Study Of NOVOTTF-200A In Bevacizumab-Naive Subjects With Recurrent Grade III Malignant Astrocytoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study Of NOVOTTF-200A In Bevacizumab-Naive Subjects With Recurrent Grade III Malignant Astrocytoma (NCT03450850), a na na study. The primary outcome is Number of Participants Showing no Evidence of Disease Progression Six Months After Initiating Treatment With the Device..

2. Clinical Question

This question is about disease status at a specified follow-up point, not a comparison between assigned treatments. The primary endpoint is listed as a count of participants, while its description frames the objective as estimating a proportion. With a single group, any estimate would describe the participants assessed under this study’s conditions; without a comparator, it would not by itself estimate what would have happened to similar participants without the device or under another treatment.

The registry record lists an enrollment of 1, but does not report the primary endpoint result, the number assessed at six months, or an analysis of the endpoint. Accordingly, the record does not establish how many participants met the endpoint or how precisely the proportion was estimated. It also does not report information that would allow readers to assess how the clinical question was operationalized beyond the stated six-month timing and RANO (2010) assessment.

3. Trial Design

The registry describes a Phase II, single-arm study of NOVOTTF-200A in bevacizumab-naive participants with recurrent WHO Grade III malignant astrocytoma. Its phase field is recorded as NA, while the official title calls the study Phase II. The design model is single-group; allocation is NA and masking is none. NOVOTTF-200A is identified as a device, and there is no separately listed control arm.

The brief summary describes participants with WHO Grade III anaplastic astrocytoma whose disease progressed during first- or second-line treatment and who had not previously received bevacizumab or experimental agents. These eligibility details characterize the intended study population, but the registry record does not report further inclusion or exclusion criteria, recruitment procedures, or the number screened and enrolled beyond the enrollment figure.

The study is listed as completed. Its recorded start date is 2020-05-21, and its primary completion date is 2023-09-07. The listed sponsor is Daniela A. Bota. These record details describe study administration; they do not establish that every planned assessment was completed or explain why the enrollment was 1.

The stated primary objective is to estimate the proportion of participants showing no evidence of disease progression six months after initiating the device, with assessment per RANO (2010) criteria. Secondary outcomes include participants experiencing any adverse events, change in quality of life, and correlations with established molecular markers, including ATRX and MGMT promoter methylation. The registry lists 4 outcome measures in total, but does not report outcome analyses. The record also does not describe a statistical analysis plan, sample-size justification, interim analyses, or the process for handling participants without six-month assessments.

Because the design has one group and no randomized comparator, its results would be descriptive of the participants observed in that group. They cannot separate a treatment-associated pattern from other explanations using a concurrent comparison. The record’s design description therefore matters when interpreting both the intended endpoint and the very limited posted results.

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

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 Number of Participants Showing no Evidence of Disease Progression Six Months After Initiating Treatment With the Device., measured over 6 months.

The primary endpoint counts participants who show no evidence of disease progression six months after initiating treatment with NOVOTTF-200A. The stated assessment standard is RANO (2010) criteria. Although the endpoint is expressed as a count, the primary objective is to estimate the proportion of participants meeting the condition at the six-month assessment.

A fixed follow-up point provides a clear way to describe disease status at a clinically specified time after treatment initiation. A binary endpoint classifies each assessed participant as either meeting or not meeting the stated condition. In general, such a measure can be summarized as a count and a proportion, with uncertainty described by a confidence interval. That general interpretation depends on knowing how many participants were assessed and how missing assessments were handled; those details are not reported in the registry record.

The record lists an enrollment of 1 but does not report the observed primary endpoint count, the number with an evaluable six-month assessment, or an estimate of the proportion. No confidence interval or primary-outcome analysis is listed. Thus the endpoint definition and timing are available, but the posted record does not give the result needed to quantify the observed six-month status or its precision.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical interpretation begins with the design. This is a single-group study, not a randomized comparison. The primary endpoint is a count of participants meeting a binary condition at six months: no evidence of disease progression under RANO (2010) criteria. The stated objective is to estimate the proportion meeting that condition. The registry record lists enrollment as 1 but reports no endpoint count, analysis, or estimate.

What does a proportion describe?

In general, a proportion is the number of participants meeting a defined condition divided by the number assessed for that condition. For this endpoint, the condition is no evidence of disease progression at the specified follow-up. The denominator should correspond to the participants included in the endpoint analysis, which may not be the same as enrollment if assessments are missing or participants are excluded. The registry record does not report the six-month denominator or how any missing assessment was treated, so an endpoint proportion cannot be recovered from the record.

Counts and proportions answer different descriptive questions. A count states how many participants met the condition; a proportion relates that count to the analyzed group size. Neither alone describes precision. In general, a confidence interval expresses a range of values compatible with the data and the method’s assumptions. With very limited information or a very small analysis group, uncertainty can be substantial. No confidence interval for the primary endpoint is reported in the registry record.

Why does the single-group design matter?

A single-group estimate describes outcomes in the participants observed after treatment. It does not provide a simultaneous untreated or alternative-treatment outcome for comparison. In a randomized study, allocation can help balance other influences between groups on average; no such allocation-based comparison is described. Therefore, even if a group-level endpoint result were available, it would not by itself identify a treatment effect relative to another course of care.

The registry records allocation as NA, masking as none, and the model as single-group. These labels describe the design but do not explain how outcome assessments were conducted or whether assessors knew treatment status. The registry record does not report those procedures. RANO (2010) is named as the assessment criteria, but details of implementation, adjudication, or reproducibility are not reported.

How should planning illustrations be understood?

The sample-size assumptions describe a planning illustration, not the study’s own design. They specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. The assumptions also distinguish participants per arm for outcomes other than time-to-event outcomes, for which the illustration concerns a total event count. These are characteristics of the planning illustration, not evidence that this single-group study had two arms or used that allocation.

Planning calculations are not observed results and are not observed power. A planning illustration can show how a hypothetical design might relate sample size to an assumed effect and analysis method, but it does not demonstrate that the actual study was designed that way or that a result was obtained. The registry record does not report the trial’s own sample-size justification, statistical power target, or protocol-level analysis plan.

Why do sparse data and over-dispersion matter in general?

For a binary endpoint, the observed count is constrained by the number assessed. When the analysis group is small, each participant’s outcome has a large influence on the reported proportion, and estimates are inherently imprecise. General methods for binary outcomes use assumptions about how observations vary across participants. If outcomes vary more than a chosen model allows, over-dispersion can make model-based uncertainty too small. That issue is a general statistical consideration; the registry record does not report a model, an over-dispersion assessment, or a method used for the primary endpoint.

It is not possible to determine which inferential method, if any, was intended from the registry record. It does not report whether the primary analysis was descriptive or hypothesis-testing, whether any adjustment was planned, or what confidence-interval procedure would be used. Nor does it report a prespecified estimand defining how intercurrent events, treatment discontinuation, or missing assessments would affect the endpoint.

These distinctions keep the interpretation aligned with what is recorded. The endpoint and its assessment time are specified; an observed endpoint value and statistical analysis are not. The design is single-group; a comparative treatment estimate is not available from this record. General statistical concepts can clarify why denominator, precision, missingness, and design matter, but they cannot supply absent study results or reconstruct an unreported analysis.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("NOVOTTF-200A")
n      <- c(1)
events <- c(1)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  NOVOTTF-200A  1  1  100.0  2.5  100.0  20.7  100.0  15.8  98.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 4 outcome measures, including the primary six-month disease-progression measure and secondary outcomes concerning adverse events, quality of life, and molecular-marker correlations. It reports 0 analyses. The registry record does not describe a multiplicity strategy, such as a hierarchy among outcomes or adjustment for testing multiple hypotheses. Without an analysis plan and posted results, readers cannot determine whether multiplicity was addressed or how any secondary findings would have been interpreted.

Missing-data procedures are not reported in the registry record. In particular, it does not state how a participant without a six-month assessment would be classified, whether the endpoint would be analyzed only among participants with evaluable assessments, or whether any imputation or sensitivity analysis was planned. Those choices can affect the denominator and the interpretation of a binary endpoint. Enrollment alone does not establish how many participants contributed to an endpoint analysis.

The analysis populations are also not described. The record does not say whether the primary analysis was intended to include all enrolled participants, only participants who initiated the device, or another defined group. It does not report adherence, treatment discontinuation, protocol deviations, or exclusions. These details are relevant to understanding which participants an estimate would describe.

Because the registry record contains no reported analyses, it is not possible to assess how multiplicity, missing outcomes, or analysis-population definitions were handled. These are unreported methodological details, not evidence that a particular procedure was or was not used outside the record.

12. 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 non-serious adverse event terms

The registry safety entries list 1 participant at risk for serious adverse events and 0 participants affected. For other adverse events, 1 participant was at risk and 1 was affected. The entry lists 0 deaths. These are participant counts, not rates or comparisons with another group.

The record does not identify the other adverse event, its severity, timing, duration, or relationship to NOVOTTF-200A. It also does not provide a narrative explaining the serious-event or death counts. The listed counts therefore cannot characterize the type or clinical importance of the event, and they should not be generalized beyond this recorded group.

With enrollment listed as 1, the safety information is sparse and offers little basis for estimating how often events might occur in a broader population. The risk-set counts are the denominators recorded for the adverse-event categories, but the registry does not explain the safety observation period or whether all events were captured. Zero recorded serious adverse events and zero deaths describe the entries in this record; they do not establish that such events are impossible or rule out safety concerns.

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

The registry record documents a study of NOVOTTF-200A in bevacizumab-naive participants with recurrent WHO Grade III malignant astrocytoma. It specifies a single-group design, a six-month primary endpoint based on RANO (2010) assessment, and secondary outcomes involving adverse events, quality of life, and molecular markers. It also lists enrollment of 1 and sparse safety counts.

The record does not report the observed primary endpoint result, the number assessed at six months, or any analysis. It therefore does not show the proportion with no evidence of disease progression, the precision of that proportion, or a comparison with another treatment or control condition. The completed status indicates the study is listed as completed; it does not replace missing outcome results.

Even if a descriptive primary result were available, a single-group design would not answer how outcomes would compare under another treatment or without NOVOTTF-200A. A treatment-associated outcome in one group is not, on its own, a comparative estimate. The posted record does not provide a randomized counterfactual comparison.

The safety counts should be read with similar restraint. They record no serious adverse events and no deaths among the listed risk group, and one participant with an other adverse event. The event details and observation procedures are not reported, so these counts cannot establish the overall nature or frequency of safety outcomes.

The appropriate conclusion is about the limits of the available record: it establishes the stated study question and design, but does not supply the outcome analysis needed to answer that question. No conclusion about benefit, lack of benefit, or comparative safety follows from the registry information alone.

14. Why This Trial Matters Statistically

This trial is statistically notable because a defined clinical endpoint appears alongside a single-group design and very limited posted results. The primary question is framed as estimating the proportion of participants without evidence of disease progression at six months. That is a meaningful descriptive target, but its interpretation depends on an observed numerator, an evaluable denominator, and a method for handling missing assessments. Those results and procedures are not reported in the registry record.

The enrollment figure of 1 emphasizes why the denominator and uncertainty matter. In a small group, each participant’s status has a substantial influence on a proportion, and the estimate may be imprecise. The record does not provide an endpoint estimate or confidence interval that would quantify this uncertainty. A study’s completion status cannot substitute for those statistical quantities.

The study also illustrates the distinction between an outcome description and a treatment comparison. A single group can be described, but without a concurrent comparator the design does not isolate differences attributable to treatment. This limitation is separate from sample size: even a precisely measured single-group proportion would not by itself provide a randomized comparison.

Finally, the record lists multiple outcome measures without reporting analyses, multiplicity handling, missing-data rules, or analysis populations. These omissions make it difficult to assess how the planned outcomes were meant to support conclusions. The statistical importance lies not in a result that can be inferred, but in recognizing which elements are specified and which are needed for a defensible interpretation.

15. 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 most consequential limitation in interpreting this study-specific record is the absence of a reported primary endpoint result. The endpoint definition and six-month timeframe are stated, but no count meeting the endpoint, analyzed proportion, confidence interval, or analysis is reported. The registry record also does not state how many participants had an evaluable six-month assessment.

The listed enrollment is 1, which sharply limits the amount of information available from the recorded group. The record does not explain whether this enrollment reflects the final number treated, why enrollment was limited to this figure, or whether additional participants were assessed but not enrolled. No explanation should be inferred from the completed status.

The single-group design means there is no like-for-like control comparison in the registry record. Any descriptive result would not establish a difference relative to another treatment or no treatment. Masking is recorded as none, but the record does not describe who performed or reviewed the RANO (2010) assessments or whether any independent review occurred.

Other trial details relevant to interpretation are not reported in the registry record: the statistical analysis plan, sample-size justification, interim analyses, endpoint missing-data rules, analysis populations, and multiplicity procedures. The record also does not give detailed results for quality of life, molecular-marker correlations, or adverse-event types. These limitations do not establish that such procedures or data were absent outside the record; they mean that they cannot be evaluated from the recorded information.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Study Of NOVOTTF-200A In Bevacizumab-Naive Subjects With Recurrent Grade III Malignant Astrocytoma — NCT03450850.
• Registry record last updated 2026-02-17; status last verified 2025-08.
• Results first posted 2025-07-16.
• 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.

19. Record Summary

The registry describes a completed, single-group study of the device NOVOTTF-200A in bevacizumab-naive participants with recurrent WHO Grade III malignant astrocytoma. Enrollment is listed as 1. The official title calls it Phase II, while the registry phase field is NA. Allocation is NA and masking is none.

The primary objective is to estimate the proportion showing no evidence of disease progression six months after initiating treatment, assessed per RANO (2010) criteria. The record lists 4 outcome measures and 0 analyses. It does not report a primary endpoint result, an analysis population, missing-data procedures, or a statistical analysis plan.

Safety entries list 0 serious adverse events among 1 participant at risk, 1 other adverse event among 1 at risk, and 0 deaths. The other event is not described. The record’s design and posted data support only a limited description; they do not provide a comparative treatment estimate or a complete account of study outcomes.