Phase II Study of Interleukin-21 (rIL-21) vs Dacarbazine (DTIC) in Patients With Metastatic or Recurrent Melanoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Phase II Study of Interleukin-21 (rIL-21) vs Dacarbazine (DTIC) in Patients With Metastatic or Recurrent Melanoma (NCT01152788), a randomized phase 2 study. The primary outcome is Progression Free Survival.

2. Clinical Question

3. Trial Design

This was a randomized, parallel-group Phase II study comparing rIL-21 with dacarbazine in people with metastatic or recurrent melanoma. The registry lists 64 enrolled participants, and the study status is completed. Masking was none, so the record describes the study as open-label. The sponsor was NCIC Clinical Trials Group. The registry dates the study start as 2010-08-05 and primary completion as 2014-11-25.

The primary endpoint was progression-free survival in the treated population. For this endpoint, the registry reports 32 participants in the rIL-21 group and 28 in the dacarbazine group. Response rate used 30 participants for rIL-21 and 28 for dacarbazine. The reason the response-rate denominator differs from the rIL-21 treated count is not reported in the registry record. These endpoint-specific analysis counts should not be treated as interchangeable.

Other registered outcomes included overall survival, response rate, and a safety and toxicity profile based on participants with grade 3, 4, or 5 adverse events. The record also describes planned examination of rIL-21 blood levels and previously removed melanoma tissue in its study summary. Results for every stated study objective are not reported in the registry record.

The study is identified as randomized, but the allocation sequence, concealment procedures, treatment schedules, and original design assumptions are not reported in the registry record. The record does not report whether interim analyses were conducted. These omissions limit how fully the conduct and analysis can be reconstructed from the registry results alone.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: treated 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.

6. Primary Endpoint

The registry lists the primary outcome as Progression Free Survival, measured over From randomization to progression or death, up to 22 months.

Progression-free survival measures the time from randomization until the first documented disease progression or death from any cause. In this study, the definition also specifies how follow-up is handled when a participant begins alternative therapy before progression is documented, or has no documented progression or alternative therapy before the last disease assessment. Those participants are censored at the relevant date specified in the registry.

General: A time-to-event endpoint uses both the timing of an event and the information from participants who have not yet had the event by the end of their observed follow-up. Censoring records that the event time is not observed after a particular point; it is not the same as recording that the event never occurred. This approach can use follow-up of different lengths without requiring every participant to experience progression or death before analysis.

Progression-free survival is useful in a trial that seeks to compare how long participants remain alive without documented progression. It captures progression as well as death, unlike an endpoint that counts death alone. The registry reports the endpoint as a median with a 95% confidence interval and also reports a hazard ratio from a log-rank analysis. The stated assessment timeframe is from randomization to progression or death, up to 22 months. The endpoint unit is reported as years. The registry does not explain the relationship between that timeframe and the unit used for the medians.

7. Results Posted in the Registry

• rIL-21 vs Dacarbazine: hazard ratio 1.10 (95% CI 0.60–2.01), reported p = 0.760 (as reported in the registry).

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.

Response 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:
  • Dacarbazine: 14.3% (4/28) versus 13.3% (4/30) on control; risk difference 1.0 percentage points (95% CI -16.8 to 18.7), risk ratio 1.07 (0.30–3.88); unadjusted two-proportion z-test p = 0.916.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Dacarbazine and the control. The interval gives the range of effects that remain compatible with the data.

Overall Survival

• 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:
  • rIL-21 vs Dacarbazine: hazard ratio 0.80 (95% CI 0.38–1.68), reported p = 0.550 (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 rIL-21 vs Dacarbazine and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes add context to the primary progression-free survival result, but they do not resolve its uncertainty. Overall survival and response rate are different measures of outcome: one records time to death, while the other records whether response was observed during the stated treatment period. Their estimates are also imprecise, so the secondary results do not provide a clear basis for a firm comparative conclusion alongside the primary result.

Safety and toxicity are another important part of the secondary outcome picture. The registry reports counts of participants with serious and other adverse events by group and lists selected serious-event terms. These are descriptive observations. They do not by themselves establish that a treatment caused an event, and the record does not provide all details needed to assess event timing, attribution, severity definitions, or the completeness of reporting.

General: Multiple outcomes create multiple opportunities to observe apparently notable results by chance. If several outcomes are tested, unadjusted p-values do not account for that repeated testing. This can make isolated secondary findings less persuasive than a result from a clearly designated primary endpoint, particularly when no multiplicity procedure is reported. The registry does not report whether secondary testing was adjusted, which outcomes were formally tested, or whether a hierarchy governed interpretation.

The secondary outcomes should therefore be considered supportive and descriptive rather than independent confirmation of the primary comparison. Their value is in showing the broader pattern of observed results and the types of information collected, while recognizing the uncertainty and the lack of reported multiplicity methods. The registry record does not report results for every outcome mentioned in the study description.

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

• Response Rate
• Overall Survival
• Safety and Toxicity Profile (Participants With Grade 3 4 5 Adverse Event)

9. Statistical Interpretation

10. Statistical Methods Explained

General: Statistical methods answer different questions. A median describes the midpoint of an observed time-to-event distribution, a hazard ratio compares event rates over time, and a confidence interval describes uncertainty around an estimate. None alone gives a complete account of a trial result. In this study, the registry reports median progression-free survival by group and a log-rank hazard-ratio comparison.

What does the median describe?

The median time to progression or death is the time by which half of the relevant estimated distribution has had the event, under the method used to account for censoring. It is a summary of the time-to-event experience, not a comparison that adjusts for other characteristics. The registry reports the rIL-21 median as 1.87 years and the dacarbazine median as 2.04 years, each with a 95% confidence interval. Those arm-level estimates should not be interpreted as proving a treatment difference simply because the point estimates are not identical. Their uncertainty and the formal comparison are relevant as well.

The registry defines progression-free survival from randomization to the first documented progression or death from any cause. A participant who stopped study treatment and received alternative therapy before documented progression was censored when alternative therapy began. A participant without progression or alternative therapy was censored at the last disease assessment. These rules affect which follow-up time contributes to the endpoint. The record does not report the frequency of each censoring circumstance or further details about how censoring was handled in the calculation.

What does the hazard ratio add?

General: A hazard is the event rate at a given point among participants still at risk. A hazard ratio expresses the relative hazard between groups over follow-up, with a value of 1 corresponding to equal hazards. The meaning of values above or below 1 depends on the order of the groups in the comparison. A hazard ratio is not a ratio of medians, nor does it directly state the probability that a participant will experience an event.

The registry reports the primary comparison as a hazard ratio of 1.10 for rIL-21 versus dacarbazine, with a 95% confidence interval from 0.6 to 2.01 and p = 0.76. The analysis method is listed as log rank. The reported hazard ratio is the sponsor's analysis; no recalculated alternative is used for this time-to-event comparison. The registry does not report the details of any model beyond the named method, including an assessment of proportional hazards or adjustments for baseline characteristics.

How should the p-value be read?

General: A p-value measures how inconsistent the observed data are with a specified null hypothesis, under the assumptions of the analysis. It is not the probability that the null hypothesis is true, and it does not measure the clinical importance of an effect. A p-value above a conventional threshold is not proof that two treatments have the same effect. The effect estimate and confidence interval remain important for understanding what differences are compatible with the data.

The registry reports p = 0.76 for the primary log-rank comparison. This is not evidence that the groups are identical. It indicates that the analysis did not produce a small p-value against its null hypothesis. The confidence interval also shows that the estimate is not sufficiently precise to narrow the comparison to a small range around the point estimate.

What is the role of the response analysis?

Response rate is a binary outcome: participants are counted according to whether a response was recorded during the stated treatment period. The registry reports 13.3% for rIL-21 among 30 participants and 14.3% for dacarbazine among 28 participants. The arm-specific confidence intervals are broad. The reported risk difference is -1.0 percentage points, with a 95% confidence interval from -18.7 to 16.8 percentage points. The registry's reported analysis does not include a p-value for this result.

General: A risk difference expresses the difference between two event proportions on the percentage-point scale. A confidence interval that spans values in both directions indicates uncertainty about which group has the higher response proportion and by how much. Small denominators can leave a binary outcome imprecisely estimated, especially when relatively few responses are recorded. This description is statistical context, not a conclusion about the clinical value of response.

What does the survival analysis for overall survival show?

Overall survival measures time from randomization to death from any cause. The registry reports medians of 6.6 months for rIL-21 and 7.3 months for dacarbazine, with 95% confidence intervals of 5.9 to 12.3 months and 5.0 to 20.3 months, respectively. The reported hazard ratio is 0.8, with a 95% confidence interval from 0.38 to 1.68 and p = 0.55 from a log-rank method. The interval includes 1 and permits uncertainty in either direction. The timeframe is stated as up to 22 months.

For both time-to-event outcomes, the reported interval and p-value concern the comparative analysis, while the medians and their intervals describe each arm. Those are related but distinct summaries. The registry does not report detailed survival curves, numbers at risk over time, or the number of events included in each comparison in the information available for these results.

What analysis details remain unknown?

The primary analysis population is described as treated, but the registry does not report a full definition of that population or how participants were handled if they did not follow their assigned treatment. It also does not report the statistical analysis plan, original sample-size justification, multiplicity procedure, or any interim-analysis plan. The analysis details for missing outcome data beyond the stated progression-free survival censoring rules are not reported in the registry record. Such details affect reproducibility and help readers distinguish a prespecified analysis from later or exploratory analyses.

11. Confidence Intervals and Precision

The primary hazard-ratio estimate is 1.10, with a 95% confidence interval from 0.6 to 2.01. This interval is wide enough to include values below and above 1, so the direction and size of the comparative association are not determined precisely. The p-value of 0.76 is consistent with the absence of a small p-value, but it does not show that the treatments are equivalent.

The arm-specific median progression-free survival estimates also have confidence intervals: 1.74 to 3.45 years for rIL-21 and 1.87 to 5.03 years for dacarbazine. These intervals communicate uncertainty around the median estimates. Their overlap is not itself a formal test of the treatment comparison; the registry reports the log-rank hazard ratio for that purpose. The medians should therefore be interpreted as descriptive summaries rather than as a separate significance test.

General: A confidence interval gives a range of values reasonably compatible with the observed data and the method's assumptions. A wider interval indicates less precision than a narrower interval. It does not mean that each value inside the interval is equally likely, and a 95% confidence interval is not a guarantee that the true value lies inside it. Interpretation depends on the design, analysis, and assumptions.

The overall-survival hazard ratio interval, 0.38 to 1.68, also includes 1 and spans a broad range of relative effects. The response-rate risk-difference interval, -18.7 to 16.8 percentage points, includes values favoring either group. Together, these intervals emphasize that the estimates are uncertain. The registry does not report enough detail to determine how much of that uncertainty reflects event counts, follow-up, or other design features.

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 calculations are planning illustrations based on the observed effects, not the trial's original design calculations. For the response-rate comparison, entries are participants per arm. For progression-free and overall survival, entries are total events, not participants per arm. An event total is not the same as an enrollment target: the number of participants needed to accumulate those events depends on follow-up and event occurrence.

The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The assumed effect to detect is a stated fraction of the observed effect. The time-to-event calculations use the Schoenfeld method. The original sample-size assumptions and justification for this trial are not reported in the registry record.

The 80% power column describes the planned number of participants per arm, or total events for a time-to-event endpoint, under which a study would have an 80% chance of detecting the assumed effect at the stated significance level, if the assumptions hold. The 90% power column describes the corresponding planning target for a 90% chance. These are design probabilities under specified assumptions, not guarantees about what a study will find.

Across the planning scenarios, a smaller assumed effect requires a larger sample or more events to detect it at the same power. The calculations use fractions of the observed effect, so they are sensitive to the observed estimate and should not be read as evidence that the assumed effect is true. They are not observed power, and they do not describe the probability that the completed study's result is correct.

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

d is the total number of events needed (Schoenfeld's formula) with 1:1 allocation and proportional hazards.

Worked calculation for this trial

1. Hazard ratio HR = 1.100, so ln(HR) = 0.0953.
2. d = 4 × (1.96 + 0.842)² / [ln(1.100)]² = 3,456.1, rounded up to 3,457 events in total 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
hr <- 1.1                              # observed hazard ratio
events_needed <- function(power, frac = 1) ceiling(round(4 * (z_a + qnorm(power))^2 / log(hr^frac)^2, 6))   # Schoenfeld, 1:1 allocation
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: events = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(events_needed(0.80, f), big.mark = ","), format(events_needed(0.90, f), big.mark = ",")))

# Simulation: given d total events under proportional hazards, events in the treatment arm are Binomial(d, hr / (1 + hr)).
# The score (log-rank type) statistic is (D1 - d / 2) / sqrt(d / 4).
set.seed(1152788)
d    <- events_needed(0.80)
reps <- 20000
D1 <- rbinom(reps, d, hr / (1 + hr))
z  <- (D1 - d / 2) / sqrt(d / 4)
cat(sprintf("Simulated power with %s events: %.3f (%d replicates)\n", format(d, big.mark = ","), mean(abs(z) > z_a), reps))

Output from running the code

100% of observed effect: events = 3,457 (80% power), 4,627 (90% power)
 75% of observed effect: events = 6,145 (80% power), 8,226 (90% power)
 50% of observed effect: events = 13,825 (80% power), 18,508 (90% power)
Simulated power with 3,457 events: 0.793 (20000 replicates)

The simulation uses the fact that, with d events in total and proportional hazards, the number of events in the treatment arm is binomial. It is an approximation that conditions on the total number of events, and it should land close to the target power.

14. Analyses Reported by the Sponsor

For the primary time-to-event comparison, the registry reports the sponsor's hazard-ratio analysis. The posted estimate is 1.10, with a 95% confidence interval from 0.6 to 2.01 and p = 0.76 using a log-rank method. The median estimates and their confidence intervals are also reported by arm. No recalculated alternative is used for this time-to-event result; the sponsor's reported analysis is the relevant comparative analysis in the registry record.

For response rate, the registry reports a risk difference of -1.0 percentage points with a 95% confidence interval from -18.7 to 16.8 percentage points. A simple unadjusted re-calculation from posted summary statistics gives a closely aligned comparison, and the record does not flag a discrepancy. The sponsor's reported result remains the analysis to prioritize. The registry does not report a p-value for the response-rate comparison.

Re-calculations from summary statistics cannot reproduce analyses that depend on participant-level data, covariate adjustment, censoring details, or other elements not reported in the registry. They serve as a check on the arithmetic implied by the posted summaries, not as a replacement for the sponsor's analysis or a new trial analysis.

15. Multiplicity, Missing Data and Analysis Populations

The registry identifies progression-free survival as the primary endpoint and lists secondary outcomes including response rate, overall survival, and safety and toxicity. It does not report a multiplicity adjustment, a testing hierarchy, or a rule for interpreting multiple secondary comparisons. When many outcomes are examined, the chance of at least one apparently unusual result can increase if each is assessed without adjustment. This general issue does not invalidate descriptive results, but it affects how strongly unadjusted secondary findings should be interpreted.

The record also does not report whether interim analyses were planned or conducted, or whether any stopping rules were used. The statistical analysis plan is not reported in the registry record. Without these details, it is not possible to determine from the registry information whether the reported analyses match a prespecified plan in every respect.

The primary population is described as the treated population. The registry does not provide a full definition of this population or report whether a separate intention-to-treat analysis was performed. It also does not explain all exclusions from the endpoint-specific denominators. In particular, response rate is reported for 30 participants in the rIL-21 group, while the primary treated population count for that group is 32; the reason for the difference is not reported in the registry record.

For progression-free survival, the registry gives censoring rules for alternative therapy and for the last disease assessment when no progression or alternative therapy is recorded. It does not report how many participants were censored for each reason, the extent of missing disease assessments, or sensitivity analyses for censoring assumptions. For overall survival, the endpoint is defined as time from randomization to death, but further details about missing status or follow-up are not reported in the registry record.

These omissions matter because analysis populations, missingness, censoring, and multiplicity influence how estimates should be interpreted. They do not change the reported numbers, but they limit independent assessment of the analysis and the robustness of the conclusions.

16. 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: hepatic failure (6.2%), atrial fibrillation (3.6%), aspartate aminotransferase increased (3.1%), infusion related reaction (3.1%), gait disturbance (3.1%).

The registry reports serious adverse events in 10 of 32 participants in the rIL-21 group and 1 of 28 participants in the dacarbazine group. Other adverse events are reported in 12 of 32 and 3 of 28 participants, respectively. These are participant counts in the recorded categories, not a complete account of every event or its timing. The registry does not report deaths in these adverse-event summaries.

The record lists hepatic failure at 6.2%, atrial fibrillation at 3.6%, and aspartate aminotransferase increased, infusion related reaction, gait disturbance, and sepsis at 3.1% each among the selected serious-event terms. The information reported does not identify the treatment arm for each listed percentage or give enough context to determine whether terms overlap within participants. These percentages should not be treated as arm-specific rates without that information.

General: Adverse-event counts describe what was recorded during a study; they do not alone establish causation. A fuller safety interpretation would consider definitions, severity grading, exposure duration, event timing, attribution, and how missing safety information was handled. Those details are not reported in the registry record.

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

The results describe what was observed in this randomized Phase II comparison and how uncertain the estimates are. For the primary endpoint, the hazard-ratio estimate is near 1, its confidence interval includes 1 and extends across a broad range, and the log-rank p-value is 0.76. The arm-specific medians are close in their point estimates, but their confidence intervals also show uncertainty. These findings do not establish that the treatments have the same effect.

Nor do the results provide a precise estimate that rules out a difference in either direction. A non-small p-value is not proof of no effect, while a point estimate alone does not establish a meaningful treatment advantage. The secondary results are uncertain as well, and the registry does not report whether the analysis of multiple outcomes was adjusted. The evidence should be read as limited by the precision of the estimates and the available analysis details.

The trial's randomized design is relevant because randomization is intended to support a fair comparison between groups. However, the registry information does not describe allocation procedures, full eligibility criteria, treatment schedules, or all analysis decisions. The report identifies no masking. These design features and missing details affect how readers assess potential bias and the scope of the results.

The findings apply to the participants and outcomes represented in the registry record, not automatically to other populations, settings, or treatment approaches. The primary analysis is described as treated, and the response denominator differs from the rIL-21 treated count without an explanation in the record. The registry also states an endpoint timeframe of up to 22 months while reporting the primary median in years, without clarifying the relationship between those descriptions.

Accordingly, the posted results are best understood as an uncertain comparison rather than a definitive answer about comparative effects. They do not support medical advice, and they do not establish whether either treatment should be used. The registry record does not report the additional design, analysis, and follow-up information that would be needed for a fuller assessment.

18. Why This Trial Matters Statistically

This trial illustrates why statistical interpretation should not stop at comparing point estimates. The primary medians differ numerically, but the comparative hazard ratio has a broad confidence interval that includes 1. The p-value is not small, yet that does not demonstrate equivalence. Looking at the estimate, interval, analysis method, and endpoint definition together gives a more informative account of the evidence than treating any one statistic as decisive.

It also shows the distinction between an arm-level summary and a comparative analysis. A median describes a time-to-event distribution within a group; a hazard ratio addresses the relative event hazard between groups under the analysis used. These measures answer related but different questions. The same distinction applies to response percentages and a risk difference: the proportions describe each group, while the difference expresses a comparison on an absolute scale.

The record makes clear that sample-size planning illustrations are not the same as the trial's original design justification. The calculations based on observed effects can show how required sample or event totals change with the assumed effect, but they cannot retroactively establish that the study had adequate power or explain the design decisions. The original assumptions are not reported in the registry record.

Finally, incomplete reporting is itself important for statistical reading. Population definitions, missing-data handling, multiplicity, interim analyses, and the details behind safety terms affect reproducibility and interpretation. Recognizing what is and is not documented helps keep conclusions proportionate to the evidence rather than filling gaps with assumptions.

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.

The randomized design is a strength for comparative inference, but the registry describes the study as unmasked. Knowledge of treatment assignment can influence outcome assessment or reporting, particularly for outcomes involving judgments, although the registry does not report whether or how such influence was assessed. The allocation procedure and concealment details are also not reported in the registry record.

The total enrollment was 64, and the primary treated population counts were 32 for rIL-21 and 28 for dacarbazine. The response-rate analysis included 30 rIL-21 participants and 28 dacarbazine participants. The reason for the differing rIL-21 counts is not reported. The confidence intervals across primary and secondary comparisons are broad, indicating that the estimates do not pin down a narrow range of effects.

The registry gives a progression-free survival censoring definition, but does not report the number censored, reasons by group, or sensitivity analyses. It does not provide details on missing outcome data, analysis-plan adherence, baseline balance, or adjusted analyses. The original sample-size justification, interim-analysis details, and multiplicity procedures are not reported in the registry record.

The primary endpoint description states a timeframe of up to 22 months and gives its unit as years. The registry does not explain how these statements relate. The record also does not report all treatment administration details, eligibility criteria, or the full results for every study objective described in the summary. Serious adverse-event terms are listed with percentages but without sufficient context to interpret them as arm-specific rates.

These limits do not alter the posted estimates, but they restrict independent evaluation of precision, bias, and generalizability. The results are most informative when interpreted as a registry account of a completed Phase II comparison, with uncertainty and reporting gaps made explicit.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Phase II Study of Interleukin-21 (rIL-21) vs Dacarbazine (DTIC) in Patients With Metastatic or Recurrent Melanoma — NCT01152788.
• Registry record last updated 2023-08-22; status last verified 2020-03.
• Results first posted 2014-07-21.
• 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 describes a completed randomized, parallel-group Phase II study of rIL-21 versus dacarbazine in metastatic or recurrent melanoma. Enrollment was 64, masking was none, and the primary endpoint was progression-free survival in the treated population. The primary comparison used a log-rank method and reported a hazard ratio of 1.10 with a 95% confidence interval from 0.6 to 2.01 and p = 0.76.

Secondary results included overall survival, response rate, and safety information. The estimates are uncertain, and the registry does not report several design and analysis details, including original sample-size assumptions, multiplicity procedures, and interim-analysis information. The results describe the posted comparison but do not establish equivalence or resolve the size and direction of possible treatment differences.