Study of Efficacy and Safety of Brolucizumab Versus Panretinal Photocoagulation Laser in Patients With Proliferative Diabetic Retinopathy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Study of Efficacy and Safety of Brolucizumab Versus Panretinal Photocoagulation Laser in Patients With Proliferative Diabetic Retinopathy (NCT04278417), a randomized phase 3 study. The primary outcome is Change From Baseline in Best-corrected Visual Acuity (BCVA) at Week 54 for the Study Eye.

2. Clinical Question

3. Trial Design

This was a Phase III, randomized, single-masked, parallel-group, multicenter study of brolucizumab 6 mg versus PRP laser in people with proliferative diabetic retinopathy. The registry records enrollment of 689 and a completed status. The recorded study dates are 2020-11-19 for the start and 2023-10-30 for primary completion. The planned study duration is described in the official title as 96 weeks.

The two strategies differed in both treatment type and schedule. Brolucizumab was given as intravitreal injections, with 3 loading injections at 6-week intervals followed by 12-week maintenance injections through Week 90. PRP began with 1-4 sessions up to Week 12, and further PRP could be given as needed. This is therefore a comparison of treatment strategies, not simply of two doses of the same intervention.

The primary outcome was change from baseline in study-eye BCVA at Week 54. The registry also lists outcomes concerning PDR status, center-involved diabetic macular edema (CI-DME), visual acuity over time, and changes in diabetic retinopathy severity scale (DRSS) scores. Follow-up outcomes extend to Week 96 for some measures.

The registry record does not report the randomization ratio, the identity of the party or parties masked, the original sample-size justification, or detailed protocol assumptions. Specific eligibility criteria beyond the primary analysis description and BCVA threshold are not reported in the registry record. The record describes a randomized design, but the posted results do not by themselves establish how every aspect of conduct or follow-up was implemented.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Full Analysis Set- Last Observation Carried Forward (FAS - LOCF), for patients with a valid measurement with no protocol deviations with impact.

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 Change From Baseline in Best-corrected Visual Acuity (BCVA) at Week 54 for the Study Eye, measured over Baseline, Week 54.

The primary endpoint is change from baseline in BCVA in the study eye at Week 54, measured in ETDRS letters. ETDRS visual acuity charts provide a standardized way to record how many letters a participant can read at a specified distance and under a defined testing protocol. The registry states that possible scores range from 0 to 100 and that a higher score represents better visual function.

Change from baseline focuses the comparison on how the measured score differs from each participant’s starting value, rather than on the Week 54 score alone. The endpoint is continuous: it retains information about the scale of change instead of reducing the result to a category such as improved or not improved. This can make it useful for comparing average visual-acuity changes between randomized groups.

The primary analysis is described as a least-squares mean analysis in the FAS-LOCF population. Last observation carried forward was used to impute missing values, and the stated analysis population required a valid measurement without protocol deviations with impact. The registry does not report the full set of covariates, the detailed model specification, or how the imputation approach was evaluated. Those details matter when judging how the endpoint estimate relates to the observed measurements and to the analysis population.

7. Results Posted in the Registry

• Panretinal Photocoagulation Laser Arm: mean -4.20 versus 0.20 on control; difference -4.40 (95% CI -6.41 to -2.39), standardized effect d = -0.33; z-test p = <0.001.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Number and Percentage of Subjects With no Proliferative Diabetic Retinopathy (PDR) at Week 54 for the Study Eye

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Panretinal Photocoagulation Laser Arm: 22.4% (65/290) versus 63.6% (187/294) on control; risk difference -41.2 percentage points (95% CI -48.5 to -33.9), risk ratio 0.35 (0.28–0.44); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically lower for Panretinal Photocoagulation Laser Arm than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Number and Percentage of Subjects With no Proliferative Diabetic Retinopathy (PDR) at Week 96 for the Study Eye

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Panretinal Photocoagulation Laser Arm: 28.4% (86/303) versus 60.6% (188/310) on control; risk difference -32.3 percentage points (95% CI -39.7 to -24.8), risk ratio 0.47 (0.38–0.57); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically lower for Panretinal Photocoagulation Laser Arm than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Number and Percentage of Subjects With Center-involved Diabetic Macular Edema (CI- DME) up to Week 54 for the Study Eye

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Panretinal Photocoagulation Laser Arm: 72.7% (248/341) versus 31.1% (108/347) on control; risk difference 41.6 percentage points (95% CI 34.8 to 48.4), risk ratio 2.34 (1.97–2.77); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for Panretinal Photocoagulation Laser Arm than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The secondary outcomes cover several dimensions beyond the primary Week 54 change in BCVA: whether PDR was absent at Week 54 and Week 96, CI-DME through follow-up, visual-acuity change accumulated over time, and DRSS improvement or worsening. This range can help describe how the treatment strategies compare across disease status and visual measures. It also means that the secondary findings address different questions and should not be collapsed into a single overall claim.

Among the posted results, the Week 54 no-PDR analysis and CI-DME through Week 54 have sponsor-reported superiority analyses. The record also includes posted counts for no PDR at Week 96, but no sponsor-reported analysis for that outcome. The listed secondary outcomes include other measures for which detailed numerical results are not included in the record summarized in the posted results. Missing detailed results should not be interpreted as evidence of no difference.

The secondary outcomes complement the primary visual-acuity endpoint, but they do not replace it. A result on PDR status or CI-DME is not the same estimand as change in BCVA, and a finding at one follow-up time does not automatically establish the result at another. For the same reason, statistical significance on one endpoint cannot be transferred to a different endpoint.

Many outcomes and time points create multiple opportunities to find a small p-value by chance. Unless multiplicity is addressed through a prespecified testing strategy or adjustment, unadjusted secondary p-values carry less confirmatory weight than a result from a designated primary analysis. The registry record does not report a comprehensive multiplicity plan or enough information to determine how the secondary outcomes were prioritized. They are best read as supportive or exploratory evidence within the reported analysis, with attention to their individual definitions and uncertainty.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Number and Percentage of Subjects With no Proliferative Diabetic Retinopathy (PDR) at Week 54 for the Study Eye
• Number and Percentage of Subjects With no Proliferative Diabetic Retinopathy (PDR) at Week 96 for the Study Eye
• Number and Percentage of Subjects With Center-involved Diabetic Macular Edema (CI- DME) up to Week 54 for the Study Eye
• Number and Percentage of Subjects With Center-involved Diabetic Macular Edema (CI- DME) up to Week 96 for the Study Eye
• Area Under the Curve in Change From Baseline in BCVA up to Week 54 and up to Week 96 - for the Study Eye
• Diabetic Retinopathy Severity Scale (DRSS): Number and Percentage of Subjects With ≥2 Steps Improvement From Baseline in Early Treatment Diabetic Retinopathy Study (ETDRS) DRSS Score at Week 54 and Week 96
• Diabetic Retinopathy Severity Scale (DRSS): Number and Percentage of Subjects With ≥2 Steps Worsening From Baseline in Early Treatment Diabetic Retinopathy Study (ETDRS) DRSS Score at Week 54 and Week 96
• Diabetic Retinopathy Severity Scale (DRSS): Number and Percentage of Subjects With ≥3 Steps Improvement From Baseline in Early Treatment Diabetic Retinopathy Study (ETDRS) DRSS Score at Week 54 and Week 96

9. Statistical Interpretation

10. Statistical Methods Explained

The registry reports an ANCOVA analysis for the primary outcome. ANCOVA, or analysis of covariance, models a continuous outcome while accounting for selected covariates. In a randomized study, such adjustment can improve precision or account for specified baseline features, but the exact covariates and model specification are not reported in the registry record. The sponsor reports a least-squares mean difference, which is a model-based comparison rather than simply a subtraction of the posted raw group averages.

What does the unadjusted recalculation represent?

The recalculated continuous comparison uses the posted group means and standard errors to estimate an unadjusted difference. The subtraction order is PRP minus brolucizumab: the PRP mean change is -4.2 and the brolucizumab mean change is 0.2, yielding the posted recalculated estimate of -4.4. The negative sign reflects that subtraction order; it does not indicate a different result from a comparison expressed as brolucizumab minus PRP. The recalculated interval is -6.41 to -2.39, with p < 0.001.

The recalculation uses an approximate pooled standard deviation of 13.36, and its standardized effect estimate is -0.329 in that same subtraction order. The standard deviation is marked as approximate because it is derived from the group standard errors and sample sizes rather than reported directly as a pooled observed spread. These recalculated quantities are descriptive checks from summary statistics. They do not adjust for covariates or account for any analysis features that are not represented in those summaries.

What does the reported test address?

The registry’s ANCOVA result reports a least-squares mean difference of 4.4, a 95% confidence interval from 2.4 to 6.4, and p < 0.001. The reported comparison is expressed in the direction brolucizumab minus PRP, opposite to the recalculated subtraction. The registry labels the result as non-inferiority and separately reports a superiority analysis with p < 0.001. A p-value describes the compatibility of the data with a specified null hypothesis under the analysis assumptions; it does not describe the size or practical importance of an effect. The non-inferiority margin and detailed testing procedure are not reported in the registry record.

Why can over-dispersion matter for binary outcomes?

For binary outcomes, each participant is classified into an outcome category, such as whether PDR was absent at a specified visit. A simple model may assume that the observed variation is fully described by its probability structure. Over-dispersion means that the data vary more than that model expects. If ignored, uncertainty estimates can be too small and tests can appear more decisive than warranted. This is a general statistical consideration; the registry record does not report an over-dispersion assessment for these outcomes.

The posted recalculated binary comparisons are unadjusted risk differences, with the direction set by comparing PRP with brolucizumab. For example, the Week 54 no-PDR risk difference is negative because the posted proportion for PRP is lower than the posted proportion for brolucizumab. Risk differences express an absolute contrast between proportions. They differ from relative measures such as risk ratios or odds ratios, which express a comparison on a relative scale. The registry also reports a Cochran-Mantel-Haenszel method for selected secondary analyses, but the detailed stratification factors are not reported in the registry record.

For continuous outcomes, a confidence interval describes a range of values compatible with the data and model at the stated confidence level. For binary outcomes, intervals for risk differences likewise communicate uncertainty in the absolute contrast. Neither kind of interval is a guarantee that the true value lies within the calculated limits. Width depends on the amount of information and variability, as well as on the analysis method.

The primary endpoint uses LOCF imputation for missing values. This approach carries a participant’s last observed measurement forward to a later measurement point. As a general matter, an imputation method relies on assumptions about what unobserved measurements would have been; LOCF can be problematic when outcomes change over time or when missingness is related to participants’ underlying outcomes. The registry does not report sensitivity analyses or enough detail to assess the consequences of this choice. The full analysis population definition is reported, but other analysis populations and their roles are not described in the available record.

11. Confidence Intervals and Precision

The primary sponsor-reported 95% confidence interval is 2.4 to 6.4 letters for the least-squares mean difference in the direction of brolucizumab minus PRP. It excludes zero and is paired with p < 0.001. The interval communicates uncertainty about the model-based difference; it does not mean that every participant experienced a change within those limits, nor does it describe the range of individual responses.

The unadjusted recalculation reports the comparison in the reverse direction, PRP minus brolucizumab, as -4.4 letters with a 95% confidence interval from -6.41 to -2.39. These estimates and intervals are expressed in different subtraction orders. They should be read accordingly rather than compared by sign alone. The recalculated interval is based on summary statistics and an approximate pooled standard deviation, while the sponsor’s interval comes from the reported ANCOVA analysis.

For the selected binary outcomes, the posted recalculated risk-difference intervals also indicate uncertainty around absolute contrasts. At Week 54, the no-PDR risk difference is -0.412, with an interval from -0.485 to -0.339; for CI-DME up to Week 54, the risk difference is 0.416, with an interval from 0.348 to 0.484. Those comparisons use PRP minus brolucizumab, and their signs depend on that ordering. The sponsor’s reported Week 54 no-PDR difference is expressed in percentage points in the opposite direction, with a 95% interval from 32.0 to 46.8.

Confidence intervals reflect sampling uncertainty under their analysis assumptions, not uncertainty from every possible source. They do not resolve questions about missing-data assumptions, multiplicity, the non-inferiority margin, or generalizability. The registry record does not report all of those details.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm for the listed continuous or binary comparisons, not total participants and not total events. The planning illustration assumes a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It uses the observed effect as a reference and considers detecting the stated fraction of that effect. The original trial’s own sample-size assumptions and justification are not reported in the registry record.

The 80% power column gives the illustrated participants per arm for a design with an 80% chance of detecting the assumed effect under those planning assumptions, if the assumptions hold. The 90% power column gives the corresponding planning number for a higher chance of detecting that effect. These are design calculations, not guarantees about a future study’s results. The figures are based on the observed effect in this trial, rather than a separately specified clinically meaningful effect.

Rows for 75% or 50% of the observed effect use smaller target effects than the row based on 100% of the observed effect. Smaller effects are harder to distinguish from random variation, so the illustrated participant requirement increases as the target effect gets smaller. Each outcome has its own planning figures because the event proportions or continuous-outcome variability differ. A planning figure should not be treated as a recommended design without considering the scientific question and the assumptions appropriate to a new study.

These figures are not observed power. They are planning illustrations calculated from the observed results, not a measure of the probability that the completed trial was capable of detecting its observed result.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -4.400; pooled standard deviation σ = 13.358.
2. n = 2 × (1.96 + 0.842)² × 13.358² / -4.400² = 144.7, rounded up to 145 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -4.4                      # observed difference in means
sigma <- 13.3578283024287                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(4278417)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 145 (80% power), 194 (90% power)
 75% of observed effect: n per arm = 258 (80% power), 345 (90% power)
 50% of observed effect: n per arm = 579 (80% power), 775 (90% power)
power.t.test: 145.6 
Simulated power at n = 145 per arm: 0.794 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The sponsor’s primary analysis is an ANCOVA least-squares mean difference of 4.4 letters, with a 95% confidence interval from 2.4 to 6.4 and p < 0.001. It is expressed as brolucizumab minus PRP. The recalculation is an unadjusted estimate from the posted group summaries and uses PRP minus brolucizumab, producing -4.4 with a 95% confidence interval from -6.41 to -2.39 and p < 0.001. The opposite signs reflect opposite subtraction orders.

The recalculated estimate is not a reconstruction of the sponsor’s ANCOVA. It cannot reproduce model adjustment or other analysis details not present in the group summaries. The registry does not flag a discrepancy between the posted result and the recalculation. The sponsor’s analysis is the relevant reported adjusted result; the recalculation is a supplementary unadjusted check.

The registry classifies the primary ANCOVA result as non-inferiority and reports a separate superiority analysis, both with p < 0.001. The non-inferiority margin, model covariates, and detailed testing sequence are not reported in the registry record. The reported classifications can therefore be described, but the record does not contain all the information needed to independently assess the full inferential framework.

15. Multiplicity, Missing Data and Analysis Populations

The registry identifies a primary endpoint and several secondary outcomes, but a complete multiplicity strategy is not reported in the registry record. In a trial with multiple outcomes and time points, testing each one at the same nominal threshold increases the chance that at least one result appears statistically significant by chance. Statistical approaches can control this risk through an ordered testing hierarchy, adjusted thresholds, or other prespecified procedures. The record does not state whether such a procedure was used for the full set of outcomes.

The primary analysis is described as FAS-LOCF, with a valid measurement and no protocol deviations with impact. The primary endpoint description states that last observation carried forward was used to impute missing values. This identifies an analysis choice, but the registry does not report the amount or pattern of missingness, sensitivity analyses, or the assumptions used to assess how missing outcomes might affect the estimates. Methods for missing data in the secondary outcomes are not reported in the registry record.

The term Full Analysis Set is accompanied by a particular inclusion description, but the registry does not provide enough detail to determine how this population differs from other analysis populations or how exclusions were handled across all outcomes. A detailed account of the analysis populations and their role in each test is not reported.

The trial is described as randomized and single-masked, but the registry does not identify who was masked or provide enough information to evaluate masking in outcome assessment. The non-inferiority margin and full testing procedure are also not reported. In general, a non-inferiority conclusion depends on a justified margin and a prespecified analysis framework; a small p-value alone does not supply those details.

The original sample-size justification, interim-analysis plan, and full statistical analysis plan are not reported in the registry record. Their absence limits assessment of whether the posted analyses follow the original prespecified plan, but it does not by itself establish that a particular procedure was or was not used.

16. 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 2% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: vitreous haemorrhage - study eye (5.6%), vitreous haemorrhage - fellow eye (4.0%), cerebral infarction (1.4%), hypertension (1.4%), acute myocardial infarction (1.2%).

The serious adverse-event figures are counts of participants affected, reported alongside the number at risk in each group. The registry records 96 affected among 347 at risk in the brolucizumab group and 105 among 342 at risk in the PRP group. Overall, 201 were affected among 689 at risk. These are descriptive counts; the record does not establish that the events were caused by either study treatment.

The registry reports 8 deaths in the brolucizumab group and 9 in the PRP group. The most frequently listed serious adverse-event terms include vitreous haemorrhage in the study eye at 5.6% and in the fellow eye at 4.0%; cerebral infarction and hypertension are each listed at 1.4%, while acute myocardial infarction and myocardial infarction are each listed at 1.2%. These terms are reported as event categories and should not be taken as evidence of treatment causation.

Counts alone do not describe event timing, duration, severity beyond the serious classification, or the relationship of each event to treatment. The registry record does not provide those details in the listed safety figures. Nor do the figures by themselves establish a comparative safety profile; they summarize the recorded events under the registry’s reporting definitions.

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

The posted primary results describe a difference in average change in study-eye visual acuity at Week 54, with the sponsor’s ANCOVA estimate favoring brolucizumab relative to PRP on the reported scale. The confidence interval communicates precision for that model-based estimate, and the reported p-value indicates that the result is statistically inconsistent with the null hypothesis under the sponsor’s analysis assumptions. The registry classifies the primary analysis as non-inferiority and also reports a superiority analysis.

These statements do not mean that every participant had the same experience or that the average estimate predicts an individual outcome. Group averages do not show the full distribution of individual changes. The result is specific to the study-eye BCVA measure, the Week 54 time point, and the analysis population and method described in the registry.

The registry’s non-inferiority classification cannot be independently assessed from the posted record alone because the margin and detailed testing procedure are not reported. Statistical significance also does not by itself establish the clinical importance of a difference. No threshold for clinical importance is reported in the registry record.

Secondary findings concern distinct outcomes, and they carry additional uncertainty because the record does not describe a full multiplicity strategy. Safety counts are descriptive and do not determine whether an event was caused by treatment. The findings should not be extended automatically to people, outcomes, or follow-up periods not represented by the trial record.

In general, a randomized comparison can support an estimate of differences between the assigned strategies in the population and setting studied, subject to implementation, missing-data, and analysis assumptions. The registry record supplies some design and analysis details, but does not report all information needed to assess those assumptions. The posted statistics therefore describe the reported trial comparison rather than establishing a universal or individual-level conclusion.

18. Why This Trial Matters Statistically

This study illustrates why the effect estimate, its direction, and its analysis method all matter. The sponsor reports a model-based difference in the direction brolucizumab minus PRP, while the recalculation uses PRP minus brolucizumab. The numerical signs differ because the subtraction order differs, not because the analyses describe opposing patterns. Reading the comparison label alongside the estimate prevents a sign from being mistaken for a treatment direction.

It also demonstrates the distinction between an adjusted sponsor analysis and an unadjusted recalculation. The posted group means and standard errors allow a simple comparison, but they do not reproduce the ANCOVA model. Agreement in the broad direction and magnitude is informative as a check, while the sponsor’s analysis remains the reported adjusted result.

The non-inferiority framing raises a further statistical question: interpretation depends on the margin and testing plan, not just a p-value. Those details are not reported in the registry record. The distinction between a reported classification and the information needed to independently evaluate it is important when reading registry results.

Finally, the endpoint set spans visual acuity, PDR status, CI-DME, and DRSS outcomes. These measures illuminate different aspects of the study question, but multiple analyses require caution about multiplicity and the weight assigned to secondary results. Confidence intervals, analysis populations, and missing-data choices all contribute to how much can be inferred from the posted findings.

19. 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.

Several trial-specific details needed for a full assessment are not reported in the registry record. These include the non-inferiority margin, the covariates and full specification of the primary ANCOVA, and the sequence or adjustment used across the primary and secondary tests. Without the margin and testing details, the reported non-inferiority classification cannot be independently evaluated from the registry summary alone.

The primary analysis uses LOCF for missing values, but the registry does not report missingness by group, sensitivity analyses, or the assumptions used to evaluate the imputation. The analysis population is defined in terms of valid measurements and protocol deviations with impact, but the record does not fully describe exclusions or other analysis populations. This limits assessment of how robust the estimate is to analysis-population and missing-data choices.

The study is single-masked, but who was masked is not reported. Detailed information about masking, adherence, outcome assessment, and treatment exposure is not available in the registry summary. The treatment strategies also differ in route, schedule, and the possibility of additional PRP, so their comparison is between the described strategies rather than isolated treatment components.

The registry lists multiple secondary outcomes, but detailed results are not present for every listed measure. Some secondary analyses have sponsor-reported results while others do not. This limits a complete account of the pattern across all outcomes and makes it important not to interpret unreported results as null findings. Safety counts likewise lack event timing and treatment-relatedness detail in the listed figures.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Study of Efficacy and Safety of Brolucizumab Versus Panretinal Photocoagulation Laser in Patients With Proliferative Diabetic Retinopathy — NCT04278417.
• Registry record last updated 2025-10-16; status last verified 2025-10.
• Results first posted 2024-08-20.
• 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.

23. Record Summary

The registry describes a completed Phase III, randomized, single-masked, parallel-group study comparing brolucizumab 6 mg with PRP laser in proliferative diabetic retinopathy. Enrollment is recorded as 689. The primary endpoint is change from baseline in study-eye BCVA at Week 54, measured in ETDRS letters.

The sponsor reports an ANCOVA least-squares mean difference of 4.4 letters, with a 95% confidence interval from 2.4 to 6.4 and p < 0.001, and classifies the analysis as non-inferiority. A separate superiority analysis is also reported with p < 0.001. The recalculated unadjusted estimate is expressed in the opposite direction.

The registry lists secondary outcomes covering PDR status, CI-DME, visual acuity over time, and DRSS changes. Safety figures include serious adverse events and deaths. Important details—including the non-inferiority margin, full statistical plan, multiplicity procedure, and sensitivity analyses for missing data—are not reported in the registry record.