Extension Study of MYL-1701P-3001 for Safety and Efficacy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Extension Study of MYL-1701P-3001 for Safety and Efficacy (NCT04674800), a na phase 3 study. The primary outcome is Incidence of Treatment Emergent Adverse Events (TEAEs)..

2. Clinical Question

The study is an extension for participants who completed the earlier MYL-1701P-3001 study, rather than a new comparison of assigned treatments. Its stated purpose is to evaluate safety, efficacy and immunogenicity of MYL-1701P in this group. The registry names changes from baseline in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) at follow-up weeks among the secondary outcomes, but does not report their results in the record summarized by these data.

The central statistical question is therefore descriptive: what event counts were recorded during the extension, and what can those counts establish about the experience of this group? Without a concurrent control, outcome differences cannot be attributed to MYL-1701P by comparison with another treatment or with no treatment. The extension can describe observed events in participants who entered it, but it cannot by itself distinguish treatment-associated events from events that might have occurred for other reasons.

3. Trial Design

The registry identifies this as a Phase 3, completed, single-group extension study. It lists enrollment of 52 participants and describes the study as open label, with no masking. Allocation is listed as not applicable, consistent with the single test arm rather than a randomized allocation between groups. The study's primary completion date is 2022-04-20; its listed start date is 2020-11-23.

Participants were eligible for the extension after successfully completing MYL-1701P-3001. The registry identifies the condition as diabetic macular edema and names MYL-1701P as the biological intervention. It describes MYL-1701P as a proposed biosimilar to Eylea. The registry's brief description states that the extension evaluates safety, efficacy and immunogenicity. Detailed eligibility criteria, treatment schedule, dosing, and follow-up procedures are not reported in the registry record.

Because all participants entered the same open-label arm, the design is suited to describing observations during follow-up, not to estimating a randomized treatment contrast. In particular, there is no concurrent control group against which to assess whether event counts or changes in visual acuity or retinal thickness differ under another treatment. Participants' prior completion of the earlier study also defines the population: results from this extension pertain to those who entered after completing that study, not necessarily to all people with diabetic macular edema.

The primary outcome is incidence of treatment-emergent adverse events by Week 20, expressed as participant counts and percentages. Secondary outcomes listed in the registry concern changes from baseline in BCVA and CRT at specified follow-up weeks. The registry lists seven outcome measures and zero analyses. The planned statistical methods, analysis details for the secondary outcomes, and any prespecified hypotheses are not reported in the registry record.

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: The extension study was open for all subjects from India who completed the parent study MYL-1701P-3001.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Subject in safety population

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.

Population: All enrolled population

6. Primary Endpoint

The registry lists the primary outcome as Incidence of Treatment Emergent Adverse Events (TEAEs)., measured over Week 20.

The primary endpoint is the incidence of treatment-emergent adverse events (TEAEs) through Week 20. The registry defines incidence as the number and percentage of participants experiencing at least one TEAE during the study period. Its unit is participants, so the endpoint is a participant-level event summary rather than a measure of events per person-time. The registry explicitly notes that categorical participant counts are used because the study duration is fixed.

In general, counting participants with at least one event provides a straightforward description of how many people experienced an event during the specified observation period. It does not, by itself, describe how many total events occurred in each person, how long participants were at risk, or the time until an event. Those are different summaries and answer different questions. A participant-level count also treats someone with one event the same as someone with multiple events for the purpose of this particular endpoint.

Safety outcomes are used in clinical studies to characterize events observed during treatment and follow-up. However, an event recorded after treatment begins is not necessarily caused by the treatment. A single-group result can describe the occurrence of events in the study population, but attributing events to treatment requires evidence beyond a simple count. The registry names the safety population as the primary endpoint population. The primary TEAE count and percentage are not reported in the registry record, so the endpoint's observed incidence cannot be interpreted from these figures alone.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant-level event count mean?

For this endpoint, the registry defines incidence by counting participants who experienced at least one TEAE during the study period, and by reporting the corresponding percentage. In general, this type of outcome summarizes whether each participant experienced an event at least once. It is not the same as counting every event, because repeated events in one participant do not create additional participants with an event. It is also distinct from a rate based on accumulated time at risk. The registry states that categorical counts are used instead of person-time-based rates because study duration is fixed.

A count is easy to interpret as a description of the study group, but it does not show when events occurred, how long they lasted, or whether several events affected the same participant. Those details may matter to a fuller safety assessment, but they are not reported in the registry record. Most importantly, the definition alone is not the result: the primary TEAE count and percentage are not reported in the registry record.

What can a single-group study estimate?

In general, a single-group study can describe outcomes observed among the participants who received the study intervention. It cannot make a randomized comparison with a separate group that received another treatment or no treatment. Random allocation, when used, helps balance participant characteristics between groups on average; it is not present in this design. Since this study is open label and has one arm, the recorded outcomes are not protected from the interpretive limitations of an unblinded, uncontrolled design.

That does not make descriptive counts meaningless. They indicate what was recorded in the enrolled group under the study's follow-up. But event counts alone cannot show what would have happened to those same participants under a different treatment. Without that counterfactual comparison, differences due to treatment cannot be isolated from other influences. The registry identifies this as an extension among participants who completed MYL-1701P-3001, so the findings also describe a selected group defined by prior study completion.

How should percentages and uncertainty be read?

In general, a percentage expresses an event count relative to the group used as its denominator. Interpretation depends on the denominator, outcome definition, and observation period. The serious-event figures list 52 participants at risk; the endpoint definition separately specifies the safety population and a Week 20 timeframe. The record does not report a confidence interval for the primary endpoint. A confidence interval, in general, expresses the range of values reasonably compatible with the observed data under a statistical model. It communicates uncertainty in an estimate; it does not resolve the limitations of a single-group design or establish causation.

Small event counts can be especially imprecise. In general, each observed participant can have a noticeable influence on an estimated frequency when a study group is limited in size. A zero count for deaths means none were recorded in the listed group; it does not prove that the underlying risk is zero. The registry gives no confidence interval or other uncertainty estimate for the listed safety counts, so their precision cannot be assessed from the record alone.

What do planning illustrations represent?

In general, sample-size planning uses assumptions about an effect, variability, significance level, allocation, and desired power to illustrate the number of participants needed for a future comparison. The registry description of the planning illustration specifies a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. Such illustrations are conditional on their assumptions; they are not observed power and do not show that a study had a particular probability of finding a result after it was completed.

The listed illustration is not the design of this extension, which has one arm and no randomized comparison. Its assumptions should therefore not be read as a description of the enrolled study's actual allocation or as evidence that the study was powered for a treatment contrast. The registry does not report the study's own sample-size justification or a formal statistical analysis plan.

What can be concluded when analyses are not listed?

The registry lists zero analyses. In general, an analysis specifies how outcome data are used to produce an estimate, comparison, or test. Without a reported analysis, it is not possible to determine from this record whether results were adjusted for covariates, how missing observations were handled, or whether a particular statistical model was used. These details are not reported in the registry record. The registry does identify the primary population as the safety population, but does not provide a fuller account of that population's definition or its analysis procedures.

For the named BCVA and CRT outcomes, a change from baseline is a comparison of a follow-up measurement with a starting measurement for a participant or group. In general, the interpretation depends on how baseline and follow-up measurements are defined, which participants contribute data, and how missing measurements are handled. The registry lists outcome time points but does not report numerical results or the method used to analyze those changes. No direction or magnitude of change can therefore be established from the 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("Single, Test Arm")
n      <- c(52)
events <- c(16)
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  Single, Test Arm  52  16  30.8  18.7  45.1  19.9  44.3  19.9  44.3

11. Multiplicity, Missing Data and Analysis Populations

The registry lists the primary TEAE endpoint and several secondary outcomes concerning changes from baseline in BCVA and CRT at specified follow-up visits. When a study assesses multiple outcomes or time points, general statistical practice recognizes a multiplicity issue: the more questions tested, the greater the chance that at least one result may appear statistically notable by chance if each is assessed separately. A prespecified approach may address this, for example by defining a primary outcome, controlling error across tests, or treating secondary results as exploratory.

The registry does not report a multiplicity adjustment, a testing hierarchy, or a detailed statistical analysis plan. The record lists seven outcome measures and zero analyses, so it does not establish how outcomes were prioritized or how any statistical tests were conducted. The secondary outcome results themselves are not reported in the registry record. Accordingly, neither their numerical findings nor any adjustment for multiple testing can be evaluated from the record.

Missing-data handling is also not reported in the registry record. In general, missing observations can affect an estimate when participants with unavailable measurements differ from those with observed measurements. Interpretation depends on the amount and pattern of missingness and the assumptions or methods used to address it. The record does not describe missing outcome counts, imputation, sensitivity analyses, or whether participants with incomplete follow-up were included in each outcome analysis.

The primary outcome population is named as the safety population, but additional analysis-population definitions are not reported in the registry record. It is therefore unclear from this record how the safety population was constituted or how the population contributing to each secondary outcome was determined. These omissions limit assessment of the analysis choices; they do not establish that any particular method was or was not used outside what the record reports.

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 1% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: cerebral infarction (1.9%).

The serious adverse-event figures list 52 participants at risk, 1 serious adverse event, and 0 deaths. The other-event category lists 16. The registry identifies Cerebral Infarction at 1.9% among the top serious terms. These values describe the entries recorded for the single test arm; they are not a comparison with an untreated or alternative-treatment group.

In general, a serious adverse event classification describes an event's seriousness under the applicable reporting criteria; it does not by itself show that treatment caused the event. The record does not provide enough detail to establish the relationship between the listed serious-event count, the term percentage, and the primary endpoint's count of participants with at least one TEAE. The 1.9% figure should be read as the registry's reported percentage for the named serious term, not as the overall TEAE incidence.

A count of 0 deaths means no deaths are listed for this group in these figures. It does not establish that the risk of death is absent. The number of participants at risk provides context for the listed counts, but the registry does not report uncertainty intervals, event narratives, or a comparative estimate. The primary endpoint's total TEAE count and percentage are not reported in the registry record, so these safety figures cannot fill that gap.

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

The record establishes that a completed, open-label, single-group extension study enrolled 52 participants with diabetic macular edema who had successfully completed MYL-1701P-3001. MYL-1701P was the sole intervention, and the study's primary outcome was defined as the incidence of participants experiencing at least one treatment-emergent adverse event through Week 20. The listed safety figures include 1 serious adverse event, 16 events in the other category, 0 deaths, and Cerebral Infarction at 1.9% among the top serious terms.

Those observations describe what the registry lists for this study group; they do not establish a causal relationship between treatment and any event. Because the study has no concurrent comparator and no random allocation, it cannot determine whether the observed counts differ from what would have occurred under another treatment. The open-label, single-group design also does not support a randomized comparative estimate.

The record does not report the primary TEAE count and percentage, so the defined primary endpoint cannot be evaluated as a complete result. It also does not report numerical findings for the named BCVA and CRT changes. Thus, the registry information does not establish the magnitude, direction, or precision of efficacy-related changes. The stated aim to evaluate efficacy and immunogenicity should not be mistaken for reported evidence on those outcomes.

More broadly, absence of a reported result is not evidence that no event occurred or that no change was observed. It means the registry record does not supply the result needed to assess that outcome. Likewise, a listed count does not describe every aspect of safety, and a single-group observation cannot show what would have happened under a different intervention. Interpretation should remain limited to the design, endpoint definitions, and particular counts recorded.

14. Why This Trial Matters Statistically

Extension studies address a descriptive question that differs from the usual randomized comparison: what outcomes were recorded among participants continuing into follow-up after completing an earlier study? This record makes that distinction important. The population was selected by successful completion of MYL-1701P-3001, and the extension used one open-label arm. Findings from this group therefore do not automatically represent all people with diabetic macular edema or people who did not enter the extension.

The study also illustrates why endpoint definitions and endpoint results must be read separately. A clear definition of TEAE incidence specifies the type of summary intended: participants with at least one event, reported as counts and percentages over the study period. But that definition cannot replace the observed primary result, which is not reported in the registry record. Selected serious-event figures offer some descriptive information, but they do not provide the missing total TEAE incidence.

Statistically, the absence of a comparator shapes what the data can answer. Counts in one arm can characterize recorded events in that arm, but cannot estimate a treatment contrast or separate treatment effects from other explanations. The named secondary outcomes also demonstrate that a list of outcome measures does not disclose their results, analysis methods, or handling of missing data. The registry lists seven outcome measures and zero analyses.

These distinctions matter when interpreting registry records as evidence. The study design, population, endpoint definition, and recorded safety counts are useful details, but they leave substantial uncertainty about efficacy outcomes and the primary safety result. Keeping descriptive findings separate from comparative or causal conclusions prevents a registry listing from being asked to answer questions its reported data do not resolve.

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 limitation for interpretation is the single-group, open-label design. There is no randomized comparator, so event counts and any outcome changes cannot be interpreted as comparative treatment effects. Participant and investigator awareness of treatment may also be relevant in an open-label study, but the registry does not report procedures intended to address this issue.

The population is limited to participants who successfully completed MYL-1701P-3001 and entered this extension. The registry lists 52 enrolled participants. It does not report how many completed follow-up, how many contributed data to each outcome, or whether any participants discontinued. Those details are important for understanding the scope of observed results and possible missing data.

The primary endpoint is defined, but its actual count and percentage are not reported in the registry record. Selected adverse-event counts are available, but the record does not provide enough information to determine their full relationship to the TEAE endpoint. It also does not report detailed event narratives, confidence intervals, or a complete statistical analysis for these counts.

Although BCVA and CRT changes are listed as secondary outcomes, their numerical results and analysis methods are not reported in the registry record. The registry does not report how missing measurements were handled, whether multiplicity was addressed, or how analysis populations were defined beyond naming the safety population for the primary endpoint. The sample-size planning description is an illustration based on stated assumptions and is not the study's reported design justification. These limitations leave the available evidence descriptive and incomplete for evaluating the stated outcomes.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Extension Study of MYL-1701P-3001 for Safety and Efficacy — NCT04674800.
• Registry record last updated 2026-08-03; status last verified 2026-07.
• Results first posted 2026-08-03.
• 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

NCT04674800 is a completed Phase 3, open-label, single-group extension study of MYL-1701P in participants with diabetic macular edema who successfully completed MYL-1701P-3001. Enrollment was 52, and the registry lists no allocation between treatment groups. MYL-1701P is described as a proposed biosimilar to Eylea.

The primary outcome was TEAE incidence through Week 20, defined as the number and percentage of participants with at least one event. Its result is not reported in the registry record. Listed safety figures include 1 serious adverse event, 16 in the other-event category, 0 deaths, and Cerebral Infarction at 1.9% among the top serious terms. Secondary outcomes include changes from baseline in BCVA and CRT, but their results are not reported.

The record does not report a statistical analysis plan, missing-data methods, or multiplicity procedures. With no concurrent comparator, the listed observations are descriptive and do not establish comparative or causal effects.