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 Extension Study of UC-961 (Cirmtuzumab) for Patients With Chronic Lymphocytic Leukemia Treated Previously With UC-961 (NCT02860676), a na phase 1 study. The primary outcome is Number of Treatment-emergent Adverse Events as Assessed by CTCAE v4.0.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02860676 |
| Phase | Phase 1 |
| Condition | Chronic Lymphocytic Leukemia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 3 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of California, San Diego |
| Results posted | Yes |
2. Clinical Question
Population
People with chronic lymphocytic leukemia who had previously received UC-961, also called cirmtuzumab. The registry record lists an enrollment of 3.
Intervention
Retreatment with cirmtuzumab by intravenous infusion. The listed schedule was 16 mg/kg every 14 days for 4 doses, followed by every 28 days for 4 doses.
Comparator
There was no separate comparison group. This was a single-group study, with no allocation to treatment groups and no masking.
Primary question
What number of treatment-emergent adverse events was observed during cirmtuzumab treatment and the stated follow-up period? The registry identifies this as the primary outcome, assessed using CTCAE v4.0, but its numerical result is not reported in the registry record.
The study was designed as a phase 1 extension study focused on safety when cirmtuzumab was given again to people who had received it previously. The registry description says the planned treatment duration was 6 to 12 months. It also describes cirmtuzumab as an investigational monoclonal antibody directed at ROR1, a protein on chronic lymphocytic leukemia cells. These descriptions provide the study rationale; they do not establish a clinical benefit or establish how well the drug worked in people.
The registry lists several additional outcomes, including overall response, progression-free survival, stable disease, partial response, and undetectable minimal residual disease. These are distinct questions from the primary safety outcome. Their numerical results are not reported in the registry record. With a single group and no control condition, the study does not make a randomized comparison of retreatment against another treatment or against no treatment.
3. Trial Design
This was a phase 1, single-group extension study sponsored by the University of California, San Diego. The registry record gives the study status as completed and lists an enrollment of 3. The record lists chronic lymphocytic leukemia as the condition and describes participants as having been treated previously with UC-961. The study title identifies the purpose as evaluating cirmtuzumab retreatment at the recommended phase 2 dose.
The treatment schedule was cirmtuzumab 16 mg/kg by intravenous infusion every 14 days for 4 doses, then every 28 days for 4 doses. The record's study description says treatment was intended for a duration of 6 to 12 months. The primary outcome timeframe is described as the period from the start of investigational treatment to discontinuation from trial participation, on average 159 days. The adverse-event description also specifies assessment during treatment and during 3 months of follow-up.
Allocation is listed as not applicable, and masking is listed as none. The single-group model means there is no concurrent control arm to serve as a like-for-like comparison. As a result, the study design can describe what was recorded during retreatment in this small enrolled group, but it cannot isolate the effect of treatment from other possible influences through a randomized comparison.
The record lists the start date as 2016-11-03 and the primary completion date as 2018-02-27. It does not report a detailed statistical analysis plan, sample-size justification, interim-analysis plan, or further information about participant selection. Those details are not reported in the registry record and should not be inferred from the phase or extension-study designation.
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 | Cirmtuzumab |
|---|---|
| STARTED | 3 |
| COMPLETED | 2 |
| NOT COMPLETED | 1 |
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 | Cirmtuzumab |
|---|---|---|
| Participants analysed | 3 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 |
| Age, Categorical: >=65 years | Participants | 3 |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 2 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 3 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 3 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 3 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Treatment-emergent Adverse Events as Assessed by CTCAE v4.0, measured over From start of investigational treatment to discontinuation from trial participation, on average 159 days.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Adverse Events |
| Endpoint classification | not reduced to a single comparison |
The primary outcome is the number of treatment-emergent adverse events assessed using CTCAE v4.0. The registry description says adverse events were assessed during cirmtuzumab treatment and during 3 months of follow-up. The stated timeframe runs from the start of investigational treatment to discontinuation from trial participation, on average 159 days.
An event count and a count of participants who experienced an event describe different aspects of safety. In general, an event count can include multiple events experienced by the same participant, whereas a participant count records whether an individual was affected. This distinction matters when interpreting a small single-group study: a participant may contribute more than one event, and an event total by itself does not show how events were distributed across people.
CTCAE v4.0 is the assessment system named in the registry record. In general, a standardized adverse-event grading system is used to organize and describe events consistently. The primary outcome is relevant to the stated safety purpose because it concerns events recorded during treatment and follow-up. However, the registry record does not report the numerical result for the primary event count, its distribution, or a summary of severity. The safety figures reported separately do not substitute for the missing primary event-count result.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a completed, single-group phase 1 study of cirmtuzumab retreatment in chronic lymphocytic leukemia. Its primary outcome is a count of treatment-emergent adverse events, but the numerical result for that outcome is not reported in the registry record. Therefore, the primary endpoint cannot be quantitatively interpreted from the information recorded. In particular, there is no reported total event count or measure of its uncertainty.
The safety summary reports that 3 participants were at risk for serious adverse events and 0 were affected. It also reports 3 participants at risk for other adverse events and 3 affected, with 0 deaths. These are participant-level figures in the registry safety summary. They should not be read as the number of all adverse-event episodes, and they do not tell how many events each affected participant experienced. The registry record does not list serious adverse-event terms.
The safety observations are descriptive. A single-group study has no concurrent control group, so the record cannot establish whether events were more or less frequent than they would have been under another treatment or without retreatment. The small enrollment listed in the record also means that the safety summary concerns a very limited group. The absence of a recorded serious event in this group does not establish that serious events cannot occur, and the report of other adverse events does not, by itself, establish their cause.
The record lists several secondary outcomes related to response and disease status, but their numerical results are not reported in the registry record. No analysis entries are listed. There are no reported effect estimates, confidence intervals, p-values, or comparative results in the registry entries. Consequently, there is no basis for judging the precision of treatment effects or for making a statistical comparison.
In general, confidence intervals communicate the range of values compatible with an estimate under a specified statistical model. Their width helps readers judge precision. No confidence interval is reported for the primary outcome or the safety figures in the registry record. Any sample-size displays associated with the posted analysis are planning illustrations, not observed power and not a substitute for reported results. Their assumptions are not the trial's own design or analysis unless the registry record says so; no such statistical plan is reported.
9. Statistical Methods Explained
The registry identifies the study as phase 1 and single-group, with no masking. These design features shape what can be learned statistically. A single-group study can describe outcomes observed among participants who received the intervention. Without a concurrent randomized comparator, it cannot separate treatment-related changes from the natural course of illness, participant characteristics, other care, or chance. Randomization is generally used to make comparison groups more comparable with respect to known and unknown factors. That protection is not part of this study design.
What does an event count represent?
The primary outcome is the number of treatment-emergent adverse events assessed using CTCAE v4.0. In general, an event count records episodes, not necessarily people. One person can experience more than one event, and an event count may therefore be larger than the number of participants affected. Conversely, a participant-level summary answers how many people experienced at least one event, not how many episodes occurred. These measures should not be treated as interchangeable.
Counts are often summarized directly when an outcome is the number of events. If a model is used, the method should reflect the count distribution and the way observations were collected. In general, a simple count model can be inadequate when event counts vary more than the model expects, a feature called over-dispersion. Over-dispersion can make standard errors too small and confidence intervals too narrow if ignored. The registry record does not report a model for the primary event count, a distributional assumption, or a method for handling over-dispersion. No such method should be presumed.
Why does follow-up matter?
Participants need time under observation for events to be detected and recorded. The registry describes the primary outcome timeframe as starting with investigational treatment and ending at discontinuation from trial participation, on average 159 days. It also states that adverse events were assessed during treatment and during 3 months of follow-up. In general, participants observed for different lengths of time may have different opportunities to experience or report events. A total event count does not account for differences in observation time unless the analysis specifically incorporates that information. The registry record does not report whether event rates per unit of time were calculated or how differing follow-up was handled.
In time-to-event analysis, the time until an event is considered, and participants who have not had an event by the end of observation may be censored. Censoring means the event time is not observed beyond a known point; it does not mean the person had no possible later event. The registry lists progression-free survival as a secondary outcome, but does not report its analysis method, event definition, censoring rules, or numerical result. These details are not reported in the registry record.
What can be said about uncertainty?
Statistical estimates are usually interpreted alongside measures of uncertainty. In general, a confidence interval describes a range of values that are reasonably compatible with the observed data under the chosen model and its assumptions. A narrow interval indicates greater precision than a wide interval, while neither width nor statistical significance alone establishes clinical importance. No interval estimate for the primary event count or safety figures is reported in the registry record. With no interval, readers cannot assess the statistical precision of those figures using the record.
For a single-group descriptive result, a confidence interval could express uncertainty about an event rate or participant proportion if such an estimate and method were reported. The registry safety summary gives counts of participants at risk and affected, but does not report a confidence interval or a comparative effect. No new rate, proportion, or interval can be inferred from these registry entries. The absence of a reported interval is especially important when interpreting a small enrolled group: observed counts alone do not establish the range of plausible underlying risks.
What do the planning illustrations mean?
General sample-size planning asks how many participants or events might be needed for a future study under stated assumptions. The record describes planning illustrations using a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect expressed as a fraction of an observed effect. It also states that time-to-event planning uses a total event count, while other planning displays use participants per arm. These are planning assumptions, not a description of this trial's single-group design. They do not establish that the trial was designed with those assumptions, and they are not observed power.
A planning calculation based on an observed effect is conditional on that estimate and on the chosen statistical model. In general, observed effects can be unstable, particularly in small studies. Planning outputs should therefore be read as illustrations of what a future design might require under their assumptions, not as evidence that the present study had adequate power or that an effect has been confirmed. The registry record does not report the trial's own sample-size justification or formal statistical plan.
There are no analysis entries reported in the registry record. This means the analysis methods, adjustment strategy, uncertainty estimates, and handling of missing data cannot be reconstructed from the record. It does not establish that no analysis was carried out outside the registry. Any more detailed account of the statistical methods would require information not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists the primary outcome as the number of treatment-emergent adverse events assessed by CTCAE v4.0. It also lists secondary outcomes for overall response rate, progression-free survival, stable disease rate, partial response rate, and undetectable minimal residual disease rate. The record lists six outcome measures and no analysis entries. Numerical results for the listed secondary outcomes are not reported in the registry record.
When a study evaluates multiple outcomes or makes multiple statistical tests, the chance of at least one apparently notable finding can increase. In general, a prespecified testing order or multiplicity adjustment can address that issue, depending on the study's goals. The registry record does not report whether multiplicity was considered, whether a hierarchy was used, or whether any adjustment was planned. No adjustment should be assumed.
The record also does not report an analysis population, such as whether the primary outcome was analyzed among all enrolled participants or under another inclusion rule. The safety summary gives participants at risk and affected, but it does not describe the population definitions or missing-observation rules used for each outcome. A missing-data method, reasons for missing data, and any sensitivity analyses are not reported in the registry record.
These omissions limit reproducibility and interpretation. They do not show that outcomes were omitted from the underlying study, nor do they establish that missing observations occurred. They mean that the registry record does not provide enough detail to determine how outcome data were analyzed or how results across the listed outcomes were interpreted together.
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 |
|---|---|---|---|
| Cirmtuzumab | 0 | 3 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Cirmtuzumab | 0 of 3 |
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 |
|---|---|
| Cirmtuzumab | 3 of 3 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Cirmtuzumab |
|---|---|---|
| Anemia | Investigations | 3 of 3 |
| Thrombocytopenia | Investigations | 3 of 3 |
| Eye disorders, other | Eye disorders | 1 of 3 |
| Abdominal pain | Gastrointestinal disorders | 1 of 3 |
| Constipation | Gastrointestinal disorders | 1 of 3 |
| Gastrointestinal disorders, other | Gastrointestinal disorders | 1 of 3 |
| Dizziness | General disorders | 1 of 3 |
| Upper respiratory infection | Infections and infestations | 1 of 3 |
| Generalized muscle weakness | Musculoskeletal and connective tissue disorders | 1 of 3 |
| Skin and subcutaneous tissue disorders, other | Skin and subcutaneous tissue disorders | 1 of 3 |
The registry safety summary reports 3 participants at risk for serious adverse events, with 0 affected, and 3 participants at risk for other adverse events, with 3 affected. It also reports 0 deaths. These figures describe affected participants in the safety summary; they are not a report of the total number of adverse-event episodes. The registry record does not list serious adverse-event terms.
In general, an event count and a participant count answer different questions. A participant who experiences multiple events can contribute multiple episodes to an event count but is counted once in a summary of affected participants. The primary endpoint is an event count, while the safety summary figures are participant-level counts. The numerical result for the primary event count is not reported in the registry record, so the safety summary cannot be used to reconstruct it.
The figures are descriptive and apply to this study group. They do not provide a comparison against another treatment or a background event rate, and the record does not report uncertainty intervals. The absence of participants recorded as affected by serious adverse events in this summary should not be interpreted as proof that serious adverse events are impossible. Likewise, the record does not establish that the other adverse events were caused by cirmtuzumab.
12. What the Result Does, and Does Not, Mean
The record establishes that a completed phase 1 extension study evaluated cirmtuzumab retreatment in people with chronic lymphocytic leukemia who had previously received UC-961. It identifies treatment-emergent adverse events as the primary outcome and gives the assessment framework and timeframe. The safety summary reports participants affected by serious and other adverse events and records no deaths. These are descriptive observations from a single group.
The record does not report the numerical result for the primary event count, so it does not allow a full quantitative account of that endpoint. It also does not report numerical results for the listed secondary outcomes. Without those results, readers cannot assess response estimates, disease-status outcomes, or progression-free survival from this registry record. There are no reported comparative estimates or uncertainty intervals with which to judge precision.
Because there is no concurrent control group, the design does not establish what would have happened to the same population under another treatment or without retreatment. The safety summary cannot determine whether an event was caused by treatment, and the design does not support a randomized treatment-effect estimate. The small enrollment listed in the record further restricts how broadly the observed safety experience can be generalized.
The record's rationale describes cirmtuzumab as an investigational drug directed at ROR1 and states that the study's goal was to examine safety and tolerability during treatment lasting 6 to 12 months. That rationale is not a result. The posted information neither establishes clinical benefit nor demonstrates lack of benefit. It also does not provide enough outcome detail to estimate how often particular events occurred or how precisely any risk was measured.
13. Why This Trial Matters Statistically
This study is statistically informative as an example of a safety-focused, single-group extension design. The question is centered on retreatment among people previously exposed to cirmtuzumab, rather than on a randomized comparison of treatment strategies. That distinction determines what the results can answer: descriptive safety observations can be recorded, but treatment effects relative to a comparator cannot be isolated by this design.
The distinction between an event count and the number of participants affected is also important. The primary outcome is an event count, while the safety summary reports affected participants. Keeping those measures separate helps avoid treating the reported safety figures as if they were the missing primary endpoint result. A participant-level count can show how many people were affected, but it does not reveal the number of episodes or their distribution across individuals.
The registry record also illustrates why outcome definitions and analysis details matter. It specifies an assessment system and describes the observation timeframe, but does not report the numerical primary outcome, analysis methods, missing-data handling, or uncertainty estimates. Without these, it is not possible to assess the precision of the primary safety result or reproduce the analysis from the record.
Finally, planning calculations should be distinguished from evidence observed in a trial. The record describes planning illustrations with assumptions that include a two-arm allocation, whereas the study itself is single-group. Such illustrations can help frame hypothetical future-study designs, but they do not change the design of this study or provide observed power. Interpreting these distinctions is central to reading small early-phase studies accurately.
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 lists an enrollment of 3, and the study has a single group with no masking. These features limit the scope of descriptive safety observations and do not provide a randomized basis for comparing outcomes with another treatment. Results from this group may not represent people with chronic lymphocytic leukemia more broadly, but the record does not report enough participant characteristics to examine how the enrolled participants compare with other populations.
The primary outcome is described, but its numerical result is not reported in the registry record. The record therefore does not provide the total treatment-emergent adverse-event count, an event distribution, or an uncertainty estimate. The separate safety figures report affected participants, not total events. Serious adverse-event terms are not listed.
The primary outcome timeframe ends at discontinuation from trial participation and is described as averaging 159 days; the adverse-event description also includes 3 months of follow-up. The record does not explain the distribution of observation times, how incomplete follow-up was handled, or whether time at risk was incorporated into an analysis. These limitations matter for interpreting event counts because opportunities for event detection can differ with observation time.
The record does not report an analysis population, missing-data approach, statistical model, multiplicity strategy, or trial-specific sample-size justification. It lists secondary outcomes, but their numerical results and analysis methods are not reported in the registry record. The record also does not report confidence intervals or comparative estimates. These are limitations of the information available in the registry record; they do not establish what analyses may have been conducted elsewhere.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Extension Study of UC-961 (Cirmtuzumab) for Patients With Chronic Lymphocytic Leukemia Treated Previously With UC-961 — NCT02860676.
- Registry record last updated 2025-12-15; status last verified 2025-12.
- Results first posted 2025-12-15.
- 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
NCT02860676 is a completed phase 1, single-group extension study sponsored by the University of California, San Diego. It concerns cirmtuzumab retreatment in people with chronic lymphocytic leukemia previously treated with UC-961. The listed regimen was 16 mg/kg by intravenous infusion every 14 days for 4 doses, then every 28 days for 4 doses. Enrollment was 3, and masking was listed as none.
The primary outcome was the number of treatment-emergent adverse events assessed using CTCAE v4.0, with assessment during treatment and 3 months of follow-up. The numerical result for that endpoint is not reported in the registry record. The safety summary reports 0 of 3 affected by serious adverse events, 3 of 3 affected by other adverse events, and 0 deaths. Listed secondary outcomes include overall response, progression-free survival, stable disease, partial response, and undetectable minimal residual disease; their numerical results are not reported in the registry record.