Study of INCB086550 in Select Solid Tumors: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of INCB086550 in Select Solid Tumors (NCT04629339), a na phase 2 study. The primary outcome is Objective Response Rate (ORR).

2. Clinical Question

The study asked whether INCB086550, an oral PD-L1 inhibitor, was associated with confirmed tumor responses when used as initial immune checkpoint inhibitor therapy in participants with selected solid tumors. The primary endpoint was objective response rate, defined using complete or partial response under RECIST v1.1 and determined by the investigator.

The registry record identifies the study as terminated and lists enrollment of 16. It does not report the objective response rate, the number of participants with a response, or the confidence interval for that endpoint. Therefore, the clinical question is identifiable from the protocol description, but the registry results do not provide the primary estimate needed to answer it.

3. Trial Design

This was a phase 2, open-label, nonrandomized, single-group study of INCB086550 in participants with selected solid tumors who were immune checkpoint inhibitor-naïve. The record describes INCB086550 as a first-in-class oral PD-L1 inhibitor intended as initial immune checkpoint inhibitor therapy. It lists non-small cell lung cancer, urothelial cancer, renal cell carcinoma, hepatocellular carcinoma, and melanoma as the conditions of interest.

The study record lists enrollment of 16 and a status of terminated. The recorded start date is 2021-09-02, and the primary completion date is 2024-03-26. The registry does not report why the study was terminated, so no reason should be inferred from the status alone.

The intervention description states that INCB086550 was administered orally twice a day. Safety data are listed by tumor and regimen, including NSCLC 400 mg BID, UC 400 mg BID, RCC 400 mg BID, Melanoma 400 mg BID, and Melanoma 400 mg BID Intermittent Dose. The precise dosing and scheduling details beyond these labels are not reported in the registry record. These safety groupings do not establish a randomized comparison, and the registry explicitly identifies the study as nonrandomized, with no like-for-like control arm.

The primary outcome was objective response rate, assessed by the investigator under RECIST v1.1 and confirmed by a repeat assessment at least 28 days later. The specified timeframe was up to 733 days. Secondary outcomes included disease control rate, duration of response, participants with any treatment-emergent adverse event, and participants with any grade 3 or higher treatment-emergent adverse event. The registry record lists five outcome measures, but does not provide the primary response result or a detailed statistical analysis plan.

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: This study was conducted at 10 study centers in Hungary, Korea, and Ukraine.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Full Analysis Set: all study participants who received ≥1 dose of study drug. Participants were analyzed according to the treatment group/dose to which they were assigned. Confidence intervals were calculated using the Clopper-Pearson method.

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 Objective Response Rate (ORR), measured over up to 733 days.

Objective response rate is the percentage of participants whose best overall response is a complete response or a partial response. In this study, response was determined by the investigator according to RECIST v1.1. A complete response required disappearance of all target and non-target lesions with no new lesions; pathological lymph nodes also had to fall below 10 mm in short axis. A partial response required at least a 30% decrease in the sum of target-lesion diameters from baseline, without new lesions or progression of non-target lesions.

The protocol definition required confirmation by at least one repeat assessment at least 28 days later. Confirmation is intended to distinguish a sustained response from a change that is not reproduced on subsequent assessment. The endpoint therefore depends on both the observed tumor measurements and the availability of the required follow-up assessment. The registry record identifies the assessment timeframe as up to 733 days.

In general, response rate is a binary participant-level endpoint: each participant is classified according to whether the defined response occurred. Reporting a percentage with a confidence interval communicates both the estimated response frequency and its statistical precision. The registry record specifies a 95% confidence interval using the Clopper-Pearson method, but does not report the response percentage or interval. The endpoint’s definition is therefore available, while its observed result is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical information reported for this study is limited. The registry specifies the primary endpoint, its assessment criteria, the analysis population, and the confidence-interval method. It does not report a detailed statistical analysis plan, a primary endpoint estimate, or a confidence interval. The explanations below distinguish methods identified in the registry from general statistical context.

What does the primary endpoint count?

The objective response rate classifies participants according to whether they had a confirmed complete or partial response. The study used investigator assessment under RECIST v1.1. The definition sets out lesion-based criteria: complete response requires disappearance of target and non-target lesions without new lesions, while partial response requires at least a 30% decrease in the sum of target-lesion diameters from baseline, with no new lesions and no progression of non-target lesions. A repeat assessment at least 28 days later was required for confirmation.

In general, a binary endpoint converts each participant’s outcome into a category, such as response or no response under the specified criteria. The rate is a summary of the proportion classified as having the event. That summary is interpretable only when the underlying number of participants assessed and the response count are available. Neither the response count nor the resulting percentage is reported in the registry record.

What population was specified?

The primary outcome population is described as the full analysis set: all study participants who received at least one dose of study drug. Participants were analyzed according to the treatment group or dose to which they were assigned. The record does not provide additional detail about how participants with missing or unevaluable response assessments were handled, or whether any participants were excluded from the full analysis set.

In general, defining an analysis population before interpreting an endpoint matters because the population determines who contributes to the estimate. For a response endpoint, assessment availability and the handling of participants without an evaluable response can affect the reported rate. The registry describes the full analysis set, but does not report how missing outcome data were treated.

What does the confidence interval method contribute?

The registry states that confidence intervals were calculated using the Clopper-Pearson method and specifies a 95% confidence interval for the primary endpoint. In general, a confidence interval expresses the statistical uncertainty around an estimate under the assumptions of the method. The Clopper-Pearson approach is an exact method for a binomial proportion. It is commonly used when an outcome is classified as an event or non-event, as with response status.

A confidence interval is not a guarantee that the true value lies within the observed bounds, nor does it resolve limitations in study design or measurement. Its width reflects statistical precision, which is influenced by the amount of information in the data and the observed event pattern. Because the response estimate and its interval are not reported, the interval’s width and the precision of the study’s response estimate cannot be assessed.

What can a single-group design establish?

The registry identifies the study as single-group, open-label, and nonrandomized. In general, a single-group study can describe outcomes among participants who received the intervention, but it does not provide the concurrent randomized comparator needed to separate treatment-associated outcomes from other explanations. Open-label assessment also means treatment was not masked, although the record does not report how this may have influenced assessment.

The safety results are arranged by tumor and regimen labels. These groupings describe the reported safety data; they do not supply a randomized control comparison. A difference in event counts between such groups cannot be attributed to a difference in treatment regimen without accounting for the group composition and other potential differences. The registry record does not report an adjusted comparative analysis.

What is not available about the statistical plan?

The registry record does not report whether interim analyses were conducted, what formal hypothesis tests were planned, how missing data were handled, or whether multiplicity adjustments were specified. It also does not report a sample-size justification. Those omissions mean that planned inferential procedures and the rationale for the enrollment target cannot be reconstructed from this record.

The record describes a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. Such planning calculations are illustrations and are not observed power. No numerical sample-size illustration is reported in the registry record for interpretation, and the two-arm planning assumptions do not change the actual single-group design.

Over-dispersion is a general concern when outcomes vary more than a chosen statistical model expects; in such cases, model-based uncertainty can be understated if that extra variability is ignored. The registry does not report a model-based analysis of the primary binary response endpoint, so there is no reported over-dispersion assessment to interpret. The specified Clopper-Pearson interval is tied to the binary outcome framework rather than a reported over-dispersion model.

Overall, the recorded methods allow the response definition and intended interval method to be understood, but do not support reconstruction of an efficacy analysis. The response result, its interval, missing-data procedures, testing strategy, and any interim monitoring are not reported in the registry record.

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("NSCLC 400 mg BID", "UC 400 mg BID", "RCC 400 mg BID", "Melanoma 400 mg BID", "Melanoma 400 mg BID Intermittent Dose")
n      <- c(1, 1, 6, 7, 1)
events <- c(0, 1, 0, 1, 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  NSCLC 400 mg BID  1  0  0.0  0.0  97.5  0.0  79.3  1.3  84.2
ARM  UC 400 mg BID  1  1  100.0  2.5  100.0  20.7  100.0  15.8  98.7
ARM  RCC 400 mg BID  6  0  0.0  0.0  45.9  0.0  39.0  0.4  41.0
ARM  Melanoma 400 mg BID  7  1  14.3  0.4  57.9  2.6  51.3  3.2  52.7
ARM  Melanoma 400 mg BID Intermittent Dose  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 the primary endpoint as objective response rate and identifies several secondary outcomes: disease control rate, duration of response, participants with any treatment-emergent adverse event, and participants with any grade 3 or higher treatment-emergent adverse event. It also lists five outcome measures. However, the registry record does not report how testing across the primary and secondary outcomes was handled. In particular, no multiplicity adjustment or testing hierarchy is reported.

In general, evaluating several outcomes can increase the chance of finding an apparently notable result by chance if each is tested separately. Multiplicity methods set out how such testing is controlled or interpreted. Without a reported strategy, the statistical status of any secondary-outcome findings cannot be determined. The registry does not provide the primary response result or detailed results for the listed secondary outcomes, so there are no posted efficacy estimates to compare across endpoints.

The primary analysis population is described as the full analysis set, comprising participants who received at least one dose of study drug. The registry record does not report the number with an evaluable primary outcome, how missing or unevaluable tumor assessments were handled, or how participants who did not complete the confirmation assessment were classified. These details matter because the response definition requires confirmation at least 28 days later.

The record does not report whether there were interim analyses, any stopping boundaries, or a prespecified statistical analysis plan. It also does not report a sample-size justification. The terminated status does not establish why the study ended or whether any stopping rule was used. Consequently, multiplicity, missing-data handling, and the conduct of interim monitoring remain unreported in the registry 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: immune-mediated neuropathy (100.0%), hyponatraemia (16.7%), iron deficiency anaemia (16.7%), pneumonia (16.7%).

The safety record lists serious adverse events and other adverse events by tumor and regimen group. Overall, it reports 3 participants with serious adverse events among 16 at risk, 14 participants with other adverse events among 16 at risk, and 5 deaths among 16 at risk. The listed group counts are: NSCLC 400 mg BID, 0 serious events and 1 other event; UC 400 mg BID, 1 and 1; RCC 400 mg BID, 2 and 6; Melanoma 400 mg BID, 0 and 5; and Melanoma 400 mg BID Intermittent Dose, 0 and 1. Deaths are listed as 1, 0, 2, 2, and 0, respectively.

The registry also lists serious adverse event terms with percentages: immune-mediated neuropathy, 100.0%; hyponatraemia, 16.7%; iron deficiency anaemia, 16.7%; and pneumonia, 16.7%. The denominator and precise interpretation of these term percentages are not reported in the registry record, so they should not be treated as percentages of all enrolled participants.

These are descriptive safety figures. A recorded event or death does not, by itself, show that the study drug caused it. The registry record does not provide enough detail to infer causality, timing, severity beyond the listed categories, or how event ascertainment differed across groups.

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

The registry establishes that this was a phase 2 study of INCB086550 in immune checkpoint inhibitor-naïve participants with selected solid tumors, and it defines objective response rate using confirmed investigator-assessed RECIST v1.1 criteria. It also reports safety counts. Those details describe the intended clinical question and some observed safety experience, but they do not supply the primary efficacy result.

The objective response rate and its 95% confidence interval are not reported in the registry record. It is therefore not possible to state what response percentage was observed, how many participants responded, or how precise the estimate was. This absence should not be interpreted as a zero response rate or as proof of no activity; it is a limitation of the result available in the registry.

The study’s single-group, nonrandomized design also limits what can be inferred. Even if an outcome estimate were available, without a concurrent control group it would describe outcomes in the treated study population rather than establish a comparative effect. The listed tumor and regimen subgroups are not randomized arms and should not be interpreted as like-for-like treatment comparisons.

The safety counts likewise describe events reported in the registry. They do not alone determine whether events were caused by the intervention. The record’s terminated status does not explain why the study ended, and no reason should be inferred. The registry does not report the missing-data procedures, multiplicity approach, or details of interim analysis that would further inform interpretation.

In general, a statistical estimate answers a defined question only in the population and under the methods used to produce it. Here, the response definition and confidence-interval method are known, but the estimate itself is absent. The reported record can therefore support a description of design and safety counts, but not a conclusion about the size or precision of the primary response outcome or a comparative treatment effect.

14. Why This Trial Matters Statistically

This study is statistically informative as an example of the difference between a clearly defined endpoint and a reported result. The registry specifies objective response rate, investigator assessment under RECIST v1.1, confirmation by a repeat assessment at least 28 days later, and a 95% Clopper-Pearson confidence interval. Yet the response percentage and interval are not reported. The endpoint’s formal definition cannot substitute for its observed estimate.

The single-group design is also important to interpretation. A study can document outcomes among participants receiving an intervention, but without a randomized concurrent control it cannot make a like-for-like comparison against another treatment. This distinction remains important even when safety results are split across tumor and regimen group labels. Such listings are descriptive rather than evidence of comparative effects.

The total enrollment of 16 helps explain why precision would be an important consideration if an outcome estimate were available, but the actual precision cannot be assessed without the response count and confidence interval. The registry does not report a sample-size justification. Its planning illustration uses assumptions for a two-arm design, while the actual study is single-group; those planning assumptions should not be mistaken for features of the trial’s observed design or for observed power.

Finally, the record illustrates why termination status, adverse event counts, and efficacy results must be kept distinct. The status does not explain the reason for termination, and reported events do not establish causality. Careful reading separates what the registry records from what remains unknown, including the primary response result, missing-data handling, and multiplicity strategy.

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 direct limitation for interpretation is that the registry record does not report the primary objective response rate, response count, or its 95% confidence interval. Although the response definition and Clopper-Pearson method are specified, the main estimate and its precision are unavailable. Results for the listed secondary outcomes are also not reported in detail.

The study was open-label, nonrandomized, and single-group. There was no concurrent control arm, so the design does not support a randomized comparison. The safety groupings by tumor and regimen should not be treated as exchangeable groups: the registry does not report a controlled comparison or adjustment for differences among them.

Enrollment was 16, across several selected solid tumor types and safety group labels. The record does not provide enough detail to assess the representativeness of the enrolled participants or the precision of tumor-specific estimates. The primary outcome population is defined as participants who received at least one dose, but the number with an evaluable response assessment and the handling of missing or unconfirmed assessments are not reported.

The status is terminated, but the reason is not reported in the registry record. The record also does not report interim-analysis procedures, the multiplicity strategy, a sample-size justification, or a detailed analysis plan. The serious adverse event term percentages are listed without their denominator or fuller context. These gaps limit interpretation of both efficacy and safety and prevent attributing event patterns or study termination to a particular cause.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Study of INCB086550 in Select Solid Tumors — NCT04629339.
• Registry record last updated 2025-03-13; status last verified 2025-02.
• Results first posted 2025-03-13.
• 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

NCT04629339 is a phase 2, open-label, nonrandomized, single-group study of INCB086550 in immune checkpoint inhibitor-naïve participants with selected solid tumors. The intervention was oral INCB086550, described as administered twice a day. The registry lists enrollment of 16, a start date of 2021-09-02, a primary completion date of 2024-03-26, and a status of terminated.

The primary endpoint was investigator-assessed objective response rate under RECIST v1.1, with response confirmation at least 28 days later. The registry specifies a 95% Clopper-Pearson confidence interval, but the response estimate and interval are not reported in the registry record. Safety listings report 3 participants with serious adverse events, 14 with other adverse events, and 5 deaths among 16 at risk. These are descriptive counts, not evidence of causality or comparative effects. The reason for termination and several statistical analysis details are not reported.