APF530 or Aloxi (Palonosetron Hydrochloride) Combined With Dexamethasone in Preventing Nausea and Vomiting in Patients Receiving Chemotherapy for Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for APF530 or Aloxi (Palonosetron Hydrochloride) Combined With Dexamethasone in Preventing Nausea and Vomiting in Patients Receiving Chemotherapy for Cancer (NCT00343460), a randomized phase 3 study. The primary outcome is Proportion of Patients With Complete Response (CR) During Acute Phase (0-24 Hours) After Administration of Chemotherapy Course 1.

2. Clinical Question

The registry describes a phase 3 randomized trial of APF530 and Aloxi, each combined with dexamethasone, for preventing chemotherapy-induced nausea and vomiting. Its official title also identifies acute-onset and delayed-onset symptoms as trial concerns, but the primary endpoint addressed only the acute 0-24-hour period after chemotherapy course 1. The study included both moderately and highly emetogenic chemotherapy groups, so treatment outcomes should be understood in the context of those distinct chemotherapy categories.

The registry does not report enough detail to establish all eligibility criteria or to determine precisely how the randomized comparison was intended to be structured across chemotherapy categories. The posted results include separate treatment arms by chemotherapy category, but the displayed comparison records use the same moderately emetogenic APF530 5 mg reference group. That feature matters when interpreting the high-risk comparisons: differences across chemotherapy categories can reflect more than the assigned antiemetic treatment.

3. Trial Design

This was a phase 3, randomized, parallel-group trial. The registry records double masking, while the official title describes the study as observer-blind. These are both descriptions in the registry record; additional details about who was masked and how masking was maintained are not reported in the registry record. Heron Therapeutics is listed as the sponsor. The study is marked completed, with total enrollment of 1428.

The listed treatments included APF530, dexamethasone, palonosetron hydrochloride, and placebo. The arm descriptions show that the cycle 1 treatment regimens paired dexamethasone with either APF530 or palonosetron, with placebo administered by the other route. For the APF530 groups, the registry lists 5 mg and 10 mg doses. The high-risk stratum also received oral dexamethasone on days 2-4, as described in the registry. The record also describes APF530 administration during later chemotherapy courses, but the primary endpoint concerns course 1.

There are six posted primary-outcome groups: two APF530 doses and an Aloxi group in each chemotherapy category. The primary endpoint population is identified as the cycle 1 modified intention-to-treat population. Its group counts are 214, 212, and 208 for the moderately emetogenic groups, and 229, 240, and 238 for the highly emetogenic groups. These are outcome-specific counts, not a description of the full randomized cohort in every analysis.

The registry lists 11 outcome measures and nine posted secondary outcomes. Secondary topics include complete control, total response, emetic episodes, rescue medication, nausea severity, durability across chemotherapy courses, and quality of life. The original trial protocol, the rationale for its planned enrollment, and the full prespecified statistical analysis plan 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.

Cycle 1

Cycle 2 - 4

Analysis population for the primary outcome, as defined in the registry: Cycle 1 - Modified Intent-to-Treat 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: Modified Intent-to-Treat Population

Only the first 6 of 7 groups are shown.

6. Primary Endpoint

The registry lists the primary outcome as Proportion of Patients With Complete Response (CR) During Acute Phase (0-24 Hours) After Administration of Chemotherapy Course 1, measured over 0-24 Hours.

The primary endpoint is the number and proportion of participants with complete response during the acute phase after chemotherapy course 1. The time window is 0-24 hours. The registry defines complete response as having no emetic episodes and using no rescue medication. Both conditions are required for a participant to count as a responder under this definition.

This endpoint combines two observable aspects of chemotherapy-associated nausea and vomiting: vomiting episodes and the need for additional medication to manage symptoms. It is a binary outcome at the participant level: each participant either meets the complete-response definition or does not. The posted results give the number meeting the definition and the number in each group.

General statistical context: a binary endpoint can summarize how often a defined outcome occurs, but it does not describe every detail of symptom experience. In this trial, complete response does not by itself quantify nausea severity, the timing or number of emetic episodes among nonresponders, or the use of rescue medication separately. Those topics appear among the registry's other outcome measures, but they are distinct from the primary endpoint.

The acute window is narrower than the delayed-onset period identified in the trial title. Therefore, a result for the primary endpoint addresses complete response during the first 24 hours after chemotherapy course 1, not complete response across all subsequent days or all treatment courses. The endpoint population is described as modified intention-to-treat; the exact criteria for inclusion in that population are not reported in the registry record.

7. Results Posted in the Registry

• Cycle 1 APF530 10 mg - Moderately: 76.9% (163/212) versus 74.8% (160/214) on control; risk difference 2.1 percentage points (95% CI -6.0 to 10.2), risk ratio 1.03 (0.92–1.14); unadjusted two-proportion z-test p = 0.609.
• Cycle 1 Aloxi 0.25 mg - Moderately: 75.0% (156/208) versus 74.8% (160/214) on control; risk difference 0.2 percentage points (95% CI -8.0 to 8.5), risk ratio 1.00 (0.90–1.12); unadjusted two-proportion z-test p = 0.956.
• Cycle 1 APF530 5 mg - Highly: 77.7% (178/229) versus 74.8% (160/214) on control; risk difference 3.0 percentage points (95% CI -5.0 to 10.9), risk ratio 1.04 (0.94–1.15); unadjusted two-proportion z-test p = 0.464.
• Cycle 1 APF530 10 mg - Highly: 81.2% (195/240) versus 74.8% (160/214) on control; risk difference 6.5 percentage points (95% CI -1.1 to 14.1), risk ratio 1.09 (0.98–1.20); unadjusted two-proportion z-test p = 0.095.

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 Emetic Episodes

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Cycle 1 APF530 10 mg - Moderately: mean 3.10 versus 3.40 on control; difference -0.30 (95% CI -1.97 to 1.37), standardized effect d = -0.03; z-test p = 0.726.
  • Cycle 1 Aloxi 0.25 mg - Moderately: mean 2.10 versus 3.40 on control; difference -1.30 (95% CI -2.60 to -0.00), standardized effect d = -0.19; z-test p = 0.049.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Cycle 1 APF530 10 mg - Moderately and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval excludes no difference, so the mean is statistically lower for Cycle 1 Aloxi 0.25 mg - Moderately than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Sustainability of Antiemetic Effect of APF530 Over Multiple Chemotherapy Courses

• 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:
  • Cycles 1, 2, 3, and 4 - Moderately: 38.0% (35/92) versus 37.4% (34/91) on control; risk difference 0.7 percentage points (95% CI -13.4 to 14.7), risk ratio 1.02 (0.70–1.48); unadjusted two-proportion z-test p = 0.924.
  • Cycles 1, 2, 3 and 4 - Highly: 52.8% (56/106) versus 37.4% (34/91) on control; risk difference 15.5 percentage points (95% CI 1.7 to 29.2), risk ratio 1.41 (1.03–1.95); unadjusted two-proportion z-test p = 0.030.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Cycles 1, 2, 3, and 4 - Moderately and the control. The interval gives the range of effects that remain compatible with the data.
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for Cycles 1, 2, 3 and 4 - Highly than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Patient's Global Satisfaction With Antiemetic Therapy During Acute Phase and Chemotherapy Course 1

• 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:
  • Cycle 1 APF530 10 mg - Moderately: 53.3% (113/212) versus 47.9% (101/211) on control; risk difference 5.4 percentage points (95% CI -4.1 to 14.9), risk ratio 1.11 (0.92–1.35); unadjusted two-proportion z-test p = 0.264.
  • Cycle 1 Aloxi 0.25 mg - Moderately: 47.1% (98/208) versus 47.9% (101/211) on control; risk difference -0.8 percentage points (95% CI -10.3 to 8.8), risk ratio 0.98 (0.80–1.20); unadjusted two-proportion z-test p = 0.878.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Cycle 1 APF530 10 mg - Moderately 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 Cycle 1 Aloxi 0.25 mg - Moderately and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes broaden the assessment beyond acute complete response. They include emetic episode counts, complete control and total response at different time windows, rescue medication, nausea severity, patient satisfaction, and whether an antiemetic effect was sustained across several chemotherapy courses. These outcomes capture related but nonidentical aspects of treatment experience, so agreement across them would provide a more rounded picture than any single measure alone.

The posted secondary results do not form a single, uniformly precise pattern. Some comparisons have estimates near the null, while others point in different directions or have confidence intervals that allow a wide range of effects. The results therefore do not convert the primary endpoint into a consistent finding across symptom measures and time periods. The secondary endpoints also differ in their analysis populations and available group counts, especially for the outcome spanning multiple courses.

The primary endpoint is limited to complete response during 0-24 hours after course 1. Secondary results extending to 0-120 hours or across courses address later periods, but they cannot be treated as interchangeable replications of the primary endpoint. An outcome such as emetic episode count also measures something different from the combined complete-response definition, and patient satisfaction is a distinct patient-reported outcome.

Unadjusted secondary comparisons carry less weight because the registry does not report how multiple outcomes and comparisons were handled in the original analysis plan. General statistical context: when many outcomes are examined, a small p-value in one analysis may arise by chance, and selective emphasis on isolated findings can overstate the overall evidence. The secondary estimates are best interpreted as descriptive and hypothesis-generating unless supported by an analysis plan and multiplicity strategy not reported in the registry record. They add context, but do not independently settle the primary treatment question.

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

• Proportion of Patients With Complete Control During the Acute Phase (0-24 Hours), Delayed-onset Phase (24-120 Hours), and During Chemotherapy Course 1
• Proportion of Patients With Total Response During the Acute Phase, Delayed-onset Phase, and During Chemotherapy Course 1
• Number of Emetic Episodes
• Time to First Treatment Failure
• First and Overall Use of Rescue Medication
• Severity of Nausea Daily and During Chemotherapy Course 1 (0-120 Hours)
• Sustainability of Antiemetic Effect of APF530 Over Multiple Chemotherapy Courses
• Quality of Life and the Impact of Nausea and Vomiting on Day 5

9. Statistical Interpretation

10. Statistical Methods Explained

General statistical context: the primary outcome is binary because each participant either met the complete-response definition or did not. For such an outcome, a risk difference expresses the difference between the proportions meeting the endpoint in two groups. A value of zero represents no difference in those proportions; positive and negative values indicate opposite directions depending on which group is subtracted from which. The registry's posted recalculations use risk differences, with confidence intervals and unadjusted p-values.

The displayed primary comparisons identify the moderately emetogenic APF530 5 mg group as the control. Its observed result is 160 participants with complete response among 214. Comparisons against it include APF530 10 mg and Aloxi in the moderately emetogenic groups, as well as the three highly emetogenic groups. Since chemotherapy category is part of the arm labels, a comparison between a moderately emetogenic reference and a highly emetogenic group combines differences in both treatment grouping and chemotherapy category. General statistical context: an effect estimate is most directly interpretable as a randomized treatment contrast when the groups being compared represent the intended randomized alternatives in a comparable population. The cross-category comparisons do not meet that simple interpretive description.

The p-values shown for these comparisons are unadjusted. A p-value measures how incompatible the observed data are with a specified null model under the assumptions of the test; it is not the probability that a treatment effect is true, and it does not measure the size or clinical importance of an effect. The registry record does not report the original test method, model, covariate adjustment, or prespecified significance threshold for the primary comparison. The planning illustration separately specifies a two-sided significance level of 0.05, but that planning assumption does not establish the analysis plan used for the trial.

A confidence interval describes a range of effect values compatible with the data and the method used to construct the interval. Its width reflects both the observed data and the analysis method. For the primary risk-difference comparisons, all displayed intervals include zero. General statistical context: this means the posted intervals do not exclude no difference at their stated confidence level. It does not prove equivalence or show that any possible difference is unimportant. The registry does not report a noninferiority or equivalence margin.

The secondary outcome for number of emetic episodes is continuous in the posted summary, with a mean and standard deviation for each arm. A mean describes the average number of episodes in the analyzed group. A standard deviation describes variation among participants; it is not a confidence interval for the mean and does not indicate how precisely the mean has been estimated. The posted summaries show notably wide variation relative to the means in some groups. General statistical context: when count data vary substantially, a simple mean-based comparison may not capture the full distribution. Over-dispersion means that the variability exceeds what a chosen statistical model expects; it can affect standard errors and uncertainty estimates if the model does not accommodate it. The registry does not report the model used for the original emetic-episode analysis, and no sponsor analysis is posted for that outcome.

The sustainability outcome and patient satisfaction outcome are binary summaries, again reported as counts of participants with the outcome and group denominators. Their interpretation depends on their own outcome definitions and analysis populations. The sustainability outcome concerns overall complete response over chemotherapy courses 1-4 and has smaller group counts than the primary course 1 outcome. The satisfaction outcome is recorded during the acute phase and has its own outcome-specific denominators. General statistical context: differences in analysis populations and denominators can occur when outcomes require different follow-up or measurements; without further record detail, the reasons for those differences cannot be determined.

The recalculated contrasts are unadjusted comparisons derived from the posted summary statistics. They are not a substitute for a prespecified trial analysis. The registry record reports no analyses for the primary outcome and lists no reported analyses for the posted secondary outcomes. Details such as model selection, handling of missing observations, covariate adjustment, and any stratified analysis are not reported in the registry record. Accordingly, the recalculations describe the available summary data without establishing what analysis the sponsor used in the full trial report.

General statistical context: multiplicity arises when multiple outcomes, treatment groups, time windows, or comparisons are examined. The more tests considered, the greater the chance that at least one result appears unusual by chance if no adjustment or hierarchy is used. The registry includes multiple outcomes and arms, but does not report a multiplicity procedure or a hierarchy for interpreting secondary outcomes. The p-values for secondary comparisons should therefore be read as exploratory descriptive evidence rather than as a family-wise confirmed set of findings.

The sample-size illustration is also a statistical calculation, but it addresses planning rather than analysis of the randomized trial. It uses the observed effect and specified fractions of that effect, with equal allocation, a normal approximation, a two-sided significance level of 0.05, and target power levels. These conditions are planning assumptions for the illustration. The trial's own original sample-size justification and planning assumptions are not reported in the registry record.

11. Confidence Intervals and Precision

The primary estimates are not highly precise in the sense of ruling out a broad range of possible risk differences. For the moderately emetogenic APF530 10 mg comparison, the recalculated risk difference is 0.021 and its 95% confidence interval extends from -0.060 to 0.102. For the corresponding Aloxi comparison, the estimate is 0.002 and the interval extends from -0.080 to 0.085. Both intervals include zero and allow for differences in either direction.

For the highly emetogenic groups, the recalculated risk differences against the posted reference are 0.030 for APF530 5 mg, 0.065 for APF530 10 mg, and 0.059 for Aloxi. Their respective confidence intervals are -0.050 to 0.109, -0.011 to 0.141, and -0.018 to 0.136. Each includes zero. These intervals also arise from comparisons against the moderately emetogenic reference, so their width is not the only interpretive limitation; the contrast itself spans chemotherapy categories.

General statistical context: a confidence interval is an uncertainty range around an estimate, not a range containing a known proportion of individual participant outcomes. A wide interval indicates that the data are compatible with a relatively broad set of effect sizes. An interval crossing zero does not demonstrate that the effect is exactly zero, and an interval that does not cross zero would not by itself address bias, multiplicity, or the appropriateness of the comparison.

The observed arm counts give context for the amount of information in the primary endpoint groups, which range from 208 to 240 participants. These counts do not remove uncertainty, particularly when the observed differences are modest relative to the variability expected in binary outcomes. The registry record does not report the original precision target or the assumptions used to plan enrollment. The confidence intervals in the posted recalculations should therefore be used to describe uncertainty in those comparisons, not as evidence that the trial was designed to establish a particular margin or degree of precision.

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 sample-size figures are planning illustrations based on the observed effect, not a reconstruction of the trial's original design. For the comparisons displayed, the entries are participants per arm. The stated convention for any time-to-event calculation is total events, using the Schoenfeld approach; the posted comparisons discussed for these outcomes are not time-to-event comparisons.

The 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 in turn to 100%, 75%, or 50% of the observed effect. For example, the APF530 10 mg moderately emetogenic primary comparison gives 6,399 participants per arm for 80% power when planning for 100% of the observed effect, and 11,461 participants per arm when planning for 75% of that effect. The corresponding 90% power figures are 8,566 and 15,342 participants per arm.

In plain terms, the 80% power column gives the calculated number of participants per arm under which the planning method would have an 80% chance of detecting the specified effect if the assumptions held. The 90% power column uses a higher target chance of detection and consequently requires more participants under the same assumptions. Smaller effects require more participants because they are harder to distinguish from random variation. This is not observed power.

Some figures are very large, particularly when the observed contrast is close to zero. That pattern reflects how the planning calculation responds to a small effect estimate; it does not mean the original trial enrolled those numbers or that the observed trial had a particular probability of success. The original sample-size justification, planned effect, and trial-specific power assumptions are not reported in the registry record. These illustrations are conditional calculations, not evidence about the adequacy of the trial'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, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.748; treatment proportion p₁ = 0.769; average p̄ = 0.758.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6055 = 1.1867.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.6053 = 0.5094.
4. n = (1.1867 + 0.5094)² / (0.0212)² = 6,398.3, rounded up to 6,399 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 <- 0.747663551401869                          # control proportion
p1 <- 0.768867924528302                          # 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(343460)
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 = 6,399 (80% power), 8,566 (90% power)
 75% of observed effect: n per arm = 11,461 (80% power), 15,342 (90% power)
 50% of observed effect: n per arm = 25,976 (80% power), 34,774 (90% power)
power.prop.test: 6398.3 
Simulated power at n = 6,399 per arm: 0.797 (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. Multiplicity, Missing Data and Analysis Populations

The trial record lists numerous outcomes, several treatment arms, two chemotherapy risk categories, and more than one time period. The posted secondary outcomes include analyses of symptoms, rescue medication, sustained response, and satisfaction. This creates multiple opportunities to examine contrasts. The registry record does not report a multiplicity adjustment, a prespecified hierarchy of outcomes, or a strategy specifying which comparisons were confirmatory and which were exploratory.

The primary endpoint is identified, but the detailed statistical analysis plan is not reported in the registry record. The record does not describe the original test method, whether covariates were included, whether treatment effects were estimated separately by chemotherapy category, or how subgroup comparisons were to be interpreted. The recalculated comparisons are unadjusted and should not be confused with sponsor analyses. The registry shows no reported analysis for the primary outcome, and no reported analyses for the secondary outcomes listed with results.

The primary population is called cycle 1 modified intention-to-treat, but the exact inclusion rules for that population are not reported in the registry record. The record also does not explain how missing endpoint data were handled, whether participants with incomplete symptom diaries were excluded, or how missingness might have affected the estimates. Outcome-specific denominators differ, but the reasons for those differences are not reported. Those variations should not automatically be interpreted as missing data or as evidence of a particular exclusion process.

General statistical context: missing-data handling can influence estimates when outcome availability differs between groups or is related to the unobserved outcome. Without the original rules and participant flow, the size or direction of any such influence cannot be assessed. Likewise, a multiplicity plan matters because unadjusted p-values across many outcomes do not control the overall false-positive risk. These omissions limit how strongly isolated secondary results can be treated as confirmatory evidence.

The registry record does not report the trial's original sample-size justification, interim analyses, stopping rules, or the full protocol. Their presence or absence cannot be inferred from the posted endpoint summaries.

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: febrile neutropenia (1.6%), pneumonia (1.3%), neutropenia (1.2%), dehydration (1.2%), pulmonary embolism (1.2%).

The registry reports serious adverse events for three cycle 1 groups and two groups covering cycles 2-4. For cycle 1, serious adverse events affected 42 of 464 participants in the APF530 5 mg group, 36 of 468 in the APF530 10 mg group, and 27 of 472 in the Aloxi 0.25 mg group. For cycles 2-4, the corresponding posted counts are 61 of 528 for APF530 5 mg and 73 of 515 for APF530 10 mg. These are counts of participants affected among the recorded at-risk group, not counts of all individual events.

The registry lists febrile neutropenia at 1.6%, pneumonia at 1.3%, neutropenia at 1.2%, dehydration at 1.2%, pulmonary embolism at 1.2%, and anaemia at 1.1% among the top serious adverse event terms. The listed terms provide frequency context but do not show treatment attribution or establish whether an event was caused by study treatment.

Other adverse events affected 335 of 464, 349 of 468, and 313 of 472 participants in the three cycle 1 groups; the cycle 2-4 groups report 422 of 528 and 413 of 515. Death counts are not reported in the registry record. The different groups and course periods should not be compared as if they had identical follow-up or populations; further details about safety definitions and exposure are not reported in the registry record.

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

The posted results describe how many participants met a specific acute complete-response definition in each listed group. They also provide recalculated unadjusted comparisons and uncertainty intervals. Those results support a descriptive account of the observed course 1 outcomes, but they do not by themselves establish that one treatment is superior, equivalent, or clinically preferable.

The endpoint is specific: no emetic episodes and no rescue medication during 0-24 hours after chemotherapy course 1. It does not encompass nausea severity by itself, later delayed-onset symptoms, or sustained control throughout multiple chemotherapy courses. The registry lists additional outcomes addressing some of those concerns, but their presence does not make the primary outcome broader than its stated definition.

The strongest caution concerns the reference used in the posted comparisons. The moderately emetogenic APF530 5 mg group is the reference for comparisons that include highly emetogenic chemotherapy groups. Since chemotherapy category differs, those comparisons do not isolate the treatment difference within a single category. The arm counts can still be read as observed outcomes in their respective groups, but cross-category differences should not be attributed solely to the drug regimen.

General statistical context: absence of a statistically clear difference is not proof that treatments are identical. Equivalence or noninferiority requires a prespecified margin and an analysis designed for that purpose; such a margin is not reported in the registry record. Similarly, a numerical difference in observed counts does not establish that the difference is reliable or important. Confidence intervals, analysis populations, multiplicity, and comparison structure all affect interpretation.

The registry record does not provide the detailed protocol or full statistical analysis plan needed to resolve those issues. The results should therefore be read as a limited account of the posted endpoint data, not as a complete statement about every clinical outcome, treatment course, or patient subgroup.

17. Why This Trial Matters Statistically

This trial illustrates why the definition and timing of an endpoint matter. Complete response is not a general measure of all nausea and vomiting; it requires both no emetic episodes and no rescue medication in a defined 0-24-hour window. A result for this endpoint answers a focused question about acute response after the first chemotherapy course.

It also illustrates the importance of comparing like with like. The treatment arms are organized by moderately and highly emetogenic chemotherapy, but the posted comparisons use the moderately emetogenic APF530 5 mg group as the common reference. A numerical contrast that crosses these categories cannot cleanly separate a treatment difference from differences associated with the chemotherapy category. Statistical interpretation depends not only on the estimate and its interval but on whether the contrast matches the clinical question.

The reported uncertainty is also instructive. Confidence intervals that include zero can be consistent with effects in either direction, and they should not be translated into a claim of equivalence. The posted p-values are unadjusted, while the registry lists numerous outcomes. Without a reported analysis hierarchy or multiplicity strategy, isolated secondary findings warrant restraint.

Finally, the planning illustrations show how sample-size calculations depend on the effect chosen for detection. Smaller assumed effects require more participants per arm under the stated assumptions. These calculations are not a record of the trial's original design rationale, which is not reported. Together, these features demonstrate how endpoint scope, comparison structure, uncertainty, and analysis planning determine what can reasonably be concluded from registry results.

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 primary outcome is restricted to the acute period after chemotherapy course 1, although the trial title includes acute and delayed nausea and vomiting and the registry lists outcomes covering later periods. The primary endpoint does not measure nausea severity directly and combines emetic episodes with rescue medication use. Separate details for those components are not part of the primary result.

The posted comparisons use the moderately emetogenic APF530 5 mg group as the reference, including comparisons against highly emetogenic groups. This makes the high-category risk differences difficult to interpret as treatment-only effects. A within-category comparison would better align with a question about treatment differences among participants receiving the same chemotherapy category, but such a recalculated comparison is not included in the registry entries.

The registry identifies a modified intention-to-treat population but does not report its exact definition, participant flow, or missing-data approach. Outcome denominators vary, and the record does not explain why. The original statistical analysis plan, analysis methods, multiplicity procedure, sample-size justification, and interim analysis information are not reported in the registry record. This limits assessment of whether the recalculated summaries match the intended confirmatory analysis.

The secondary comparisons are unadjusted and cover multiple outcomes and time windows. Their results should not be treated as a single confirmatory family. Safety summaries report affected participants and selected serious-event terms, but detailed event-level context, attribution, exposure-adjusted comparisons, and deaths are not reported in the registry record. These limitations concern the available registry information and do not establish that the full trial report lacks such details.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: APF530 or Aloxi (Palonosetron Hydrochloride) Combined With Dexamethasone in Preventing Nausea and Vomiting in Patients Receiving Chemotherapy for Cancer — NCT00343460.
• Registry record last updated 2026-03-02; status last verified 2026-02.
• Results first posted 2016-12-28.
• 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

NCT00343460 is a completed phase 3 randomized parallel-group trial sponsored by Heron Therapeutics, with enrollment of 1428. It compared APF530 with Aloxi, each combined with dexamethasone, in patients receiving chemotherapy for cancer. The registry records double masking; the official title describes an observer-blind trial.

The primary outcome was complete response during 0-24 hours after chemotherapy course 1 in the cycle 1 modified intention-to-treat population. Complete response meant no emetic episodes and no rescue medication. The posted arm counts cover APF530 5 mg, APF530 10 mg, and Aloxi 0.25 mg in moderately and highly emetogenic chemotherapy groups.

Recalculated unadjusted primary comparisons use the moderately emetogenic APF530 5 mg group as their reference. Their confidence intervals include zero, and the comparisons involving highly emetogenic groups cross chemotherapy categories. Nine secondary outcomes are posted, along with safety summaries. The registry does not report the full statistical analysis plan, original sample-size justification, or missing-data methods.