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 A Phase 2a Study Evaluating BIVV020 in Adults With Persistent/Chronic Immune Thrombocytopenia (ITP) (NCT04669600), a na phase 2 study. The primary outcome is Percentage of Participants With a Durable Platelet Response.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04669600 |
| Phase | Phase 2 |
| Condition | Immune Thrombocytopenia (ITP) |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 12 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Bioverativ, a Sanofi company |
| Results posted | Yes |
2. Clinical Question
Population
Adults with persistent or chronic immune thrombocytopenia (ITP) were studied. The registry describes two categories for the primary endpoint: participants who had not used sutimlimab before enrollment (“naive”) and those who had (“switchers”). The record does not report further eligibility details in the information available for this analysis.
Intervention
Participants received SAR445088 (BIVV020). The record identifies the intervention as a drug but does not report its dose or administration schedule in the information.
Comparator
There was no separate comparator group: the study was open-label, non-randomized, and single-group. It therefore does not directly compare BIVV020 with placebo, usual care, or another treatment.
Primary question
From Week 3 to Week 24, what percentage of participants met the study’s category-specific criteria for a durable platelet response without receiving rescue ITP therapy? The registry describes the endpoint but does not report the observed percentage or its confidence interval.
The endpoint distinguishes participants by prior sutimlimab use. A naive participant counted as a responder if the platelet count met the stated threshold at at least half of scheduled visits, with an alternative increase-from-baseline criterion for participants whose baseline platelet count was below 15 × 10^9/L. A switcher had to meet a maintenance platelet-count threshold at at least half of scheduled visits. Both definitions required that the participant not receive rescue ITP therapy.
This is a question about the frequency and durability of a defined response among participants receiving the study drug, not a randomized estimate of how BIVV020 compares with another intervention. The registry’s primary objective was to evaluate the effect of BIVV020 on durability of platelet response. It also lists objectives concerning safety, tolerability, pharmacokinetics, response rate, time to response, rescue therapy, and immunogenicity. Those objectives describe what the study set out to assess; they do not establish that results for each objective are reported in the registry record.
3. Trial Design
This was a phase 2a, multicenter, open-label, non-randomized, single-group study of SAR445088 (BIVV020) in adults with persistent or chronic ITP. The registry lists enrollment of 12 participants and a completed study. The recorded study start was 2021-02-04, and the primary completion date was 2022-02-15. Participants received SAR445088 (BIVV020); there was no separate control arm described.
Open-label means that treatment assignment was not masked from participants and investigators, as reflected by the registry’s masking designation of none. Non-randomized and single-group mean that participants were not assigned by chance to one of multiple trial groups for a controlled comparison. Consequently, the design can describe outcomes observed among treated participants, but it does not isolate treatment effects from changes over time, other care, or features of the participants in the way a randomized control group can help do.
The primary outcome was the percentage of participants with a durable platelet response from Week 3 to Week 24. The registry defines different response thresholds for naive participants and switchers, based on prior sutimlimab use, and requires absence of rescue ITP therapy. The stated analysis population was the intent-to-treat population, which the registry defines as all exposed participants. It says that the number analyzed was the number in each category—naive participant and switcher—but does not report the category counts in the information available for this analysis.
The registry also lists secondary outcomes covering treatment-emergent adverse events, serious adverse events, potentially clinically significant laboratory abnormalities, plasma concentrations, number of responders, and time to first platelet response. The registry record does not report randomization, masking, a comparator regimen, a protocol-level sample-size justification, or a detailed account of how each secondary outcome was analyzed. Those details should not be inferred from the study’s phase or design labels.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: The study consisted of a screening period (up to 56 days), treatment period (up to 81 weeks), and follow-up visits (up to 22 weeks). A total of 12 participants \[either switchers: who had received and responded to sutimlimab (BIVV009) in study TDR16218 (NCT03275454) or naïve: who have not previously received sutimlimab\] were enrolled in this study.
Overall Study
| Stage | SAR445088 |
|---|---|
| STARTED | 12 |
| COMPLETED | 5 |
| NOT COMPLETED | 7 |
Reasons for not completing this period:
| Reason | SAR445088 |
|---|---|
| Withdrawal by Subject | 1 |
| Other | 6 |
Analysis population for the primary outcome, as defined in the registry: Results are based on the overall number of participants analyzed = intent-to-treat (ITT) population which consisted of all exposed participants. Number analyzed = number of participants for each category (naive participant and switcher).
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: Enrolled population consisted of all participants from screened population who had been allocated to a treatment regardless of whether the treatment was received or not.
| Characteristic | Unit | SAR445088 |
|---|---|---|
| Participants analysed | 12 | |
| Age, Continuous | years | 54.7 (SD 10.1) |
| Sex: Female, Male: Female | Participants | 4 |
| Sex: Female, Male: Male | Participants | 8 |
| 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 | 3 |
| Race (NIH/OMB): White | Participants | 7 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 2 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Participants With a Durable Platelet Response, measured over From Week 3 to Week 24.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | percentage of participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of participants with a durable platelet response from Week 3 to Week 24. It is a binary participant-level outcome: each participant either meets the specified response definition or does not. The registry describes the result as a percentage of participants and identifies a 95% confidence interval as the measure of uncertainty. The actual percentage and interval are not reported in the registry record.
The definition depends on prior sutimlimab use. A naive participant is a responder if the platelet count is at least 50 × 10^9/L at at least 50% of scheduled visits. For a naive participant whose baseline platelet count was below 15 × 10^9/L, the alternative criterion is an increase of at least 20 × 10^9/L from baseline at at least 50% of scheduled visits. A switcher is a responder if the maintenance platelet count is at least 30 × 10^9/L at at least 50% of scheduled visits. Both categories require no rescue ITP therapy.
Requiring the criterion at repeated scheduled visits makes the endpoint a measure of response durability over the specified assessment period, rather than a response at a single visit. The rescue-therapy condition is part of the endpoint definition: a participant receiving rescue ITP therapy does not satisfy the stated responder criteria. In general, repeated-measure definitions can capture persistence while also depending on visit attendance and the handling of missing measurements. The registry record does not report those handling rules or the observed endpoint result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a primary endpoint intended to quantify durable platelet response, but it does not report the observed percentage of participants meeting that endpoint or the 95% confidence interval. Therefore, the primary outcome cannot be quantified from the registry information available for this analysis. The study’s enrollment was 12, but the number analyzed in each primary-endpoint category is not reported in the record. It would be inappropriate to infer the response rate from the enrollment count or from other outcomes.
The design also determines what can be concluded. Participants received BIVV020 in a single group, without random allocation or a concurrent comparator. Any reported outcome in such a design describes the participants’ experience during the study; it does not by itself estimate a contrast against an untreated group or another treatment. Differences from participants’ prior status, changes over time, and other influences cannot be separated from treatment effects through a randomized comparison in this design.
The primary endpoint is not a single platelet-count threshold applied identically to everyone. It uses distinct criteria for naive participants and switchers, and includes a special baseline-dependent criterion for some naive participants. The threshold must be met at at least half of scheduled visits, and participants must not receive rescue ITP therapy. These details matter when interpreting any eventual estimate: the result would refer to the registry’s operational definition of durable response, not to every possible definition of platelet improvement.
Precision cannot be judged without the endpoint estimate and its confidence interval. In general, a confidence interval describes the range of values compatible with the data under the analysis method and its assumptions; it does not guarantee that the true value lies within a particular interval. With a small enrolled group, a percentage estimate can be especially sensitive to the outcome of individual participants, and its uncertainty may be substantial. This is a general statistical consideration, not a reported finding about the unreported primary result.
The record lists the study as completed and includes safety counts for the SAR445088 group: 2 participants with serious adverse events among 12 at risk, 8 with other adverse events among 12 at risk, and 0 deaths. These counts describe observed events in the treated group and do not establish whether events were caused by the study drug. The record lists serious-event terms, each with a reported frequency of 8.3%, but does not provide enough context in the information to attribute those events to treatment.
The trial’s stated objectives included safety and tolerability, pharmacokinetics, response rate, time to response, rescue therapy, and immunogenicity. A listed objective or outcome is not itself a result. The number of analysis entries is zero in the registry information used for this account, and results for many objectives are not reported in the registry record. Conclusions should therefore remain limited to the design, endpoint definitions, and explicitly posted safety counts.
9. Statistical Methods Explained
The statistical information in the registry record is limited. It identifies a percentage endpoint, a 95% confidence interval, an intent-to-treat analysis population, and the endpoint’s response criteria. It does not report a statistical analysis plan, the method used to calculate the primary confidence interval, the primary endpoint estimate, or an analysis entry. The following explanations describe general statistical concepts; they do not assert that a particular unreported method was used in this study.
What does a percentage endpoint represent?
A participant-level binary outcome classifies each participant into one of two states for the specified definition, such as meeting or not meeting the durable-response criteria. The percentage is a summary of how frequent the qualifying outcome was in the analysis group. Its interpretation depends on the denominator, the participants included, and how the endpoint criteria are applied. The registry states that the primary endpoint is a percentage of participants, but does not report the actual percentage or the category-specific denominator counts.
Here, the endpoint criteria are applied across scheduled visits within the stated period. The required platelet-count thresholds differ for naive participants and switchers, and the naive definition includes an alternative increase-from-baseline rule for participants whose baseline platelet count was below 15 × 10^9/L. Each definition also requires that the participant not receive rescue ITP therapy. Thus, a percentage for this endpoint would summarize the proportion meeting a compound, repeated-visit definition, not simply the proportion with a platelet count above one common threshold on one occasion.
What does a confidence interval add?
In general, a confidence interval expresses uncertainty around an estimated quantity. For a participant percentage, it communicates how much statistical uncertainty remains about the response frequency, given the observed data and the method used. A narrower interval indicates greater precision under that method; a wider interval indicates less precision. The registry specifies a 95% confidence interval for the primary endpoint, but does not report its limits or the calculation method. Without those details, the precision of the primary estimate cannot be assessed.
A confidence interval is not a guarantee that the true response frequency falls inside its endpoints, nor does it describe the range of outcomes for individual participants. Its meaning relies on the chosen statistical procedure and its assumptions. For small groups, different interval procedures can yield different degrees of coverage and width. The record does not identify which procedure was used, so no method-specific interpretation can be made.
Why does the analysis population matter?
The registry says the primary analysis used the intent-to-treat population, defined as all exposed participants. It further says the number analyzed was the number of participants in each category, naive participant and switcher. This definition clarifies the broad population intended for analysis, but it does not supply the actual number in each category or explain how incomplete visit data were handled. The record does not report whether every exposed participant had enough scheduled measurements to classify the primary endpoint.
In general, missing measurements can affect a repeated-visit endpoint because the responder rule depends on the proportion of scheduled visits meeting a threshold. Different approaches to missing visits can change who is considered evaluable or how the proportion of qualifying visits is calculated. The registry record does not report whether missing measurements were treated as non-response, excluded from the denominator, imputed, or handled in another way. None of these approaches should be assumed.
What is the effect of having one study group?
This study was non-randomized and single-group. General statistical interpretation of a single-group result focuses on the outcome observed among participants who received the intervention, rather than on a between-group treatment contrast. Without a concurrent randomized control group, a change or response during follow-up cannot be attributed to the intervention with the same protection against confounding that random allocation is designed to provide. The record does not report a comparator or a comparative treatment-effect estimate.
Open-label status also means treatment was not masked. In general, lack of masking can influence behaviors or outcome assessment, depending on the outcome and how it is measured. That is a design consideration, not evidence that bias occurred in this trial. The registry information does not describe blinded endpoint assessment or procedures intended to reduce such influence.
What do the planning assumptions mean?
The registry information describes sample-size planning illustrations based on the observed effect, rather than the trial’s own design. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. For time-to-event illustrations, the listed quantity is total events; for other illustrations, it is participants per arm. These are planning concepts, not observed trial outcomes or observed power.
The registry record does not report the observed primary effect needed to interpret an effect-based planning illustration, nor does it report the trial’s own sample-size justification. The study itself was single-group, while the planning assumptions describe a two-arm allocation. Those assumptions should not be mistaken for the actual trial design or evidence that the study had a particular power. No calculated planning values are reported in the information available for this analysis.
Why can over-dispersion matter?
In general, over-dispersion occurs when observed variability is greater than a statistical model assumes. It can make standard errors too small and confidence intervals too narrow if the model does not account for that extra variability. This concept is relevant to some count or rate analyses, but the primary endpoint is described as a percentage of participants, and the registry does not report a model-based analysis or an over-dispersion assessment. No conclusion about over-dispersion in this study is possible from the record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary objective and multiple secondary objectives and outcomes. It does not report a multiplicity adjustment, a testing hierarchy, or another strategy for controlling the chance of false-positive findings across multiple statistical tests. Therefore, whether or how multiplicity was addressed is not reported in the registry record. In general, when several hypotheses are tested, the chance of at least one nominally significant result can increase; the appropriate approach depends on the analysis plan and the purpose of the outcomes. No unreported approach should be assumed.
The primary analysis population is described as the intent-to-treat population, consisting of all exposed participants. The record says that the number analyzed was the number in each category, naive participant and switcher. It does not report the category-specific counts, the number with complete primary-endpoint data, or a participant flow describing exclusions from each analysis. The enrollment count alone does not establish how many participants contributed to every outcome.
The primary endpoint relies on platelet measurements at scheduled visits from Week 3 to Week 24 and uses the percentage of visits meeting a threshold. The registry record does not state how missing visits or missing platelet measurements were handled, how participants who discontinued were classified, or whether any imputation or sensitivity analyses were used. These are important details because the endpoint is based on repeated observations and a threshold applied across visits.
The record also does not report whether interim analyses were planned or conducted, whether any outcomes were changed, or whether analyses followed a prespecified statistical analysis plan. These items are not reported in the registry record; their absence from the available information should not be interpreted as evidence that a particular method was or was not used.
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 |
|---|---|---|---|
| SAR445088 | 2 | 12 | 16.7% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| SAR445088 | 0 of 12 |
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 |
|---|---|
| SAR445088 | 8 of 12 |
Most frequent serious adverse event terms
| Event term | Organ system | SAR445088 |
|---|---|---|
| Appendicitis | Infections and infestations | 1 of 12 |
| Cerebrovascular Accident | Nervous system disorders | 1 of 12 |
| Abdominal Pain Upper | Gastrointestinal disorders | 1 of 12 |
Most frequent non-serious adverse event terms
| Event term | Organ system | SAR445088 |
|---|---|---|
| Covid-19 | Infections and infestations | 3 of 12 |
| Fatigue | General disorders | 3 of 12 |
| Diarrhoea | Gastrointestinal disorders | 2 of 12 |
| Influenza | Infections and infestations | 1 of 12 |
| Post-Acute Covid-19 Syndrome | Infections and infestations | 1 of 12 |
| Sinusitis | Infections and infestations | 1 of 12 |
| Lymphadenopathy | Blood and lymphatic system disorders | 1 of 12 |
| Decreased Appetite | Metabolism and nutrition disorders | 1 of 12 |
| Hyperglycaemia | Metabolism and nutrition disorders | 1 of 12 |
| Aphasia | Nervous system disorders | 1 of 12 |
Serious events with the highest arm-level rate: appendicitis (8.3%), cerebrovascular accident (8.3%), abdominal pain upper (8.3%).
For the SAR445088 group, the registry lists 12 participants at risk for serious adverse events and 2 participants affected. It lists 12 participants at risk for other adverse events and 8 affected. The registry also reports 0 deaths. These are participant counts in the study group, not estimates from a comparison with another group.
The serious-event terms listed are Appendicitis, Cerebrovascular Accident, and Abdominal Pain Upper, each reported at 8.3%. These entries describe the terms and frequencies recorded; they do not by themselves establish that the events were caused by SAR445088. The registry record does not report causal attribution details in the information available for this analysis.
In general, adverse-event counts depend on the definitions, observation period, and collection procedures used. A count of participants affected does not convey event severity beyond the stated category, duration, recurrence, or clinical outcome. The registry lists treatment-emergent adverse events and serious adverse events among its outcomes, but the information does not give the complete event-level detail needed to interpret every safety aspect. The counts should be read as descriptive observations from a small, single-group study, not as a controlled estimate of comparative safety.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a completed phase 2a, open-label, non-randomized, single-group study evaluated BIVV020 in adults with persistent or chronic ITP. It defines a primary endpoint intended to capture durable platelet response from Week 3 to Week 24, with different criteria for naive participants and switchers and a requirement that responders not receive rescue ITP therapy. It also records safety counts for the SAR445088 group.
The record does not report the primary endpoint percentage or its 95% confidence interval. It therefore does not allow a reader to determine from this information how many participants met the durable-response definition or how precise that estimate was. The absence of a posted primary estimate is not evidence that no responses occurred; it means the result is not reported in the registry record.
The design does not provide a randomized comparison. Accordingly, the available information cannot establish how outcomes would have differed under another treatment or no study drug. A response observed during follow-up, if reported, would be descriptive of this treated group and would not alone establish a causal treatment effect.
The safety counts—2 participants with serious adverse events, 8 with other adverse events, and 0 deaths, with 12 at risk for each adverse-event category—are also descriptive. They do not identify whether an event was attributable to the intervention or quantify comparative risk. The serious-event terms and their reported frequencies should be understood as registry entries, not causal conclusions.
In general, a small study can contribute useful descriptive evidence and inform later research questions, while estimates may remain imprecise and the design may limit causal interpretation. That general point does not supply the unreported efficacy result or validate any particular conclusion about BIVV020. Interpretation should stay within the outcomes and methods that the registry actually reports.
13. Why This Trial Matters Statistically
This trial is statistically notable because its primary endpoint makes durability explicit. Rather than defining response from a single platelet measurement, the registry requires the applicable platelet-count criterion at at least 50% of scheduled visits across the stated follow-up period. It also makes rescue ITP therapy part of the responder definition. These choices shape the meaning of the outcome: a reported percentage would refer to participants satisfying the complete rule, not simply participants with one favorable measurement.
The endpoint also uses separate definitions according to prior sutimlimab use. For naive participants, the record specifies a platelet-count threshold and an alternative increase-from-baseline rule for those with a low baseline count. Switchers have a maintenance platelet-count threshold. Such distinctions can be statistically and clinically important because an overall percentage combines participants assessed under different criteria. The registry says the number analyzed was determined within the naive and switcher categories, but does not report their counts or category-specific results.
The study’s single-group, non-randomized design frames the evidence as descriptive rather than comparative. It can document outcomes in the enrolled, exposed participants, but cannot directly estimate a randomized contrast against a control group. The open-label design is another consideration when judging how outcomes were collected and assessed; the record does not describe additional masking procedures.
Finally, the distinction between a defined endpoint and a posted result is essential. The registry contains detailed criteria for the primary outcome, yet the outcome estimate and its confidence interval are not reported in the information available for this analysis. Statistical interpretation requires both the definition and the observed data. Without the latter, the primary response frequency and its precision remain unknown.
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 immediate limitation is that the primary endpoint result is not reported in the registry record. Although the endpoint definition and 95% confidence interval measure are specified, the observed percentage and interval are unavailable in the information. The category-specific numbers analyzed and category-specific results are also not reported, preventing assessment of how the naive and switcher groups contributed to any combined estimate.
The study enrolled 12 participants and had a single group. The record therefore offers no randomized comparator for distinguishing outcomes under BIVV020 from outcomes that might have occurred under another intervention or without it. Its open-label design also means masking was absent. These features constrain causal and comparative interpretation, regardless of the endpoint definition.
Several details needed to assess the endpoint analysis are not reported in the registry record: the statistical method for the confidence interval, handling of missing scheduled visits and platelet measurements, classification of participants who discontinued, and any sensitivity analyses. Since response requires meeting a threshold across repeated visits, these analysis choices could affect the estimated percentage. The record also does not provide a protocol-level sample-size justification or the detailed statistical analysis plan.
The listed safety counts are limited descriptive summaries. The information does not include complete event-level context, attribution, duration, or comparative safety data. The listed serious-event terms do not establish causality. The record also lists secondary outcomes but does not report their full results in the information available for this analysis. These limitations concern what can be interpreted from the registry record, not proof that unreported information was never collected.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Phase 2a Study Evaluating BIVV020 in Adults With Persistent/Chronic Immune Thrombocytopenia (ITP) — NCT04669600.
- Registry record last updated 2025-09-10; status last verified 2025-09.
- Results first posted 2024-02-22.
- 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
NCT04669600 is a completed phase 2a, multicenter, open-label, non-randomized, single-group study evaluating SAR445088 (BIVV020) in adults with persistent or chronic ITP. Enrollment was 12. The recorded start date was 2021-02-04, and the primary completion date was 2022-02-15. Participants received SAR445088 (BIVV020).
The primary endpoint was the percentage of participants with a durable platelet response from Week 3 to Week 24. Its criteria differ for naive participants and switchers and require no rescue ITP therapy. The record specifies a 95% confidence interval, but the primary endpoint estimate and interval are not reported in the registry record.
For the SAR445088 group, the registry reports 2 participants with serious adverse events and 8 with other adverse events, each among 12 at risk, and 0 deaths. The study has no randomized comparator, and the listed safety counts are descriptive. Further details on missing data handling, multiplicity, interim analyses, and the statistical analysis plan are not reported in the registry record.