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 Basket Study of Leronlimab (PRO 140) in Patients With CCR5+ Locally Advanced or Metastatic Solid Tumors (NCT04504942), a na phase 2 study. The primary outcome is Number of Participants With Adverse Events (AEs), and Serious Adverse Events (SAEs)..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04504942 |
| Phase | Phase 2 |
| Condition | Solid Tumor, Adult |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 16 |
| Arms in the primary outcome | n/a |
| Lead sponsor | CytoDyn, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
Adults with CCR5+ locally advanced or metastatic solid tumors were the population of interest. The registry lists the condition as “Solid Tumor, Adult,” and the primary safety population consists of N=16 participants who received at least one dose of leronlimab. The record does not report further eligibility details or describe the tumor types represented among participants.
Intervention
Participants received leronlimab, also identified as PRO 140. The listed arm is Leronlimab 525mg. The registry describes the drug as a humanized IgG4 monoclonal antibody to the C-C chemokine receptor type 5, or CCR5.
Comparator
There was no comparator arm: the study is recorded as single group, with no masking and no randomized allocation. The registry record therefore does not provide a concurrent control group for comparing outcomes.
Primary question
The primary endpoint counts participants with adverse events and serious adverse events after treatment. It addresses the frequency of participants reported to have these events during the stated follow-up period. It is a safety-focused endpoint, not a measure of tumor response or comparative treatment effect.
The study also lists secondary outcomes concerning progression-free survival, overall response rate, time to new metastases, circulating tumor cell change, and overall survival. Results for those outcomes are not reported in the registry record. Accordingly, the posted primary results address adverse-event counts, while the listed secondary outcomes do not establish what happened to tumor control or survival in this study.
3. Trial Design
This is a phase II, single-group study of leronlimab in patients with CCR5+ locally advanced or metastatic solid tumors. The registry records no randomized allocation and no masking. With no comparator group, the design can describe outcomes among treated participants but cannot make a direct randomized comparison between leronlimab and another treatment or control condition.
The registry lists enrollment as 16, and the primary safety population is N=16 participants who received at least one dose. There is a difference between those entries and the brief summary, which describes a single-arm phase II study with 30 patients. The registry record does not explain this difference, so the listed enrollment and the safety population should be kept distinct from the brief-summary figure rather than treated as interchangeable.
The listed intervention is Leronlimab 525mg. The study status is completed. The start date is 2020-05-01, and the primary completion date is 2021-11-07. The primary endpoint timeframe runs from first treatment until completion of the last study visits, up to approximately 16 months. The population definition for that endpoint includes participants who received at least one dose.
Several secondary outcomes are listed, including progression-free survival and overall survival, but the record does not report their results. The statistical analysis plan, the sample-size justification, and any interim analysis plan are not reported in the registry record. With no randomized comparator and a small treated population, the design is principally descriptive for the posted safety counts; it does not by itself separate treatment-related events from events associated with the underlying cancer or other circumstances.
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 | Leronlimab 525mg |
|---|---|
| STARTED | 16 |
| COMPLETED | 6 |
| NOT COMPLETED | 10 |
Reasons for not completing this period:
| Reason | Leronlimab 525mg |
|---|---|
| Withdrawal by Subject | 2 |
| 7 patients were on-going at the time when study was closed by sponsor. | 7 |
| Disease Progression | 1 |
Analysis population for the primary outcome, as defined in the registry: The population (N=16) consists of all subjects who received at least one dose of leronlimab (PRO 140).
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: All patients who received at least one dose of leronlimab (PRO 140) were included in the baseline analysis population.
| Characteristic | Unit | Leronlimab 525mg |
|---|---|---|
| Participants analysed | 16 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 12 |
| Age, Categorical: >=65 years | Participants | 3 |
| Age, Continuous | years | 54.87 (SD 15.36) |
| Sex: Female, Male: Female | Participants | 8 |
| Sex: Female, Male: Male | Participants | 8 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 1 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 15 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 2 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 14 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 16 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Adverse Events (AEs), and Serious Adverse Events (SAEs)., measured over From the time of first treatment (T1) until the last study visits completion (up to approximately 16 months).
| 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 adverse events and serious adverse events. The registry defines the safety population as N=16 participants who received at least one dose of leronlimab. Adverse events were elicited through direct questioning and participant reports. The definition also includes abnormalities in visit evaluations, physical examination findings, or laboratory results when the investigator considered them clinically significant to the participant.
The stated timeframe begins at first treatment and continues through completion of the last study visits, up to approximately 16 months. Thus, the endpoint is a count of participants reported to have events during the defined observation period, not a measure of how severe every event was, how long each event lasted, or how often events recurred. The registry reports counts of participants with serious and other adverse events; it does not give event-level timing or duration in the posted primary results.
In general, participant counts are used in safety reporting because they indicate how many people experienced an event category at least once, rather than how many total episodes occurred. A participant may experience more than one event, so participant counts and event counts answer different questions. The registry does not specify in the primary endpoint description how event categories overlap, and the counts should not be added together.
This endpoint is used to characterize observed safety events in the treated population. It does not establish that leronlimab caused an event. In an uncontrolled study, the counts describe what was reported during follow-up, without a concurrent group to estimate how often similar events might occur under a different treatment or without study treatment.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary results report that 3 participants had serious adverse events and 11 participants had other adverse events in the Leronlimab 525mg group. The registry separately lists 12 deaths. These are counts of participants, not counts of event episodes. The registry does not explain how deaths overlap with adverse-event categories, so the figures should not be summed or treated as mutually exclusive groups.
The record lists Sepsis, Metastatic neoplasm, Oesophageal carcinoma, and Urinary retention among the top serious terms, each at 6.2%. Those entries identify reported terms, but the record does not give enough detail to infer whether any term was considered related to treatment, how many total episodes occurred, or the timing and clinical course of the events. A reported serious event is not, by itself, evidence that the study drug caused it.
The denominator is important for reading these counts: the primary population includes N=16 participants who received at least one dose. However, the record does not provide confidence intervals for the safety counts. Without an interval or other uncertainty measure, the posted counts do not show precisely how much the observed frequencies might vary across comparable groups. General statistical interpretation: with a limited number of observed participants, a small change in the number of people with an event can substantially change the apparent frequency; this limits how firmly a descriptive count can characterize a broader population.
The trial has no randomized comparator. Consequently, these results cannot estimate a between-group difference or establish whether event counts are higher or lower than they would have been under another condition. Participants had advanced or metastatic solid tumors, and the record does not provide information that would allow the observed deaths or serious events to be separated into treatment effects and effects of underlying disease or other causes.
The registry lists secondary outcomes including progression-free survival, overall response rate, time to new metastases, circulating tumor cell change, and overall survival. Their results are not reported in the registry record. The safety counts therefore should not be read as evidence about response, disease progression, or survival benefit. They describe the posted adverse-event findings in this treated group, within the specified follow-up framework, and no more.
The brief summary describes 30 patients, whereas the enrollment and primary safety population are listed as 16. The registry record does not reconcile those figures. This difference should be kept in mind when interpreting the scope of the posted results: the adverse-event counts are explicitly tied to the population of N=16 who received at least one dose.
9. Statistical Methods Explained
What does a participant count represent?
A participant count records how many people met the stated event criterion during follow-up. Here, the primary endpoint concerns participants with adverse events and serious adverse events, and the population is defined as people who received at least one dose. A participant count differs from a total event count: one participant could have multiple adverse events, while the participant count generally counts that person once within a given category. The registry does not report the total number of event episodes or fully describe overlap between the reported categories.
General statistical explanation: counts are easiest to interpret alongside the population in which they were observed and the observation period. The listed safety population is N=16, and the endpoint timeframe extends from first treatment through the last study visits, up to approximately 16 months. Follow-up duration matters because participants observed for different lengths of time have different opportunities for an event to be recorded. The record gives an overall timeframe but does not report individual follow-up durations.
What does a serious adverse event count say?
A serious adverse event is a safety classification, not a statement about causation. The registry reports participants with serious adverse events and gives several serious terms. These results describe what was recorded during the study. They do not independently establish whether an event was caused by the intervention, by the underlying condition, or by another factor. Attribution requires information about assessment and context; those details are not reported in the registry record.
The top serious terms are each listed with 6.2%. Those percentages should be read as reported, without assuming an unreported denominator or inferring that the categories are exclusive. The record does not provide the full event listing, event timing, or a detailed explanation of how the displayed terms were selected.
How would uncertainty be described?
General statistical explanation: a confidence interval is a range of values compatible with the data under a specified statistical procedure. It communicates uncertainty around an estimate and is not a guarantee that the true value lies within the interval. The registry does not report confidence intervals for the primary safety counts. Therefore, the reported counts can be described, but their precision cannot be assessed from a posted interval.
General statistical explanation: uncertainty is especially important when a result is based on a limited number of observations. A count may be accurate for the participants observed, but the same count does not necessarily predict what would be seen in another group. The study’s single-group design also means that no comparative effect estimate can be derived from a concurrent control arm.
What does the design permit?
The registry identifies the study as single group, with no randomized allocation and no masking. In general, a single-group study can report outcomes among treated participants, but it cannot balance prognostic factors across randomized groups or directly estimate a treatment-versus-control contrast. Observed outcomes may reflect the intervention, the disease, other care, or other influences. The record does not report a statistical adjustment plan that would address these issues.
The study lists several secondary outcomes, including time-to-event outcomes and measures of tumor response. Statistical methods for those outcomes, including censoring rules and model specifications, are not reported in the registry record. No analyses are listed in the record. As a result, there is no basis to describe the specific inferential procedures used for those outcomes.
How should planning calculations be distinguished from study findings?
General statistical explanation: a sample-size calculation is a planning exercise based on assumptions about the effect to detect, the significance level, allocation, and statistical model. It is not an observed result and is not evidence that a study had a particular probability of finding an effect after the data were collected. A calculation based on an observed effect is a retrospective planning illustration, not observed power. The record does not report the trial’s own sample-size justification, and it does not report a prespecified statistical analysis plan.
The registry’s brief summary describes 30 patients, while enrollment and the primary safety population are listed as 16. The record does not explain this difference. For the posted primary safety results, the population definition explicitly identifies N=16 participants who received at least one dose. Keeping the stated population and the reported outcome counts together is essential to avoid implying that the counts apply to a different number of people.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists several secondary outcomes alongside the primary safety endpoint: progression-free survival, overall response rate, time to new metastases, change in circulating tumor cells, and overall survival. It does not report results for these outcomes. The number of outcome measures is listed as 7, while no analyses are listed. The statistical analysis plan and any approach to handling multiple outcome tests are not reported in the registry record.
Multiplicity arises when several outcomes or statistical tests are examined. General statistical explanation: the more tests conducted, the greater the chance that at least one result appears notable by chance if each is judged separately. A prespecified hierarchy or adjustment can help define how conclusions are drawn, but the record does not state whether any such approach was planned. Because outcome results and testing details are absent, no multiplicity-adjusted interpretation can be made.
Missing-data handling is also not reported in the registry record. The safety endpoint population includes participants who received at least one dose, but the record does not describe how incomplete follow-up, missed assessments, or withdrawal from the study were handled. It does not report whether every participant had the same observation period or how missing event information was treated.
The record does not report an analysis population for the secondary outcomes, a protocol for censoring time-to-event observations, or methods for handling missing measurements. These details matter because exclusion, censoring, or incomplete observation can affect estimates. No assumptions should be made about those procedures from the posted participant counts alone.
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 |
|---|---|---|---|
| Leronlimab 525mg | 3 | 16 | 18.8% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Leronlimab 525mg | 12 of 16 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Leronlimab 525mg | 11 of 16 |
Most frequent serious adverse event terms
| Event term | Organ system | Leronlimab 525mg |
|---|---|---|
| Sepsis | Infections and infestations | 1 of 16 |
| Metastatic neoplasm | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1 of 16 |
| Oesophageal carcinoma | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1 of 16 |
| Urinary retention | Renal and urinary disorders | 1 of 16 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Leronlimab 525mg |
|---|---|---|
| Chills | General disorders | 2 of 16 |
| Headache | Nervous system disorders | 2 of 16 |
| Hypokalaemia | Metabolism and nutrition disorders | 2 of 16 |
| Injection site reaction | General disorders | 2 of 16 |
| Insomnia | Psychiatric disorders | 2 of 16 |
| Nausea | Gastrointestinal disorders | 2 of 16 |
| Alopecia | Skin and subcutaneous tissue disorders | 1 of 16 |
| Anxiety | Psychiatric disorders | 1 of 16 |
| Arthralgia | Musculoskeletal and connective tissue disorders | 1 of 16 |
| Arthritis | Musculoskeletal and connective tissue disorders | 1 of 16 |
Serious events with the highest arm-level rate: sepsis (6.2%), metastatic neoplasm (6.2%), oesophageal carcinoma (6.2%), urinary retention (6.2%).
The primary safety results list 3 participants with serious adverse events and 11 with other adverse events in the Leronlimab 525mg group. The safety population is N=16 participants who received at least one dose. These are participant counts, not totals of all event episodes. The registry also lists 12 deaths; it does not state in the reported figures how deaths overlap with adverse-event counts.
The serious terms listed among the top entries are Sepsis, Metastatic neoplasm, Oesophageal carcinoma, and Urinary retention, each reported at 6.2%. The record does not provide enough information to infer event causation, timing, or whether the terms represent unique participants. It also does not report the investigator’s relatedness assessment for these entries.
General statistical explanation: safety counts describe observations in the study population and are not causal comparisons. Because this study has no control group, the counts cannot determine whether the events occurred more or less often than they would have under another treatment or no study treatment. The figures should be read as descriptive reports for the stated population and follow-up period, not as proof that the intervention caused or prevented an event.
12. What the Result Does, and Does Not, Mean
The results show that the registry recorded serious adverse events in 3 participants and other adverse events in 11 participants in the treated group. It also lists 12 deaths and four top serious terms, each with a reported value of 6.2%. The counts refer to the safety population of N=16 participants who received at least one dose, during a timeframe from first treatment through completion of the last study visits, up to approximately 16 months.
These are descriptive safety findings. They do not establish that leronlimab caused the reported events, and they do not compare the observed counts with a control group. No randomized comparison is recorded. The posted results also do not provide confidence intervals or other measures of precision for the safety counts, so the extent of statistical uncertainty is not quantified in the registry record.
The registry lists disease-response and survival outcomes, including progression-free survival, overall response rate, time to new metastases, circulating tumor cell change, and overall survival. Results for these outcomes are not reported in the registry record. The posted safety results therefore cannot support a conclusion about tumor response, disease progression, or survival.
The brief summary describes 30 patients, while enrollment and the safety population are listed as 16. The record does not reconcile these entries. The specific primary safety population is defined as N=16, so the event counts should be interpreted in relation to that population rather than assumed to represent the brief-summary figure.
Overall, the registry record supports a narrow reading: it reports event counts among participants treated in a single-group phase II study. It does not establish comparative safety, causal attribution, or efficacy.
13. Why This Trial Matters Statistically
This study illustrates why a result needs to be interpreted in relation to its design and endpoint. The primary outcome counts participants with adverse events and serious adverse events, which makes it a safety description rather than an efficacy measure. Even when an event count is clearly reported, it does not answer whether the intervention caused the event or how the count compares with another treatment.
The single-group design is central to that distinction. Without a randomized comparator, the registry can describe what was observed among treated participants but cannot estimate a controlled treatment contrast. This matters particularly in a population described as having locally advanced or metastatic solid tumors, where outcomes may reflect underlying disease and other influences as well as study treatment.
The record also shows why the analysis population and enrollment statements should be read carefully. The listed enrollment and primary safety population are 16, while the brief summary describes 30 patients. The record does not explain the difference. Identifying the population attached to the reported outcome is necessary for a clear account of what the counts represent.
Finally, the study lists several secondary outcomes but does not report their results. Statistical interpretation depends not only on the outcomes named in a registry but also on the results, analysis procedures, and missing-data handling. Those elements are not reported for the listed secondary outcomes. The record therefore offers limited material for evaluating efficacy or the broader statistical plan, while still providing a defined set of descriptive safety counts.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The primary limitation for interpreting the posted results is the single-group design. No randomized comparator is recorded, so the adverse-event counts cannot be interpreted as differences relative to another treatment or control. The record also lists no masking. These design features constrain causal and comparative conclusions.
The safety population is N=16 participants who received at least one dose. The brief summary, however, describes a study with 30 patients, while enrollment is listed as 16. The registry record does not explain the difference. This leaves an unresolved inconsistency in the record’s descriptions of study size, even though the primary endpoint population is explicitly defined.
The registry gives counts for participants with serious and other adverse events and lists deaths, but it does not report detailed event-level information, timing, duration, or a clear account of overlap among categories. It also does not report relatedness assessments for the listed serious terms. Therefore, the counts do not establish causation or provide a complete account of individual event courses.
Confidence intervals for the safety results are not reported in the registry record. Results for the listed secondary outcomes are also not reported. The statistical analysis plan, sample-size justification, interim analysis plan, missing-data procedures, and methods for the secondary outcomes are not reported in the registry record. These omissions limit assessment of precision, analytic choices, and the completeness of outcome reporting.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Basket Study of Leronlimab (PRO 140) in Patients With CCR5+ Locally Advanced or Metastatic Solid Tumors — NCT04504942.
- Registry record last updated 2026-01-23; status last verified 2021-09.
- Results first posted 2026-01-23.
- 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 describes a completed phase II, single-group study of leronlimab in patients with CCR5+ locally advanced or metastatic solid tumors. The listed arm is Leronlimab 525mg, with no randomized allocation and no masking. The study start date is 2020-05-01, and the primary completion date is 2021-11-07.
Enrollment is listed as 16, and the primary safety population is N=16 participants who received at least one dose. The brief summary describes 30 patients; the registry record does not explain the difference. The primary endpoint counts participants with adverse events and serious adverse events over a timeframe ending at the last study visits, up to approximately 16 months.
The posted results include 3 participants with serious adverse events, 11 with other adverse events, and 12 deaths. Results for the listed secondary outcomes are not reported in the registry record. The statistical analysis plan and missing-data procedures are also not reported.