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 Phase 2 Study to Evaluate RPT193 in Adults With Moderate to Severe T2-high Asthma (NCT05935332), a randomized phase 2 study. The primary outcome is Proportion of Participants With a Loss of Asthma Control Event as Defined by Criteria Listed.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05935332 |
| Phase | Phase 2 |
| Condition | Asthma |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 38 |
| Arms in the primary outcome | n/a |
| Lead sponsor | RAPT Therapeutics, Inc., a member of the GSK plc group of companies |
| Results posted | Yes |
2. Clinical Question
Population
Adults with moderate-to-severe T2-high asthma who were partially controlled on inhaled corticosteroid and long-acting beta-2 agonist therapy. The study summary specifies medium or high doses of inhaled corticosteroids. Further eligibility details are not reported in the registry record.
Intervention
RPT193 400 mg. The registry record does not provide further details about the dosing schedule or route of administration.
Comparator
Placebo, in a parallel-group comparison. The record does not give further details about the placebo regimen.
Primary question
Over 14 weeks, how many participants experienced a loss-of-asthma-control event under the listed criteria? The registry record does not report the primary-outcome counts or an analysis comparing the study arms.
The primary outcome was intended to capture worsening asthma control through several types of events: a reduction in peak expiratory flow, increased use of short-acting beta-2 agonist inhalations, an increase in inhaled corticosteroid dose, or evidence of a severe asthma exacerbation. The record describes the outcome as a count of participants with events, but does not provide the counts by arm or explain how multiple qualifying events in one participant were handled.
This is a proof-of-concept study rather than a record with a reported efficacy conclusion. The design establishes a randomized comparison of RPT193 with placebo in the specified population, but the posted results do not give an estimate of the treatment difference for the primary outcome. Thus, the clinical question can be identified from the protocol description, while its answer cannot be assessed from the primary results reported in the registry record.
3. Trial Design
This was a Phase 2, randomized, parallel-group study comparing RPT193 400 mg with placebo. The registry describes the study as multi-center, double-blind, placebo-controlled, and proof-of-concept. Masking is recorded as quadruple. The registry record does not identify which roles were masked or describe the randomization procedure, allocation concealment, or details of the study drug schedule.
The study enrolled 38 participants. The listed arms each had 19 participants at risk for adverse events. The stated population was adults with moderate-to-severe T2-high asthma who were partially controlled on inhaled corticosteroid and long-acting beta-2 agonist therapy; the brief study description specifies medium or high doses of inhaled corticosteroids. Additional eligibility criteria are not reported in the registry record.
The study began on 2023-07-05, and the primary completion date is recorded as 2024-06-21. Its status is listed as terminated. The reason for termination, whether recruitment or follow-up differed from plan, and whether the termination affected the planned analyses are not reported in the registry record. The primary outcome timeframe is 14 weeks.
Besides the primary loss-of-asthma-control outcome, listed secondary outcomes include change in forced expiratory volume in one second at Week 14 compared with baseline and the number of participants with non-serious treatment-emergent adverse events experienced by at least 5% of participants. Numerical results for those secondary outcomes are not reported in the registry record. The record also does not provide a detailed statistical analysis plan or results for an efficacy comparison.
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 | RPT193 400 mg | Placebo |
|---|---|---|
| STARTED | 19 | 19 |
| COMPLETED | 10 | 8 |
| NOT COMPLETED | 9 | 11 |
Reasons for not completing this period:
| Reason | RPT193 400 mg | Placebo |
|---|---|---|
| Discontinued treatment | 9 | 11 |
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 | RPT193 400 mg | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 19 | 19 | 38 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 14 | 17 | 31 |
| Age, Categorical: >=65 years | Participants | 5 | 2 | 7 |
| Age, Continuous | years | 57.53 (SD 12.638) | 52.16 (SD 11.701) | 54.84 (SD 12.317) |
| Age, Continuous | years | 60 (32 to 74) | 55 (27 to 70) | 58 (27 to 74) |
| Sex: Female, Male: Female | Participants | 16 | 12 | 28 |
| Sex: Female, Male: Male | Participants | 3 | 7 | 10 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 1 | 1 | 2 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 4 | 0 | 4 |
| Race (NIH/OMB): White | Participants | 14 | 15 | 29 |
| Race (NIH/OMB): More than one race | Participants | 0 | 2 | 2 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 1 | 1 |
| Region of Enrollment: United States | participants | 17 | 17 | 34 |
| Region of Enrollment: Czechia | participants | 2 | 0 | 2 |
| Region of Enrollment: Bulgaria | participants | 0 | 2 | 2 |
6. Primary Endpoint
The registry lists the primary outcome as Proportion of Participants With a Loss of Asthma Control Event as Defined by Criteria Listed, measured over 14 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 proportion of participants with a loss-of-asthma-control event during the 14-week timeframe. The record describes the measure as a count of participants, with an event defined by one or more listed indicators: a reduction of at least 30% in peak expiratory flow, at least 6 additional short-acting beta-2 agonist inhalations, an increase by a factor of 4 or more in inhaled corticosteroids, and/or evidence of a severe asthma exacerbation.
These criteria combine changes in measured lung function, rescue medication use, treatment escalation, and severe exacerbation evidence. General: A composite endpoint can represent more than one clinically relevant way an outcome may occur. It can also make interpretation depend on the component definitions and on whether the components differ in frequency or importance. The registry record does not report component-specific counts, how overlapping criteria were handled, or whether each component was analyzed separately.
The endpoint is expressed as participants with an event rather than as a continuous measurement. That makes the outcome categorical at the participant level: each participant either meets the event definition or does not, under the endpoint rules. However, the primary outcome result by arm and the statistical comparison are not reported in the registry record. The endpoint's stated purpose and measurement rules can therefore be described, but the posted record does not show the observed primary outcome or the precision of an arm-to-arm estimate.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes that 38 participants were enrolled in a randomized comparison of RPT193 400 mg and placebo. It lists 19 participants at risk in each arm for adverse-event reporting. It also identifies a 14-week primary outcome based on loss-of-asthma-control criteria. These details describe the study's design and outcome framework; they are not themselves evidence of a difference in the primary endpoint.
The primary outcome is not reported as arm-specific event counts or as an estimated contrast. The record explicitly does not reduce the outcome to a single comparison because it has several categories or time points. No primary-outcome effect estimate, confidence interval, or p-value is reported in the registry record. Without those results, it is not possible to assess the direction, size, or statistical precision of an arm difference from the posted primary-outcome data.
The adverse-event results are counts. No serious adverse events were recorded among the 19 participants at risk in either arm, and no deaths were recorded in either arm. The record lists 6 participants with other, non-serious events in the RPT193 arm and 3 in the placebo arm. These are descriptive counts; they do not establish a causal difference between treatments. The record does not supply event-level details or a statistical comparison for these counts.
The listed secondary outcomes include change in FEV1 at Week 14 and non-serious treatment-emergent adverse events experienced by at least 5% of participants. Their numerical findings are not reported in the registry record. Nor are analysis populations, missing-data handling, or the statistical methods used for the outcomes reported. In particular, the record does not state whether the reported counts include all randomized participants, only participants who received treatment, or another analysis population.
Statistical interpretation depends on estimates as well as counts. General: An effect estimate describes the size and direction of a contrast; a confidence interval describes the range of values compatible with the data under the model and assumptions used. A p-value addresses compatibility with a specified null model, not the probability that a treatment works. Because the registry record does not report these inferential results for the primary endpoint, no such conclusion can be drawn from it. The status is listed as terminated, but the reason and its relationship to outcome availability are not reported in the registry record.
9. Statistical Methods Explained
The design and posted results support only a limited statistical account. The study is described as randomized, quadruple-masked, and parallel-group, with RPT193 400 mg compared with placebo. The primary endpoint is a participant-level event outcome over 14 weeks. The registry record does not report a statistical analysis plan or the methods used to analyze the primary endpoint.
What does randomization contribute?
General: Randomization assigns participants to study arms by chance. When implemented as planned, it can reduce systematic differences between arms at the start of a trial, including differences that are not measured. It does not guarantee that groups will be identical, particularly in a study with a modest enrollment. The registry record identifies the study as randomized but does not report how the sequence was generated, how allocation was concealed, or whether any randomization restrictions were used.
What does masking mean?
The record states that masking was quadruple and describes the study as double-blind. It does not identify the people or roles covered by the quadruple-masking designation, nor does it report how masking was maintained or assessed. General: Masking is intended to limit the influence of knowledge about assigned treatment on care, participant behavior, outcome assessment, or data handling. Those are general purposes; the registry record does not document whether masking was successful in this study.
How should the primary outcome be understood statistically?
The endpoint counts participants who meet a loss-of-control definition involving several possible criteria. General: A binary participant-level outcome can be summarized as the number of participants with an event and the number without one, within each arm. An arm comparison can then be expressed using an effect measure such as a difference in event proportions or a relative measure. The choice of effect measure, model, and uncertainty interval should follow the analysis plan. No such primary-outcome counts, effect estimate, confidence interval, or p-value are reported in the registry record, so no particular analysis can be attributed to this trial.
The endpoint combines peak expiratory flow, rescue inhaler use, inhaled corticosteroid escalation, and severe exacerbation evidence. General: Composite outcomes can increase the range of events captured, but a combined result may conceal different patterns across components. A sound interpretation often considers component counts and their definitions as well as the combined endpoint. Component-specific results and rules for participants meeting more than one criterion are not reported in the registry record.
What can be concluded from the adverse-event counts?
The registry lists serious and other adverse events by arm, with participants at risk and participants affected. General: These counts describe what was recorded during the relevant collection period; they do not by themselves quantify uncertainty or establish that an observed difference arose from treatment rather than chance or other factors. A formal comparison would require a specified method and its assumptions. The registry record does not report such a comparison, event-level details, or a confidence interval for the adverse-event counts.
What does the sample-size illustration represent?
General: A sample-size calculation uses assumptions about the effect to detect, the probability of a false positive, statistical power, allocation, and the analysis method. The registry record's planning illustration is described as using a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect to detect set as a stated fraction of the observed effect. The illustration is not the trial's own design justification and should not be interpreted as observed power. The record does not report a sample-size justification for the trial. No numerical planning results are reported in the registry record.
In general, power is a design-stage probability under specified assumptions, not a measure of whether a completed trial has demonstrated an effect. A calculation based on an observed effect is especially sensitive to that estimate and is only a planning illustration. The registry record does not provide a primary-outcome estimate from which to judge the assumptions behind a trial-specific calculation.
What other method details are absent?
The registry record does not report the primary analysis model, the chosen effect measure, covariate adjustment, confidence-interval method, significance testing procedure, or any interim analysis. It does not report procedures for missing data, analysis populations, protocol deviations, or handling of multiple endpoints. General: These choices affect how an estimate is constructed and how uncertainty is assessed. Their absence means the analysis cannot be independently reconstructed from the posted record. It does not establish that a method was or was not used; the method is simply not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary loss-of-asthma-control outcome and secondary outcomes for FEV1 change at Week 14 and non-serious treatment-emergent adverse events experienced by at least 5% of participants. It does not report how many hypotheses were tested, whether testing was hierarchical, or whether any adjustment for multiple comparisons was planned or performed. Multiplicity procedures are therefore not reported in the registry record.
General: When several outcomes or comparisons are tested, the chance of finding at least one apparently notable result by chance can rise. Prespecified testing sequences or other multiplicity methods can address that issue, but their use cannot be inferred from a list of outcomes. The registry record does not provide a statistical analysis plan describing such procedures.
Missing-data methods and analysis populations are also not reported in the registry record. There is no description of how participants with incomplete follow-up were handled, whether any outcome data were imputed, or how participants who stopped treatment or deviated from the protocol were included in analyses. The reason for the terminated status and whether it affected outcome collection or analysis are not reported in the registry record.
General: These details matter because an analysis can depend on who is included and how unavailable measurements are addressed. Without the relevant definitions and results, readers cannot determine whether the outcome analysis followed an intention-to-treat, per-protocol, or other population approach. The absence of these details is an information limitation, not evidence that a particular analysis or procedure was 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 |
|---|---|---|---|
| RPT193 400 mg | 0 | 19 | 0.0% |
| Placebo | 0 | 19 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| RPT193 400 mg | 0 of 19 |
| Placebo | 0 of 19 |
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 |
|---|---|
| RPT193 400 mg | 6 of 19 |
| Placebo | 3 of 19 |
Most frequent non-serious adverse event terms
| Event term | Organ system | RPT193 400 mg | Placebo |
|---|---|---|---|
| Urinary tract infection | Infections and infestations | 2 of 19 | 1 of 19 |
| Influenza | Infections and infestations | 0 of 19 | 2 of 19 |
| Viral upper respiratory tract infection | Infections and infestations | 2 of 19 | 0 of 19 |
| Nausea | Gastrointestinal disorders | 2 of 19 | 0 of 19 |
| Blood glucose increased | Investigations | 1 of 19 | 1 of 19 |
The registry reports no serious adverse events among the 19 participants at risk in the RPT193 400 mg arm and none among the 19 at risk in the placebo arm. It also reports no deaths in either arm. For other, non-serious adverse events, 6 participants were affected in the RPT193 arm and 3 in the placebo arm.
These figures are participant counts, not event counts or rates. They describe what the registry record lists, but do not show when events occurred, their type or severity beyond the serious/non-serious distinction, or whether they were judged related to study treatment. The record does not provide a statistical comparison or uncertainty interval for these safety results. No serious event being recorded in either arm is not proof that serious events cannot occur; the posted counts describe only the participants and observations recorded in this study.
The registry also lists a secondary outcome concerning non-serious treatment-emergent adverse events experienced by at least 5% of participants. The numerical results for that specifically listed outcome are not reported in the registry record. The other-event counts should therefore be read as the posted adverse-event summary, not as a substitute for a detailed account of the prespecified secondary outcome or event-by-event safety data.
12. What the Result Does, and Does Not, Mean
The registry record identifies the study question, population, treatment comparison, and primary endpoint. It describes a randomized, masked Phase 2 study of RPT193 400 mg versus placebo in adults with moderate-to-severe T2-high asthma who were partially controlled on inhaled corticosteroid and long-acting beta-2 agonist therapy. The primary endpoint concerns participants experiencing a loss-of-asthma-control event over 14 weeks.
What the posted results do not provide is the primary outcome result by arm or a statistical comparison. The registry record therefore does not allow readers to judge the observed primary-outcome difference, its direction, its size, or its precision. It also does not report the numerical results for the listed secondary outcomes. No conclusion about an efficacy effect can be drawn from the endpoint description alone.
The adverse-event summary records zero serious adverse events and zero deaths in both arms, alongside 6 participants with other events in the RPT193 arm and 3 in the placebo arm. These counts do not, on their own, establish that the treatments differ in safety. The registry does not include the event-level information or inferential results needed for a fuller comparison.
General: A result's interpretation depends on more than whether a comparison is described as statistically significant. The magnitude of an estimate, its uncertainty, the relevance and definition of the endpoint, and the completeness of follow-up all matter. Here, the primary estimate and its uncertainty are not reported in the registry record, and missing-data methods and analysis populations are also not reported. The trial's terminated status is recorded, but the reason and its implications for the results are not reported in the registry record. These gaps limit what can be concluded from the posted information; they do not establish what an unreported analysis would have found.
13. Why This Trial Matters Statistically
This trial illustrates the distinction between a registered study design and a reported statistical result. The record specifies a randomized, parallel-group comparison, a defined asthma population, and a composite loss-of-control endpoint. Those details make the research question identifiable. However, without arm-specific primary-outcome results and an analysis estimate, the central statistical comparison cannot be evaluated from the registry record.
The endpoint also demonstrates why definitions matter. Loss of asthma control can be identified by several different criteria in this study, including changes in peak expiratory flow, additional short-acting beta-2 agonist use, inhaled corticosteroid escalation, or severe exacerbation evidence. General: Combining criteria can capture multiple forms of worsening, but readers benefit from knowing how often each component occurred and how the combined endpoint was constructed. Those details are not reported in the registry record.
The adverse-event counts offer a separate example of limits to interpretation. Counts are useful descriptive information, but without detail on event types, follow-up, and uncertainty, they cannot establish a comparative safety effect. The registry record lists no serious adverse events or deaths in either arm and provides counts for other events; it does not provide a formal statistical comparison.
The status is recorded as terminated. Because the reason for termination and its effect on enrollment, follow-up, or analysis are not reported, the status should not be treated as an explanation for the missing efficacy results. The record's value is in documenting the trial framework and some safety counts while making clear that the principal outcome analysis is not available in the registry record.
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 principal limitation for statistical interpretation is that the primary endpoint result is not reported by arm, and no primary-outcome analysis is reported. The outcome involves several loss-of-control criteria, but component-specific counts and information on overlapping criteria are not reported in the registry record. The listed secondary outcomes also lack numerical results in the registry record.
The registry record does not report the statistical analysis plan, analysis population, missing-data approach, effect measure, uncertainty intervals, or inferential testing for the primary endpoint. It also does not report how multiplicity was addressed. This limits independent assessment of the planned estimand, the handling of incomplete observations, and the precision of any comparison.
The study status is listed as terminated, but the reason is not reported in the registry record. The record does not explain whether termination affected recruitment, follow-up, or reporting. While 38 participants were enrolled and 19 participants per arm are listed as at risk for adverse events, these figures do not establish how many participants contributed data to each efficacy outcome.
Safety reporting is limited to serious-event and other-event participant counts, plus deaths. Detailed event terms, timing, exposure duration, and treatment relatedness are not reported in the registry record. The record also does not identify the roles covered by quadruple masking or provide details of randomization and allocation concealment. These omissions constrain interpretation of the design and results; they do not imply that any particular method or event occurred.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Phase 2 Study to Evaluate RPT193 in Adults With Moderate to Severe T2-high Asthma — NCT05935332.
- Registry record last updated 2026-03-23; status last verified 2026-03.
- Results first posted 2026-03-23.
- 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 randomized, quadruple-masked, parallel-group Phase 2 study of RPT193 400 mg versus placebo in adults with moderate-to-severe T2-high asthma who were partially controlled on inhaled corticosteroid and long-acting beta-2 agonist therapy. Enrollment was 38, and the primary outcome was the number of participants with a loss-of-asthma-control event over 14 weeks. The study status is listed as terminated.
The registry lists no serious adverse events and no deaths in either arm. Other adverse events affected 6 participants in the RPT193 arm and 3 in the placebo arm. Primary-outcome results, numerical secondary-outcome results, and statistical analyses are not reported in the registry record. The reason for termination, analysis populations, and missing-data methods are also not reported.