A Study to Evaluate the Efficacy and Safety of Pemigatinib (INCB054828) in Subjects With Myeloid/Lymphoid Neoplasms With FGFR1 Rearrangement - (FIGHT-203): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study to Evaluate the Efficacy and Safety of Pemigatinib (INCB054828) in Subjects With Myeloid/Lymphoid Neoplasms With FGFR1 Rearrangement - (FIGHT-203) (NCT03011372), a na phase 2 study. The primary outcome is Percentage of Participants Who Achieved Complete Response (CR) as Determined by Investigator Assessment According to the Response Criteria for Myeloid/Lymphoid Neoplasms With FGFR1 Rearrangement.

2. Clinical Question

3. Trial Design

This was a phase 2, open-label, monotherapy, multicenter study of pemigatinib in people with myeloid/lymphoid neoplasms with FGFR1 rearrangement. Its design is identified as single-group, with allocation listed as not applicable and masking listed as none. The record therefore describes an evaluation of participants receiving the study drug without a separate randomized control group. The sponsor is Incyte Corporation.

The registry lists 47 participants as enrolled. The primary endpoint population is narrower by definition: it consists of enrolled participants with an FGFR1 rearrangement who received at least one dose of study drug. The record says that this population includes both previously treated and treatment-naive participants, but does not state how many participants met the endpoint population criteria. Enrollment should therefore not be treated as the endpoint denominator without that information.

The study start date is 2017-04-25, the primary completion date is 2024-10-30, and the status is completed. The primary endpoint timeframe is described as up to 2513 days (120 21-day treatment cycles). This is the stated endpoint timeframe, not a reported participant-level follow-up duration.

The primary outcome was investigator-assessed complete response. Secondary outcomes include investigator-assessed complete or partial response, complete and partial cytogenetic response assessments, duration of complete response, duration of response, progression-free survival, and overall survival. Their inclusion identifies additional outcome questions, but the registry record does not report results for them in the information available for this analysis.

The record does not report a sample-size justification, interim-analysis plan, or a detailed statistical analysis plan. It also does not give enough information to characterize treatment exposure, withdrawals, or follow-up completeness. As a single-group study, its design can describe outcomes observed among participants receiving pemigatinib, but does not by itself estimate a randomized treatment contrast.

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 21 study centers in Belgium, Canada, France, Germany, Italy, Japan, Spain, United Kingdom, and the United States.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Full Efficacy-Evaluable Population: all enrolled participants with an FGFR1 rearrangement and who received at least 1 dose of study drug. For this report, the full EEP included both previously treated and treatment-naive participants. Confidence intervals were calculated based on the exact method for binomial distribution.

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 Percentage of Participants Who Achieved Complete Response (CR) as Determined by Investigator Assessment According to the Response Criteria for Myeloid/Lymphoid Neoplasms With FGFR1 Rearrangement, measured over up to 2513 days (120 21-day treatment cycles).

The primary endpoint is the percentage of participants achieving complete response according to investigator assessment and the response criteria for myeloid/lymphoid neoplasms with FGFR1 rearrangement. In statistical terms, this is a binary outcome summarized as a proportion: each participant is classified as having achieved complete response or not having achieved it, and the endpoint expresses the proportion classified as responders in the defined efficacy-evaluable population. The registry record does not provide the observed proportion or the number of participants who achieved complete response.

The criteria require improvements across several disease features. They include bone marrow findings, the degree of osteomyelofibrosis, peripheral blood measures, and resolution of extramedullary disease that was present before therapy. Persistent low-level dysplasia was permitted because the assignment of dysplasia is subjective. The record states that investigator response criteria were the same for chronic phase and blast phase.

As a general statistical point, a prespecified response definition makes an endpoint more reproducible by stating which observations count as a response. An endpoint that combines multiple clinical and laboratory components also requires careful application of each criterion; meeting only some components would not satisfy a definition that requires all listed improvements. Complete response is used as the primary measure of response, while the listed secondary outcomes include other response categories and time-to-event outcomes. The endpoint timeframe was up to 2513 days (120 21-day treatment cycles). The registry record does not report the primary response result, so neither the response percentage nor its precision can be described.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

How to read a response percentage

The primary outcome is a binary response measure expressed as a percentage of participants. In general, a binary outcome assigns each person to one of two categories, such as achieving complete response or not achieving complete response. The percentage is meaningful only alongside its analysis population and denominator. Here, the registry defines the primary population as enrolled participants with an FGFR1 rearrangement who received at least one dose of study drug. It does not report the number in that population or the number meeting the complete-response definition. The result therefore cannot be reconstructed or checked from the posted record.

What the confidence interval communicates

The primary outcome lists a 95% confidence interval as its measure of dispersion. In general, a confidence interval communicates the uncertainty around an estimated quantity under the statistical method used. A narrower interval indicates greater precision, while a wider interval indicates less precision; neither establishes that the estimate is free of bias. The registry record does not give the interval limits, so the precision of the response estimate cannot be evaluated.

The population description says confidence intervals were calculated using an exact method, but the description ends before the method is fully specified. The exact procedure is therefore not reported in the registry record. In general, exact methods for proportions can be useful when outcomes are represented by counts and a normal approximation may be questionable. Their interval limits depend on the observed count and denominator, neither of which is available for the primary result. No numerical interval can be inferred from the enrollment figure alone.

Why a single-group design matters

This is a single-group study, rather than a randomized comparison. In general, an estimate from one group answers a descriptive question about the proportion observed in that group; it does not directly quantify a difference between treatments. A confidence interval around a single-group proportion would describe uncertainty about that proportion, not uncertainty about a randomized treatment effect. A single-group response estimate may be useful for describing observed outcomes, but interpretation of cause and effect requires attention to the design and possible alternative explanations.

The study is open-label and uses investigator assessment for the primary endpoint. In general, an assessment based on defined criteria can improve consistency, but open-label assessment means the treatment assignment is not masked. The record does not report details of independent review for the primary complete-response outcome. It does identify cytogenetic outcomes assessed by local analysis and investigator evaluation, and one partial cytogenetic outcome assessed by CRC assessment; those are secondary outcomes, not the primary endpoint.

Endpoint construction and classification

Complete response is defined using several domains rather than a single laboratory value. The criteria cover bone marrow, osteomyelofibrosis, peripheral blood, and extramedullary disease. The record specifies thresholds and findings for these domains, and says that persistent low-level dysplasia was permitted because dysplasia assignment is subjective. It also states that the investigator criteria were the same for chronic phase and blast phase. In general, combining multiple components can make an endpoint clinically descriptive of several aspects of disease status, while requiring consistent measurement and application of each component.

The registry lists the primary parameter as a number and the unit as a percentage of participants. The intended summary is therefore a count-based response proportion with a confidence interval, not a mean change in a continuous measure. The registry record does not report the response numerator, endpoint denominator, estimate, or interval. It also does not report how participants with incomplete assessment or missing endpoint data were handled. Those omissions limit reproducibility and interpretation.

Planning assumptions are not observed results

The record describes assumptions used for planning illustrations: 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. It distinguishes planning illustrations for time-to-event outcomes, which count total events, from other outcomes, which use participants per arm. These assumptions describe hypothetical planning scenarios; they are not the study's observed power, and they do not establish the study's original design justification. The study itself is a single-group trial, while the illustration assumptions refer to two-arm planning. The sample-size justification for the trial is not reported in the registry record.

In general, a significance level is a threshold used in a specified hypothesis-testing procedure, and a two-sided procedure allows departures in either direction. A normal approximation estimates a sampling distribution using a normal model. Such planning calculations depend on their assumptions and should not be confused with evidence that the trial had a particular probability of detecting an effect. No numerical planning results are included in the information available for this analysis.

Other outcomes and time-to-event measures

The listed secondary outcomes include response percentages and time-to-event outcomes. In general, a duration endpoint concerns how long an outcome persists, while progression-free survival and overall survival concern time until defined events. Interpretation of such measures typically depends on explicit event definitions, censoring rules, and follow-up. Those analysis details and numerical estimates are not reported in the registry record. Consequently, the listed outcome names should not be mistaken for reported findings.

The registry lists no analysis entries. It also does not report interim analyses or a full statistical analysis plan. Without those details, the statistical procedures used for secondary outcomes, any adjustment for multiple testing, and handling of missing data cannot be established. The absence of those details is distinct from evidence that a particular procedure was or was not used.

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("Pemigatinib 13.5 mg")
n      <- c(45)
events <- c(31)
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  Pemigatinib 13.5 mg  45  31  68.9  53.4  81.8  54.3  80.5  54.2  80.5

11. Multiplicity, Missing Data and Analysis Populations

The registry lists multiple outcomes: the primary investigator-assessed complete-response percentage and secondary measures that include other response categories, cytogenetic responses, duration of response, progression-free survival, and overall survival. When a study evaluates multiple outcomes, general statistical practice recognizes that repeated hypothesis tests can increase the chance of at least one apparently notable result arising by chance. Whether and how that concern was addressed depends on the analysis plan. A multiplicity strategy is not reported in the registry record, so it is not possible to say whether the analyses were adjusted, ordered hierarchically, or treated as descriptive.

The record does not report a complete statistical analysis plan or interim analyses. It also lists no analysis entries. This means the posted information does not establish the planned testing sequence, analysis models, or decision rules. It would be inappropriate to infer those choices from the phase, endpoint, or design alone.

The primary endpoint population is described as enrolled participants with an FGFR1 rearrangement who received at least one dose of study drug. It includes previously treated and treatment-naive participants. The number meeting these criteria is not reported. Although enrollment is listed as 47, that total should not be substituted for the efficacy-evaluable denominator without confirmation that every enrolled participant met the population definition.

Missing-data handling is also not reported in the registry record. In general, missing outcome assessments can affect the estimated response proportion, and different rules for classifying or excluding participants can lead to different results. The record does not say how unavailable assessments, withdrawal, or incomplete follow-up were treated for the primary endpoint or secondary outcomes. The number of participants with missing endpoint data is likewise not reported.

The primary endpoint description mentions an exact confidence-interval method, but the method text is incomplete in the registry record. Thus, even aside from the absent estimate, the precise interval procedure cannot be fully identified. These gaps limit independent reproduction of the endpoint analysis and assessment of how analysis-population choices, missing data, and multiple outcomes may shape interpretation.

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: acute kidney injury (8.5%), angina pectoris (4.3%), atrioventricular block complete (4.3%), myocardial infarction (4.3%), pneumonia (4.3%).

The safety group is titled Pemigatinib 13.5 mg and lists 47 participants at risk for serious adverse events and 47 at risk for other adverse events. The registry reports 27 participants affected by serious adverse events and 46 affected by other adverse events. It also lists 16 deaths. These are group-level counts; the record does not provide event-level timing or participant-level overlap, so the counts should not be added together or treated as mutually exclusive categories.

The serious adverse event terms listed with percentages are acute kidney injury, 8.5%; angina pectoris, 4.3%; atrioventricular block complete, 4.3%; myocardial infarction, 4.3%; pneumonia, 4.3%; and syncope, 4.3%. These figures describe the listed terms in the safety record. The record does not give corresponding event counts for each term or clarify whether a participant could contribute to more than one term.

In general, an adverse event recorded during a study is not necessarily caused by the study treatment. The listed counts and terms do not establish causality, severity beyond the serious-event classification, or clinical course. The relationship of the reported deaths to treatment, their causes, and their timing are not reported in the registry record. The safety figures are therefore descriptive and should be interpreted within those limits.

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

The registry record establishes that a phase 2, open-label, single-group study evaluated pemigatinib monotherapy in myeloid/lymphoid neoplasms with FGFR1 rearrangement. It specifies an investigator-assessed complete-response endpoint, defines the population intended for that endpoint, and gives a detailed response definition. These design and endpoint details clarify what the study set out to measure.

The primary response result is not reported in the registry record. There is no posted complete-response percentage, numerator, denominator, or confidence interval in the information available for this analysis. Accordingly, the record does not allow readers to assess how often complete response was observed or how precisely it was estimated. The secondary outcomes are listed, but their results are also not reported.

The record does report selected safety information for the Pemigatinib 13.5 mg group: 27 participants affected by serious adverse events, 46 affected by other adverse events, and 16 deaths. It lists several serious adverse event terms and their percentages. These figures describe events recorded in the group; they do not establish that pemigatinib caused them. The registry information does not provide the timing and causes of deaths or the relationship of the events to treatment.

More generally, a single-group study describes outcomes among participants who received the study drug, but does not provide a concurrent randomized comparison. Even if a response estimate were available, it would not by itself quantify how outcomes differ from another treatment or establish what would have happened to comparable participants under a different treatment. Interpretation must also account for the open-label design, investigator assessment, and the absence of reported analysis details.

The trial's completed status and enrollment figure are not substitutes for outcome results. The enrollment of 47 does not establish the number in the primary efficacy-evaluable population, whose definition requires an FGFR1 rearrangement and receipt of at least one dose. No sample-size justification, missing-data method, multiplicity strategy, or full analysis plan is reported in the registry record. The record therefore supports a description of study design, endpoint criteria, and selected safety counts, but not a conclusion about the magnitude or precision of the primary efficacy outcome.

14. Why This Trial Matters Statistically

This trial is statistically notable for the contrast between a detailed primary endpoint definition and the absence of a posted primary result. The registry specifies a complete-response endpoint, its investigator-assessment basis, the population definition, and a 95% confidence interval as the measure of uncertainty. Yet it does not report the response count, percentage, denominator, or interval. This illustrates why endpoint definitions and outcome estimates are both necessary: a carefully specified measurement does not reveal the result unless the observed data and analysis are also available.

The endpoint combines multiple disease features, including bone marrow, osteomyelofibrosis, peripheral blood, and extramedullary disease. Such a definition can characterize response across several domains, but makes transparent criteria and consistent assessment important. The record notes that low-level dysplasia was permitted because its assignment is subjective. It also states that the same investigator criteria applied to chronic phase and blast phase, while not reporting subgroup-specific results.

The single-group, open-label design is important when considering what a response percentage could establish. In general, a one-group estimate describes observed outcomes in that group; it is not a randomized comparison. A clear distinction between descriptive response and comparative effect is especially important when the registry does not report a control group or analysis results.

The safety data also illustrate the distinction between counts and causal conclusions. The record lists serious and other adverse event counts, deaths, and selected serious event terms, but does not report event-level attribution, timing, or causes of death. Statistical description of an event count is not equivalent to evidence that treatment caused that event.

Finally, the registry identifies several secondary outcomes and a confidence-interval approach, but leaves important analysis details unreported. The analysis population size, missing-data handling, multiplicity strategy, and full interval method are not available. These limitations matter because readers need both the result and the analytical context to judge precision, reproducibility, and the scope of the conclusions that a study can support.

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 main trial-specific limitation in the posted information is that the primary complete-response result is absent. The record gives no response count, percentage, or confidence interval, and does not report the number of participants in the efficacy-evaluable population. Although 47 participants are listed as enrolled, the endpoint population additionally requires an FGFR1 rearrangement and receipt of at least one dose, so the enrolled total cannot be assumed to be the endpoint denominator.

The study is open-label and single-group, with investigator assessment of the primary outcome. No concurrent randomized comparator is described. The record does not report details of independent review for the primary endpoint or subgroup results by prior treatment status, chronic phase, or blast phase. The criteria are stated to be the same for chronic and blast phase, but this does not establish that results were similar across them.

The registry lists a 95% confidence interval and mentions an exact method, but the method description is incomplete. No interval limits are posted. The record does not report missing-data handling, treatment of incomplete assessments, a multiplicity strategy, interim analyses, or a full statistical analysis plan. It also does not give participant-level follow-up or numerical results for the listed time-to-event outcomes.

Safety interpretation is limited by the absence of event-level details. The record lists group counts, selected serious event terms and percentages, and deaths, but does not report the timing or causes of deaths or whether events were considered related to treatment. These limitations mean the posted record can describe the design and selected safety counts, but cannot support a full appraisal of efficacy results, uncertainty, or event attribution.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study to Evaluate the Efficacy and Safety of Pemigatinib (INCB054828) in Subjects With Myeloid/Lymphoid Neoplasms With FGFR1 Rearrangement - (FIGHT-203) — NCT03011372.
• Registry record last updated 2025-11-18; status last verified 2025-11.
• Results first posted 2025-11-18.
• 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 record identifies NCT03011372 as a completed phase 2, open-label, multicenter, single-group monotherapy study sponsored by Incyte Corporation. It evaluated pemigatinib in myeloid/lymphoid neoplasms with FGFR1 rearrangement and lists 47 participants enrolled. The study start date is 2017-04-25 and the primary completion date is 2024-10-30.

The primary endpoint is the investigator-assessed percentage achieving complete response, with a stated timeframe of up to 2513 days (120 21-day treatment cycles). The primary response estimate and its confidence interval are not reported in the registry record. The record lists secondary response, cytogenetic, duration, progression-free survival, and overall survival outcomes without numerical results in the information available for this analysis.

For the Pemigatinib 13.5 mg safety group, the record lists 27 participants affected by serious adverse events, 46 affected by other adverse events, and 16 deaths. The relationship of events and deaths to treatment is not reported.