Magrolimab + Azacitidine Versus Azacitidine + Placebo in Untreated Participants With Myelodysplastic Syndrome (MDS): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Magrolimab + Azacitidine Versus Azacitidine + Placebo in Untreated Participants With Myelodysplastic Syndrome (MDS) (NCT04313881), a randomized phase 3 study. The primary outcome is Percentage of Participants With Complete Remission (CR).

2. Clinical Question

3. Trial Design

This was a Phase 3, randomized, double-blind, parallel-group study comparing magrolimab plus azacitidine with placebo plus azacitidine. The official title describes it as multicenter. The registry lists 539 participants enrolled and identifies myelodysplastic syndromes as the condition studied. Participants were treatment-naïve and had intermediate-, high-, or very high-risk disease according to the Revised International Prognostic Scoring System.

The listed study start date is 2020-09-09, and the primary completion date is 2023-09-13. The registry status is terminated. The reason for termination is not reported in the registry record, so the status alone does not establish why the study ended or whether any particular result led to that decision.

The experimental regimen combined magrolimab with azacitidine; the control regimen combined placebo with azacitidine. The registry describes placebo dosing intended to mirror magrolimab dosing. It includes parts of the priming schedules but does not give a complete maintenance regimen in the available arm description. Specific details about which participants or study personnel were masked are not reported in the registry record.

The primary outcome was complete remission, assessed by the investigator using International Working Group criteria. The stated primary objective also names overall survival, while the posted primary outcome result is for complete remission. The registry lists additional outcomes, including response, transfusion independence, event-free survival, and other disease measures. The originally intended sample-size justification, trial-specific statistical analysis plan, and planned interim analyses 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: 854 participants were screened.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Participants from intent-to-treat analysis set were analyzed.

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: The Intent-to-treat (ITT) Analysis Set included all participants who were randomized in the study, with treatment assignments designated according to the treatment that participants were randomized to.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants With Complete Remission (CR), measured over From randomization up to 31.01 months.

The primary endpoint is the percentage of participants who achieved complete remission, abbreviated CR. The registry defines CR using investigator-assessed International Working Group criteria: morphologic blasts of 5% or less, recovery of absolute neutrophil count, platelets, and hemoglobin from complete blood counts, and the specified peripheral-blast criteria. A remission had to occur on or before the start of any new anticancer therapy, including stem cell therapy.

This endpoint expresses the proportion of participants who met a defined response criterion during the assessment period. It is a binary outcome at the participant level: a participant either met the CR definition or did not. Reporting the percentage gives a direct description of how frequently the specified remission criteria were reached in each randomized group. The registry reports the outcome over the period from randomization up to 31.01 months.

As a general statistical point, a response percentage is useful for comparing groups on the frequency of a defined event, but it does not by itself describe how long a response lasts or how long participants live. Those questions require different outcome measures. Duration of CR and overall survival are named in the study’s objectives or outcome list, but results for them are not reported in the primary result. The CR result should therefore be interpreted as evidence about this specific response endpoint, rather than as a complete account of every clinical outcome in the study.

7. Results Posted in the Registry

• Magrolimab + Azacitidine: 21.3% (57/268) versus 23.6% (64/271) on control; risk difference -2.3 percentage points (95% CI -9.4 to 4.7), risk ratio 0.90 (0.66–1.23); unadjusted two-proportion z-test p = 0.514.

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.

Objective Response Rate (ORR)

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Magrolimab + Azacitidine: 53.7% (144/268) versus 58.7% (159/271) on control; risk difference -4.9 percentage points (95% CI -13.3 to 3.4), risk ratio 0.92 (0.79–1.06); unadjusted two-proportion z-test p = 0.248.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Magrolimab + Azacitidine and the control. The interval gives the range of effects that remain compatible with the data.

Red Blood Cell (RBC) Transfusion Independence Rate

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Magrolimab + Azacitidine: 27.9% (39/140) versus 35.2% (44/125) on control; risk difference -7.3 percentage points (95% CI -18.5 to 3.8), risk ratio 0.79 (0.55–1.13); unadjusted two-proportion z-test p = 0.198.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Magrolimab + Azacitidine and the control. The interval gives the range of effects that remain compatible with the data.

Event Free Survival (EFS)

• Endpoint type: Time to event: compared as a hazard ratio.
• Test: Hazard ratio as reported by the sponsor (Log Rank); it was not recalculated.
• Result:
  • Magrolimab + Azacitidine vs Placebo + Azacitidine: hazard ratio 0.98 (95% CI 0.75–1.28), reported p = 0.879 (as reported in the registry).
• Interpretation:
  • The 95% confidence interval includes no difference (a ratio of 1), so these data do not show a statistically significant difference between Magrolimab + Azacitidine vs Placebo + Azacitidine and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes cover different aspects of response and disease course, including objective response, red blood cell transfusion independence, and event-free survival. Their measures are not all the same: some are percentages, while event-free survival is reported as a median time and a hazard ratio. Across the posted secondary results, the estimates do not form a consistent body of evidence establishing a clear advantage for magrolimab plus azacitidine. The numerical patterns should be considered descriptive and interpreted endpoint by endpoint, rather than combined into a single treatment effect.

These secondary findings do not change the interpretation of the primary CR result. They provide additional context, but they do not substitute for the primary endpoint or for the overall survival result named in the study objective, which is not reported in the registry record. The secondary outcome list also includes several measures for which results are not included in the posted results described in the registry record.

Multiplicity matters because testing many outcomes creates more opportunities for apparently notable findings to arise by chance. As a general statistical point, interpretation is stronger when the testing hierarchy and any adjustment for multiple comparisons are prespecified and reported. The registry record does not report a multiplicity procedure for the secondary outcomes. Accordingly, nominal or unadjusted secondary results carry less weight as confirmatory evidence than the prespecified primary analysis. The registry does not provide enough information to determine whether a particular secondary endpoint was formally protected by a testing strategy.

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

• Duration of CR (DOCR)
• Objective Response Rate (ORR)
• Duration of Response (DOR)
• Red Blood Cell (RBC) Transfusion Independence Rate
• Event Free Survival (EFS)
• Percentage of Participants With CR in Participants With TP53 Mutation
• Minimal Residual Disease (MRD)-Negative Response Rate
• Time to Transformation to AML

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is binary: each participant is classified according to whether the specified complete-remission criteria were met. The registry reports a percentage for each group and a confidence interval for each percentage. It also reports a comparative analysis using an odds ratio and a Cochran-Mantel-Haenszel method. A separate simple recalculation expresses the comparison as a risk difference. These measures describe the same underlying outcome in different ways and should not be treated as interchangeable quantities.

What does the risk difference describe?

As a general statistical explanation, a risk difference subtracts the event proportion in one group from the event proportion in the other, using a stated group order. A value of zero corresponds to equal proportions. The recalculated estimate is -0.024 for magrolimab plus azacitidine relative to placebo plus azacitidine; its 95% confidence interval runs from -0.094 to 0.047. Because the interval crosses zero, the recalculated interval does not isolate a difference in one direction. The accompanying unadjusted p-value is 0.514. This simple comparison is not the sponsor’s reported analysis.

What does an odds ratio describe?

As a general explanation, an odds ratio compares the odds of the event in one group with the odds in the other. An odds ratio of 1 represents equal odds. The registry’s primary analysis reports an odds ratio of 0.876, with a 95% confidence interval from 0.585 to 1.312. Since the interval includes 1, the result does not establish a statistically clear difference in odds. The registry identifies the Cochran-Mantel-Haenszel method for this analysis. The record does not describe the stratification variables or other implementation details, so those should not be inferred.

Why are the reported and recalculated estimates different?

The recalculated risk difference is an unadjusted comparison from posted summary statistics. The sponsor’s reported result is an odds ratio from the Cochran-Mantel-Haenszel analysis. These analyses use different effect measures and may incorporate different analytic features. Their estimates and p-values should therefore not be expected to match exactly. There is no discrepancy flag in the registry information. The sponsor’s own analysis is the primary reported analysis, while the unadjusted calculation is a supplemental description of the posted group summaries.

What do confidence intervals and p-values contribute?

As a general statistical explanation, a confidence interval conveys the range of effect estimates that are reasonably compatible with the data and the method used. It communicates precision as well as direction. A p-value measures how incompatible the observed data are with a specified null hypothesis under the test’s assumptions; it is not the probability that the null hypothesis is true, nor a measure of clinical importance. The primary p-value reported by the registry is 0.522. Its interpretation belongs with the reported odds ratio and confidence interval, not in isolation.

What is not described about the analysis?

The registry record does not report the trial’s complete statistical analysis plan, the original sample-size justification, details of any interim analyses, the multiplicity procedure, or the handling of missing data. The primary outcome states that the intent-to-treat analysis set was analyzed, but does not provide a fuller account of the analysis population rules. These gaps limit assessment of prespecified versus exploratory analyses and of how incomplete observations may have affected the reported estimates. They should not be filled by assumptions about standard practice.

The endpoint timeframe is from randomization up to 31.01 months. That is the stated observation window, not a claim that every participant was followed for the same duration. As a general point, differences in follow-up can matter for interpreting outcomes, particularly time-to-event outcomes; the registry record does not supply further participant-level follow-up details for this endpoint.

11. Confidence Intervals and Precision

The primary CR estimates have 95% confidence intervals of 16.5% to 26.7% for magrolimab plus azacitidine and 18.7% to 29.1% for placebo plus azacitidine. These intervals show that the percentages are estimated with uncertainty; they do not identify a single exact underlying response rate. The intervals overlap, and the reported comparative analysis also has a confidence interval that includes the no-difference value.

The unadjusted risk-difference interval is -0.094 to 0.047. Its width reflects uncertainty in the estimated group contrast, and it spans values on both sides of zero. The registry’s odds-ratio interval, 0.585 to 1.312, likewise includes 1. Neither interval supports a precise conclusion that the underlying group effect lies entirely in one direction. The point estimates are the central estimates from their respective methods, not guarantees of the true effect.

As a general statistical explanation, confidence intervals are sensitive to the amount of information in the data and to the variability of the outcome. A wider interval indicates less precision than a narrower one, all else equal. An interval crossing a null value does not prove no effect; it indicates that the data and method do not distinguish the observed result from that null value at the interval’s stated confidence level.

The CR analysis includes 268 participants in the magrolimab group and 271 in the placebo group. The registry describes the analysis population as intent-to-treat but does not explain missing-data handling or report how many participants lacked an evaluable CR assessment. Those details would help readers understand the basis of the precision estimates. The posted estimates should consequently be read together with the stated analysis population and the limitations of the registry record.

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 illustrations based on the observed effect, not the trial’s original design calculation. For the binary outcomes, the figures are participants per arm. For the time-to-event outcome, the figures are total events. The planning assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is set at 100%, 75%, or 50% of the observed effect. The trial’s own original sample-size assumptions and justification are not reported in the registry record.

The 80% power column describes the planning sample size or event total associated with an 80% probability of detecting the chosen effect under those assumptions, if that effect and the model assumptions were true. The 90% power column uses a higher target probability of detection and therefore generally requires more information. These are forward-looking design calculations, not probabilities that the completed trial succeeded or failed.

The planning figures show how the required information changes as the assumed effect is reduced. A smaller target effect is harder to distinguish from random variation, so it requires more participants or events. The rows based on fractions of the observed effect are hypothetical planning scenarios; they do not mean that those smaller effects were observed in the trial. For the event-free survival planning illustration, the unit is events rather than participants because the calculation is framed around total events.

These figures are not observed power. Observed power is not a useful substitute for reading the estimated effect, its confidence interval, and the reported test. The planning exercise illustrates how much information would be needed under stated assumptions; it does not alter the uncertainty in the completed trial’s posted results.

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, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.236; treatment proportion p₁ = 0.213; average p̄ = 0.224.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.5900 = 1.1564.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.5898 = 0.4964.
4. n = (1.1564 + 0.4964)² / (-0.0235)² = 4,956.6, rounded up to 4,957 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
p0 <- 0.236162361623616                          # control proportion
p1 <- 0.212686567164179                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^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 (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(4313881)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 4,957 (80% power), 6,636 (90% power)
 75% of observed effect: n per arm = 8,895 (80% power), 11,907 (90% power)
 50% of observed effect: n per arm = 20,195 (80% power), 27,035 (90% power)
power.prop.test: 4956.6 
Simulated power at n = 4,957 per arm: 0.798 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-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 the registry-reported Cochran-Mantel-Haenszel odds ratio of 0.876, with a 95% confidence interval from 0.585 to 1.312 and p = 0.522. This is the reported inferential analysis for the primary complete-remission outcome. Its confidence interval includes the odds-ratio null value of 1, and the p-value does not indicate a statistically clear difference under the reported test.

The recalculated result is an unadjusted risk difference of -0.024, with a 95% confidence interval from -0.094 to 0.047 and p = 0.514. It uses a different effect measure and a simple calculation from the posted group summaries, rather than the sponsor’s stated method. The estimates and p-values are therefore not expected to be identical. The registry information does not flag a discrepancy. The sponsor’s own analysis takes precedence for describing the trial’s reported primary statistical test; the unadjusted calculation is a supplementary perspective, not a replacement.

For context, the reported CR percentages are 21.3% and 23.6% in the magrolimab and placebo groups, respectively. The numerical direction of the observed rates is consistent with the negative recalculated risk difference under its stated group order, but neither the sponsor analysis nor the unadjusted analysis establishes a clear between-group difference.

15. Multiplicity, Missing Data and Analysis Populations

The registry identifies complete remission as the posted primary outcome and describes an intent-to-treat analysis population. It also lists numerous secondary outcomes, including duration of CR, objective response rate, duration of response, transfusion independence, event-free survival, outcomes for participants with TP53 mutation, minimal residual disease-negative response, and time to transformation to acute myeloid leukemia. The registry lists 15 outcome measures and 10 analyses.

When several outcomes or statistical tests are considered, the chance of at least one apparently positive result can increase. As a general statistical explanation, multiplicity procedures can control the overall error rate or define a prespecified hierarchy for interpreting tests. The multiplicity strategy, any testing hierarchy, and any adjustment used for secondary analyses are not reported in the registry record. Consequently, secondary results should not be treated as equally confirmatory with the primary result.

The primary outcome specifies the intent-to-treat analysis set, but the registry record does not report how missing outcome assessments were handled, whether any imputation was used, or how participants without an evaluable assessment were treated in each analysis. The number of participants in the posted CR groups is given, but that does not by itself explain missingness or establish the analysis rules for all outcomes. These matters are important because the way incomplete observations are handled can affect estimates and their uncertainty.

The registry record also does not report the original sample-size justification, trial-specific interim analyses, or a full statistical analysis plan. These omissions prevent a complete assessment of prespecification and analysis decisions. They do not justify assuming that a particular procedure was or was not used; the appropriate description is that those details are not reported in the registry record.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: febrile neutropenia (22.1%), infusion related reaction (11.8%), anaemia (9.5%), pneumonia (9.1%), sepsis (7.6%).

The registry reports serious adverse event counts for 263 participants at risk in the magrolimab plus azacitidine group and 264 participants at risk in the placebo plus azacitidine group. Serious adverse events affected 189 and 136 participants, respectively. Other adverse events affected 246 and 256 participants in the two groups. The registry also reports 145 deaths in the magrolimab group and 132 in the placebo group. These are counts, and the registry record does not provide context about causes of death or individual event timing.

The listed serious adverse event terms include febrile neutropenia (22.1%), infusion related reaction (11.8%), anaemia (9.5%), pneumonia (9.1%), sepsis (7.6%), and pyrexia (6.5%). These figures describe terms listed in the registry and should be read as reported, not as a complete account of every safety event or a causal comparison between groups.

As a general statistical point, safety counts require context about the population at risk, follow-up, event definitions, and whether participants can contribute more than one event. The registry figures alone do not establish that a regimen caused an event or explain the clinical significance of the differences in counts. They should be interpreted as descriptive safety reporting rather than as a standalone comparative test.

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

The posted primary data show CR percentages of 21.3% with magrolimab plus azacitidine and 23.6% with placebo plus azacitidine. The sponsor’s odds-ratio analysis and the unadjusted risk-difference recalculation both have confidence intervals that include their respective no-difference values. The primary result therefore does not establish a statistically clear difference between the groups on this endpoint.

That conclusion is narrower than saying the regimens are equivalent or that there is no possible difference. A result that is not statistically clear can reflect an effect close to no difference, uncertainty around the estimate, or both. The confidence intervals describe a range of effects compatible with the data and method; they do not prove that every value in that range is equally likely, nor do they decide whether any possible difference would matter clinically.

The CR endpoint addresses whether participants met the specified remission criteria during the reported timeframe. It does not by itself establish how long remission lasted, whether overall survival differed, or how other outcomes changed. Although overall survival is named in the study’s primary objective, an overall survival result is not reported in the registry record. Event-free survival and other secondary outcomes are separate measures and should not be substituted for it.

The registry status is terminated, but the reason for termination is not reported in the registry record. No conclusion about the cause of termination should be drawn from the status alone. The safety counts and listed serious adverse event terms are descriptive and do not, without further context, establish causation or a complete comparative safety profile.

In sum, the registry reports the observed response proportions, a sponsor analysis, and several secondary outcome results. The uncertainty around the primary comparison and the unreported details of missing-data handling, multiplicity, interim analyses, and the original sample-size rationale limit what can be concluded beyond those posted statistics.

18. Why This Trial Matters Statistically

This trial illustrates why an effect estimate, its uncertainty, and the analysis method should be read together. The primary CR rates alone give the observed response proportions in each randomized group. The sponsor’s odds ratio and the unadjusted risk difference express the comparison on different scales, while their confidence intervals show that the data do not pin down a single precise group effect.

It also demonstrates the distinction between a nonsignificant result and proof of equivalence. The reported primary test does not establish a statistically clear difference, but the confidence interval still spans a range of effects. Without a stated equivalence or noninferiority framework and its margins, the result should not be described as evidence that the regimens are equivalent. Such a framework is not reported in the registry record.

The registry includes several clinically distinct secondary measures. Considering them alongside the primary endpoint is useful for understanding what was assessed, but multiple outcomes require careful interpretation. Without a reported multiplicity strategy, secondary findings are less suitable as confirmatory evidence. The stated objective also includes overall survival, while an overall survival result is not reported, underscoring the importance of distinguishing an objective from a posted outcome result.

Finally, the planning illustrations show that sample-size requirements depend on the effect a study aims to detect and on its assumptions. They are not a retrospective measure of whether the completed study had adequate power. The original design justification is not reported in the registry record. This trial therefore provides a practical example of separating observed results from planning assumptions and of keeping conclusions within the bounds of the reported analysis.

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.
• Participant counts were reconstructed from posted percentages and arm sizes, so small rounding differences are possible.

Several trial-specific gaps in the registry record constrain interpretation. The study is marked terminated, but the reason for termination is not reported. The record gives a primary completion date, but does not explain the termination decision, its timing relative to the analysis, or its relationship to the posted findings. No causal explanation should be inferred.

The stated primary objective names both complete remission and overall survival, but the posted primary outcome result is for complete remission. Overall survival results are not reported in the registry record. The available secondary results include event-free survival, but that outcome is not a substitute for overall survival. Results for all listed outcomes are not included among the posted outcome details described in the record.

Some treatment-arm descriptions are incomplete. The magrolimab priming schedule is described, but the maintenance description is truncated; the placebo dosing description is also incomplete. The record does not specify which roles were masked despite identifying the study as double-blind. These omissions limit detailed reconstruction of treatment delivery and masking procedures.

The registry does not report the original sample-size justification, the full statistical analysis plan, interim-analysis details, the multiplicity strategy, or missing-data methods. It identifies the intent-to-treat set for the primary analysis, but does not provide a fuller account of analysis rules or missing CR assessments. These are relevant limitations for evaluating prespecification and the robustness of estimates. The registry also gives adverse event counts and selected serious-event terms without enough detail in these results to establish causes, event timing, or a full comparative safety interpretation.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Magrolimab + Azacitidine Versus Azacitidine + Placebo in Untreated Participants With Myelodysplastic Syndrome (MDS) — NCT04313881.
• Registry record last updated 2024-06-27; status last verified 2024-06.
• Results first posted 2024-03-21.
• 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 record describes NCT04313881, a randomized, double-blind, parallel-group Phase 3 study of magrolimab plus azacitidine versus placebo plus azacitidine in previously untreated participants with higher-risk myelodysplastic syndrome. It lists 539 participants enrolled and identifies the study status as terminated.

The posted primary endpoint is investigator-assessed complete remission from randomization up to 31.01 months. The CR percentages were 21.3% and 23.6% in the magrolimab and placebo groups. The sponsor-reported Cochran-Mantel-Haenszel odds ratio was 0.876, with a 95% confidence interval from 0.585 to 1.312 and p = 0.522.

The registry also reports selected secondary outcomes and safety counts. Overall survival results, the reason for termination, and several details of the statistical plan are not reported in the registry record.