A Study Comparing Two Different PROCRIT Doses to a Dose of ARANESP in Anemic Cancer Patients Receiving Chemotherapy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study Comparing Two Different PROCRIT Doses to a Dose of ARANESP in Anemic Cancer Patients Receiving Chemotherapy (NCT00386152), a randomized phase 2 study. The primary outcome is Hemoglobin (Hb) Change From Baseline to Study Week 7.

2. Clinical Question

3. Trial Design

The registry identifies this as a randomized, open-label, parallel-group Phase 2 study. It enrolled 235 participants and is listed as terminated. The record gives a start date of 2006-11 and a primary completion date of 2008-03. It does not report why the study was terminated, so the status alone does not explain whether termination related to recruitment, conduct, safety, or another reason.

Participants were assigned to one of three drug groups: epoetin alfa (PROCRIT) 80,000 Units, epoetin alfa (PROCRIT) 120,000 Units, or darbepoetin alfa (ARANESP) 500 mcg. Each regimen was described as a subcutaneous injection once every 3 weeks for up to 13 weeks. Because the study was open-label and masking was listed as none, participants and study personnel were not masked according to the registry record. No further details about allocation concealment or the randomization sequence are reported in the registry record.

The primary outcome was mean hemoglobin change from baseline to Study Week 7, with baseline defined as the hemoglobin value consistent with inclusion criteria and obtained within 72 hours of the first study-medication dose. The primary analysis population was per-protocol, a subset of the modified intent-to-treat population with specified treatment exposure, measurement, and eligibility conditions. The record also lists secondary outcomes involving packed red blood cell transfusion, attaining a hemoglobin threshold, and the number of patients with hemoglobin at or above that threshold. The secondary outcome timeframe is up to 16 weeks.

The registry record does not report the trial’s original sample-size justification, planned statistical analysis plan, or whether interim analyses were planned or conducted. The enrollment figure should not be treated as the number analyzed for every endpoint: the outcome populations differ, and the primary and secondary results use different denominators.

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: Number of participants randomized:- epoetin alfa (80,000 Units): 77, epoetin alfa (120,000 Units): 80, darbepoetin alfa (500 mcg): 78; Number of participants treated:- epoetin alfa (80,000 Units): 75, epoetin alfa (120,000 Units): 77, darbepoetin alfa (500 mcg): 75.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: per-protocol (PP) population that includes a subset of the modified intent-to-treat (mITT) population with subjects who were randomized and received at least one dose of study medication, had transfusion-unrelated Hb values obtained at both baseline and Week 7, met inclusion and exclusion criteria, and had no major protocol violations up to Week 7

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 Hemoglobin (Hb) Change From Baseline to Study Week 7, measured over Baseline (Week 1) and Week 7.

The primary endpoint is mean change in hemoglobin from baseline to Study Week 7, measured in g/dL. For each treatment group, the reported mean describes the average change among participants in the per-protocol population who met the outcome’s measurement and eligibility conditions. The standard deviation describes variation in individual changes around that group mean. A mean change captures the direction and average size of change, while the spread helps show how much participant-level changes varied.

Hemoglobin is relevant to the study’s stated question because the trial aimed to compare hemoglobin response in anemic cancer patients receiving chemotherapy. Using change from baseline places each participant’s Week 7 value in relation to their own qualifying baseline value, rather than treating the Week 7 measurement alone as the endpoint. The registry defines baseline as a hemoglobin value consistent with the inclusion criteria, obtained within 72 hours of the first study-medication dose.

The primary measure is a continuous outcome, not a count of participants who crossed a threshold. This distinction matters: a mean change summarizes the group’s average numerical movement, whereas a response rate depends on a specified definition of response. The secondary outcomes include threshold-based hemoglobin results, but they answer different questions and should not be substituted for the primary mean-change endpoint.

The registry record does not report a clinically important difference threshold for hemoglobin change or explain how such a threshold would be used in interpreting the endpoint. The results therefore describe the observed group means and their unadjusted comparisons; they do not, on their own, establish whether a difference would be clinically important.

7. Results Posted in the Registry

• Epoetin Alfa (120,000 Units): mean 0.40 versus 0.64 on control; difference -0.24 (95% CI -0.74 to 0.26), standardized effect d = -0.18; z-test p = 0.347.
• Darbepoetin Alfa (500 Mcg): mean 0.84 versus 0.64 on control; difference 0.20 (95% CI -0.29 to 0.69), standardized effect d = 0.15; z-test p = 0.423.

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 of Patients Receiving at Least 1 Packed Red Blood Cell (PRBC) Transfusion During Study

• 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:
  • Epoetin Alfa (120,000 Units): 28.6% (22/77) versus 16.9% (12/71) on control; risk difference 11.7 percentage points (95% CI -1.7 to 25.0), risk ratio 1.69 (0.90–3.16); unadjusted two-proportion z-test p = 0.092.
  • Darbepoetin Alfa (500 Mcg): 23.0% (17/74) versus 16.9% (12/71) on control; risk difference 6.1 percentage points (95% CI -6.9 to 19.0), risk ratio 1.36 (0.70–2.64); unadjusted two-proportion z-test p = 0.361.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Epoetin Alfa (120,000 Units) and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Darbepoetin Alfa (500 Mcg) and the control. The interval gives the range of effects that remain compatible with the data.

Number of Patients (Hb >= 11 g/dL) During Study.

• 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:
  • Epoetin Alfa (120,000 Units): 62.3% (48/77) versus 71.8% (51/71) on control; risk difference -9.5 percentage points (95% CI -24.5 to 5.6), risk ratio 0.87 (0.69–1.09); unadjusted two-proportion z-test p = 0.220.
  • Darbepoetin Alfa (500 Mcg): 75.7% (56/74) versus 71.8% (51/71) on control; risk difference 3.8 percentage points (95% CI -10.5 to 18.2), risk ratio 1.05 (0.87–1.28); unadjusted two-proportion z-test p = 0.599.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Epoetin Alfa (120,000 Units) and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Darbepoetin Alfa (500 Mcg) and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes cover two related but distinct aspects of the study course: receipt of at least one packed red blood cell transfusion and whether hemoglobin reached or exceeded 11 g/dL during the stated follow-up. Both can add context to the primary endpoint, which measures average hemoglobin change at Study Week 7. The threshold outcome is closer to a responder-style summary, while transfusion is a separate event; neither is interchangeable with the continuous primary measure.

Across the posted comparisons, the estimates do not provide a consistent, precise separation between the reference group and the other groups. Their intervals include no difference, and the posted p-values are unadjusted. These patterns are broadly compatible with the primary outcome’s uncertainty, but they should not be treated as independent confirmation of it. Secondary outcomes may be influenced by different processes, follow-up, and analysis populations.

These results carry less inferential weight because the record lists multiple outcomes and comparisons without reporting a multiplicity plan. When many hypotheses are examined, the chance of at least one apparently notable result can increase. Adjustment procedures or a prespecified hierarchy can address that concern, but the registry record does not report such procedures. The absence of a reported multiplicity method does not prove that none was used; it means the record does not establish how these results were prioritized or interpreted.

The registry lists no reported analyses for the secondary endpoints. Consequently, the posted counts and unadjusted comparisons are best read as descriptive and exploratory evidence. They may help characterize the observed pattern, but they do not replace a prespecified confirmatory analysis, establish equivalence, or show that the outcomes move together at the individual level. No joint or mediation analysis is reported in the registry record.

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

• Number of Patients Receiving at Least 1 Packed Red Blood Cell (PRBC) Transfusion During Study
• Time to Achieve Hb >= 11 g/dL During Study
• Number of Patients (Hb >= 11 g/dL) During Study.

9. Statistical Interpretation

10. Statistical Methods Explained

The primary endpoint is continuous: each participant contributes a hemoglobin change, and the group result is expressed as a mean. A mean is useful for describing the average change across a group, but it can conceal variation among individuals. The standard deviation is a descriptive measure of that variation. It is not the uncertainty in the estimated mean; uncertainty about a group mean or a difference between means is conveyed by a standard error or confidence interval.

The reported primary comparisons use the epoetin alfa 80,000 Units group as the reference. A mean difference is the estimated contrast between the group means, expressed in the same units as the endpoint, g/dL. A negative estimate for the 120,000 Units comparison means the reported mean change in that group was lower than the reference-group mean change; a positive estimate for the darbepoetin alfa comparison means its reported mean change was higher. These are descriptions of the direction of the estimates, not conclusions that one regimen is better.

A confidence interval communicates uncertainty around an estimated contrast. Its endpoints mark values that remain compatible with the data under the interval procedure and its assumptions. An interval that includes zero includes the possibility of no mean difference. When it also covers values in both directions, the estimate does not precisely determine which group had the larger mean change. The registry record gives interval endpoints, but does not specify the confidence level or the method used to construct them.

The p-values reported for these comparisons are unadjusted. In general, a p-value measures how unusual data at least as incompatible with a specified null model would be if that model and the calculation’s assumptions held. It is not the probability that the null hypothesis is true, nor does it measure the probability that a result arose by chance. An unadjusted p-value also does not address the consequences of testing multiple outcomes or comparisons.

For a binary outcome, such as whether a participant received at least one transfusion, the registry reports participant counts and risk-difference comparisons. A risk difference contrasts the proportions with the event between groups, expressed on an absolute scale. An interval around a risk difference describes uncertainty in that contrast. When the interval includes zero, it remains compatible with no absolute difference as well as differences in either direction. Relative measures such as risk ratios or odds ratios answer a different question by expressing a comparison on a relative scale. They should not be conflated with an absolute risk difference.

General statistical interpretation also depends on the data-generating and analysis procedures. Randomization can support comparisons between groups, but it does not remove uncertainty, measurement limitations, or the effects of missing outcome data. Open-label conduct can matter when outcomes or decisions involve judgment. Hemoglobin is a measured laboratory value, but the registry record does not describe laboratory procedures, assessor blinding, or how measurements after treatment discontinuation were handled.

The primary analysis population was per-protocol and was defined as a subset of the modified intent-to-treat population. It included randomized subjects who received at least one dose, had transfusion-unrelated hemoglobin values at baseline and Week 7, and met inclusion and exclusion criteria. The description in the registry record is incomplete at its end, and further details of the population definition are not reported. The record does not report the number excluded from this analysis, reasons for exclusion, or a missing-data method.

For secondary outcomes, the posted summary comparisons are also unadjusted. The record lists no reported analyses for those endpoints. It does not state whether the comparisons were prespecified, whether covariate adjustment was planned, or what inferential procedures were used. Those details should not be inferred from the presence of estimates, intervals, or p-values.

The sample-size planning illustration uses a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It considers effects equal to a stated fraction of the observed effect. These are planning assumptions for interpreting the illustration, not descriptions of the trial’s original design. The original sample-size justification and statistical plan are not reported in the registry record.

In general, over-dispersion means that observed variation is greater than a statistical model expects. When that occurs, methods that assume less variation can understate uncertainty and make intervals too narrow or tests too optimistic. The primary endpoint is continuous and its reported standard deviations provide descriptive information about variability; the registry record does not report an over-dispersion assessment or a model-based analysis. This general concept should not be mistaken for a finding that over-dispersion occurred in this study.

11. Confidence Intervals and Precision

Precision concerns how narrowly the data locate an estimated difference. The primary comparison intervals are wide relative to their point estimates and include zero. For epoetin alfa 120,000 Units versus 80,000 Units, the reported mean difference is -0.24 g/dL, with an interval from -0.740 to 0.260. For darbepoetin alfa 500 mcg versus 80,000 Units, it is 0.2 g/dL, with an interval from -0.290 to 0.690. Each interval covers values on both sides of zero, so neither estimate precisely establishes the direction of the underlying mean difference.

An interval is not a guarantee that the true value lies within its endpoints, nor does it assign a probability to a particular treatment effect after observing the data. In general, intervals reflect both the estimate and its uncertainty under a specified statistical procedure. The registry record does not report the confidence level or the interval-construction method, so those properties should not be assumed from the endpoints alone.

The intervals are also not tests of clinical importance. The record does not state a threshold for a meaningful hemoglobin difference. Even a statistically clear difference would need to be interpreted against an appropriate clinical threshold; conversely, an interval including zero does not prove that all clinically relevant differences are absent. Whether the ranges include effects considered important cannot be determined from the registry record.

Precision is influenced by the amount of information available, outcome variability, and analysis choices. The primary results use a per-protocol population, while the posted secondary outcomes use other denominators. Those differences matter when comparing apparent precision across endpoints. The record does not provide a full account of exclusions, missing measurements, or a sensitivity analysis, limiting assessment of how robust the intervals are to those issues.

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 80% power and participants per arm for 90% power. They are not total event counts: the registry’s planning note specifies total events only for time-to-event outcomes, and these posted outcomes are not time-to-event outcomes. Each planning comparison is a two-arm illustration; figures should be read for the particular endpoint and pair of groups rather than as a single sample-size requirement for the whole study.

The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is set to the stated fraction of the observed effect. Rows for planning for 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect therefore represent different assumed target effects. The registry’s original design assumptions and sample-size justification are not reported in the registry record.

The 80% power column represents the number of participants per arm that the planning calculation associates with an 80% chance of rejecting the no-difference model if the specified effect and assumptions were true. The 90% column gives the corresponding planning target for a 90% chance under those assumptions. These are design calculations, not guarantees about a future study, and they depend on the assumed effect and variability.

Smaller effects are harder to distinguish from random variation, so detecting them generally requires more participants. The displayed figures illustrate that pattern as the target is reduced from the observed effect to smaller fractions. This is a planning illustration, not observed power. It should not be read as evidence about the probability that the completed study detected an effect or as a reconstruction of the study’s original design.

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 = -0.240; pooled standard deviation σ = 1.334.
2. n = 2 × (1.96 + 0.842)² × 1.334² / -0.240² = 485.1, rounded up to 486 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 <- -0.24                      # observed difference in means
sigma <- 1.3341622423412                     # 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(386152)
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 = 486 (80% power), 650 (90% power)
 75% of observed effect: n per arm = 863 (80% power), 1,155 (90% power)
 50% of observed effect: n per arm = 1,941 (80% power), 2,598 (90% power)
power.t.test: 486.1 
Simulated power at n = 486 per arm: 0.803 (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. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary outcome and multiple secondary outcomes, but does not report a statistical plan for controlling multiplicity. Multiplicity arises when several outcomes, comparisons, or analyses are examined. Even if each individual test uses a conventional threshold, conducting many tests can increase the chance of at least one result appearing notable by chance. Adjustment methods, a prespecified hierarchy, or a clear distinction between confirmatory and exploratory outcomes can help guide interpretation; none is described in the registry record.

The record contains no reported analyses for the secondary outcomes and does not specify whether the posted comparisons were planned in advance. It also does not report subgroup analyses, covariate adjustment, sensitivity analyses, interim analyses, or stopping rules. These absences do not prove that such procedures were not conducted; they mean the registry record does not document them. The reported p-values are unadjusted, so they should not be interpreted as accounting for the number of outcomes or comparisons.

Missing-data handling is another important unknown. The primary endpoint required hemoglobin values at both baseline and Week 7, and the population definition specifies transfusion-unrelated values. The registry record does not state how missing Week 7 measurements were handled, how many participants lacked required measurements, or whether any imputation or sensitivity analysis was used. It also does not explain how treatment discontinuation or transfusion affected the analysis beyond the stated restriction on hemoglobin values.

The primary analysis population is described as a per-protocol subset of the modified intent-to-treat population. It includes randomized participants who received at least one dose, had qualifying hemoglobin measurements at both time points, and met inclusion and exclusion criteria. The complete population description and the number analyzed are not reported in the registry record. The posted secondary outcomes use their own denominators, and the record does not fully explain the relation between those groups and the primary population.

Because the trial was open-label, treatment knowledge could potentially affect aspects of conduct or outcome assessment. Hemoglobin is a laboratory measure, but the registry does not describe whether laboratory assessment was blinded or how measurement quality was controlled. These uncertainties are reasons to interpret the reported estimates cautiously, not evidence that bias necessarily occurred.

15. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

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: pneumonia (5.3%), dehydration (5.2%), febrile neutropenia (4.0%), atrial fibrillation (4.0%), neutropenia (2.7%).

The registry reports serious adverse event figures by group as participants at risk and participants affected. For epoetin alfa 80,000 Units, 75 were at risk and 28 were affected; for epoetin alfa 120,000 Units, 77 were at risk and 23 were affected; for darbepoetin alfa 500 mcg, 75 were at risk and 25 were affected. These are descriptive counts. The record does not provide a comparative safety analysis, adjusted estimates, or uncertainty intervals for these figures.

The registry also lists serious adverse event terms with percentages: Pneumonia, 5.3%; Dehydration, 5.2%; Febrile neutropenia, 4.0%; Atrial fibrillation, 4.0%; Neutropenia, 2.7%; and Abdominal pain, 2.7%. The record does not establish in this listing whether these percentages are arm-specific, nor does the listing support causal attribution to a study drug. They should be read as reported event summaries, not as comparisons of risk between treatments.

Other adverse events were reported for participants at risk and affected in each group, but those summaries do not by themselves establish severity or causation. Death counts are not reported in the registry record. The study’s terminated status does not explain why it ended and should not be interpreted as a safety finding.

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

The posted primary results describe mean hemoglobin change from baseline to Study Week 7 in a per-protocol population. They show positive reported mean changes in all three groups, with unadjusted comparisons whose intervals include zero and span values in both directions. The results therefore leave substantial uncertainty about the size and direction of differences between the groups for this endpoint.

This interpretation is narrower than a conclusion about whether a treatment works. The primary endpoint is a laboratory measure, the comparison is based on a selected analysis population, and the record does not report a clinically important difference threshold. The registry record also does not provide a complete analysis plan or a detailed account of missing measurements. These limits prevent a strong claim that the groups are the same, that one is superior, or that any observed difference has a particular clinical importance.

The secondary results add descriptive information about transfusions and reaching a hemoglobin threshold during follow-up. They do not resolve the uncertainty in the primary comparison. Their unadjusted nature, the absence of reported multiplicity procedures, and the lack of reported secondary analyses mean they should be interpreted cautiously rather than as confirmatory evidence.

The study’s design has features relevant to comparison: it was randomized and used parallel groups. At the same time, it was open-label, and the primary endpoint was analyzed in a per-protocol subset. Randomization alone does not ensure that every analysis population retains the same protection against bias as the randomized groups, particularly when inclusion in an analysis depends on post-randomization measurements or criteria.

In short, the registry record supports a description of the posted group summaries and unadjusted contrasts, not a definitive conclusion about equivalence, superiority, or clinical benefit. The terminated status, without a reported reason, is additional context but does not explain the results or establish their reliability.

17. Why This Trial Matters Statistically

This study illustrates why the endpoint, analysis population, and comparison need to be read together. A mean change in hemoglobin answers a different question from the proportion reaching a threshold or the number receiving a transfusion. These outcomes can provide complementary descriptions, but a result on one scale does not automatically establish a result on another.

It also demonstrates the importance of uncertainty. Point estimates can suggest a direction, but intervals that span zero and include values on both sides do not establish a clear direction for the underlying group difference. The p-values do not replace that interval-based reading, and unadjusted p-values do not account for examining multiple outcomes and comparisons.

The population definition is equally important. The primary results are reported for a per-protocol subset requiring treatment exposure and qualifying measurements. That is not the same as an analysis of all randomized participants. Without details on exclusions and missing data, readers cannot fully assess how the analyzed subset relates to the trial’s randomized population.

Finally, planning illustrations based on observed effects are useful for understanding how assumptions about target effect size influence future sample-size needs. They are not a substitute for the original design rationale, which is not reported in the registry record, and they do not indicate observed power. Together, these features make the study useful for statistical interpretation while underscoring why registry summaries should be read with attention to design, precision, and reporting gaps.

18. 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 registry record provides limited information about why the study was terminated. It lists the status as terminated but does not report the reason or describe whether termination affected recruitment, follow-up, or outcome availability. No explanation should be inferred from the status alone.

The primary endpoint population is restricted to a per-protocol subset with treatment and measurement requirements. The record does not report the number excluded from that population, the reasons for exclusion, or a primary analysis in the full randomized population. This limits assessment of possible selection effects and of how directly the primary result represents the randomized comparison.

Although the primary endpoint description specifies baseline timing and transfusion-unrelated measurements, the record does not explain how missing data were handled or whether additional measurements were used in sensitivity analyses. It also does not report a full statistical analysis plan, the original sample-size justification, interval construction methods, or the confidence level of the reported intervals. The reason for using the per-protocol population as the primary analysis population is not reported in the registry record.

The trial was open-label, and the registry does not describe masking of laboratory personnel or other outcome-assessment safeguards. The record also does not report how the randomization sequence was generated or whether allocation was concealed. These are reporting limitations, not evidence that the conduct was necessarily biased.

For secondary outcomes, no analyses are listed as reported, and no multiplicity approach is documented. Safety summaries are descriptive and do not include comparative uncertainty estimates in the record. Together, these gaps constrain evaluation of robustness, confirmatory status, and the precision of conclusions beyond the posted summaries.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: A Study Comparing Two Different PROCRIT Doses to a Dose of ARANESP in Anemic Cancer Patients Receiving Chemotherapy — NCT00386152.
• Registry record last updated 2013-07-19; status last verified 2013-07.
• Results first posted 2009-06-01.
• 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.

22. Record Summary

The registry record describes a randomized, open-label, parallel-group Phase 2 study in anemic cancer patients receiving chemotherapy. It enrolled 235 participants and is listed as terminated. The study compared epoetin alfa at 80,000 Units or 120,000 Units with darbepoetin alfa at 500 mcg, administered subcutaneously once every 3 weeks for up to 13 weeks.

The primary outcome was mean hemoglobin change from baseline to Study Week 7 in a per-protocol population. The posted group means and unadjusted comparisons show substantial uncertainty, with both comparison intervals including zero. Secondary outcomes concerned transfusion and reaching a hemoglobin threshold during follow-up; their posted comparisons are also unadjusted, and the registry lists no reported analyses for them.

The record does not report the reason for termination, the original sample-size justification, a complete statistical plan, or methods for handling missing data and multiplicity. Those reporting gaps limit how firmly the posted summaries can support broader conclusions.