This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Reported estimates are kept separate from the interpretation that follows them, and all numerical results are those posted to the registry.
1. Trial at a Glance
GALATHEA asked whether benralizumab, given at 30 mg or 100 mg, reduced the annual rate of COPD exacerbations compared with placebo over 56 weeks in patients with a baseline blood eosinophil count of at least 220/µL. Neither dose produced a statistically significant reduction in the primary endpoint.
| Feature | GALATHEA |
|---|---|
| Phase | Phase 3 |
| Condition | Moderate to very severe chronic obstructive pulmonary disease, with exacerbation history |
| Design | Randomized, parallel-group, triple-masked, placebo-controlled |
| Arms | 3: benralizumab 30 mg (Arm A), benralizumab 100 mg (Arm B), placebo |
| Enrollment | 1656 |
| Primary endpoint | Annual COPD exacerbation rate over 56 weeks in patients with baseline EOS ≥220/µL |
| Primary analysis | Negative binomial model; rate ratio versus placebo for each dose |
| Primary purpose | Treatment |
| ClinicalTrials.gov | NCT02138916 |
| Lead sponsor | AstraZeneca (industry) |
2. Clinical Question
The central question was whether benralizumab could reduce the frequency of COPD exacerbations in patients whose blood eosinophil count suggested an eosinophilic component to their disease. Because two doses were tested against a common placebo group, the trial answers two related superiority questions rather than one.
Population
Patients with moderate to very severe COPD and a history of exacerbations. The primary analysis population was the full analysis set with baseline EOS ≥220/µL; patients with EOS <220/µL formed a separate cohort analysed as a secondary endpoint.
Intervention
Benralizumab 30 mg (Arm A) or benralizumab 100 mg (Arm B), administered as investigational product (IP) through the 56-week treatment period.
Comparator
Placebo, under triple masking, so that participants, care providers and investigators were unaware of assignment.
Primary question
In patients with baseline EOS ≥220/µL, does either dose of benralizumab lower the annual COPD exacerbation rate relative to placebo?
3. Trial Design
Benralizumab 30 mg
- Lower of the two benralizumab doses
- Compared with the shared placebo group
- Treatment period from first IP to week 56
Benralizumab 100 mg
- Higher of the two benralizumab doses
- Compared with the shared placebo group
- Treatment period from first IP to week 56
Placebo
- Common comparator for both doses
- Matched under triple masking
- Patients continued background COPD therapy, which was included as a model covariate
Shared framework
- Randomized, parallel-group allocation
- Triple masking
- Eosinophil cohort (≥220 vs <220/µL) defines the primary population
- All tests framed as superiority, two-sided 95% CIs
4. Eosinophil Cohorts and Analysis Populations
The trial was built around a biomarker hypothesis: that patients with higher blood eosinophil counts would be most likely to benefit from an eosinophil-targeted therapy. The registry defines analysis populations by baseline EOS, and the eosinophil cohort also appears as a covariate in most models.
| Analysis population | Role |
|---|---|
| Full analysis set, baseline EOS ≥220/µL | Primary endpoint and most secondary efficacy endpoints |
| Full analysis set, baseline EOS <220/µL | Secondary analysis of the annual exacerbation rate in the lower-eosinophil cohort |
| Participants at risk for adverse events | Serious adverse events by arm: 554 (30 mg), 552 (100 mg), 550 (placebo) |
A full analysis set generally follows the intention-to-treat principle, analysing randomized patients according to their assigned group. Restricting the primary analysis to a biomarker-defined subset is not the same as a post hoc subgroup analysis: here, the EOS ≥220/µL population was the prespecified target of the primary endpoint, so its comparison carries confirmatory status.
5. Endpoints
Primary endpoint
| Endpoint | Registry definition | Time frame |
|---|---|---|
| Annual COPD Exacerbation Rate Over 56 Weeks, baseline EOS ≥220/µL | A COPD exacerbation is defined by symptomatic worsening of COPD requiring use of systemic corticosteroids for at least 3 days (a single depot injectable dose of corticosteroids is considered equivalent to a 3-day course), and/or use of antibiotics, and/or an inpatient hospitalization or death due to COPD. The annual exacerbation rate is the number of exacerbations per year; its raw rate is the number of exacerbations divided by the treatment period, normalized to an annual rate, and is estimated by a negative binomial model. The rate ratio between two treatment groups is also estimated through this model. | From first IP to week 56 |
Secondary endpoints with posted analyses
| Endpoint (shortened) | Population | Unit | Time frame |
|---|---|---|---|
| Annual COPD exacerbation rate over 56 weeks | EOS <220/µL | Exacerbations per year | From first IP to week 56 |
| Mean change from baseline to week 56 in pre-bronchodilator FEV1 (L) | EOS ≥220/µL | Liter | First IP up to end of treatment week 56 |
| Mean change from baseline in SGRQ total score | EOS ≥220/µL | Percentage | First IP up to week 56 |
| Mean change from baseline in CAT total score | EOS ≥220/µL | Score on a scale | First IP up to week 56 |
| Mean change from baseline in E-RS: COPD total score | EOS ≥220/µL | Score on a scale | First IP up to week 56 |
| Mean change from baseline in total rescue medication use | EOS ≥220/µL | Puffs/day | First IP up to week 56 |
| Mean change from baseline in proportion of nights with awakenings due to respiratory symptoms | EOS ≥220/µL | Proportion of nights | First IP up to week 56 |
| Annual EXACT-PRO exacerbation rate over 56 weeks | EOS ≥220/µL | Exacerbations per year | Immediately following first IP up to week 56 |
| Number of participants having at least 1 COPD exacerbation | EOS ≥220/µL | Participants | Immediately following first IP up to week 56 |
| Annual COPD exacerbation rate associated with ER or hospitalization over 56 weeks | EOS ≥220/µL | Exacerbations per year | Immediately following first IP up to week 56 |
The primary endpoint is a count outcome with variable exposure time: patients contribute different lengths of follow-up, and some experience several exacerbations while many experience none. That structure drives the choice of the negative binomial model described below.
6. Primary Endpoint Results
Both primary comparisons used a negative binomial model in the full analysis set with baseline EOS ≥220/µL. The model included treatment group, EOS cohort, region, background therapy and the number of exacerbations in the previous year. Both were superiority hypotheses with two-sided 95% confidence intervals.
Benralizumab 30 mg vs placebo
Rate ratio for annual COPD exacerbations
95% CI: 0.8–1.15 · P = 0.6490
Full analysis set, baseline EOS ≥220/µL · Negative binomial model
What the estimate means. A rate ratio of 0.96 means that, after adjustment for the model covariates, the estimated annual exacerbation rate in the 30 mg group was 4% lower than in the placebo group. This is a ratio of model-estimated rates, not a difference in the number of exacerbations and not the proportion of patients who avoided an exacerbation.
What it does not mean. It does not show that benralizumab 30 mg reduces exacerbations. The point estimate is close to 1, and the result is fully compatible with no effect.
Precision. The 95% CI of 0.8 to 1.15 spans values from a 20% lower rate to a 15% higher rate. The data are consistent with modest benefit, no difference, or modest harm, so the comparison does not pin down the direction of any effect.
The p-value. P = 0.6490 describes how compatible the observed data are with a true rate ratio of 1 under the model. It does not measure the size of the effect, and a large p-value is not evidence that the effect is exactly zero; it simply indicates the trial did not distinguish this dose from placebo.
Cautions. Negative binomial rate ratios assume the covariates act multiplicatively on the rate and that overdispersion is adequately captured by a single dispersion parameter. Because the primary population is defined by baseline EOS, conclusions apply to that biomarker-selected group.
Benralizumab 100 mg vs placebo
Ratio for annual COPD exacerbations
95% CI: 0.69–1.00 · P = 0.0525
Full analysis set, baseline EOS ≥220/µL · Negative binomial model
| Comparison | Effect measure (registry label) | Estimate | 95% CI (two-sided) | P-value |
|---|---|---|---|---|
| Benralizumab 30 mg vs placebo | Rate ratio | 0.96 | 0.8 to 1.15 | 0.6490 |
| Benralizumab 100 mg vs placebo | Risk Ratio (RR) | 0.83 | 0.69 to 1.00 | 0.0525 |
What the estimate means. A ratio of 0.83 means the model-estimated annual exacerbation rate with benralizumab 100 mg was 17% lower than with placebo in the EOS ≥220/µL population.
What it does not mean. It does not establish a treatment effect. With P = 0.0525 and an upper confidence limit of 1.00, the comparison did not meet the conventional two-sided 0.05 threshold. Describing it as a "trend" or "near-significant" result invites over-interpretation; the prespecified test was not met.
Precision. The 95% CI runs from 0.69 to 1.00, ranging from a 31% lower rate to no difference. The interval sits almost entirely below 1, so the data lean toward a reduction, but they cannot exclude a rate ratio of 1.
The p-value. A p-value just above or just below 0.05 carries nearly the same evidential weight; the 0.05 line is a decision rule, not a boundary in nature. At the same time, a p-value just above 0.05 does not measure how large the effect is, and it cannot be rescued by pointing to the point estimate.
Cautions. With two doses tested against one placebo group, some form of multiplicity control is normally needed to keep the familywise type I error at its nominal level. The registry does not describe the procedure, but any adjustment would make the threshold for each comparison stricter, not looser. The consistency of this result with the 30 mg arm should also be weighed: a clearer effect at 100 mg than at 30 mg is compatible with a dose-response, but also with chance variation around a small or null effect.
7. Secondary Exacerbation Endpoints
Several secondary endpoints examined exacerbations from different angles: in the lower-eosinophil cohort, using a patient-reported definition (EXACT-PRO), as the proportion of patients with any exacerbation, and restricted to more severe events leading to an emergency room (ER) visit or hospitalization.
| Endpoint | Comparison | Method | Estimate (registry label) | 95% CI | P-value |
|---|---|---|---|---|---|
| Annual exacerbation rate, EOS <220/µL | 30 mg vs placebo | Negative binomial | 1.07 (Risk Ratio) | 0.86 to 1.34 | 0.5236 |
| Annual exacerbation rate, EOS <220/µL | 100 mg vs placebo | Negative binomial | 1.02 (Risk Ratio) | 0.82 to 1.27 | 0.8812 |
| Annual EXACT-PRO exacerbation rate | 30 mg vs placebo | Negative binomial | 1.09 (Rate ratio) | 0.89 to 1.34 | 0.4080 |
| Annual EXACT-PRO exacerbation rate | 100 mg vs placebo | Negative binomial | 0.98 (Rate ratio) | 0.80 to 1.21 | 0.8688 |
| At least 1 COPD exacerbation | 30 mg vs placebo | Cochran-Mantel-Haenszel | 0.90 (Odds Ratio) | 0.66 to 1.22 | 0.4850 |
| At least 1 COPD exacerbation | 100 mg vs placebo | Cochran-Mantel-Haenszel | 0.89 (Odds Ratio) | 0.65 to 1.21 | 0.4489 |
| Exacerbations with ER visit or hospitalization | 30 mg vs placebo | Negative binomial | 1.06 (Rate ratio) | 0.73 to 1.53 | 0.7733 |
| Exacerbations with ER visit or hospitalization | 100 mg vs placebo | Negative binomial | 0.58 (Rate ratio) | 0.39 to 0.89 | 0.0114 |
All populations are the full analysis set with baseline EOS ≥220/µL except the first two rows (EOS <220/µL). The EOS <220/µL models included treatment group, region and number of exacerbations in the previous year (the 100 mg model also included EOS cohort). The ER/hospitalization models replaced the prior-exacerbation count with an indicator for previous-year exacerbations associated with hospitalization.
Reading the secondary exacerbation results
- Lower-eosinophil cohort. Both rate ratios sit slightly above 1 with intervals spanning 1. This is what a biomarker hypothesis would predict if any benefit were concentrated in the high-eosinophil group, but because the primary comparison in that group was not positive either, the contrast between cohorts is not informative about effect modification. A formal interaction test would be needed to claim that the effect differs by EOS level.
- EXACT-PRO. The patient-reported exacerbation definition gave estimates of 1.09 and 0.98, both close to 1. The symptom-based and treatment-based definitions tell a consistent story of little difference from placebo.
- Any exacerbation. Odds ratios of 0.90 and 0.89 summarise a binary outcome (at least one event versus none) rather than a rate. They discard information on repeat events, so they are expected to be less sensitive than the rate analysis, and neither interval excludes 1.
- ER or hospitalization. The 100 mg estimate of 0.58 corresponds to a 42% lower estimated rate of severe exacerbations, with a 95% CI of 0.39 to 0.89 and a nominal P = 0.0114. The 30 mg estimate was 1.06. A favourable secondary result after a primary endpoint that was not met should be treated as hypothesis-generating: it is one of many secondary comparisons, severe events are less frequent (which produces wider intervals and more sampling variability), and there is no corresponding signal at the lower dose.
8. Secondary Lung-Function and Patient-Reported Endpoints
Continuous endpoints were analysed with mixed models for repeated measures. Each model included treatment group, the baseline value of the outcome, EOS cohort, region, background therapy, visit and a treatment-by-visit interaction. Estimates are mean differences versus placebo; negative values favour benralizumab for the symptom scores, rescue medication and night awakenings, while positive values favour benralizumab for FEV1.
| Endpoint (EOS ≥220/µL) | Comparison | Mean difference | 95% CI | P-value |
|---|---|---|---|---|
| Pre-bronchodilator FEV1 (L) | 30 mg vs placebo | 0.007 | -0.035 to 0.048 | 0.7550 |
| Pre-bronchodilator FEV1 (L) | 100 mg vs placebo | 0.021 | -0.021 to 0.062 | 0.3285 |
| SGRQ total score | 30 mg vs placebo | -1.011 | -2.887 to 0.865 | 0.2906 |
| SGRQ total score | 100 mg vs placebo | -2.136 | -4.020 to -0.251 | 0.0264 |
| CAT total score | 30 mg vs placebo | -0.19 | -1.08 to 0.70 | 0.6782 |
| CAT total score | 100 mg vs placebo | -0.81 | -1.70 to 0.08 | 0.0753 |
| E-RS: COPD total score | 30 mg vs placebo | -0.585 | -1.260 to 0.089 | 0.0889 |
| E-RS: COPD total score | 100 mg vs placebo | -0.703 | -1.378 to -0.028 | 0.0413 |
| Rescue medication use (puffs/day) | 30 mg vs placebo | -0.348 | -0.728 to 0.032 | 0.0728 |
| Rescue medication use (puffs/day) | 100 mg vs placebo | -0.487 | -0.868 to -0.107 | 0.0121 |
| Proportion of nights with awakenings | Benralizumab 30 mg | -0.041 | -0.077 to -0.006 | 0.0235 |
| Proportion of nights with awakenings | Benralizumab 100 mg | -0.044 | -0.080 to -0.008 | 0.0158 |
For the night-awakening endpoint the registry names only the benralizumab group in the comparison field; as with the other mean-difference analyses, the estimate is a difference from placebo.
What the pattern shows
FEV1 differences of 0.007 L and 0.021 L are small, with intervals centred near zero, so the trial provides no evidence of a lung-function effect. Among patient-reported and diary outcomes, the point estimates are consistently in the favourable direction, and several 100 mg comparisons (SGRQ, E-RS: COPD, rescue medication) and both night-awakening comparisons have intervals excluding zero. The 100 mg SGRQ difference of -2.136 units has a 95% CI of -4.020 to -0.251, meaning the data are compatible with anything from a very small to a moderate improvement relative to placebo.
These nominally significant results must be read in context. They are secondary endpoints, several are correlated measures of the same underlying symptom burden, and the primary endpoint was not met. A consistent direction across correlated outcomes is less persuasive than it looks, because the outcomes are not independent pieces of evidence.
9. Safety: Serious Adverse Events
The registry reports the number of participants with at least one serious adverse event in each arm.
| Arm | Participants with serious adverse events | Participants at risk |
|---|---|---|
| Benralizumab 30 mg | 151 | 554 |
| Benralizumab 100 mg | 177 | 552 |
| Placebo | 176 | 550 |
The counts in the 100 mg and placebo arms are nearly identical, and the 30 mg arm has fewer participants with serious events. No formal statistical comparison of serious adverse events is posted, and safety counts of this kind are descriptive: they are not adjusted for exposure time and group all serious events together, regardless of cause or relatedness. A risk ratio with an exact or Wald confidence interval is the usual summary if a formal comparison is wanted, but individual event types, not the overall serious-event count, are generally more informative about specific harms.
10. Statistical Methodology
Negative binomial regression for exacerbation rates
Exacerbations are counts, recorded over treatment periods that vary between patients because of discontinuation or withdrawal. A Poisson model assumes the variance equals the mean, but exacerbation counts are typically overdispersed: a minority of patients exacerbate repeatedly while many have none. The negative binomial model adds a dispersion parameter so that between-patient heterogeneity widens the standard errors appropriately, and it uses the log of the treatment period as an offset so that rates are compared per unit of time.
Here Yi is the exacerbation count, ti the treatment period, Xi the covariates (EOS cohort, region, background therapy, prior-year exacerbations) and k the dispersion parameter. The rate ratio is exp(βtrt).
Mixed models for repeated measures
FEV1, SGRQ, CAT, E-RS: COPD, rescue medication and night awakenings were measured repeatedly. The mixed models included visit, treatment and a treatment-by-visit interaction, allowing a separate treatment difference at each visit; the week-56 (or overall) contrast is then extracted from the model. Adjusting for the baseline value of each outcome reduces residual variance and improves precision. Mixed models use all available post-baseline measurements and give valid estimates if missing data are missing at random given the observed data, an assumption that cannot be verified from the data alone.
Cochran-Mantel-Haenszel test for the binary exacerbation endpoint
The proportion of patients with at least one exacerbation was compared with a CMH test controlling for EOS cohort, region and background therapy. The CMH approach combines 2×2 tables across strata into a common odds ratio, which protects against confounding by the stratifying variables and assumes the odds ratio is broadly similar across strata.
Covariate adjustment
Every posted model adjusts for prognostic variables, most importantly the number of exacerbations in the previous year, which is one of the strongest predictors of future exacerbations. In a randomized trial, covariate adjustment is not needed to remove bias; its role is to increase precision and to align the analysis with factors that may have been used to balance the design.
Hypothesis framework
All posted analyses are superiority tests with two-sided 95% confidence intervals. For ratio measures the null value is 1; for mean differences it is 0. Superiority is concluded when the interval excludes the null value and the p-value falls below the prespecified significance level.
11. Multiple Comparisons and Nominal P-values
GALATHEA produced two primary comparisons and twenty posted secondary comparisons. The registry does not describe the multiplicity procedure, so the table below classifies results by their role rather than by any formal testing hierarchy.
| Analysis | Role | Interpretation |
|---|---|---|
| Exacerbation rate, EOS ≥220/µL, 30 mg and 100 mg | Primary | Confirmatory; neither comparison reached P < 0.05 |
| Exacerbation rate, EOS <220/µL | Secondary | Supports understanding of the biomarker hypothesis; not a test of interaction |
| EXACT-PRO, any exacerbation, ER/hospitalization | Secondary | Supportive; nominal p-values only |
| FEV1, SGRQ, CAT, E-RS: COPD, rescue medication, night awakenings | Secondary | Supportive; correlated outcomes; nominal p-values only |
12. Statistical Methods Explained
Why was a negative binomial model used instead of a Poisson model or a t-test?
Exacerbation counts are non-negative integers, heavily skewed, and recorded over unequal follow-up. A t-test on raw counts ignores both the count nature of the data and unequal exposure. A Poisson model handles counts and exposure but assumes variance equals the mean; when some patients exacerbate much more often than others, Poisson standard errors are too small and p-values too optimistic. The negative binomial model relaxes that assumption through its dispersion parameter.
What does a rate ratio of 0.83 with a 95% CI of 0.69 to 1.00 tell us?
It says the best estimate is a 17% lower annual exacerbation rate with 100 mg than with placebo, but the plausible range extends to no difference at all. The upper limit touching 1.00 matches the P value of 0.0525: the interval and the test carry the same information, and neither supports a claim of superiority at the two-sided 0.05 level.
Why is the 100 mg primary result labelled a "risk ratio" when it is a rate ratio?
The label is a registry entry choice. The analysis is a negative binomial model of exacerbations per year, which estimates a ratio of rates. A true risk ratio compares the probability of an event over a fixed period and would be estimated from binary data. Confusing the two can change the clinical reading: a 17% lower rate of events is not the same as a 17% lower chance of having any event.
Why was the proportion with at least one exacerbation analysed with a CMH odds ratio?
Dichotomising the outcome converts each patient's count into "any exacerbation: yes or no". A CMH test compares these proportions while stratifying on EOS cohort, region and background therapy, producing a common odds ratio across strata. The odds ratio is not the same as a risk ratio; when the outcome is common, an odds ratio lies further from 1 than the corresponding risk ratio would.
Does the positive ER/hospitalization result at 100 mg rescue the trial?
No. A rate ratio of 0.58 with a 95% CI of 0.39 to 0.89 is a notable estimate, but it is one of many secondary comparisons after a primary endpoint that was not met, and the 30 mg estimate for the same endpoint was 1.06. Its role is to generate hypotheses about whether severe events respond differently from overall exacerbations, not to confirm efficacy.
Why include a treatment-by-visit interaction in the mixed models?
Without it, the model forces the treatment effect to be identical at every visit. With it, the difference versus placebo can evolve over the 56 weeks, which is realistic for outcomes such as symptom scores. The reported mean difference is then a specific contrast from that flexible model, while the repeated-measures structure accounts for the correlation of measurements within the same patient.
13. Statistical Interpretation vs Clinical Interpretation
Statistical interpretation
Neither prespecified primary comparison excluded a rate ratio of 1. The 30 mg estimate was close to 1; the 100 mg estimate favoured benralizumab but its interval reached 1.00. Secondary findings are nominal and should be viewed as exploratory.
Clinical interpretation
In this population the trial did not demonstrate that benralizumab lowers the overall COPD exacerbation rate. Signals in severe exacerbations and some patient-reported outcomes at 100 mg describe where further study might focus, not established benefit.
14. Limitations
- Primary endpoint not met: neither dose achieved a statistically significant reduction in the primary endpoint, which limits confirmatory conclusions from any secondary endpoint.
- Multiplicity: two doses and many secondary endpoints create numerous opportunities for nominally significant findings by chance; the registry does not document the testing hierarchy.
- Shared placebo group: the two dose comparisons are correlated, so apparent agreement or disagreement between doses partly reflects the same control data.
- Biomarker threshold: the 220/µL EOS cut-point dichotomises a continuous measurement; results for patients near the threshold may not differ meaningfully from those just across it.
- Cohort comparison is not an interaction test: contrasting the EOS ≥220 and <220/µL results does not by itself establish that treatment effect depends on eosinophil level.
- Model assumptions: negative binomial estimates rely on correctly specified dispersion and multiplicative covariate effects; mixed models rely on data being missing at random.
- Reporting scope: ClinicalTrials.gov does not report baseline characteristics by cohort, subgroup analyses beyond the EOS cohorts, or long-term follow-up in the posted analyses, so these aspects cannot be assessed from the registry.
- Safety summary: serious adverse event counts are aggregated and not exposure-adjusted, so they describe overall frequency rather than specific harms.
15. Why This Trial Matters Statistically
GALATHEA is a useful teaching case precisely because its primary result was not positive. It shows how count outcomes are modelled, how a near-threshold p-value should be read, and why secondary signals after a failed primary endpoint need restraint.
| Concept | How it appears in GALATHEA |
|---|---|
| Negative binomial regression | Annual exacerbation rates with overdispersion and variable exposure time |
| Rate ratio | Primary effect measure: 0.96 (30 mg) and 0.83 (100 mg) versus placebo |
| Rate ratio vs risk ratio | Registry labels differ for estimates from the same model |
| Confidence intervals | An upper limit of 1.00 aligned with P = 0.0525 |
| P-values | Near-threshold primary result; many nominal secondary p-values |
| Mixed-effects models | Repeated measures for FEV1, SGRQ, CAT, E-RS: COPD, rescue medication, night awakenings |
| Cochran-Mantel-Haenszel test | Stratified odds ratio for at least one exacerbation |
| Odds ratio | Binary exacerbation endpoint summary |
| Multi-arm design | Two doses sharing a placebo group |
| Biomarker-defined population | Primary analysis restricted to baseline EOS ≥220/µL |
| Multiplicity | Secondary findings after a primary endpoint that was not met |
16. Related Tutorials
Learn more about the methods used in this trial:
17. Related Calculators
18. Sources
- ClinicalTrials.gov: NCT02138916 – Benralizumab Efficacy in Moderate to Very Severe Chronic Obstructive Pulmonary Disease (COPD) With Exacerbation History (GALATHEA).
- PubMed: PMID 31112385.
- PubMed: PMID 31575508.
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19. Record Summary
GALATHEA was a randomized, triple-masked, three-arm phase 3 trial enrolling 1656 patients with moderate to very severe COPD. In the prespecified EOS ≥220/µL population, the negative binomial rate ratios for annual exacerbations were 0.96 (95% CI 0.8–1.15; P = 0.6490) for 30 mg and 0.83 (95% CI 0.69–1.00; P = 0.0525) for 100 mg versus placebo, so neither comparison met its superiority test. The most useful reading combines the relative rate estimates, their confidence intervals, an honest treatment of the near-threshold p-value, and appropriate caution about nominally significant secondary endpoints in a multi-arm, multi-endpoint design.