero recorded serious adverse events does not establish that serious events are impossible, nor does the count of other adverse events show that they were caused by study treatment. This study record is too limited to characterize uncommon harms or establish a treatment effect. Its statistical contribution, based on the registry information, is a clearly specified response definition and a limited set of recorded design and safety details rather than a reported estimate of platelet-count response.
13. Why This Trial Matters Statistically
This study is statistically informative in part because its primary outcome definition is explicit. It specifies a change from baseline, an absolute platelet-count threshold, a time window, and the role of rescue therapy. Such operational detail matters: readers can distinguish the endpoint’s classification rule from broader claims about platelet counts or clinical benefit. The definition also makes clear that meeting only one platelet-count condition does not count as a response.
The record also illustrates why design context matters when reading outcomes. This was an open-label, single-group study, not a randomized comparison. A response count, if reported, would describe the participants meeting the rule in this study; it would not estimate a difference against an untreated or alternative-treatment group. Keeping descriptive evidence distinct from comparative evidence is important in clinical biostatistics.
At the same time, the registry does not report the primary response count or an analysis result. That absence limits statistical interpretation even though the endpoint is defined. The safety counts offer a similarly constrained description: they identify what was recorded in the at-risk group but do not establish causation or precisely characterize rare events.
The sample-size material is explicitly a planning illustration with assumptions for a two-arm design, while the recorded trial is single-group. Recognizing that mismatch helps prevent planning calculations from being treated as properties of the actual trial or as observed power. Overall, the entry highlights how endpoint definitions, analysis populations, outcome reporting, and design must be considered together before drawing statistical conclusions.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The primary limitation for interpreting the main outcome is that the registry record does not report the number of participants who met the platelet-count response definition. It also does not report the endpoint denominator, participant-level measurements, or an uncertainty estimate. Consequently, the response frequency and its precision cannot be assessed.
The study has no separate comparator group and is recorded as open label. These design features limit comparative and causal interpretation. The record does not describe how platelet counts were assessed, whether assessors were masked, or how rescue therapy was determined. It also does not report the complete dose-escalation schedule: the arm description names 120 mg / 180 mg but its dosing text is incomplete.
The registry records enrollment of 6, while the outcome population is defined as the Treated Set. It does not provide a participant flow or explain the relationship between enrollment, treatment, and endpoint availability. Missing-data handling and reasons for any incomplete follow-up are not reported in the registry record. The reason for the terminated status is also not reported.
Finally, the recorded safety counts are descriptive, and detailed event terms are absent for serious adverse events. The record does not provide an analysis plan, multiplicity approach, or inferential results. These limitations mean that the available information is insufficient to evaluate a treatment effect, the robustness of an efficacy analysis, or the frequency of less common safety outcomes.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Multiple Rising Does Study (Subcutaneous Doses) of BI 655064 in Male and Female Patients With Chronic Primary Immune Thrombocytopenic Purpura (ITP). — NCT02009761.
- Registry record last updated 2024-03-15; status last verified 2023-08.
- Results first posted 2024-03-15.
- 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 describes a Phase 1, open-label, single-group study of subcutaneous BI 655064 in patients with chronic primary immune thrombocytopenic purpura. The brief summary states that treatment was given once weekly for up to 12 weeks. Enrollment is listed as 6, and the primary outcome is the number of participants meeting a platelet-count response definition that combines a rise from baseline, an absolute platelet-count threshold, and no rescue therapy.
The primary response count is not reported in the registry record. Safety figures list 0 serious adverse events among 6 at risk, 6 participants with other adverse events among 6 at risk, and 0 deaths. The study status is terminated; its reason is not reported. The record does not provide a comparator, a complete dose-escalation schedule, missing-data methods, or statistical analysis results.