Durvalumab and Stereotactic Radiotherapy for Advanced NSCLC: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Durvalumab and Stereotactic Radiotherapy for Advanced NSCLC (NCT04786093), a randomized phase 2 study. The primary outcome is Quality of Life Scores.

2. Clinical Question

3. Trial Design

This was a randomized Phase II study with a parallel-group design and no masking. It was intended to compare two radiation schedules, each combined with durvalumab, in people with advanced non-small cell lung cancer. The SAbR arm delivered each radiation fraction every other day, while the PULSAR arm delivered each fraction every four weeks. These are the treatment schedules described in the registry; the record does not give further details about treatment dose, duration, or the process used to individualize the PULSAR schedule.

The registry lists enrollment as one subject. That subject enrolled on the PULSAR arm, terminated treatment early, and did not provide the data needed to evaluate the primary quality-of-life measure. The study status is terminated. The reason for termination and the timing or circumstances of the early treatment discontinuation are not reported in the registry record. The stated study start and primary completion dates are recorded, but the registry does not provide an account of how the study reached termination.

The primary outcome was quality-of-life scores at 2 years post-treatment using the EORTC-QLQ30 questionnaire. The record also lists secondary outcomes covering local control, out-of-field control, progression-free survival, overall survival, overall response rate, and instances of toxicity. The registry lists seven outcome measures, but the record does not provide a usable primary endpoint result or an analysis comparing the two arms.

The study summary describes planned follow-up for up to 2 years after treatment completion or until death, whichever occurred first, with assessments at 1, 3, 6, 9, 12, 15, 18, 21, and 24 months following treatment. Subjects removed from therapy for unacceptable adverse events were to be followed until the event resolved or stabilized. These are descriptions of the intended follow-up approach, not evidence that those assessments occurred for the enrolled subject. The registry record does not report a statistical analysis plan, a sample-size justification, or the allocation procedure.

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

Analysis population for the primary outcome, as defined in the registry: 1 subject was enrolled on the PULSAR arm but terminated treatment early and data was not collected necessary to evaluate this measure.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: 1 subject is enrolled on the PULSAR arm but terminated treatment early. No patients were enrolled on the SAbR while the study awaited sponsor modification until closure.

6. Primary Endpoint

The registry lists the primary outcome as Quality of Life Scores, measured over 2 years post-treatment.

The primary endpoint was quality-of-life score, described as a mean score on a scale, with full-range dispersion, assessed 2 years post-treatment. The registry identifies the EORTC-QLQ30 questionnaire as the instrument. Its stated score range is 0-100, and higher scores indicate better results according to the record. Quality-of-life measures are used to capture a patient-reported aspect of health and functioning that may not be represented by tumor-control or survival outcomes. That is a general rationale for measuring quality of life; the registry does not describe which questionnaire domains were prioritized or how a clinically meaningful change was defined.

The endpoint was intended to assess quality of life in the setting of durvalumab plus stereotactic radiotherapy delivered on either the SAbR or PULSAR schedule. The planned timeframe was 2 years post-treatment. However, the one subject enrolled on the PULSAR arm terminated treatment early, and the necessary data were not collected to evaluate this measure. Consequently, the registry does not report a mean score, a range of observed scores, or a comparison between the treatment schedules for the primary endpoint. The endpoint’s definition and intended use can be described, but its observed values and precision cannot.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The design is described as randomized, parallel-group, and unmasked. In general, random allocation is intended to make treatment groups comparable at the outset, while a parallel-group trial assigns participants to one treatment strategy for follow-up. Masking refers to whether participants or study personnel are kept unaware of assigned treatment. In an unmasked study, treatment assignment is known. These design labels describe intended methods; they do not guarantee balance or remove every possible source of bias. With enrollment of one subject, the registry does not provide an informative comparison between the two schedules.

What would a mean score represent?

The primary outcome is specified as a mean score on the EORTC-QLQ30 at 2 years post-treatment. In general, a mean is a measure of the average observed score in a group. The registry gives a score range of 0-100 and says higher scores indicate better results. A group mean would be more interpretable alongside information about the spread of individual scores, which is why dispersion matters: individuals can have different experiences even when their group average is similar. Here, however, the required data were not collected for the enrolled subject, and no mean or full-range summary is reported.

A confidence interval is a statistical way to express uncertainty around an estimated quantity. In general, a narrow interval indicates greater precision than a wide interval, under the assumptions of the analysis. An interval cannot be interpreted without an estimate and an analysis appropriate to the data. The registry record does not report a primary endpoint estimate or confidence interval, so the precision of a treatment-schedule comparison cannot be assessed.

How should the randomization be interpreted?

Randomization is valuable because it can reduce systematic differences between groups in expectation. It does not ensure that observed groups are balanced, particularly when enrollment is very limited. Nor does the word randomized establish that allocation was concealed or that the sequence was generated in a particular way. The sequence-generation and concealment methods are not reported in the registry record. The two arms use different radiation schedules, and the study is unmasked, so the record also does not describe protections against performance or assessment bias.

The study’s parallel design means the stated comparison is between separate arms, rather than a within-person crossover. A treatment effect for such a comparison would ordinarily require outcome data from both arms and a defined comparison method. The record does not report such an analysis for quality of life. The design classification alone cannot supply the missing outcome information.

What do the planning illustrations mean?

The registry’s planning assumptions describe illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The stated effect to detect is a fraction of the observed effect. These assumptions describe planning calculations, not an analysis of the enrolled subject’s outcome and not the trial’s own documented design justification. The record does not report a sample-size justification, and the planning illustrations should not be read as evidence that the study had adequate power or as observed power. A planning estimate is conditional on the assumptions and effect used; it does not remedy the absence of primary endpoint data.

For general context, statistical power is the probability that a specified analysis would detect an effect of a specified size under the assumptions of a design. It is not a measure of whether a treatment works, and a post hoc calculation using an observed effect does not establish the strength of evidence. The record says the sample-size illustrations use the observed effect and specified planning assumptions. No numerical illustration values are needed to interpret the central limitation: there is no reported primary quality-of-life estimate to support an arm comparison.

Why does over-dispersion matter in general?

For count outcomes, a statistical model may assume that variability follows a particular relationship to the average count. Over-dispersion means that the observed variability is greater than that assumption allows. If it is ignored, standard errors can be too small and confidence intervals too narrow, making evidence appear more precise than it is. This is general statistical context for count analyses. The registry record does not report a count model, an over-dispersion assessment, or an analysis method for the secondary outcomes; no conclusion about the methods used in this trial should be drawn from this general explanation.

Time-to-event outcomes such as progression-free survival and overall survival generally require definitions of the event, censoring, and the analysis population. Censoring occurs when the event time is not observed during the available follow-up, and appropriate methods account for that partial information. The registry lists these outcomes but does not report event definitions, follow-up results, or analysis methods. The record also does not report a statistical plan specifying covariate adjustment, interim monitoring, or methods for dealing with missing data.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary quality-of-life outcome and secondary outcomes covering local control, out-of-field control, progression-free survival, overall survival, overall response rate, and instances of toxicity. When a study examines multiple outcomes, time points, or subgroup comparisons, multiplicity can increase the chance of at least one apparently notable result occurring by chance. Statistical plans can address this through a prespecified hierarchy or other adjustment. The registry record does not report a multiplicity strategy, and the primary outcome description does not specify a comparison across multiple questionnaire domains.

The record lists zero analyses. It does not provide an analysis plan, an outcome analysis population, or a method for handling missing measurements. The primary quality-of-life data were not collected as necessary to evaluate the measure for the one subject enrolled on PULSAR. The reason those data were unavailable and any further details on missingness are not reported in the registry record. Missing outcome data can prevent an estimate or make an estimate dependent on assumptions about why data are absent; no such assumptions or methods are documented.

The registry’s planned follow-up visits and provisions for following subjects after unacceptable adverse events describe intended procedures, not a reported account of completed assessments. The record does not state whether any secondary endpoint data were collected or how incomplete follow-up would be handled for survival or tumor-control outcomes. It also does not define an intention-to-treat, per-protocol, or safety population. Therefore, the posted results do not support conclusions about which participants were included in particular analyses or how missing observations might affect them.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: lung infection (100.0%), tumor pain (100.0%).

The safety entries should be interpreted with attention to the registry’s at-risk and affected counts. For the SAbR plus durvalumab arm, the record lists zero at risk for serious adverse events, other adverse events, and deaths, with zero affected in the corresponding fields. Because the at-risk count is zero, these entries do not show that a group of treated participants had no events; they do not provide a denominator for assessing event frequency in that arm.

For the PULSAR plus durvalumab arm, the record lists one at risk and one affected for serious adverse events, and one at risk and one affected for other adverse events. It also lists one death. The record does not give a cause of death or state whether the death was related to treatment. The serious terms listed are lung infection and tumor pain, each recorded as 100.0%. The registry does not clarify the denominator or whether those terms refer to distinct events, so the percentages should not be interpreted as comparative rates.

These entries are descriptive safety information, not a controlled estimate of risk. The record does not report event timing, severity details beyond the serious-event listing, attribution, or a comparison adjusted for exposure. No causal conclusion about durvalumab, radiation, or their combination follows from the reported counts.

12. What the Result Does, and Does Not, Mean

The registry record establishes that a randomized Phase II study was intended to compare durvalumab with stereotactic radiotherapy delivered on the SAbR or PULSAR schedule. It also establishes the intended primary endpoint: EORTC-QLQ30 quality-of-life scores at 2 years post-treatment, with a score range of 0-100 and higher scores described as better. These details tell readers what question the trial was designed to address.

The record does not establish an answer to that question. Enrollment was one subject, assigned to the PULSAR arm, and the subject terminated treatment early. The data needed to evaluate the primary endpoint were not collected. There is no reported quality-of-life score or comparative estimate, and no uncertainty interval with which to judge precision. The absence of a reported endpoint result is not evidence that the two schedules had the same outcome, nor is it evidence that one schedule had a better outcome.

Similarly, the registry’s list of secondary outcomes is not a report of findings for local control, progression-free survival, overall survival, response, or toxicity. The safety entries provide limited descriptive counts, but do not permit a comparative safety estimate or establish whether the death was related to treatment. The SAbR arm’s zero at-risk entries are especially important to read as denominator information rather than as proof of an absence of events in an exposed group.

In general, a clinical trial result is most informative when the outcome estimate, its uncertainty, the analysis population, and the methods are all reported. The registry record does not provide those elements for the primary comparison. It therefore supports a description of the study’s intended design and its limited reported enrollment, but not a conclusion about treatment benefit, lack of benefit, equivalence, or comparative safety. The reason for termination and the reasons the endpoint data were unavailable are not reported in the registry record.

13. Why This Trial Matters Statistically

This study is statistically notable because its registry record illustrates the difference between a planned randomized comparison and an interpretable comparative result. Randomization can support causal comparison when outcomes are measured and analyzed, but a design label cannot replace outcome data. With one subject enrolled on the PULSAR arm and no data collected to evaluate the primary quality-of-life measure, the intended comparison between SAbR and PULSAR remains unanswered in the record.

The endpoint also highlights the distinction between defining a measure and reporting its result. The registry identifies a questionnaire, score range, direction of interpretation, and assessment timeframe. Those specifications make the intended outcome clear, but they cannot establish an observed score or its precision. Without an estimate and uncertainty interval, readers cannot assess the magnitude or variability of a difference between schedules.

The safety entries emphasize why counts need denominators and context. Zero at risk in one arm is not equivalent to observing zero events among an exposed group. A reported percentage for serious-event terms likewise needs a clearly defined denominator and event-counting method to support interpretation. Comparative safety conclusions require more than isolated arm-level entries.

Finally, the record lists multiple secondary outcomes but reports no analyses. This makes it important to distinguish planned outcome coverage from posted evidence. The trial’s record is useful for understanding the intended question, treatment schedules, endpoint, and the limits of the available results; it does not provide the evidence needed to compare outcomes across arms.

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 central limitation is the absence of evaluable primary endpoint data. The registry reports one subject enrolled on the PULSAR arm, early treatment termination, and no data necessary to assess the quality-of-life measure. No primary endpoint estimate, comparison, or measure of precision is reported. With no reported outcome information for the intended comparison, the registry cannot answer the primary question.

The record also does not report the reason for study termination or the reason for early treatment discontinuation. Although it describes planned follow-up through 2 years and additional follow-up for adverse events, it does not establish which planned assessments occurred. The study’s allocation sequence and concealment methods are not reported, nor are details of dose, treatment duration, or PULSAR personalization.

For the secondary outcomes, the registry lists outcomes but does not report their analysis results or methods. Definitions, analysis populations, handling of missing data, and any multiplicity approach are not reported in the registry record. The safety information is limited by the reported at-risk counts, lack of event-level context, and absence of attribution or cause-of-death information. The serious-term percentages do not have an explained denominator in the record.

These are limitations of what the registry reports. They do not establish why the study ended or why data were unavailable, and they do not support conclusions about what would have been observed had the study continued.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Durvalumab and Stereotactic Radiotherapy for Advanced NSCLC — NCT04786093.
• Registry record last updated 2026-05-05; status last verified 2026-02.
• Results first posted 2026-05-05.
• 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.

18. Record Summary

NCT04786093 is a randomized, unmasked, parallel-group Phase II study of durvalumab with stereotactic radiotherapy for advanced non-small cell lung cancer. It compared an SAbR schedule, with radiation fractions every other day, with a PULSAR schedule, with fractions every four weeks. The primary outcome was EORTC-QLQ30 quality-of-life score at 2 years post-treatment, on a 0-100 scale where higher scores indicate better results.

The registry lists enrollment as one subject, enrolled on PULSAR. Treatment was terminated early, and the data needed to evaluate the primary outcome were not collected. The study status is terminated. The record lists secondary outcomes for tumor control, survival, response, and toxicity, but does not report comparative analyses. Safety entries include one affected and one at risk in the PULSAR arm for serious and other adverse event fields, and one death; the SAbR arm entries list zero at risk. The cause of death, reason for termination, and primary endpoint result are not reported in the registry record.