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 Comparing the Efficacy and Safety Between IBI308 and Docetaxel in Patients With Advanced or Metastatic NSCLC (NCT03150875), a randomized phase 3 study. The primary outcome is Overall Survival.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03150875 |
| Phase | Phase 3 |
| Condition | Non-small Cell Lung Cancer |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 290 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Innovent Biologics (Suzhou) Co. Ltd. |
| Results posted | Yes |
2. Clinical Question
Population
Participants had advanced or metastatic squamous cell lung cancer after failure of first-line platinum-based therapy. The primary endpoint population was all randomized participants, with an exclusion for docetaxel-arm participants who initiated immunotherapy before receiving docetaxel or before disease progression. The registry record does not describe further eligibility criteria in the information summarized for these results.
Intervention
The intervention was IBI308, identified in the arm results as sintilimab. It was given by injection at 200 mg every 3 weeks. The listed treatment duration ran from randomization to the first documented tumor progression per RECIST v1.1 criteria.
Comparator
The comparator was docetaxel, given by injection at 75 mg/m2 every 3 weeks. Its listed duration also ran from randomization to the first documented tumor progression per RECIST v1.1 criteria. Participants were randomized, and the trial was open-label.
Primary question
The primary question was how overall survival, defined as time from randomization to death due to any cause, compared between the treatment groups. The reported medians were 11.79 months for sintilimab and 8.25 months for docetaxel; the corresponding 95% confidence intervals were 10.28 to 15.27 months and 6.47 to 9.82 months. These are descriptive estimates; the registry record does not report a hazard ratio or a formal comparison for this endpoint.
3. Trial Design
This was a randomized, open-label, multicenter, parallel phase 3 study, identified as ORIENT-3. It compared IBI308, reported in the outcome arms as sintilimab, with docetaxel in patients with advanced or metastatic squamous cell lung cancer after failure of first-line platinum-based therapy. The registry record lists an enrollment of 290. It does not report the allocation ratio or details of the randomization procedure.
The treatment schedules differed: sintilimab was listed as 200 mg every 3 weeks, while docetaxel was listed as 75 mg/m2 every 3 weeks. For both arms, the described treatment duration ended at the first documented tumor progression per RECIST v1.1 criteria. The trial was open-label, so participants and trial personnel were not masked to assigned treatment. The registry record does not report whether outcome assessment was independently blinded.
The posted primary endpoint results give arm sizes of 145 for sintilimab and 135 for docetaxel. The primary analysis population excluded docetaxel-arm participants who initiated immunotherapy before receiving docetaxel or disease progression. The record does not state the number excluded under this rule or provide further detail about how exclusions were handled in the analysis. The survival results use follow-up through the database cutoff date of 31-July-2020, up to approximately 35 months. The registry lists the study as completed, with a start date of 2017-09-01 and primary completion date of 2023-02-22; these dates do not alter the stated cutoff for the reported primary outcome.
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 | Sintilimab | Docetaxel |
|---|---|---|
| STARTED | 145 | 145 |
| Treated | 144 | 130 |
| Crossover to Certain Treatment | 0 | 0 |
| COMPLETED | 0 | 0 |
| NOT COMPLETED | 145 | 145 |
Analysis population for the primary outcome, as defined in the registry: All randomized participants excluding participants in the docetaxel arm who initiated immunotherapy before receiving docetaxel or disease progression.
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 | Sintilimab | Docetaxel | Total |
|---|---|---|---|---|
| Participants analysed | 145 | 135 | 280 | |
| Age, Continuous | Years | 60.6 (SD 8.19) | 59.5 (SD 8.41) | 60.1 (SD 8.30) |
| Sex: Female, Male: Female | Participants | 9 | 13 | 22 |
| Sex: Female, Male: Male | Participants | 136 | 122 | 258 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 145 | 135 | 280 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 145 | 135 | 280 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: China | participants | 145 | 135 | 280 |
6. Primary Endpoint
The registry lists the primary outcome as Overall Survival, measured over Through database cutoff date of 31-July-2020 (up to approximately 35 months).
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | 95% Confidence Interval |
| Unit | Months |
| Endpoint classification | Time-to-Event Analysis |
Overall survival measures the time from randomization until death from any cause. It is commonly used in cancer trials because it is a direct, clinically interpretable time-to-event outcome and does not depend on a judgment about whether a tumor has progressed. Counting death due to any cause also avoids needing to classify the cause of each death for this endpoint.
The reported summary is the median: the time by which half of the analyzed participants are estimated to have experienced the event, while the other half have not yet experienced it or have been censored. It is not the average survival time, nor does it describe every participant’s individual course. The reported 95% confidence interval conveys uncertainty around each arm’s median estimate. The intervals are not themselves a test of the difference between arms.
The primary endpoint was assessed through the database cutoff date of 31-July-2020, up to approximately 35 months. Its analysis population was all randomized participants except docetaxel-arm participants who initiated immunotherapy before receiving docetaxel or disease progression. The registry record does not report how censoring was implemented, how incomplete follow-up was handled, or a formal between-arm estimate such as a hazard ratio. Therefore, the arm-specific medians can be described, but the registry results do not provide a complete inferential comparison of survival.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted median overall survival was 11.79 months in the sintilimab arm, with a 95% confidence interval from 10.28 to 15.27 months. In the docetaxel arm, the median was 8.25 months, with a 95% confidence interval from 6.47 to 9.82 months. These estimates describe the time-to-death distributions in the stated analysis population through the registry’s database cutoff date. They do not mean that every participant survived for the median duration, and they do not estimate an individual’s expected survival.
The confidence intervals indicate uncertainty in the arm-specific median estimates. They should not be treated as a confidence interval for the difference between treatment groups. The registry record does not report a hazard ratio, a confidence interval for a between-arm survival effect, or a p-value for the primary endpoint. It therefore does not give the information needed to characterize the size and precision of a formal comparative survival estimate from the sponsor’s analysis.
The registry’s brief summary describes overall survival as approximately 9 months compared with 6 months in the docetaxel group. The posted arm results give medians of 11.79 and 8.25 months, respectively. The brief summary’s approximate figures and the detailed posted medians are not identical. The record does not explain the source or calculation behind the approximate summary, so the posted median estimates are the more specific figures to describe, while recognizing that both appear in the registry record.
There is a separate posted comparison for overall response rate. The reported proportions were 25.5% for sintilimab and 2.2% for docetaxel, with 95% confidence intervals of 18.6% to 33.4% and 0.5% to 6.4%, respectively. The registry reports an unadjusted p < 0.001 for the comparison. This is a secondary outcome, and its result does not substitute for the missing formal survival comparison. Secondary results also require caution because the registry record does not report a multiplicity adjustment or a prespecified hierarchy for interpreting multiple outcomes.
Randomization supports a comparative trial design, but an open-label design can affect care and assessments beyond the assigned treatment. The primary endpoint is death from any cause, which is less dependent on subjective assessment than response outcomes, but interpretation still depends on the analysis population, follow-up, censoring, and analysis methods. Details on those methods are not reported in the registry record. The results describe the trial’s posted estimates; they do not establish that the same estimates would apply to populations or treatment settings not described in the record.
9. Statistical Methods Explained
The primary outcome is a time-to-event measure. Each participant’s survival time begins at randomization and ends at death due to any cause, or is censored if the event is not observed during the available follow-up. In general, censoring allows participants with incomplete event follow-up to contribute information until their last known observation. The registry record does not report the exact censoring rules or the analysis model used for the primary result.
What does a median survival estimate describe?
A median is the point in the estimated survival distribution at which the probability of remaining alive has reached one half. It gives a central summary of the distribution without requiring an average survival time to be estimable. The median does not describe the full shape of the survival curves: distributions can have the same median but differ before or after that point. Nor does a median alone quantify the relative event rate between arms.
The registry reports a median and a 95% confidence interval for each arm. In general, a confidence interval describes the uncertainty associated with an estimated quantity under the analysis method. It is not a range containing the individual survival times, and the separate arm intervals are not a direct interval for an arm-to-arm contrast. No primary-endpoint hazard ratio or formal comparison is reported in the registry record, so a comparative survival effect and its precision cannot be recovered from the medians alone.
How should the response comparison be read?
Overall response rate is a binary outcome: each participant is classified according to whether a response was recorded under the stated assessment criteria. The registry lists response according to RECIST v1.1 as assessed by investigators. The reported percentages are 25.5% for sintilimab and 2.2% for docetaxel, each with an arm-specific 95% confidence interval. These intervals describe uncertainty in each proportion, not the difference between proportions.
The registry also reports an unadjusted p < 0.001 for the response comparison. In general, a p-value describes how compatible the observed data are with a specified null hypothesis under the test’s assumptions; it is not the probability that the null hypothesis is true, nor a measure of clinical importance. The word “unadjusted” matters because the record does not report an adjustment for testing multiple outcomes. The registry comparison is in the direction of docetaxel relative to sintilimab, but the posted percentages make the arm-specific response pattern easier to interpret directly.
What do the planning illustrations mean?
The registry includes planning illustrations based on fractions of the observed response effect. They give participants per arm for 80% power and for 90% power: for planning at 100% of the observed effect, the figures are 34 and 45; at 75%, they are 71 and 95; and at 50%, they are 182 and 243. These are hypothetical planning calculations, not observed trial results and not the trial’s original sample-size justification. The record states that the illustration uses a two-sided significance level of 0.05, equal allocation, and a normal approximation. It also states that the effect to detect is the stated fraction of the observed effect.
In general, a planning calculation asks how much information a future study might need to detect an assumed effect under selected statistical assumptions. Smaller assumed effects generally require more participants to achieve a chosen power, all else equal. These illustrations do not show the probability that the completed trial detected an effect, and they should not be described as observed power. The registry record does not report the original sample-size assumptions or justification for this trial.
Why can outcome methods affect interpretation?
Response and progression outcomes depend on tumor assessment and the criteria used to classify it. The record identifies RECIST v1.1 and investigator assessment for the listed response and progression-free survival outcomes. It also names duration of response and treatment-emergent adverse events. General statistical interpretation depends on the precise endpoint definition, timing, handling of missing assessments, and analysis population. Further details on those matters are not reported in the registry record.
Over-dispersion is a general issue when the variability in count data exceeds what a simple model assumes; it can make standard errors too small if not handled appropriately. It is not a stated feature of the primary endpoint results here, and the registry record does not report a model for count outcomes. No such modeling assumption should be inferred from the posted summaries.
10. Multiplicity, Missing Data and Analysis Populations
Multiplicity arises when a study evaluates more than one outcome or performs several statistical tests. If each test is interpreted without a plan for the overall testing process, the chance of at least one seemingly positive result can increase. Trials may address this through prespecified hierarchies, adjusted significance thresholds, or other procedures. The registry record does not report a multiplicity strategy, a testing hierarchy, or whether such procedures were used for secondary outcomes.
The posted response comparison is labeled unadjusted and has p < 0.001. That result should be read as an unadjusted comparison, not as evidence that the full family of outcome tests was controlled at a stated error rate. The record names secondary endpoints but does not report a full set of numerical estimates for all of them. It also does not report interim analyses or whether any interim testing rules were used.
Missing-data handling is important for both time-to-event and assessment-based outcomes. For survival, censoring and loss to follow-up affect how the survival distribution is estimated. For tumor response, missing or unevaluable assessments can affect the denominator and classification rules. The registry record does not report detailed missing-data methods, the amount of missing outcome information, or sensitivity analyses addressing missingness. It is therefore not possible to assess from this record whether missing data could have influenced the estimates.
The primary analysis population is defined as all randomized participants except docetaxel-arm participants who initiated immunotherapy before receiving docetaxel or disease progression. This is a specific exclusion stated for the primary endpoint. The record does not report the number of participants affected, the reasons for the treatment change, or additional analyses using a different population definition. The number and handling of participants excluded from secondary analyses are also not reported in the registry record.
The registry record gives arm sizes for the posted primary survival estimates and response results, but does not provide a full accounting of analyzed and excluded participants for every outcome. It also does not report whether covariate adjustment was used. These omissions limit assessment of the analysis population, outcome completeness, and the strength of inferential claims beyond the descriptive arm-specific estimates.
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 |
|---|---|---|---|
| Sintilimab | 56 | 144 | 38.9% |
| Docetaxel | 34 | 130 | 26.2% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Sintilimab | 108 of 144 |
| Docetaxel | 101 of 130 |
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 |
|---|---|
| Sintilimab | 132 of 144 |
| Docetaxel | 117 of 130 |
Most frequent serious adverse event terms
| Event term | Organ system | Sintilimab | Docetaxel |
|---|---|---|---|
| Pneumonia | Infections and infestations | 12 of 144 | 14 of 130 |
| Pyrexia | General disorders | 5 of 144 | 3 of 130 |
| Haemoptysis | Respiratory, thoracic and mediastinal disorders | 4 of 144 | 2 of 130 |
| White blood cell count decreased | Investigations | 0 of 144 | 5 of 130 |
| Asthenia | General disorders | 2 of 144 | 2 of 130 |
| Upper respiratory tract infection | Infections and infestations | 2 of 144 | 2 of 130 |
| Neutrophil count decreased | Investigations | 0 of 144 | 4 of 130 |
| Interstitial lung disease | Respiratory, thoracic and mediastinal disorders | 4 of 144 | 0 of 130 |
| Anal abscess | Infections and infestations | 1 of 144 | 2 of 130 |
| Dyspnoea | Respiratory, thoracic and mediastinal disorders | 1 of 144 | 2 of 130 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Sintilimab | Docetaxel |
|---|---|---|---|
| Anaemia | Blood and lymphatic system disorders | 48 of 144 | 43 of 130 |
| Asthenia | General disorders | 25 of 144 | 33 of 130 |
| Decreased appetite | Metabolism and nutrition disorders | 34 of 144 | 23 of 130 |
| Pyrexia | General disorders | 31 of 144 | 21 of 130 |
| Cough | Respiratory, thoracic and mediastinal disorders | 29 of 144 | 19 of 130 |
| Neutrophil count decreased | Investigations | 7 of 144 | 38 of 130 |
| White blood cell count decreased | Investigations | 6 of 144 | 39 of 130 |
| Alopecia | Skin and subcutaneous tissue disorders | 0 of 144 | 45 of 130 |
| Weight decreased | Investigations | 29 of 144 | 14 of 130 |
| Constipation | Gastrointestinal disorders | 23 of 144 | 14 of 130 |
Serious events with the highest arm-level rate: pneumonia (10.8%), white blood cell count decreased (3.8%), pyrexia (3.5%), neutrophil count decreased (3.1%), haemoptysis (2.8%).
The registry reports serious adverse events for 56 of 144 participants at risk in the sintilimab group and 34 of 130 participants at risk in the docetaxel group. Other adverse events are reported for 132 of 144 participants and 117 of 130 participants, respectively. These are counts and denominators from the posted safety groups; they should not be converted into comparative risk claims without considering the outcome definitions, follow-up, and analysis methods.
The listed serious adverse event terms include pneumonia (10.8%), white blood cell count decreased (3.8%), pyrexia (3.5%), neutrophil count decreased (3.1%), haemoptysis (2.8%), and interstitial lung disease (2.8%). The registry record does not provide further detail in these results about event duration, severity grading, recurrence, or the rules used to identify and group events. The listed percentages should not be interpreted as mutually exclusive categories or added together.
The safety information also lists deaths: 108 in the sintilimab group and 101 in the docetaxel group. The primary endpoint defines overall survival as time to death from any cause, but the safety listing does not establish that these deaths were treatment-related. The record does not report a causal attribution for these counts. Descriptive safety counts alone do not establish a comparative safety effect.
12. What the Result Does, and Does Not, Mean
The registry’s primary endpoint estimates describe median overall survival of 11.79 months for sintilimab and 8.25 months for docetaxel in the stated analysis population, with arm-specific 95% confidence intervals. The results provide a descriptive comparison through the database cutoff date of 31-July-2020, up to approximately 35 months. They do not provide a reported hazard ratio or formal between-arm survival test, so the registry record does not quantify the comparative survival effect using those measures.
The posted response results offer an additional secondary outcome, but response is not interchangeable with survival. Its unadjusted comparison must be interpreted in light of the absence of a reported multiplicity procedure. The registry also names other secondary outcomes without providing full comparative numerical details in the record summarized for these results. Safety counts similarly describe events in the listed groups but do not by themselves determine whether one treatment has a different overall safety profile.
Random assignment is a strength for comparing the groups, but the open-label design and the specific exclusion from the primary analysis population matter when interpreting results. The registry record does not report key analytical details, including a primary survival model, censoring rules, missing-data procedures, or a formal comparison estimate. The record also does not supply a basis for extending the estimates to patients or care settings beyond the study population described.
These findings should be read as registry-posted estimates, not as individualized predictions or treatment guidance. They do not establish what outcome a particular person would experience, and the numerical summaries do not capture all relevant clinical considerations. The statistical record supports describing the arm-specific outcomes and their stated uncertainty, while leaving several questions about comparative inference and analysis methods unresolved.
13. Why This Trial Matters Statistically
This trial is statistically notable because it uses a randomized parallel-group design to compare two treatments and reports a time-to-event primary outcome. Overall survival has a clear event definition—death due to any cause—and the registry gives medians with confidence intervals for both arms. Those features allow readers to understand the observed survival summaries and their arm-specific uncertainty without relying only on a brief narrative summary.
The example also shows why endpoint summaries and formal comparative estimates are not interchangeable. Separate medians describe each group, but a hazard ratio or other prespecified contrast would be needed to summarize the between-group survival relationship directly. The registry record does not report that formal survival comparison. This is an important interpretive gap, even when the arm-specific medians are available.
The trial also illustrates the importance of reading secondary findings within the wider testing context. The response comparison is reported with an unadjusted p-value, while the registry record does not state how multiple outcomes were handled. Without that context, a nominally small p-value should not be treated as a complete account of confirmatory evidence. The named but incompletely reported secondary outcomes further limit assessment of consistency across outcomes.
Finally, the record distinguishes observed trial results from planning calculations: the response-based sample-size illustrations are hypothetical and are not the original design rationale or evidence of observed power. Keeping those concepts separate helps avoid a common statistical misinterpretation. Overall, the record offers useful descriptive outcome information while illustrating the value of complete reporting of analysis methods, comparison estimates, missing-data handling, and multiplicity procedures.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The primary survival result is presented as arm-specific medians and confidence intervals, without a reported hazard ratio, confidence interval for the comparative effect, or p-value. The registry record therefore does not provide a direct formal estimate of the between-arm survival contrast. The median alone also cannot describe the full survival pattern over follow-up.
The summary gives an approximate survival description that differs from the detailed posted medians. The record does not explain how the approximate figures were derived. The database cutoff date is specified, but the registry does not report detailed follow-up distributions, censoring rules, or the number of participants at risk over time. These omissions make it harder to assess how the survival estimates were built and how much information remained at later follow-up.
The primary endpoint population excludes a specified group in the docetaxel arm, but the record does not state how many participants met that exclusion or provide further analysis-population detail. It does not report missing-data procedures, sensitivity analyses, covariate adjustment, or the original sample-size justification. These details matter for evaluating robustness and the applicability of the analysis.
The open-label design is relevant particularly to investigator-assessed outcomes. The record does not say whether outcome assessors were blinded or provide details about independent review. The response comparison is unadjusted, and multiplicity methods are not reported. Numerical results for several named secondary outcomes are not reported in the registry record, limiting assessment of the full pattern across outcomes.
Safety results are descriptive and do not include detailed event definitions, severity distributions, exposure-adjusted rates, or attribution information for the deaths listed in the safety data. The registry information therefore supports a cautious account of the posted estimates, but not broader claims that require these additional methods and details.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study Comparing the Efficacy and Safety Between IBI308 and Docetaxel in Patients With Advanced or Metastatic NSCLC — NCT03150875.
- Registry record last updated 2023-02-28; status last verified 2023-02.
- Results first posted 2021-06-23.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry describes a randomized, open-label, multicenter, parallel phase 3 study of IBI308, reported in the results as sintilimab, versus docetaxel for advanced or metastatic squamous cell lung cancer after failure of first-line platinum-based therapy. The listed enrollment is 290. The study is marked completed.
The primary outcome was overall survival, defined as time from randomization to death due to any cause. Through the database cutoff date of 31-July-2020, the reported median was 11.79 months for sintilimab and 8.25 months for docetaxel. The registry record does not report a formal between-arm survival estimate.
Secondary outcomes named in the record include investigator-assessed progression-free survival, response rate, duration of response, and treatment-emergent adverse events. A numerical response comparison is posted; complete comparative results for the other named outcomes are not reported in the registry record. Safety counts and selected serious adverse event terms are also listed. Important details about multiplicity, missing data, and several analysis methods are not reported.