Study to Evaluate the Safety, Tolerability of BCX9930 in Participants With Either Complement 3 Glomerulopathy (C3G), Immunoglobulin A Nephropathy (IgAN), or Primary Membranous Nephropathy (PMN): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study to Evaluate the Safety, Tolerability of BCX9930 in Participants With Either Complement 3 Glomerulopathy (C3G), Immunoglobulin A Nephropathy (IgAN), or Primary Membranous Nephropathy (PMN) (NCT05162066), a non-randomized phase 2 study. The primary outcome is Percent Change From Baseline in 24-hour uPCR at Week 12.

2. Clinical Question

The study objective was to assess the safety and therapeutic potential of BCX9930 in the three kidney-disease cohorts. The primary endpoint focused on a measured change in urinary protein excretion, expressed through the urinary protein/creatinine ratio. The registry description states that a decrease in uPCR means improvement of renal disease; that describes the measure’s intended direction, not an observed study result.

The clinical question is descriptive rather than a controlled treatment comparison. With non-randomized allocation and no reported comparator arm, any change recorded during treatment could not by itself establish how outcomes would have differed without BCX9930. The registry record does not report primary endpoint analyses or results, so it does not answer whether uPCR changed in these participants.

3. Trial Design

This was an open-label, non-randomized, parallel phase 2 study of oral BCX9930. The three planned cohorts corresponded to C3G, IgAN, and PMN. Each cohort description anticipated approximately 14 eligible participants. The registry record reports enrollment of 2 overall, substantially fewer than those planned cohort descriptions, but it does not report how participants were distributed among the cohorts.

The study started on 2022-02-18, had a listed primary completion date of 2022-09-23, and is recorded as terminated. The reason for termination is not reported in the registry record. The record does not provide further information about the timing or circumstances of treatment discontinuation, or how long individual participants received treatment.

Because allocation was non-randomized and no control group is reported, the study does not support a direct comparison of BCX9930 with an alternative treatment or with no treatment. The open-label design also means that participants and investigators were not masked to the intervention. This matters especially for outcomes that could be affected by expectations or assessment decisions; the primary endpoint is a laboratory-based ratio, but the registry record does not describe safeguards or assessment procedures.

The planned enrollment descriptions are not the same as the enrollment achieved. The record reports 2 participants and provides safety counts for 2 participants at risk. It does not report cohort-specific enrollment or primary endpoint observations. The protocol’s sample-size justification, any interim analyses, and the reason for choosing the planned cohort sizes 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: At the time the study was discontinued, only participants with historical C3G were enrolled.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Safety population with available data was analyzed

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: Safety population included all participants who received at least one dose of the study drug.

6. Primary Endpoint

The registry lists the primary outcome as Percent Change From Baseline in 24-hour uPCR at Week 12, measured over Baseline, Week 12.

The primary endpoint was percent change from baseline in 24-hour uPCR at Week 12. uPCR is the urinary protein/creatinine ratio, described in the registry as urine protein concentration (mg/dL) divided by urine creatinine concentration (mmol/dL). Expressing protein relative to creatinine helps account for differences in urine concentration when assessing urinary protein.

Proteinuria is relevant to kidney disease, and the registry description states that a decrease in uPCR means improvement of renal disease. The endpoint therefore records change in a measure connected to urinary protein excretion over the specified period. It is a continuous measure, and the planned summary statistic was the mean with standard deviation.

The registry identifies baseline and Week 12 as the measurement time points and specifies a safety population with available data for analysis. It does not report the observed baseline or Week 12 values, the mean percent change, or a measure of uncertainty around that change. Consequently, the endpoint’s rationale can be described, but its observed result cannot be interpreted from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical interpretation is constrained by what the registry record reports: an endpoint definition, an analysis population description, and safety counts, but no primary outcome analyses. General statistical concepts can clarify what the planned summaries would mean, but they cannot fill in unreported study results.

What does a mean percent change describe?

Percent change expresses the change in a measurement relative to its baseline value. The registry planned to summarize the Week 12 change in uPCR using a mean. In general, a mean is the arithmetic average across the observations included in an analysis. It describes the center of those observations, but can be influenced by unusually high or low values. The registry record does not report the individual observations or the mean percent change, so neither the direction nor the size of the average is known.

The primary endpoint is continuous: it can take a range of numerical values rather than only a category such as event or no event. A continuous outcome can retain information about the magnitude of changes. Its interpretation depends on the distribution of participant-level values and on how missing measurements are handled; those details are not reported in the registry record.

What does the standard deviation add?

The planned standard deviation describes how spread out observed values are around their mean. In general, a larger standard deviation indicates greater variability among observations, while a smaller one indicates that observations are more concentrated around the mean. It is not the same as a confidence interval: a standard deviation describes variation in the data, whereas a confidence interval describes uncertainty in an estimate. Neither a standard deviation nor a confidence interval for the primary endpoint is reported.

General statistical explanation: a confidence interval gives a range of values that are compatible with the data and the assumptions of the method. Its width reflects precision: wider intervals indicate less precision. Since the registry record has no reported primary endpoint estimate or interval, it is not possible to describe the precision of the uPCR result.

Why does the design affect statistical interpretation?

Random allocation can help make groups comparable, on average, with respect to factors that affect outcomes. This study is recorded as non-randomized and no control group is reported, so a randomized between-group treatment contrast is not available. Parallel design indicates separate groups or cohorts rather than a crossover arrangement, but it does not create a control comparison when all reported intervention information concerns BCX9930.

Open-label status means masking was not used. General statistical explanation: knowledge of treatment assignment can affect participant-reported outcomes, clinical decisions, and assessment. A laboratory measurement may be less open to subjective assessment than a report of symptoms, but the record does not describe the laboratory procedures or other protections against bias.

Why can small counts be difficult to interpret?

Event counts are direct descriptions of observed participants, not estimates that automatically generalize to a larger population. When few participants are observed, each participant represents a substantial part of the available information, and estimates are generally imprecise. The safety record reports counts for 2 participants at risk. No comparative safety analysis or uncertainty interval is reported.

Over-dispersion is a general concern when count data vary more than a statistical model expects. It can make standard errors and uncertainty estimates unreliable if the model assumes less variability than is present. The registry record does not report a count model, an over-dispersion assessment, or inferential analyses; there is no basis to say that such a model was used.

What do planning calculations mean?

General statistical explanation: sample-size planning calculations describe how many observations a hypothetical study might need under specified assumptions. They are not observed power and do not recover an unreported result. The planning illustration associated with the study is described as using a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. The record does not report numerical planning outputs or a primary endpoint effect from which to judge such an illustration. These assumptions are not evidence that the actual study used a two-arm randomized design.

The registry record does not report the analysis model, handling of repeated or incomplete measurements, covariate adjustment, interim analyses, or a protocol-based sample-size justification. Statistical methods beyond the stated mean and standard deviation summary should therefore not be inferred.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 9 outcome measures, including the primary endpoint and secondary outcomes covering urinary protein excretion, estimated glomerular filtration rate, and adverse events. It does not report how analyses across multiple outcomes were prioritized or whether any adjustment for multiple testing was planned. Multiplicity matters in general because examining many outcomes can increase the chance of apparently notable findings arising by chance. No multiplicity-adjusted result is reported.

For the primary endpoint, the analysis population is described as the safety population with available data. This indicates that the endpoint analysis concerns participants in that population for whom data were available; it does not explain how many had usable baseline and Week 12 measurements or how missing observations were handled. The registry record does not report an imputation method, sensitivity analysis, or reasons for missing endpoint data.

The record does not describe an intention-to-treat analysis population, a per-protocol population, or additional rules for inclusion in analyses. The enrollment count and the safety denominator do not establish how many participants contributed primary endpoint data. Without those details and without reported endpoint results, the analysis population and missing-data assumptions cannot be evaluated further.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

For BCX9930, the registry record reports 2 participants at risk for serious adverse events and 0 participants affected. It also reports 2 participants at risk and 2 affected in the other adverse-event category, with 0 deaths. These are participant counts, not a detailed description of event types, severity, timing, or duration.

The record does not list serious adverse-event terms. It also does not identify which specific events make up the other category in these safety figures. Separate secondary outcomes include treatment-emergent adverse events, discontinuations due to such events, serious events, and severe adverse events or laboratory abnormalities, but no analyses for those outcomes are reported.

With only 2 participants at risk, these figures describe the observed study record and should not be read as a stable estimate of safety in a larger population. A count of zero serious events does not demonstrate that no such events could occur. The registry record does not report comparative safety data, and the non-randomized design does not provide a control group for estimating relative safety.

12. What the Result Does, and Does Not, Mean

The registry record documents an open-label phase 2 study of BCX9930 in three kidney-disease cohorts, an enrollment of 2, and a primary endpoint focused on percent change in 24-hour uPCR at Week 12. It also records limited safety counts. These details describe the study and the information available in the registry; they do not establish an efficacy result.

In particular, no primary endpoint analysis is reported. The observed mean change, variability, and uncertainty are therefore unavailable. The registry record does not show whether uPCR increased, decreased, or remained unchanged among participants with available data. Its explanation that a decrease indicates improvement describes the endpoint’s clinical interpretation, not what happened in the study.

The record also cannot establish a causal treatment effect. The study was non-randomized and no control group is reported, so there is no controlled contrast to separate a treatment effect from changes that could occur over time or for other reasons. Open-label status and the absence of reported analysis details add limits to interpretation.

The safety counts are likewise descriptive and based on 2 participants at risk. They do not establish the frequency of events in a broader population. The study status is recorded as terminated, but the reason is not reported in the registry record. Nothing in the reported information explains why the study ended or what its termination implies about the intervention.

Thus, the record is informative about the study’s design, stated endpoint, enrollment, and recorded adverse-event counts, but it does not provide evidence sufficient to quantify the primary outcome or compare BCX9930 with an alternative.

13. Why This Trial Matters Statistically

This trial is statistically informative because it illustrates the difference between a registered study objective and an analyzable result. The record defines a continuous primary endpoint and an analysis population, yet reports no primary endpoint analyses. Without an estimate and its uncertainty, the endpoint’s clinical rationale cannot be converted into a result about participants in the study.

The contrast between planned cohort descriptions and recorded enrollment is also important. Each cohort description anticipated approximately 14 eligible participants, while overall enrollment is reported as 2. These figures represent planning and actual enrollment, respectively; they should not be conflated. The record does not provide enough cohort-level detail to determine where those participants were enrolled or how many contributed to endpoint data.

The design further clarifies why study structure matters. Non-randomized allocation, open-label conduct, and no reported control group limit the kinds of statistical conclusions that could be drawn. A before-and-after endpoint can describe change, but without a suitable comparison it does not independently estimate what would have happened in the absence of the intervention.

Finally, small safety counts call for restraint. Zero serious adverse events among the recorded participants is a description of the observed count, not proof of safety across a wider population. The record’s termination status and lack of reported endpoint analyses also make completeness and interpretation especially important questions, while the reason for termination remains unreported.

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 of this registry record is the absence of primary endpoint results. It identifies the Week 12 uPCR measure and the safety population with available data, but does not report the number with evaluable measurements, the mean percent change, its standard deviation, or an uncertainty interval. The study’s primary statistical question therefore cannot be answered from the record.

Enrollment was 2, while the cohort descriptions anticipated approximately 14 eligible participants in each disease group. Cohort-specific enrollment and outcome values are not reported. The record also does not explain the reason for termination, participant-level follow-up, or whether planned assessments were completed.

The non-randomized, open-label design and absence of a reported control group prevent a controlled treatment comparison. The registry record does not report the methods used for endpoint analysis, missing data, multiplicity, or sample-size justification. These omissions restrict assessment of both potential bias and statistical precision.

Safety information is limited to participant counts, with no serious adverse-event terms listed and no detailed account of events in the other category. The small number at risk makes the counts highly limited as a basis for characterizing safety beyond the recorded participants. No comparative safety analysis is reported.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Study to Evaluate the Safety, Tolerability of BCX9930 in Participants With Either Complement 3 Glomerulopathy (C3G), Immunoglobulin A Nephropathy (IgAN), or Primary Membranous Nephropathy (PMN) — NCT05162066.
• Registry record last updated 2024-05-02; status last verified 2024-04.
• Results first posted 2024-05-02.
• 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.

18. Record Summary

NCT05162066 was an open-label, non-randomized, parallel phase 2 study of oral BCX9930 in C3G, IgAN, or PMN. It recorded enrollment of 2 and is listed as terminated. The registry gives a primary endpoint of percent change from baseline in 24-hour uPCR at Week 12, analyzed in the safety population with available data.

No primary endpoint analyses are reported. Safety figures list 0 participants with a serious adverse event, 2 with an event in the other adverse-event category, and 0 deaths, among 2 participants at risk. The reason for termination, endpoint results, and further statistical analysis details are not reported in the registry record.