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 1/2a Study of VK-2019 in Patients With Epstein-Barr Virus (EBV)-Positive Nasopharyngeal Carcinoma (NPC) (NCT03682055), a non-randomized phase 1, phase 2 study. The primary outcome is All Cohorts: The Frequency, Severity, and Duration of AEs and DLTs, AEs Leading to Discontinuation, and AEs Leading to Death..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03682055 |
| Phase | Phase 1, Phase 2 |
| Condition | Nasopharyngeal Carcinoma, Nasopharyngeal Cancer |
| Allocation | Non-Randomized |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 14 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Cullinan Therapeutics Inc. |
| Results posted | Yes |
2. Clinical Question
Population
Patients with EBV-positive recurrent or metastatic nasopharyngeal carcinoma (NPC). The registry lists nasopharyngeal carcinoma and nasopharyngeal cancer as conditions.
Intervention
VK-2019, described as an oral EBNA-1 targeting agent and a novel small molecule EBNA1 inhibitor. The cohorts are described as receiving VK-2019 once daily.
Comparator
No control treatment is described. The study is non-randomized and uses a single-group model; its cohorts are dose-escalation or dose-expansion cohorts, not a like-for-like control comparison.
Primary question
The study identifies safety and tolerability, including adverse events (AEs) and dose-limiting toxicities (DLTs), as its primary focus. Its stated aims also include determining the Maximum Tolerated Dose and Recommended Phase 2 Dose and evaluating the pharmacokinetic profile of VK-2019.
The registry describes an early-phase study rather than a randomized test of VK-2019 against another treatment. Phase 1 includes accelerated titration cohorts, a Rolling Six cohort, and dose expansion cohorts; Phase 2a dose expansion cohorts could be opened based on efficacy criteria in Phase 1 dose-escalation cohorts. These descriptions indicate that the study was organized around dose evaluation and possible expansion, not around estimating a controlled treatment contrast.
The registered primary outcome concerns the frequency, severity, and duration of AEs and DLTs, as well as AEs leading to discontinuation and AEs leading to death. The registry also lists objective response rate (ORR) for Phase 1 dose-escalation and dose-expansion cohorts as a secondary outcome. However, the posted record does not contain an analysis entry for these outcomes. The clinical question is therefore best read as a description of the study's aims, not as evidence of an estimated treatment effect.
3. Trial Design
This is a Phase 1/2a, open-label, multicenter, non-randomized, single-group study of VK-2019. The registry reports enrollment of 14 and identifies Cullinan Therapeutics Inc. as the sponsor. The study started on 2019-04-04, had a primary completion date of 2020-06-23, and is listed as terminated. The reason for termination is not reported in the registry record.
The study has several cohort types. Phase 1 dose escalation included accelerated titration cohorts and a Rolling Six cohort. Phase 1 dose expansion cohorts could be opened at doses meeting prespecified criteria for clinical and/or biological activity. Phase 2a dose expansion cohorts could be opened at doses meeting prespecified efficacy criteria in Phase 1 dose-escalation cohorts. All are described as receiving VK-2019 once daily. The posted information does not give the dose levels or describe which expansion cohorts were opened.
Open-label means masking was absent, as also stated in the registry. Non-randomized allocation and the single-group model mean there is no randomized control group for estimating a treatment contrast. Cohorts represent different stages or strategies within the study; they should not be treated as comparable treatment arms. Differences across cohorts could reflect their different roles and enrollment patterns, as well as participant or treatment characteristics that are not described in the record.
The registry lists pharmacokinetic and pharmacodynamic correlative studies in the official title, while its brief summary emphasizes dose determination and pharmacokinetic evaluation. The details of those studies and their analyses are not reported in the registry record. The posted record lists two outcome measures and no analysis entries. This limits what can be concluded from the registration information: it documents the planned framework and some cohort-level safety counts, but it does not provide a complete statistical analysis or a controlled efficacy estimate.
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 | Cohort 1 (Phase 1 Accelerated Titration) | Cohort 2 (Phase 1 Accelerated Titration) | Cohort 3 (Phase 1 Accelerated Titration) | Cohort 4 (Phase 1 Accelerated Titration) | Cohort 5 (Phase 1 Accelerated Titration) | Cohort 6 (Phase 1 Rolling 6) |
|---|---|---|---|---|---|---|
| STARTED | 1 | 2 | 1 | 2 | 1 | 7 |
| COMPLETED | 0 | 0 | 0 | 0 | 0 | 0 |
| NOT COMPLETED | 1 | 2 | 1 | 2 | 1 | 7 |
Reasons for not completing this period:
| Reason | Cohort 1 (Phase 1 Accelerated Titration) | Cohort 2 (Phase 1 Accelerated Titration) | Cohort 3 (Phase 1 Accelerated Titration) | Cohort 4 (Phase 1 Accelerated Titration) | Cohort 5 (Phase 1 Accelerated Titration) | Cohort 6 (Phase 1 Rolling 6) |
|---|---|---|---|---|---|---|
| Lack of Efficacy | 1 | 2 | 1 | 2 | 1 | 3 |
| Withdrawal by Subject | 0 | 0 | 0 | 0 | 0 | 1 |
| Termination of Study by Sponsor | 0 | 0 | 0 | 0 | 0 | 3 |
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.
Only the first 6 of 7 groups are shown.
| Characteristic | Unit | Cohort 1 (Phase 1 Accelerated Titration) | Cohort 2 (Phase 1 Accelerated Titration) | Cohort 3 (Phase 1 Accelerated Titration) | Cohort 4 (Phase 1 Accelerated Titration) | Cohort 5 (Phase 1 Accelerated Titration) | Cohort 6 (Phase 1 Accelerated Titration) |
|---|---|---|---|---|---|---|---|
| Participants analysed | 1 | 2 | 1 | 2 | 1 | 7 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 | 1 | 1 | 1 | 1 | 7 |
| Age, Categorical: >=65 years | Participants | 0 | 1 | 0 | 1 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 1 | 1 | 0 | 0 | 0 | 1 |
| Sex: Female, Male: Male | Participants | 0 | 1 | 1 | 2 | 1 | 6 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 1 | 2 | 1 | 1 | 1 | 3 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 0 | 0 | 0 | 1 | 0 | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 | 0 | 1 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 | 0 | 3 |
| Region of Enrollment: Hong Kong | participants | 0 | 0 | 0 | 0 | 1 | 2 |
| Region of Enrollment: United States | participants | 1 | 2 | 1 | 2 | 0 | 2 |
| Region of Enrollment: France | participants | 0 | 0 | 0 | 0 | 0 | 3 |
6. Primary Endpoint
The registry lists the primary outcome as All Cohorts: The Frequency, Severity, and Duration of AEs and DLTs, AEs Leading to Discontinuation, and AEs Leading to Death., measured over 24 months.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The registered primary outcome covers the frequency, severity, and duration of adverse events and dose-limiting toxicities, plus adverse events leading to discontinuation and adverse events leading to death. The listed unit is participants, and the stated timeframe is 24 months. These measures are used in early-phase studies to characterize tolerability and identify safety events relevant to dose evaluation. DLTs are particularly relevant to dose-escalation decisions because they describe toxicities that can constrain treatment dosing under the study's definitions.
The registry describes the outcome parameter as a count of participants, but the outcome title encompasses several distinct aspects of safety. A count alone does not convey event severity, duration, timing, recurrence, or whether events led to a treatment change. Those details matter when interpreting safety, and the posted record does not provide a full participant-level account or an endpoint analysis that integrates those dimensions.
The cohort information reports counts of participants at risk and affected for serious and other adverse events, along with deaths. These descriptive entries are not, by themselves, a complete result for every component named in the primary endpoint. In particular, the registry record does not report an analysis of DLT frequency, event duration, severity distributions, discontinuations due to AEs, or the relationship between individual events and treatment. The primary endpoint should therefore be understood as the planned safety construct, while the posted cohort counts offer only a limited description of safety events.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies safety as the primary outcome, but it does not post analysis entries for the registered outcomes. The available safety information is descriptive and separated by cohort. For example, the serious-adverse-event fields show participants at risk and affected within the listed cohorts, and other fields report participants affected by other adverse events and deaths. These entries should be read as cohort-level counts, not as an estimate of the comparative effect of VK-2019.
In Cohort 1 (Phase 1 Accelerated Titration), the serious-adverse-event count is 0 among 1 participant at risk, while the other-adverse-event count is 1 among 1 at risk; deaths are 0. In Cohort 2 (Phase 1 Accelerated Titration), 2 participants were at risk for serious adverse events and 2 were affected; the other-adverse-event count is also 2 among 2 at risk, and deaths are 1. Cohort 3 (Phase 1 Accelerated Titration) reports 0 serious adverse events among 1 at risk, 1 other adverse event among 1 at risk, and 0 deaths. Cohort 4 (Phase 1 Accelerated Titration) reports 0 serious adverse events among 2 at risk, 2 other adverse events among 2 at risk, and 0 deaths. Cohort 5 (Phase 1 Accelerated Titration) reports 1 serious adverse event among 1 at risk, 1 other adverse event among 1 at risk, and 0 deaths. Cohort 6 (Phase 1 Rolling 6) reports 3 serious adverse events among 7 at risk, 7 other adverse events among 7 at risk, and 0 deaths.
The listed serious-event terms include Urinary Tract Infection at 100.0%, Malignant neoplasm progression and Pleural Effusion at 50.0% each, and Tumour Pain, Dyspnoea, and Tracheal Stenosis at 14.3% each. The registry excerpt does not clarify the denominator or calculation basis for these percentages. They should not be interpreted as percentages of all enrolled participants or as treatment-attributable risks without that context.
Because the trial is non-randomized and single-group, these counts do not establish what would have occurred under another treatment or without VK-2019. The different cohort structures are not control groups. A death recorded in a cohort is a reported event, but the registry information does not establish its cause or its relationship to treatment. Likewise, a count of participants affected does not show the duration or clinical course of an event.
The record describes a study intended to assess safety, dose, and pharmacokinetics; the available results do not resolve those aims through a reported analysis. There are no posted estimates of uncertainty, hypothesis tests, or adjusted analyses. Interpretation should remain limited to the stated design and the descriptive safety entries, without implying comparative benefit or harm.
9. Statistical Methods Explained
Early-phase studies and confirmatory comparative trials answer different statistical questions. This study is registered as Phase 1/2a, non-randomized, open-label, and single-group. Its cohort structure supports dose escalation and potential expansion, while its primary focus is safety and tolerability. It is not designed in the registry as a randomized comparison against a control treatment.
What does a single-group design show?
In a single-group study, observed events can be described among participants who received the study intervention. Without a concurrent randomized comparator, those observations do not directly estimate how outcomes would differ under another treatment. Background illness, prior treatment, disease progression, follow-up, and other factors may affect the events recorded. General statistical principle: randomization helps balance measured and unmeasured factors on average, while a non-randomized study cannot rely on that protection for causal comparisons.
The trial's cohort types also have distinct purposes. Accelerated titration, Rolling Six, and expansion cohorts are not interchangeable groups simply because they appear in the same study. General principle: comparisons between groups require care when group membership is related to dose, timing, eligibility, or the stage of study. The record does not report enough detail to assess whether or how cohort-level comparisons were planned.
Why are counts useful, and what do they leave out?
Counts of participants with events are straightforward descriptive measures. They can indicate whether events were observed in a cohort and provide a basic account of affected participants. But counts do not, on their own, describe event timing, duration, repeated events in the same participant, severity distributions, exposure time, or causal attribution. A participant count is also different from an event count: a participant may experience more than one event, while a count of participants affected records whether participants had an event rather than how many events occurred. The registered primary outcome is expressed in participants, but the posted safety information does not provide detail for every named aspect of that endpoint.
General statistical principle: a rate may be useful when participants have different lengths of follow-up, because it relates events to time at risk. However, the registry information does not report person-time or a rate analysis. No such rate should be inferred from the counts. Nor should an event percentage be interpreted without knowing its denominator and construction. The serious-event terms include percentages, but their calculation basis is not reported in the registry record.
What would uncertainty estimates add?
A confidence interval is a statistical range expressing uncertainty around an estimate under a specified method and assumptions. It can show whether a result is precise or compatible with a broad range of values. General statistical principle: estimates based on limited information are often uncertain, and intervals help make that uncertainty visible. The registry record does not post confidence intervals or other uncertainty estimates for the safety counts. No precision estimate can be inferred from the presented counts alone.
Hypothesis tests and p-values address questions defined by an analysis plan, such as whether data are inconsistent with a specified null hypothesis under model assumptions. They do not measure the probability that a treatment works, and they do not by themselves establish clinical importance. The record lists no analysis entries and no p-values for the outcomes. This is not evidence that an unreported test was negative; it means inferential results are not reported in the registry record.
How should dose escalation be understood?
Dose-escalation studies use safety observations to inform decisions about dose development. The study summary names the Maximum Tolerated Dose and Recommended Phase 2 Dose as aims. Those are objectives, not outcomes that can be assumed to have been established. The registry descriptions mention criteria for clinical, biological, or efficacy activity when describing possible expansion cohorts, but the specific criteria and dose decisions are not reported in the registry record. General principle: a dose-selection conclusion depends on the protocol's rules, the observed toxicities, and the analysis used; it cannot be recovered from cohort counts alone.
The record names pharmacokinetic and pharmacodynamic correlative studies, and the summary specifically mentions pharmacokinetic evaluation. General principle: pharmacokinetic analyses describe drug exposure and its pattern over time, while pharmacodynamic analyses examine biological responses associated with exposure. The record does not include the measurements, methods, or findings, so those aims cannot be evaluated from the posted information.
What is the role of planning calculations?
Sample-size calculations are planning illustrations rather than observed trial results. General principle: a calculation for a future study depends on assumptions about the effect to detect, variability or event frequency, significance level, allocation, and statistical method. It does not show that a completed study had a specified probability of detecting an effect, and it is not observed power. The registry record does not report a trial-specific sample-size justification or statistical plan. The presence of planning assumptions in an analysis context would not establish that those assumptions governed this trial.
General principle: over-dispersion occurs when observed variability exceeds what a statistical model assumes. When present, standard errors and confidence intervals from a model that ignores it may be too small, making results appear more precise than they are. The registry record does not report a model for the outcomes or evidence about over-dispersion, so this issue cannot be assessed for the study. More broadly, method choice, population definition, missing-data handling, and outcome definitions are necessary to interpret an analysis; these details are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary safety outcome and ORR as a secondary outcome for Phase 1 dose-escalation and dose-expansion cohorts. It does not report a statistical analysis plan describing how these outcomes were analyzed, whether additional outcomes were tested, or whether any adjustment for multiple comparisons was used. When many outcomes or subgroup comparisons are examined, the chance of finding an apparently unusual result can increase. General statistical principle: multiplicity methods can address that issue, but their relevance depends on the planned hypotheses and analysis strategy. No specific multiplicity approach is reported in the registry record.
The record does not report missing-data rules, the number of participants with evaluable data for each outcome, or how incomplete follow-up was handled. This matters for safety because the opportunity to observe events can depend on follow-up duration and treatment exposure. It also matters for ORR because response assessment requires defined evaluation criteria and an evaluable population. Those details are not reported in the registry record.
The analysis populations are also not described. The record does not state whether results used all enrolled participants, participants who received treatment, or another defined population. The registered primary outcome's timeframe is 24 months, but the posted information does not explain the follow-up completeness or timing of outcome ascertainment for each cohort.
No analysis entries are listed. Therefore, there is no basis in the registry record to determine how multiplicity, missing outcomes, or analysis populations were handled. Their absence from the posted record is an information limitation, not proof that these matters were ignored in study conduct.
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 |
|---|---|---|---|
| Cohort 1 (Phase 1 Accelerated Titration) | 0 | 1 | 0.0% |
| Cohort 2 (Phase 1 Accelerated Titration) | 2 | 2 | 100.0% |
| Cohort 3 (Phase 1 Accelerated Titration) | 0 | 1 | 0.0% |
| Cohort 4 (Phase 1 Accelerated Titration) | 0 | 2 | 0.0% |
| Cohort 5 (Phase 1 Accelerated Titration) | 1 | 1 | 100.0% |
| Cohort 6 (Phase 1 Rolling 6) | 3 | 7 | 42.9% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Cohort 1 (Phase 1 Accelerated Titration) | 0 of 1 |
| Cohort 2 (Phase 1 Accelerated Titration) | 1 of 2 |
| Cohort 3 (Phase 1 Accelerated Titration) | 0 of 1 |
| Cohort 4 (Phase 1 Accelerated Titration) | 0 of 2 |
| Cohort 5 (Phase 1 Accelerated Titration) | 0 of 1 |
| Cohort 6 (Phase 1 Rolling 6) | 0 of 7 |
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 |
|---|---|
| Cohort 1 (Phase 1 Accelerated Titration) | 1 of 1 |
| Cohort 2 (Phase 1 Accelerated Titration) | 2 of 2 |
| Cohort 3 (Phase 1 Accelerated Titration) | 1 of 1 |
| Cohort 4 (Phase 1 Accelerated Titration) | 2 of 2 |
| Cohort 5 (Phase 1 Accelerated Titration) | 1 of 1 |
| Cohort 6 (Phase 1 Rolling 6) | 7 of 7 |
Most frequent serious adverse event terms
| Event term | Organ system | Cohort 1 (Phase 1 Accelerated Titration) | Cohort 2 (Phase 1 Accelerated Titration) | Cohort 3 (Phase 1 Accelerated Titration) | Cohort 4 (Phase 1 Accelerated Titration) | Cohort 5 (Phase 1 Accelerated Titration) | Cohort 6 (Phase 1 Rolling 6) |
|---|---|---|---|---|---|---|---|
| Malignant neoplasm progression | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 0 of 1 | 1 of 2 | 0 of 1 | 0 of 2 | 0 of 1 | 0 of 7 |
| Tumour Pain | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 0 of 1 | 0 of 2 | 0 of 1 | 0 of 2 | 0 of 1 | 1 of 7 |
| Dyspnoea | Respiratory, thoracic and mediastinal disorders | 0 of 1 | 0 of 2 | 0 of 1 | 0 of 2 | 0 of 1 | 1 of 7 |
| Pleural Effusion | Respiratory, thoracic and mediastinal disorders | 0 of 1 | 1 of 2 | 0 of 1 | 0 of 2 | 0 of 1 | 0 of 7 |
| Tracheal Stenosis | Respiratory, thoracic and mediastinal disorders | 0 of 1 | 0 of 2 | 0 of 1 | 0 of 2 | 0 of 1 | 1 of 7 |
| Urinary Tract Infection | Infections and infestations | 0 of 1 | 0 of 2 | 0 of 1 | 0 of 2 | 1 of 1 | 0 of 7 |
| Gastrostomy tube site complication | Injury, poisoning and procedural complications | 0 of 1 | 0 of 2 | 0 of 1 | 0 of 2 | 0 of 1 | 1 of 7 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Cohort 1 (Phase 1 Accelerated Titration) | Cohort 2 (Phase 1 Accelerated Titration) | Cohort 3 (Phase 1 Accelerated Titration) | Cohort 4 (Phase 1 Accelerated Titration) | Cohort 5 (Phase 1 Accelerated Titration) | Cohort 6 (Phase 1 Rolling 6) |
|---|---|---|---|---|---|---|---|
| Not Reported | Social circumstances | 1 of 1 | 2 of 2 | 1 of 1 | 2 of 2 | 1 of 1 | 7 of 7 |
Serious events with the highest arm-level rate: urinary tract infection (100.0%), malignant neoplasm progression (50.0%), pleural effusion (50.0%), tumour pain (14.3%), dyspnoea (14.3%).
The safety entries are organized by cohort and distinguish serious adverse events, other adverse events, and deaths. For each cohort, the record reports participants at risk and participants affected. These counts describe what is recorded for the listed cohorts; they do not indicate that an event was caused by VK-2019. The record does not report event-level attribution or a causal assessment.
The serious-event terms are accompanied by percentages: Urinary Tract Infection, 100.0%; Malignant neoplasm progression, 50.0%; Pleural Effusion, 50.0%; Tumour Pain, 14.3%; Dyspnoea, 14.3%; and Tracheal Stenosis, 14.3%. The denominator and precise calculation basis for these percentages are not reported in the registry record. They therefore should not be read as incidence among all enrolled participants or compared directly with the cohort counts without clarification.
Deaths are recorded in the cohort data, including 1 in Cohort 2 (Phase 1 Accelerated Titration). A recorded death is not, by itself, evidence of a treatment-related death; the registry information does not report a causal relationship. The entries also do not provide the timing, severity grading, duration, or clinical course needed to characterize each event fully.
General statistical principle: small cohort counts can be unstable and highly sensitive to the experience of individual participants. These descriptive figures are useful for documenting reported events, but they do not support precise comparisons between cohorts or a comparative estimate against an untreated or control group.
12. What the Result Does, and Does Not, Mean
The registry record documents an early-phase study of VK-2019 in EBV-positive recurrent or metastatic NPC. Its stated aims include evaluating safety, identifying the Maximum Tolerated Dose and Recommended Phase 2 Dose, and assessing pharmacokinetics. It also registers ORR as a secondary outcome for Phase 1 dose-escalation and dose-expansion cohorts. These are study objectives; the existence of an objective does not establish that the objective was achieved.
The posted information includes cohort-level counts of participants affected by serious and other adverse events, deaths, and a list of serious-event terms with percentages. These entries show that adverse events and deaths were recorded in the study cohorts. They do not establish the cause of an event, quantify a treatment effect, or give a complete account of severity, duration, or follow-up. The reason the study was terminated is not reported in the registry record.
The study is non-randomized and single-group. It therefore does not provide a randomized comparison that can separate outcomes associated with VK-2019 from outcomes that might have occurred due to disease or other factors. The cohort descriptions also do not create a control comparison: the cohorts are part of dose escalation and potential expansion, and the registry does not establish that they are comparable.
Because the record lists no analysis entries, it does not provide inferential results for the primary safety outcome or the secondary ORR outcome. It also does not post uncertainty estimates or a complete statistical plan. The available information cannot establish efficacy, a benefit-harm balance, or the dose conclusion named in the study aims. Nor does absence of posted analyses mean that outcomes were absent; it means that the registry record does not report those analyses.
General statistical principle: interpretation depends not only on observed counts but also on outcome definitions, follow-up, analysis populations, missingness, and uncertainty. Those elements are not sufficiently to support conclusions beyond the study design and the descriptive entries. The most defensible reading is a limited account of an early-phase study's structure and recorded safety data, rather than a comparative treatment result.
13. Why This Trial Matters Statistically
Early-phase clinical studies raise statistical questions that differ from those in large randomized comparisons. In this study, the design combines dose escalation with possible dose expansion, and its registered primary outcome emphasizes adverse events and dose-limiting toxicities. That makes it important to distinguish the study's developmental aims from claims about comparative efficacy. The registry identifies dose determination and pharmacokinetic evaluation as aims, but does not report analyses that resolve those questions.
The cohort structure is also important for interpretation. Accelerated titration, Rolling Six, and expansion cohorts have different roles in the study description. Treating them as interchangeable groups could lead to misleading comparisons, especially when the record does not provide dose levels, participant characteristics, or analysis methods. The non-randomized, single-group design means that the reported counts are descriptive rather than a controlled estimate of treatment effect.
Safety reporting illustrates why denominators and definitions matter. The cohort entries give counts of participants at risk and affected, while serious-event terms are accompanied by percentages whose denominator is not explained in the record. Without the calculation basis, follow-up details, and event attribution, readers cannot translate those entries into a clear comparative risk estimate.
More broadly, the record demonstrates the distinction between a registered outcome and a reported analysis. Safety, ORR, pharmacokinetics, and dose selection appear among the study's aims or outcomes, but the registry lists no analysis entries. Statistical interpretation must therefore remain tied to what is actually documented. This is especially important in a study with small cohort counts, where a few observations can strongly shape descriptive patterns and uncertainty is not quantified in the posted information.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The registry record provides limited detail for interpreting the cohort-level safety entries. It does not report participant characteristics, dose levels, treatment exposure, event timing, follow-up completeness, severity grading, or the treatment attribution of individual events. It also does not explain the denominator for the serious-event percentages. These omissions prevent a full account of how often events occurred relative to exposure or how events varied across participants.
The study is non-randomized, open-label, and single-group, so the record does not support a randomized treatment comparison. Cohort membership is connected to dose-escalation or expansion roles, and the available descriptions do not establish comparability across cohorts. The registry does not state which expansion cohorts were opened or how dose decisions were made.
The study is listed as terminated, but the reason for termination is not reported in the registry record. The record does not report analysis populations, missing-data procedures, interim analyses, a statistical analysis plan, or a sample-size justification. It also does not provide analysis entries for the registered outcomes, including ORR and the primary safety endpoint. As a result, the posted information does not show whether all planned analyses were completed or how any incomplete outcome data were addressed.
The primary outcome names several dimensions of safety, including frequency, severity, duration, DLTs, discontinuations, and deaths. The cohort counts do not provide a complete result for all of those components. These limitations are specific to the information available in the registry record and should not be taken as evidence about analyses or study procedures that are not described there.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Phase 1/2a Study of VK-2019 in Patients With Epstein-Barr Virus (EBV)-Positive Nasopharyngeal Carcinoma (NPC) — NCT03682055.
- Registry record last updated 2023-08-15; status last verified 2023-07.
- Results first posted 2023-08-15.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT03682055 is a Phase 1/2a, open-label, multicenter, non-randomized, single-group study of VK-2019 in EBV-positive recurrent or metastatic NPC. The registry reports enrollment of 14, a start date of 2019-04-04, a primary completion date of 2020-06-23, and terminated status. Cullinan Therapeutics Inc. is listed as sponsor.
The study's primary outcome concerns AEs and DLTs, including events leading to discontinuation or death, with a stated timeframe of 24 months. ORR is listed as a secondary outcome for Phase 1 dose-escalation and dose-expansion cohorts. The posted cohort safety information includes serious-event and other-event counts, deaths, and serious-event terms with percentages.
The registry lists no analysis entries. It does not report a control-group comparison, a reason for termination, the basis for the serious-event percentages, or a complete statistical analysis plan. The record therefore supports a description of the study design and posted safety entries, but not a comparative efficacy conclusion or a complete assessment of the study's stated dose and pharmacokinetic aims.