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, Tolerability, Pharmacokinetics, Pharmacodynamics, and Efficacy of SAR442501 in Pediatric Participants With Achondroplasia (NCT06067425), a randomized phase 2 study. The primary outcome is Stage 1: Number of Participants With Treatment-Emergent Adverse Events (TEAEs), Treatment-Emergent Serious Adverse Events (SAEs) and Adverse Events of Special Interest (AESIs).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT06067425 |
| Phase | Phase 2 |
| Condition | Osteochondrodysplasia |
| Allocation | Randomized |
| Design model | Sequential |
| Masking | None (open label) |
| Enrollment | 16 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Sanofi |
| Results posted | Yes |
2. Clinical Question
Population
Children from birth up to 12 years of age with achondroplasia were eligible for the study. The registry lists osteochondrodysplasia as the condition and records an enrollment of 16 participants. The safety population included enrolled participants who received at least 1 dose of study drug, regardless of the amount administered.
Intervention
The intervention was subcutaneous SAR442501. Stage 1 included a low-dose group, called Dose A, and a high-dose group, called Dose B. The registry record does not report the dose amounts or describe the dosing schedule.
Comparator
The listed groups are Dose A and Dose B. No placebo or untreated comparator is listed. Although the record labels allocation as randomized, it also describes a sequential-cohort study; the implementation of allocation between groups is not reported in the registry record.
Primary question
The primary safety question was how many participants had treatment-emergent adverse events, serious adverse events, or adverse events of special interest during follow-up. The registry describes these outcomes for Stage 1, but does not report a single comparative effect estimate or an inferential test of the groups.
This is a safety-focused question as well as a study of tolerability, pharmacokinetics, pharmacodynamics, and efficacy. The specified primary outcome counts participants with events; it does not measure event severity on a continuous scale or establish whether an event was caused by treatment. The registry defines treatment-emergent events by their timing and worsening after study drug starts, while serious events are identified by specified consequences or medical importance. Adverse events of special interest are events requiring particular sponsor monitoring.
Several secondary outcomes concern growth and body proportions, including growth velocity, height, and segment ratios at Weeks 26 and 52. Their inclusion indicates that the study planned to describe outcomes beyond safety. However, numerical results for those secondary measures are not reported in the registry record. The clinical question that can be addressed from the posted results is therefore limited to the recorded safety counts, not the effects on growth or other clinical outcomes.
3. Trial Design
The registry identifies NCT06067425 as a Phase 2 study of subcutaneous SAR442501 in pediatric participants with achondroplasia. Its official title describes an open-label, multi-center, two-stage sequential-cohort dose-escalation study. The brief summary describes evaluation of safety, tolerability, and efficacy in children from birth up to 12 years of age. Sanofi is listed as the sponsor.
The study is marked randomized and unmasked in the registry. The model is listed as sequential, and the arm descriptions name three cohorts but contain no further descriptions. The posted adverse-event groups are Stage 1 Dose A, described as low dose, and Stage 1 Dose B, described as high dose. How randomization was implemented, how participants entered the cohorts, the dose amounts, and the details of any later stage are not reported in the registry record. The open-label designation means masking is not listed; it does not establish how outcome assessments were conducted.
The registry records an enrollment of 16. The study started on 2023-10-10, had a primary completion date of 2025-02-12, and is marked terminated. The primary safety timeframe runs from the first dose on Day 1 until early termination of the study, described as approximately 58 weeks for Dose A and 46 weeks for Dose B. These are group-specific follow-up descriptions, not a statement that every participant was observed for the full period.
The primary outcome is a count of participants with treatment-emergent adverse events, serious adverse events, and adverse events of special interest. Secondary outcomes include changes in growth velocity and height measures and several body-proportion ratios at Weeks 26 and 52. The registry lists 31 outcome measures, but no analyses are listed. The study’s rationale for its enrollment target, detailed statistical analysis plan, and explanation for termination are not reported in the registry record.
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: Study was divided into 2 stages: Stage 1 (participants aged \>=3 to \<12 years) and Stage 2 (participants aged birth to \<3 years). No participant was enrolled into Stage 2 prior to the termination of the study. The 16 participants enrolled in the study were all from stage 1, only results of Stage 1 are presented. The study was early terminated by the Sponsor for reasons not related to safety concerns. As pre-specified in statistical analysis plan, the results are presented by dose level and Stage.
Overall Study
| Stage | Stage 1: SAR442501 Dose A (Low Dose) | Stage 1: SAR442501 Dose B (High Dose) |
|---|---|---|
| STARTED | 10 | 6 |
| COMPLETED | 0 | 0 |
| NOT COMPLETED | 10 | 6 |
Reasons for not completing this period:
| Reason | Stage 1: SAR442501 Dose A (Low Dose) | Stage 1: SAR442501 Dose B (High Dose) |
|---|---|---|
| Withdrawal by Subject | 2 | 0 |
| Study terminated by Sponsor decision, which was not related to safety concerns | 8 | 6 |
Analysis population for the primary outcome, as defined in the registry: The Safety population included all enrolled participants who had received at least 1 dose of study drug, regardless of the amount of study drug administered.
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 included all participants from screened population who were allocated to study drug regardless of whether the study drug was received or not, and regardless of replacement.
| Characteristic | Unit | Stage 1: SAR442501 Dose A (Low Dose) | Stage 1: SAR442501 Dose B (High Dose) | Total |
|---|---|---|---|---|
| Participants analysed | 10 | 6 | 16 | |
| Age, Continuous | years | 6.8 (SD 2.3) | 8.5 (SD 2.5) | 7.5 (SD 2.5) |
| Sex: Female, Male: Female | Participants | 5 | 1 | 6 |
| Sex: Female, Male: Male | Participants | 5 | 5 | 10 |
| Race/Ethnicity, Customized: Asian | Participants | 6 | 6 | 12 |
| Race/Ethnicity, Customized: Black or African American | Participants | 1 | 0 | 1 |
| Race/Ethnicity, Customized: White | Participants | 3 | 0 | 3 |
6. Primary Endpoint
The registry lists the primary outcome as Stage 1: Number of Participants With Treatment-Emergent Adverse Events (TEAEs), Treatment-Emergent Serious Adverse Events (SAEs) and Adverse Events of Special Interest (AESIs), measured over From the first dose of study drug administration (Day 1) up to early termination of the study, approximately 58 weeks (Stage 1: SAR442501 Dose A) and 46 weeks (Stage 1: SAR442501 Dose B).
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint counts participants with treatment-emergent adverse events (TEAEs), treatment-emergent serious adverse events (SAEs), and adverse events of special interest (AESIs). It is a count-based safety endpoint: it records whether participants experienced events in these categories rather than measuring the total number of event episodes or the severity of symptoms on a graded scale.
The registry defines an adverse event as an untoward medical occurrence temporally associated with study drug, whether or not it is considered related to the drug. A TEAE is newly reported, or reported to worsen in severity, after study drug starts and up to 5 days post last dose. An SAE is an event meeting criteria such as death, life-threatening status, inpatient hospitalization or its prolongation, persistent or significant disability, congenital anomaly or birth defect, or another important medical event. An AESI is a serious or nonserious event of particular scientific and medical concern for the sponsor’s product or program, requiring ongoing monitoring and immediate notification to the sponsor.
Counting participants with events is useful in safety monitoring because it conveys how many people were affected within each group. It does not by itself show causation, event duration, recurrence, or whether groups differ beyond chance variation. The registry’s posted data do not give separate numerical results for each component of the primary endpoint or an inferential comparison. Thus, the endpoint definition is available, but the full primary-outcome analysis is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted adverse-event summaries describe 10 participants at risk in the Dose A group and 6 in the Dose B group. For serious adverse events, 1 participant was recorded as affected in Dose A and 0 in Dose B. For other adverse events, the recorded affected counts were 5 in Dose A and 4 in Dose B. No deaths were recorded in either group. Pneumonia is listed among the top serious-event terms at 10.0%. These are descriptive counts, not estimates of a treatment effect.
The group sizes are small, so each participant represents a substantial part of the observed group count. A count of 0 serious adverse events in Dose B means that none were recorded in that group during the registry’s specified observation period; it does not establish that the underlying risk is zero. Likewise, the presence of a serious event in Dose A does not establish that SAR442501 caused it. The registry’s adverse-event definition explicitly includes events whether or not considered related to study drug.
The event summaries should not be read as a direct comparison of dose effects. The groups may have different follow-up periods, described as approximately 58 weeks for Dose A and 46 weeks for Dose B, and the registry does not report person-time or an adjustment for differences in observation. In addition, the study is described as open-label and sequential cohort, while allocation is also labeled randomized. The record does not explain these design details sufficiently to assess how comparable the groups were or how assignment was carried out.
The primary endpoint includes TEAEs, SAEs, and AESIs, but the posted adverse-event figures do not provide separate counts for all three categories or a single combined primary-endpoint result. The registry also lists no analyses. There is therefore no posted confidence interval, hypothesis test, or adjusted estimate from which to assess statistical precision or evidence of a between-group difference. The figures support a description of observed counts only.
Other planned outcomes concern growth velocity, height, and body-proportion measures at Weeks 26 and 52. Their results are not reported in the registry record. Consequently, these safety counts cannot answer whether growth or body proportions changed, and they cannot establish efficacy. Nor do the posted counts establish that one dose is safer than the other. Any such conclusion would require fuller outcome reporting and an analysis that accounts for the design, follow-up, and uncertainty.
9. Statistical Methods Explained
The posted primary outcome is a binary participant-level safety outcome: a participant either is or is not counted as having an event in a specified category during the relevant observation period. The registry expresses the outcome as a count of participants. In this setting, the most direct interpretation is descriptive: state the number at risk and the number recorded as affected in each group. Counts preserve the underlying scale of the reported data and avoid implying a level of precision that a small study may not support.
What does a participant count tell us?
A count tells how many participants met the event definition, but it does not describe how many event episodes occurred. One participant may have experienced more than one event, and the count of affected participants does not reveal that detail. Nor does it convey severity for events that do not meet the SAE definition, duration, timing within follow-up, or attribution to study drug. Those questions require event-level descriptions or additional summaries, which are not reported in the registry record.
For comparisons between groups, a proportion or a model-based estimate can sometimes add context, but those quantities require a clear denominator and an explicit analysis. The posted figures identify participants at risk and participants affected, but the registry record does not provide confidence intervals or a formal comparison. No new effect estimate should be inferred from the descriptive counts alone. In particular, the absence of an event in a small group is compatible with uncertainty about the event rate beyond the observed participants.
Why does follow-up matter?
Safety counts accumulate over a period of observation. The registry describes follow-up to early termination as approximately 58 weeks for Dose A and 46 weeks for Dose B. If observation differs between groups, the same number of affected participants can represent different amounts of time at risk. A time-adjusted analysis may be appropriate in some settings, but person-time summaries and such an analysis are not reported in the registry record. The posted counts should therefore be understood within their stated follow-up windows, not as directly standardized rates.
The endpoint also has distinct components. TEAEs concern new or worsening events after treatment begins, SAEs are defined by seriousness criteria, and AESIs are designated for special monitoring. These categories are not interchangeable. An event may be serious or nonserious, and an AESI may also be serious or nonserious. The registry gives a primary endpoint that names all three, but the posted group summaries do not give a separate full result for each component. Combining or interpreting them as one clearly specified outcome would require details not reported in the record.
What can randomization and masking establish?
In general, random allocation can help balance prognostic factors between groups, while masking can reduce some differences in assessment or reporting. Here, the record marks allocation as randomized and masking as none, and describes a sequential-cohort dose-escalation design. The precise allocation process and cohort procedures are not reported. It is therefore not possible to assess from the registry record how much protection randomization provided against confounding or how open-label conduct may have affected reporting and assessment. These are general considerations, not findings about what occurred in this study.
For the same reason, the group counts should not be treated as a causal contrast. Differences in observed counts may reflect chance, group composition, exposure duration, event ascertainment, or other factors, in addition to any dose-related effect. The registry does not report an adjusted analysis that could address these issues.
What is not available for inferential review?
The registry lists 31 outcome measures and 0 analyses. It does not report a confidence interval, p-value, analysis model, or a single comparative estimate for the primary safety outcome. It also does not report a statistical analysis plan or a sample-size justification. General statistical practice would use a prespecified analysis and report uncertainty alongside an estimate, especially when interpreting sparse event counts. That general principle cannot substitute for missing study-specific methods or results.
The sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. No resulting planning values are reported in the registry record. Such an illustration, when available, would concern future planning under stated assumptions; it would not be observed power or evidence that a study had adequate power after completion. No planning conclusion can be drawn from the record without the corresponding estimates and assumptions.
The study also lists secondary growth outcomes at Weeks 26 and 52, but their numerical results and analyses are not reported in the registry record. A full statistical assessment would need outcome definitions, analysis populations, missing-data handling, multiplicity procedures, and results with appropriate uncertainty. Without those details, interpretation is restricted to the descriptive safety counts and the endpoint definitions actually recorded.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 31 outcome measures, including the primary safety outcome and secondary growth and body-proportion outcomes. It reports 0 analyses. A multiplicity strategy—how the risk of false-positive findings across several outcomes or time points would be controlled or interpreted—is not reported in the registry record. No inferential findings are posted that can be judged against such a strategy.
Missing-data methods are also not reported in the registry record. The safety population is defined as enrolled participants who received at least 1 dose, regardless of the amount administered. The record does not explain how participants with incomplete follow-up were handled, whether event ascertainment was complete through early termination, or how missing measurements for the secondary outcomes were treated. The specified endpoint timeframe ends at early termination, so the amount of observed follow-up may vary among participants.
The registry does not describe an intention-to-treat population or another efficacy analysis population. The stated safety population is the only analysis-population definition available in the record. It does not report the number of participants included in each outcome analysis beyond the at-risk counts in the adverse-event summaries.
These omissions matter because conclusions depend on which outcomes and time points are analyzed, how incomplete observations are handled, and who is included. Without these methods and the corresponding analyses, the posted counts cannot establish statistical significance, confirmatory evidence across outcomes, or robustness to missing data. The registry record also does not report whether any interim analyses were conducted or how such analyses, if any, were accounted for.
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 |
|---|---|---|---|
| Stage 1: SAR442501 Dose A (Low Dose) | 1 | 10 | 10.0% |
| Stage 1: SAR442501 Dose B (High Dose) | 0 | 6 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Stage 1: SAR442501 Dose A (Low Dose) | 0 of 10 |
| Stage 1: SAR442501 Dose B (High Dose) | 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 |
|---|---|
| Stage 1: SAR442501 Dose A (Low Dose) | 5 of 10 |
| Stage 1: SAR442501 Dose B (High Dose) | 4 of 6 |
Most frequent serious adverse event terms
| Event term | Organ system | Stage 1: SAR442501 Dose A (Low Dose) | Stage 1: SAR442501 Dose B (High Dose) |
|---|---|---|---|
| Pneumonia | Infections and infestations | 1 of 10 | 0 of 6 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Stage 1: SAR442501 Dose A (Low Dose) | Stage 1: SAR442501 Dose B (High Dose) |
|---|---|---|---|
| Blood 25-Hydroxycholecalciferol Decreased | Investigations | 2 of 10 | 2 of 6 |
| Labyrinthitis | Infections and infestations | 1 of 10 | 0 of 6 |
| Nasopharyngitis | Infections and infestations | 1 of 10 | 0 of 6 |
| Pneumonia | Infections and infestations | 1 of 10 | 0 of 6 |
| Viral Upper Respiratory Tract Infection | Infections and infestations | 1 of 10 | 0 of 6 |
| Thrombocytosis | Blood and lymphatic system disorders | 1 of 10 | 0 of 6 |
| Headache | Nervous system disorders | 1 of 10 | 0 of 6 |
| Cough | Respiratory, thoracic and mediastinal disorders | 1 of 10 | 0 of 6 |
| Rhinitis Allergic | Respiratory, thoracic and mediastinal disorders | 0 of 10 | 1 of 6 |
| Constipation | Gastrointestinal disorders | 1 of 10 | 0 of 6 |
Serious events with the highest arm-level rate: pneumonia (10.0%).
The serious-event figures are participant counts within the two Stage 1 dose groups. Dose A had 10 participants at risk, with 1 participant recorded as affected by a serious adverse event. Dose B had 6 participants at risk, with 0 recorded as affected. No deaths were recorded in either group. Pneumonia is listed as a top serious-event term at 10.0%.
These figures describe what was recorded during the specified study observation period. They do not establish that study drug caused an event, and the zero count in Dose B does not establish absence of risk. The registry defines serious adverse events by medical consequences or importance, whether or not they are considered related to study drug. The serious-event counts also should not be confused with the separate counts for other adverse events: 5 participants in Dose A and 4 in Dose B were recorded as affected by other adverse events.
The group observation periods differ in the registry description, and no time-adjusted event rate or uncertainty interval is reported. The serious-event figures are therefore best read as descriptive counts, not as a statistical comparison of dose safety. The registry record does not provide enough detail to interpret the pneumonia term beyond its listing among the top serious-event terms.
12. What the Result Does, and Does Not, Mean
The posted results mean that the registry records adverse events in both Stage 1 dose groups, including a serious adverse event in Dose A, and no recorded serious adverse events or deaths in Dose B. The summaries also record other adverse events in each group. These are observations among the participants followed in this study, not estimates that can be applied directly to other children or settings.
The counts do not establish whether SAR442501 caused any event. The registry’s definition includes adverse events regardless of whether they were considered related to study drug. Nor do the counts show that one dose is safer than the other. Group sizes are small, follow-up periods are described differently, and no comparative statistical analysis or uncertainty interval is reported.
The study was designed to assess safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy, and it lists secondary outcomes related to growth and body proportions. The registry record does not report numerical results for those secondary measures. It also does not provide a full analysis of the primary endpoint’s separate TEAE, SAE, and AESI components. The available safety summaries therefore cannot answer whether growth outcomes changed or whether an efficacy objective was met.
Termination is the recorded status, but the reason for termination is not reported in the registry record. The listed dates and follow-up descriptions do not explain why the study ended or whether planned follow-up was completed. Overall, the data support a narrow descriptive account of the recorded event counts. They do not support a claim of benefit, lack of benefit, or comparative safety.
13. Why This Trial Matters Statistically
This study illustrates why safety results need to be read with both the event definition and the observation window in view. A participant count is easy to interpret at a basic level, but it does not capture the number of event episodes, exposure time, severity beyond the category definition, or causal attribution. Those distinctions matter when the groups are small and follow-up differs.
The record also shows the importance of distinguishing a trial’s stated outcome from its posted results. The primary endpoint names TEAEs, SAEs, and AESIs, yet the available group summaries do not provide a complete separate analysis of those categories or a comparative estimate. The registry lists many outcome measures but no analyses. Planned outcomes alone do not supply evidence about their results.
Design labels need context as well. The study is marked randomized, open-label, and sequential cohort, but the registry does not explain how allocation and cohort progression worked. Without those details, readers cannot judge how well the groups can be compared or what aspects of outcome assessment may be affected by the lack of masking.
Finally, a zero observed count is not a precise statement that an event cannot occur. Statistical interpretation needs uncertainty as well as counts, particularly for infrequent events. The absence of reported confidence intervals, analysis methods, and missing-data procedures limits the conclusions that can be drawn. These limitations are not resolved by a planning illustration or by the number of outcomes listed. The record supports transparent description, while leaving important questions for fuller reporting.
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 registry record gives limited detail about the study procedures. Although allocation is labeled randomized and the model is described as sequential, the method of randomization, cohort entry rules, dose amounts, and progression between stages are not reported. The arm descriptions for the named cohorts contain no further information. These omissions make it difficult to assess the intended group comparisons and how the design was implemented.
The study is marked terminated, but the reason is not reported in the registry record. The registry gives a primary completion date and describes follow-up through early termination, but does not state whether follow-up was complete for each participant or explain how early termination affected the planned assessments. The stated follow-up windows differ between the Dose A and Dose B groups.
The primary endpoint combines several safety categories, while the posted summaries do not provide separate results for all components or a complete primary-endpoint analysis. There are no listed analyses, confidence intervals, or inferential comparisons. The record also lacks a statistical analysis plan, a sample-size justification, missing-data methods, and details about multiplicity or interim analyses.
The record lists secondary growth and body-proportion outcomes, but their results are not reported. It also does not report the relationship of events to study drug or detailed event-level information beyond the top serious-event term. With the available data, interpretation is limited to the descriptive event counts and definitions; conclusions about efficacy, comparative dose effects, or generalizability are not established.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Efficacy of SAR442501 in Pediatric Participants With Achondroplasia — NCT06067425.
- Registry record last updated 2026-06-25; status last verified 2026-05.
- Results first posted 2026-06-25.
- 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
NCT06067425 is a Phase 2, open-label study of subcutaneous SAR442501 in pediatric participants with achondroplasia. The registry describes a multi-center, sequential-cohort, dose-escalation design and lists Stage 1 Dose A and Dose B safety groups. Allocation is marked randomized, but the implementation details are not reported. Enrollment is recorded as 16, the sponsor is Sanofi, and the study status is terminated.
The primary safety outcome counts participants with TEAEs, SAEs, and AESIs. The posted summaries record serious-event counts of 1 among 10 participants at risk in Dose A and 0 among 6 in Dose B; no deaths were recorded. Other adverse events were recorded in 5 participants in Dose A and 4 in Dose B. Pneumonia is listed among top serious-event terms at 10.0%.
The registry lists 31 outcome measures and 0 analyses. Results for the listed secondary growth outcomes, comparative estimates, uncertainty intervals, and detailed analysis methods are not reported in the registry record. The posted safety counts are descriptive and do not establish causation, efficacy, or comparative dose safety.