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 A Study of DCC-2618 (Ripretinib) In Patients With With Advanced Gastrointestinal Stromal Tumors (GIST) (NCT04282980), a na phase 2 study. The primary outcome is Progression-Free Survival (PFS).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04282980 |
| Phase | Phase 2 |
| Condition | Gastrointestinal Stromal Tumors |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 39 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Zai Lab (Shanghai) Co., Ltd. |
| Results posted | Yes |
2. Clinical Question
Population
People with advanced gastrointestinal stromal tumors who had progressed on prior anticancer therapies. The registry record describes an efficacy analysis set of 38 participants who received continuous ripretinib treatment since C1D1; the study enrolled 39 participants overall.
Intervention
DCC-2618, also called ripretinib in the registry record. The listed regimen was 150mg once a day, using 50mg per tablet, with 28 days as a treatment cycle.
Comparator
There was no comparator arm. This was a single-group study with no masking and no randomized allocation. The registry record does not describe a concurrent control group.
Primary question
What was the progression-free survival, as assessed by independent radiologic review, among participants receiving ripretinib after prior anticancer therapies? The registry record does not report the primary endpoint estimate.
The study’s primary objective was to evaluate progression-free survival in people with advanced gastrointestinal stromal tumors whose disease had progressed during prior anticancer therapies. Progression-free survival was defined from the first dose of study drug to the first occurrence of disease progression based on independent radiology review or death due to any cause, whichever occurred first. This endpoint brings together two clinically important ways that a participant can experience an event during follow-up.
The registry lists objective response rate, overall survival, time to best response, and disease control rate for 12 weeks as secondary outcomes. These outcomes address different aspects of the observed clinical course: tumor response, survival, timing of best response, and disease status over a specified period. Their result estimates are not reported in the registry record.
Because the study had a single group, its primary question is descriptive: what progression-free survival was observed among participants treated in this study? It cannot, by design, provide a randomized comparison of ripretinib with another treatment. The registry record also does not report a primary endpoint value or its confidence interval, so the magnitude and precision of the observed progression-free survival cannot be described from the recorded information.
3. Trial Design
This was a multicenter, phase 2, single-arm, open-label study of DCC-2618 in people with advanced gastrointestinal stromal tumors who had progressed on prior anticancer therapies. The study is listed as completed, with an enrollment of 39 participants. The recorded start date is 2020-04-23 and the primary completion date is 2021-02-26. These are registry dates, not estimates of each participant’s treatment or follow-up duration.
All participants were assigned to the DCC-2618 group; the registry records no allocation and no masking. The listed regimen was 150mg once a day, with 50mg per tablet and 28 days as a treatment cycle. The registry describes the primary endpoint timeframe as approximately 10 months since the first subject enrolled. That timeframe should not be interpreted as the follow-up duration for every participant.
The efficacy analysis set consisted of 38 participants who had received continuous ripretinib treatment since C1D1. The registry states that one subject discontinued treatment due to clinical progression during the intensive blood sampling period. The enrollment count and the efficacy analysis count are therefore not the same; the record does not provide further detail about how all participants contributed to each outcome analysis.
A single-arm, open-label design can describe outcomes and adverse events observed among enrolled participants. It does not create a randomized, like-for-like contrast with another treatment group, and observed outcomes can reflect the characteristics of the participants, their prior therapies, subsequent care, and the study’s assessment procedures. A detailed protocol rationale for choosing this design is not reported in the registry record.
The registry lists five outcome measures in total: progression-free survival as the primary outcome and four secondary outcomes. It records zero analyses, but does not explain how this administrative entry relates to the analyses used to produce any posted results. No randomized treatment comparison, masking procedure, or comparator-group outcome is reported.
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: 50 patients were assessed for eligibility, 11 experienced screen failure.
Overall Study
| Stage | DCC-2618 |
|---|---|
| STARTED | 39 |
| COMPLETED | 20 |
| NOT COMPLETED | 19 |
Reasons for not completing this period:
| Reason | DCC-2618 |
|---|---|
| Remained on treatment | 6 |
| Survival follow-up | 11 |
| Withdrawal of informed consent | 1 |
| Lost to Follow-up | 1 |
Analysis population for the primary outcome, as defined in the registry: Efficacy analyses were performed using the efficacy analysis set (EAS), consisting of the 38 participants who had received continuous ripretinib treatment since C1D1. 1 subject discontinued treatment due to clinical progression during the intensive blood sampling period and a total of 38 subjects who entered treatment period (continuous dose period) were included in the Efficacy Analysis Set (EAS).
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 | DCC-2618 |
|---|---|---|
| Participants analysed | 39 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 32 |
| Age, Categorical: >=65 years | Participants | 7 |
| Age, Continuous | years | 55.1 (36.8 to 73.6) |
| Sex: Female, Male: Female | Participants | 12 |
| Sex: Female, Male: Male | Participants | 27 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 39 |
| 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 | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: China | participants | 39 |
| ECOG performance status: 0 | Participants | 7 |
| ECOG performance status: 1 | Participants | 28 |
| ECOG performance status: 2 | Participants | 4 |
6. Primary Endpoint
The registry lists the primary outcome as Progression-Free Survival (PFS), measured over Approximately 10 months since the first subject enrolled..
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | 90% Confidence Interval |
| Unit | months |
| Endpoint classification | Time-to-Event Analysis |
Progression-free survival is a time-to-event endpoint. In this study, the clock began at the first dose of study drug, and the event was the first occurrence of disease progression based on independent radiology review or death due to any cause, whichever occurred first. A participant who had neither recorded event by the end of observed follow-up would ordinarily contribute time up to the point at which their status was last known; the registry record does not describe its censoring rules.
The endpoint is used to summarize how long participants remain without documented progression or death under the study’s definition. Independent radiologic review is specified as the basis for identifying progression, which distinguishes the assessment source from an unreviewed clinical judgment. The record does not provide additional information about the review process, such as its procedures for resolving disagreements.
A median progression-free survival would mark the time by which half of the relevant population had experienced an event, under the analysis method used. A confidence interval would convey uncertainty around that estimate. Neither the median nor its 90% confidence interval is reported in the registry record. Consequently, the recorded endpoint definition explains what was intended to be measured, but the available entry does not establish the observed duration or the precision of an estimate.
Progression-free survival is not the same as overall survival: the primary endpoint includes progression as well as death, while overall survival is listed separately as a secondary outcome. The registry record does not report results for either endpoint.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry describes a completed, phase 2, single-arm study with 39 participants enrolled and an efficacy analysis set of 38 participants. It identifies progression-free survival as the primary endpoint and defines how progression or death counted as an event. However, the primary endpoint result itself is not reported in the registry record. In particular, no median progression-free survival or 90% confidence interval is stated. The available information therefore supports a description of the study question and analysis population, but not a numerical account of the observed primary outcome.
The study also lists objective response rate, overall survival, time to best response, and disease control rate for 12 weeks as secondary outcomes. Their estimates are not reported in the registry record. Without outcome estimates, there is no basis in this record to describe response frequency, survival duration, or disease control in the study group. The listed secondary endpoints should not be mistaken for findings.
The single-arm design is central to interpretation. Outcomes among participants receiving ripretinib can be described, but there is no concurrent comparator arm against which to estimate a treatment contrast. Differences between this group and people treated in another setting would not be randomized comparisons and could reflect differences in participant characteristics, prior therapy, follow-up, or assessment. The record does not report a comparative treatment effect.
The efficacy analysis set included 38 participants who received continuous ripretinib treatment since C1D1; the record says one subject discontinued because of clinical progression during intensive blood sampling. The relationship between that exclusion and the endpoint analysis is not fully detailed. A change in analysis population can matter for interpretation, especially when discontinuation is related to clinical status, but the record does not give enough information to quantify any effect.
For safety, the registry records 10 participants affected in the serious adverse-event category among 39 at risk, and lists serious-event terms with percentages. These entries describe recorded events in this study group; they do not by themselves establish that the study drug caused an event. The record also lists 20 deaths in its adverse-event summary but does not state their relationship to treatment in the information. No comparison group is available to place these counts in a randomized context.
In general, confidence intervals help show how much uncertainty surrounds an estimate, while a point estimate alone does not convey that uncertainty. Here, the primary endpoint estimate and interval are absent, so neither the magnitude nor the precision of progression-free survival can be evaluated from the registry entry. The absence of a reported result is not evidence of a particular outcome.
9. Statistical Methods Explained
General statistical context: A time-to-event analysis uses both the time until an event and information from participants who have not experienced the event by the end of their observed follow-up. Those participants are commonly censored: their follow-up contributes information up to the last time their event status is known, without treating them as if an event had occurred. The registry defines the progression-free survival event but does not report the censoring rules or details of follow-up completeness.
The primary endpoint is described as a median, with a 90% confidence interval. General statistical context: the median time-to-event estimate is the time at which the estimated event-free proportion reaches the midpoint of the population under the analysis method. It is a summary of the observed event-time distribution, not a guarantee about an individual participant’s course. A confidence interval expresses uncertainty in the estimate under the statistical model and analysis assumptions. The interval’s stated confidence level is 90%. The median and interval are not reported in the registry record, so their values, width, and interpretation cannot be assessed.
The event definition combines progression identified through independent radiologic review and death due to any cause. This means that either event can end progression-free follow-up, with the first one determining the recorded event time. The endpoint timeframe is described as approximately 10 months since the first subject enrolled. This is a study-level timeframe and does not establish equal follow-up for every participant. The record does not specify the analysis cut-off date or participant-level follow-up distribution.
General statistical context: independent review can provide an assessment distinct from the treating team’s routine evaluation, but the label alone does not describe how images were reviewed, how reviewers were kept unaware of clinical information, or how disagreements were resolved. Those operational details are not reported in the registry record. Open-label describes the study’s masking status, recorded as none; it does not, by itself, tell how much any assessment may have been influenced by knowledge of treatment.
The analysis population matters because the enrolled group and the efficacy analysis set differ. The record reports 39 enrolled participants and 38 in the efficacy analysis set, defined as those who received continuous ripretinib treatment since C1D1. It also notes one discontinuation due to clinical progression during intensive blood sampling. General statistical context: excluding participants from an efficacy analysis can change the population represented by the estimate, and excluding people for reasons associated with their clinical course can affect interpretation. The record does not specify the full analysis-population rules, missing-data methods, or whether other analysis sets were used.
General statistical context: a confidence interval is most informative when read together with its point estimate and the method used to calculate it. The interval reflects sampling uncertainty under the stated model; it does not account automatically for every possible source of bias, such as selection into a single-arm study or differences between participants and an external population. Since no endpoint estimate or interval is recorded, no statement about its precision or compatibility with particular values can be made.
What does the single-group design allow?
A single-group study can estimate outcomes in the participants who received the study intervention, subject to the analysis choices and available follow-up. Without a comparator arm, it cannot isolate a treatment contrast from other influences through random assignment. General statistical context: randomization is used in comparative trials to help balance prognostic factors across groups on average. That feature is absent from this study’s design. An external comparison would require suitable data and careful assumptions; no such comparison is reported in the registry record.
How should hazard ratios be understood?
General statistical context: a hazard ratio compares event rates over time between groups under a time-to-event model. It is a relative measure and is not the same as a difference in median survival or a direct measure of how much longer an individual lives without an event. The registry’s statistical description says only sponsor-reported hazard ratios are used for time-to-event comparisons, but this study is single-arm and the record does not report a hazard ratio for the primary endpoint. There is no basis to state or interpret one.
What can be concluded from the listed planning assumptions?
The registry describes a planning illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It also distinguishes time-to-event planning as total events and other planning as participants per arm. These are planning conventions, not observed study outcomes and not evidence of the study’s achieved power. They do not change the fact that the actual trial was a single-group study, and the record does not report a trial-specific sample-size justification.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists progression-free survival as the primary outcome and objective response rate, overall survival, time to best response, and disease control rate for 12 weeks as secondary outcomes. It records five outcome measures and zero analyses. These entries do not explain which outcomes were formally tested, whether any were considered confirmatory, or how the analyses were prioritized. The statistical plan for multiplicity is not reported in the registry record.
General statistical context: when several outcomes or repeated statistical tests are considered, the chance of obtaining at least one apparently notable result can increase if no adjustment or prespecified hierarchy is used. Multiplicity procedures can control that risk, but their appropriateness depends on the research question and analysis plan. No adjustment method, testing hierarchy, or interim analysis plan is reported in the registry record. It is therefore not possible to determine how any reported statistical tests, if available elsewhere, should be interpreted together.
The registry identifies an efficacy analysis set of 38 participants who received continuous ripretinib treatment since C1D1, from 39 participants enrolled. It notes one discontinuation due to clinical progression during intensive blood sampling. It does not describe the complete eligibility rules for the analysis set, analysis populations for secondary outcomes, missing-data handling, or the censoring approach for progression-free survival. These details are important because the analysis population and handling of incomplete observations can affect an estimate.
The record does not report the extent of missing outcome data, reasons for missingness beyond the stated discontinuation, imputation methods, sensitivity analyses, or whether follow-up continued after treatment discontinuation. Nor does it provide a detailed statistical analysis plan. These omissions limit assessment of the robustness of any endpoint findings, which themselves are not reported in the registry record.
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 |
|---|---|---|---|
| DCC-2618 | 10 | 39 | 25.6% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| DCC-2618 | 20 of 39 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| DCC-2618 | 39 of 39 |
Most frequent serious adverse event terms
| Event term | Organ system | DCC-2618 |
|---|---|---|
| Gastrointestinal haemorrhage | Gastrointestinal disorders | 3 of 39 |
| Anaemia | Blood and lymphatic system disorders | 2 of 39 |
| Pyrexia | General disorders | 1 of 39 |
| Cardiac dysfunction | Cardiac disorders | 1 of 39 |
| Acute kidney injury | Renal and urinary disorders | 1 of 39 |
| Abdominal pain upper | Gastrointestinal disorders | 1 of 39 |
| Acute myocardiac infarction | Cardiac disorders | 1 of 39 |
| Pneumonia | Infections and infestations | 1 of 39 |
| Inra-abdomina fluid collection | Gastrointestinal disorders | 1 of 39 |
| Aabdominal pain | Gastrointestinal disorders | 1 of 39 |
Most frequent non-serious adverse event terms
| Event term | Organ system | DCC-2618 |
|---|---|---|
| Anaemia | Blood and lymphatic system disorders | 26 of 39 |
| Alopecia | Skin and subcutaneous tissue disorders | 17 of 39 |
| Asthenia | General disorders | 13 of 39 |
| Bilirubin conjugated increased | Investigations | 13 of 39 |
| Blood bilirubin increased | Investigations | 13 of 39 |
| Weight decreased | Investigations | 10 of 39 |
| Abdominal distension | Gastrointestinal disorders | 9 of 39 |
| Hypokalaemia | Metabolism and nutrition disorders | 9 of 39 |
| Myalgia | Musculoskeletal and connective tissue disorders | 9 of 39 |
| Palmar-plantar erythrodysaesthesia syndrome | Skin and subcutaneous tissue disorders | 9 of 39 |
Serious events with the highest arm-level rate: gastrointestinal haemorrhage (7.7%), anaemia (5.1%), pyrexia (2.6%), cardiac dysfunction (2.6%), acute kidney injury (2.6%).
The registry’s adverse-event summary lists 39 participants at risk for serious adverse events and 10 affected. It lists gastrointestinal haemorrhage at 7.7%, anaemia at 5.1%, pyrexia at 2.6%, cardiac dysfunction at 2.6%, acute kidney injury at 2.6%, and abdominal pain upper at 2.6% among the top serious-event terms. These percentages are registry entries; the record does not provide further detail about event timing, severity grades, recurrence, or whether a participant could contribute more than one event term.
General statistical context: an adverse-event percentage may refer to participants with an event or to events, depending on the registry’s counting conventions. Without a fuller definition, the percentages should be read as recorded frequencies, not converted into event counts or treated as a complete account of all possible harms. Serious adverse events and other adverse events are different categories in the registry summary; the listed serious-event terms should not be taken to represent every adverse event observed.
The summary lists 20 deaths. The registry information does not state the relationship of these deaths to study treatment, nor does it provide a comparative group. Counts and event terms in a single-group study describe what was recorded during the study; they do not establish causation or quantify excess risk relative to another treatment.
12. What the Result Does, and Does Not, Mean
The available registry entry establishes that a completed phase 2, single-arm study evaluated DCC-2618, also called ripretinib, in people with advanced gastrointestinal stromal tumors after prior anticancer therapies. It records an enrollment of 39 participants and an efficacy analysis set of 38 participants who received continuous treatment since C1D1. It defines progression-free survival as the time from first dose to progression based on independent radiology review or death due to any cause, whichever occurred first.
What the record does not establish is the observed value of the primary endpoint. The median progression-free survival and 90% confidence interval are not reported in the registry record. Results for the listed secondary outcomes are also not reported. The definitions and planned outcomes identify what the study set out to measure, but they are not substitutes for outcome estimates. In the absence of those results, the registry entry cannot support a numerical characterization of progression-free survival, response, overall survival, time to best response, or disease control.
The design also sets a limit on what a study estimate could mean. With no comparator arm and no random allocation, an outcome observed in the study group would describe that group’s experience, not a randomized estimate of the effect of ripretinib relative to another treatment. Differences from another population or study could arise for reasons other than treatment. The record contains no comparative treatment effect.
The safety summary records serious adverse events and deaths, but does not establish that the study drug caused them. The record does not give a randomized control group or the treatment-attribution details needed to make a causal comparison. General statistical context: observed counts can help describe events in a study population, while causal claims require a design and analysis capable of separating treatment effects from other influences.
These limits should not be mistaken for evidence that the intervention was effective or ineffective. The primary and secondary outcome estimates are simply not reported in the registry record. Conclusions about the magnitude, precision, comparative effect, and robustness of the clinical outcomes would require results and analysis details not present in the record.
13. Why This Trial Matters Statistically
This study is statistically informative as an example of how a precisely defined endpoint and an analysis population do not, on their own, communicate an outcome. The registry gives a progression-free survival definition, identifies independent radiologic review, specifies a 90% confidence interval as the dispersion measure, and describes an efficacy analysis set of 38 participants. Yet the endpoint estimate and interval are not reported in the registry record. Readers can identify the intended estimand, but cannot assess its magnitude or precision from this entry.
The enrollment of 39 and efficacy analysis set of 38 also make population definitions salient. The registry notes that one subject discontinued because of clinical progression during intensive blood sampling. That detail illustrates why accounting for participants and explaining analysis-set membership matters: a participant’s clinical course may be related to both treatment continuation and endpoint assessment. The record does not provide enough detail to evaluate how the analysis handled that circumstance.
The single-arm design highlights the distinction between describing outcomes and estimating comparative effects. An observed progression-free survival distribution in a treatment group could summarize that group’s follow-up, but it would not provide a randomized comparison with another treatment. This is important when interpreting a phase 2 study, because the endpoint and its statistical precision answer a different question from a controlled treatment contrast.
Finally, the entry lists several secondary outcomes and serious adverse-event terms, but outcome results, analysis procedures, and multiplicity handling are not reported. A complete statistical interpretation depends not only on which outcomes were selected, but also on the prespecified analysis methods, handling of missing data, and reporting of estimates with uncertainty. The registry record leaves those parts unresolved.
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 main trial-specific limitation for statistical interpretation is that the registry record does not report the primary progression-free survival estimate or its 90% confidence interval. It also does not report results for the secondary outcomes. Thus, despite the endpoint definitions and study status being recorded, the entry does not permit assessment of observed efficacy estimates or their precision.
The single-arm, open-label design includes no randomized comparator. Observed outcomes cannot be interpreted as a randomized contrast, and the record does not provide an external control analysis. The registry also does not report detailed procedures for independent radiologic review, including how disagreements were handled, or provide censoring rules and follow-up completeness.
The difference between 39 enrolled participants and 38 in the efficacy analysis set is explained only in part: one subject discontinued due to clinical progression during intensive blood sampling, and the efficacy set is described as participants receiving continuous ripretinib since C1D1. The full analysis-set criteria, missing-data methods, and sensitivity analyses are not reported in the registry record.
The registry lists five outcome measures but does not describe a multiplicity plan, testing hierarchy, interim analyses, or detailed statistical analysis plan. A trial-specific sample-size justification is also not reported. The listed planning illustration uses a two-arm equal-allocation framework, whereas the study itself is single-group; it should not be read as a description of the trial’s allocation or as observed power.
For safety, the registry gives event categories, affected participants, selected event percentages, and a death count, but does not provide attribution details or a comparator group. These limitations leave both the clinical outcome estimates and some aspects of their analysis and safety context unresolved.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study of DCC-2618 (Ripretinib) In Patients With With Advanced Gastrointestinal Stromal Tumors (GIST) — NCT04282980.
- Registry record last updated 2025-03-03; status last verified 2024-12.
- Results first posted 2025-03-03.
- 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 record describes a completed, multicenter, phase 2, single-arm, open-label study of DCC-2618, also called ripretinib, in people with advanced gastrointestinal stromal tumors who had progressed on prior anticancer therapies. It lists 39 enrolled participants and a regimen of 150mg once a day, with 50mg per tablet and 28 days as a treatment cycle.
Progression-free survival was the primary endpoint, defined from first dose to progression based on independent radiologic review or death due to any cause, whichever occurred first. The efficacy analysis set included 38 participants who received continuous treatment since C1D1. The median primary endpoint result and its 90% confidence interval are not reported in the registry record. Results for the listed secondary outcomes are also not reported.
The registry lists 10 participants affected by serious adverse events among 39 at risk, selected serious-event terms, and 20 deaths. It does not provide a randomized comparator or, in the recorded information, establish treatment attribution for these events.