M7824 and Topotecan or Temozolomide in Relapsed Small Cell Lung Cancers: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for M7824 and Topotecan or Temozolomide in Relapsed Small Cell Lung Cancers (NCT03554473), a non-randomized phase 1, phase 2 study. The primary outcome is Proportion of Evaluable Participants Who Experience a Partial Response (PR) or Complete Response (CR) Reported Along With an 80% Confidence Interval..

2. Clinical Question

3. Trial Design

This was a phase 1 and phase 2 study with sequential, nonrandomized allocation and no masking. The registry lists 37 participants enrolled. The study is recorded as completed, with a start date of 2018-09-11 and a primary completion date of 2022-06-01. The sponsor was the National Cancer Institute (NCI).

The study had distinct treatment arms. Arm A used M7824 monotherapy on a 21-day cycle; the registry says participants with progressive disease could receive M7824 with temozolomide. Arm B combined M7824 on day 1 with topotecan on days 1-5 of a 21-day cycle. Arm C combined M7824 on days 1 and 15 with temozolomide on days 1-5 of a 28-day cycle. The registry describes safety evaluation followed by additional enrollment for efficacy in the combination arms.

Because assignment was not randomized, differences between arms may reflect differences in the participants or treatment context as well as the regimens. General statistical point: random allocation helps balance measured and unmeasured characteristics on average, whereas nonrandomized comparisons do not have that protection. The arms should therefore be read as separate study groups rather than as controlled estimates of relative treatment effects. The registry record does not report the allocation criteria or a statistical plan for comparing the arms.

The listed secondary outcomes include grade 3 and/or grade 4 adverse events, progression-free survival, duration of response, and overall survival. The registry record does not report numerical results for those outcomes in the information available for this account.

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: Relapsed Small Cell Lung Cancers (SCLC). Extrapulmonary Small Cell Cancer (ESCC).

Arm A M7824 Relapsed SCLC

Reasons for not completing this period:

Arm B M7824 + Topotecan Relapsed SCLC

Arm C M7824 + Temozolomide Relapsed SCLC

Arm C M7824 + Temozolomide ESCC

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: 7/37 participants were not analyzed because 7 participants were not evaluable for response. They did not complete a full cycle followed by restaging.

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.

6. Primary Endpoint

The registry lists the primary outcome as Proportion of Evaluable Participants Who Experience a Partial Response (PR) or Complete Response (CR) Reported Along With an 80% Confidence Interval., measured over 6 weeks (Arm B) or 8 weeks (Arm C).

The primary endpoint is the proportion of evaluable participants who have a partial response or complete response. It uses tumor response criteria, RECIST v1.1, rather than relying only on a subjective judgment that a participant improved. Under the registry description, a partial response requires at least a 30% decrease in the sum of target-lesion diameters from baseline. A complete response requires disappearance of target lesions, with pathological lymph nodes reduced in short axis to <10 mm.

A response proportion gives a direct summary of how often the specified tumor response occurred in the evaluable population. The confidence interval communicates uncertainty around that proportion: in general, an interval estimates a range of values compatible with the observed data under the method used. The registry specifies an 80% confidence interval, but the interval itself and the response count are not reported in the registry record.

The stated assessment time is 6 weeks for Arm B and 8 weeks for Arm C. These differing assessment times matter when interpreting or comparing response proportions: response is assessed at the time specified for the arm, not at a common time across those arms. The registry record does not state the corresponding response assessment timeframe for Arm A in the primary endpoint description.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a response proportion represent?

For a binary outcome such as response, each evaluable participant is classified according to whether the specified event occurred. The proportion summarizes the share of the analyzed population meeting the response definition. In this trial, the event is a partial response or complete response under RECIST v1.1. General explanation: a proportion is easy to interpret, but it depends on a clearly defined event and analysis population. Here, the registry identifies both the response criteria and the reason some enrolled participants were not evaluable. It does not report the observed response count or proportion.

Why report a confidence interval?

A response proportion is an estimate based on observed participants, not a certainty about the underlying population. A confidence interval expresses the statistical uncertainty associated with that estimate. The registry specifies an 80% confidence interval. The particular interval limits and the method used to calculate them are not reported in the registry record. General explanation: narrower intervals indicate greater precision under the assumptions of the chosen method; wider intervals indicate more uncertainty. Interval width is influenced by the amount of outcome information and by the observed distribution of responses. The interval does not resolve possible selection bias, differences between arms, or other design limitations.

What does RECIST contribute?

RECIST v1.1 supplies an operational definition for classifying tumor response. The registry describes partial response as at least a 30% decrease in the sum of target-lesion diameters from baseline, and complete response as disappearance of target lesions with pathological lymph nodes reduced in short axis to <10 mm. Standardized criteria can make outcome classification more consistent, but they do not make assessment error impossible. The registry record does not report details of blinded review, independent review, or adjudication of response assessments.

How should the assessment time be considered?

The registry gives 6 weeks for Arm B and 8 weeks for Arm C. These are the stated primary outcome timeframes for those arms. General explanation: an outcome measured at different times may not be directly comparable across groups, since the opportunity for an event to occur and the timing of assessment differ. The record does not specify a common-time comparison, nor does the primary endpoint description state the corresponding timeframe for Arm A.

What do the design labels mean?

The study is recorded as phase 1 and phase 2, sequential, nonrandomized, and unmasked. General explanation: a sequential design can use information gathered at one stage when proceeding to later enrollment, but the registry description does not establish exactly how decisions were made in practice. Nonrandomized allocation means treatment assignment was not randomized; observed differences may be associated with participant characteristics or other factors as well as treatment. No masking means treatment assignment was not concealed from participants or investigators according to the registry classification. The registry record does not report further operational details or a statistical model for between-arm comparisons.

What can be said about sample-size planning?

The registry describes planning illustrations using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. It explicitly distinguishes those illustrations from the trial's own design. General explanation: such calculations describe hypothetical planning under stated assumptions; they are not observed power and do not show the probability that the trial detected a true effect. The registry record does not report the trial's sample-size justification or a prespecified target effect.

What is not specified?

The registry record does not report the method used to calculate the confidence interval, a hypothesis test for the primary endpoint, an adjustment for prognostic factors, or an analysis plan for comparing arms. It also does not report the primary response result. Those omissions mean that the endpoint can be explained from its definition, but the numerical estimate and the full analytical procedure cannot be evaluated from the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The trial lists a primary response outcome and several secondary outcomes, including grade 3 and/or grade 4 adverse events, progression-free survival, duration of response, and overall survival. The registry record does not report whether or how multiplicity was addressed. General statistical point: when multiple outcomes, treatment groups, or analyses are considered, the chance of finding an apparently notable result by chance can increase. A prespecified strategy can clarify which results are confirmatory and how uncertainty should be interpreted. No such strategy is reported in the registry record, so it is not possible to determine whether any adjustment or hierarchy was planned.

For the primary endpoint, the registry states that 7/37 participants were not analyzed because they were not evaluable for response: they did not complete a full cycle followed by restaging. The record does not report imputation, sensitivity analyses, or an analysis of those participants as nonresponders. It also does not report additional details about reasons for non-evaluability or whether any other participants were excluded from particular analyses. General statistical point: missing outcome data can affect an estimate if the participants with missing assessments differ systematically from those with observed assessments.

The registry identifies the response analysis population as evaluable participants, but a broader intention-to-treat analysis is not described in the record. The precise analysis populations for secondary outcomes and safety outcomes are not fully specified in the information; those details are not reported in the registry record. As a result, readers should distinguish the stated evaluable response population from the full enrollment and avoid assuming that every listed outcome uses the same denominator.

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: disease progression (30.8%), pleural effusion (20.0%), pneumonitis (20.0%), lung infection (10.5%), sepsis (10.5%).

The registry lists serious adverse event counts by arm as participants at risk and participants affected: Arm A, 13 at risk and 8 affected; Arm B, 5 at risk and 1 affected; and Arm C, 19 at risk and 12 affected. It separately lists other adverse event counts: Arm A, 13 at risk and 13 affected; Arm B, 5 at risk and 5 affected; and Arm C, 19 at risk and 19 affected. The listed death counts are 13 for Arm A, 5 for Arm B, and 18 for Arm C.

The registry's listed serious adverse event terms and percentages include disease progression, 30.8%; pleural effusion, 20.0%; pneumonitis, 20.0%; lung infection, 10.5%; sepsis, 10.5%; and abdominal pain, 7.7%. The record does not provide further denominator or arm-specific detail for these listed term percentages in the information available for this account.

General statistical point: these figures describe events recorded in study groups; they do not establish that treatment caused an event. The arms were nonrandomized and differ in their treatment regimens. The registry record does not report a controlled safety comparison or an attribution analysis. Counts and percentages should therefore be read as descriptive safety information, not as causal estimates or direct evidence of relative risk between regimens.

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

The registry record establishes that this trial studied M7824 as monotherapy and in combination with topotecan or temozolomide, and that it defined response using RECIST v1.1. It also specifies an 80% confidence interval for the primary response proportion and gives the response assessment times for Arms B and C. These details explain what the investigators intended to measure.

The record does not report the primary response count, proportion, or confidence interval. Therefore it does not establish how often evaluable participants had a partial or complete response, or how precise an estimate would be. The absence of those results in the registry record should not be interpreted as evidence that no responses occurred or that a treatment had no effect.

The nonrandomized design also prevents a straightforward causal comparison of arms. General statistical point: a difference in outcomes between groups can arise from treatment, participant characteristics, assessment timing, or other factors. Randomization can reduce imbalance on average, but this study is recorded as nonrandomized. Its arms should not be treated as equivalent groups created for a definitive comparative test.

The safety counts and listed adverse event terms describe events recorded in the registry. They do not, by themselves, establish treatment causation. The record does not give a controlled safety comparison, and the groups should not be compared as if assignment were randomized.

In short, the trial record supports a description of the study design, endpoint definition, and recorded safety counts. It does not provide the numerical primary efficacy result needed to assess the observed response proportion or its uncertainty. It also does not support a conclusion that any regimen is superior or that an observed event was caused by treatment.

13. Why This Trial Matters Statistically

This study is statistically informative as an example of how an early-phase, sequential trial can define a response question while using several treatment approaches. The registry distinguishes M7824 monotherapy from combinations with topotecan and temozolomide, and describes safety evaluation and subsequent enrollment for efficacy in the combination arms. That structure makes it important to separate the study's descriptive aims from a randomized comparison.

The primary endpoint is explicit about the response criteria and specifies an 80% confidence interval. Those elements matter because a response proportion without its uncertainty can give an incomplete picture of the evidence. However, the registry record does not report the response count, estimate, or interval. A well-defined endpoint is useful for interpretation, but it cannot substitute for the numerical result.

The record also illustrates why analysis populations require attention. It states that 7/37 participants were not evaluable because they did not complete a full cycle followed by restaging. Such exclusions affect the population to which a response estimate would apply, and the registry does not describe a missing-data analysis.

Finally, the nonrandomized allocation is central to statistical interpretation. It limits what can be inferred from differences between arms and reinforces the distinction between descriptive observations and causal treatment comparisons. Together, the endpoint definition, missing response results, and design features show why readers need both numerical estimates and transparent methods before drawing conclusions from a clinical trial.

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 limitation for interpreting efficacy is that the registry record does not report the response count, response proportion, or 80% confidence interval. The endpoint can be described, but its observed magnitude and precision cannot be assessed from the record.

The response analysis excludes 7/37 participants who did not complete a full cycle followed by restaging. The record does not report further information about these participants, how missing response outcomes were handled, or whether sensitivity analyses were conducted. The results would apply to the evaluable population as defined, and the registry does not establish how that population relates to all enrolled participants.

Allocation was nonrandomized and the trial was unmasked. The arms therefore do not provide a like-for-like randomized comparison, and differences between them could be related to factors other than treatment. Arm B and Arm C also have different response assessment timeframes, 6 weeks and 8 weeks respectively. The primary endpoint description does not report the assessment timeframe for Arm A.

The registry record does not report the method for calculating the confidence interval, a comparative statistical analysis plan, a multiplicity strategy, or the trial's sample-size justification. It describes planning illustrations but does not report those as the trial's own design. The listed safety information is descriptive; controlled safety comparisons and further denominator details for the listed serious event terms are not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: M7824 and Topotecan or Temozolomide in Relapsed Small Cell Lung Cancers — NCT03554473.
• Registry record last updated 2025-05-09; status last verified 2025-04.
• Results first posted 2025-05-09.
• 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

NCT03554473 is a completed, nonrandomized, unmasked, sequential phase 1 and phase 2 trial sponsored by the National Cancer Institute (NCI). It enrolled 37 participants and studied M7824 alone or with topotecan or temozolomide in relapsed small cell lung cancer. The listed primary endpoint is the proportion of evaluable participants with a partial or complete response under RECIST v1.1, with an 80% confidence interval specified. The registry reports that 7/37 participants were not evaluable for response because they did not complete a full cycle followed by restaging. The response estimate and confidence interval are not reported in the registry record. The safety record lists adverse event counts by arm and several serious adverse event terms with percentages. Because allocation was nonrandomized, the arms are not a controlled like-for-like comparison.