This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Calaspargase Pegol or Pegaspargase and Combination Chemotherapy in Treating Younger Patients With Newly Diagnosed High-Risk Acute Lymphoblastic Leukemia (NCT00671034), a randomized phase 3 study. The primary outcome is Pharmacokinetics (PK) (Half-life of SC-PEG E. Coli L-asparaginase (EZN-2285) Compared to Pegaspargase During Induction and Consolidation Therapy).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00671034 |
| Phase | Phase 3 |
| Condition | Acute Lymphoblastic Leukemia, Adult B Acute Lymphoblastic Leukemia, Childhood B Acute Lymphoblastic Leukemia |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 166 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Children's Oncology Group |
| Results posted | Yes |
2. Clinical Question
Population
Younger patients with newly diagnosed high-risk acute lymphoblastic leukemia (ALL). The registry lists acute lymphoblastic leukemia, adult B acute lymphoblastic leukemia, and childhood B acute lymphoblastic leukemia among the conditions. It does not report a more specific age range in this record.
Intervention
Calaspargase pegol given with combination chemotherapy. The arm description lists chemotherapy by oral, intravenous, subcutaneous, and intrathecal routes; some patients also undergo radiation therapy to the head. Treatment may continue for up to 4 years.
Comparator
Pegaspargase given with combination chemotherapy. The described chemotherapy routes and possible head radiation are the same as in the calaspargase pegol arm description. The record does not report how many participants were assigned to each treatment arm.
Primary question
How does the mean half-life of plasma asparaginase compare between the treatments during induction and consolidation therapy? Half-life is defined in the registry as the time taken for drug concentration to decrease by half. The primary analysis is restricted to patients with pharmacokinetic data collected.
This is a pharmacokinetic question: it concerns the time course of drug concentration, rather than a direct comparison of remission, survival, or other clinical outcomes. The registry also lists secondary outcomes that include minimal residual disease, complete remission, event-free survival, asparaginase level, asparagine concentrations, immunogenicity, and toxicities. Numerical findings for these outcomes are not reported in the registry record, so the record does not establish the direction or size of any treatment differences.
3. Trial Design
The registry describes NCT00671034 as a randomized, parallel-group Phase 3 trial with no masking. Its title and brief summary frame the comparison as calaspargase pegol plus combination chemotherapy versus pegaspargase plus combination chemotherapy for younger patients with newly diagnosed high-risk ALL. The enrollment is 166. The sponsor is Children's Oncology Group, and the record marks the study as completed.
The listed study start is 2008-07-21, and primary completion is 2011-02-01. Those dates describe the record’s study milestones; they do not supply the timing of individual participants’ treatment or follow-up. The arm descriptions say treatment may continue for up to 4 years, but do not report how long participants actually received treatment.
The treatment descriptions list cyclophosphamide, cytarabine, daunorubicin hydrochloride, dexamethasone, doxorubicin hydrochloride, mercaptopurine, and calaspargase pegol among the interventions. Laboratory biomarker analysis is also listed. The arm descriptions state that chemotherapy is given by oral, intravenous, subcutaneous, and intrathecal routes, and that some patients also undergo radiation therapy to the head. The description for the comparator arm specifies pegaspargase together with combination chemotherapy.
There is a naming inconsistency within the registry record. The treatment descriptions present the comparison as calaspargase pegol versus pegaspargase, while the adverse-event group labels name Arm I as Calaspargase Pegol 2100, Arm II as Calaspargase Pegol 2500, and Arm III as Pegaspargase 2500. The record does not explain how these three safety groups correspond to the treatment-arm descriptions. Randomization details, allocation concealment, the planned statistical analysis, and arm-specific enrollment 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.
Overall Study
| Stage | Arm I (Calaspargase Pegol 2100) | Arm II (Calaspargase Pegol 2500) | Arm III (Pegaspargase 2500) |
|---|---|---|---|
| STARTED | 69 | 42 | 55 |
| COMPLETED | 30 | 22 | 31 |
| NOT COMPLETED | 39 | 20 | 24 |
Reasons for not completing this period:
| Reason | Arm I (Calaspargase Pegol 2100) | Arm II (Calaspargase Pegol 2500) | Arm III (Pegaspargase 2500) |
|---|---|---|---|
| Adverse Event | 5 | 7 | 1 |
| Death | 3 | 2 | 1 |
| Physician Decision | 12 | 4 | 5 |
| VHR ALL feature | 8 | 3 | 5 |
| Refusal | 5 | 3 | 5 |
| includes Alternative therapy, etc. | 6 | 1 | 7 |
Analysis population for the primary outcome, as defined in the registry: Analysis restricted to patients who had PK data collected
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.
| Characteristic | Unit | Arm I (Calaspargase Pegol 2100) | Arm II (Calaspargase Pegol 2500) | Arm III (Pegaspargase 2500) | Total |
|---|---|---|---|---|---|
| Participants analysed | 69 | 42 | 55 | 166 | |
| Age, Categorical: <=18 years | Participants | 62 | 40 | 51 | 153 |
| Age, Categorical: Between 18 and 65 years | Participants | 7 | 2 | 4 | 13 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 | 0 |
| Age, Continuous | years | 11.9 (SD 5.58) | 9.9 (SD 6.09) | 10.79 (SD 5.54) | 11.3 (SD 5.72) |
| Sex: Female, Male: Female | Participants | 31 | 28 | 23 | 82 |
| Sex: Female, Male: Male | Participants | 38 | 14 | 32 | 84 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 14 | 12 | 18 | 44 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 53 | 28 | 35 | 116 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 2 | 2 | 2 | 6 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 4 | 1 | 1 | 6 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 1 | 1 | 0 | 2 |
| Race (NIH/OMB): Black or African American | Participants | 4 | 1 | 6 | 11 |
| Race (NIH/OMB): White | Participants | 56 | 35 | 43 | 134 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 4 | 4 | 5 | 13 |
6. Primary Endpoint
The registry lists the primary outcome as Pharmacokinetics (PK) (Half-life of SC-PEG E. Coli L-asparaginase (EZN-2285) Compared to Pegaspargase During Induction and Consolidation Therapy), measured over Post Day 29 of Induction and Post Day 22 of Consolidation.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | hours |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the mean half-life of plasma asparaginase, measured in hours. The record defines half-life as the time taken for drug concentration to decrease by half. Pharmacokinetics describes how drug concentrations change over time; half-life is one way to characterize the rate of that change. In general, a longer half-life means that concentration takes longer to fall by half, but this endpoint alone does not establish a difference in clinical outcomes.
The registry specifies measurements after Day 29 of induction and after Day 22 of consolidation. It identifies the parameter as a mean and the accompanying variability measure as a standard deviation. The primary analysis is restricted to patients who had pharmacokinetic data collected. The registry record does not report the number of patients with those data, the mean half-life in either treatment group, standard deviations, a between-group estimate, or a confidence interval.
Pharmacokinetic endpoints can help characterize and compare drug exposure patterns. In general, this information can be relevant to understanding how long a drug remains in circulation. It should not be treated as a direct measure of leukemia response or safety. The registry lists clinical and laboratory outcomes separately, including remission, minimal residual disease, event-free survival, asparaginase level, and toxicity. Those outcomes would be needed to answer questions distinct from the primary half-life comparison. Their numerical results are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies a randomized comparison of two asparaginase treatment approaches within combination chemotherapy, but it does not report numerical results for the primary endpoint. In particular, there are no group means, standard deviations, estimated treatment contrast, confidence interval, or primary-outcome p-value in the record. Without those results, the size, direction, and precision of the pharmacokinetic difference cannot be assessed from this record.
The endpoint is mean half-life at specified points in induction and consolidation, in patients with pharmacokinetic data collected. That restriction matters when interpreting the target population. The registry does not report how many participants contributed to this analysis, why some participants might lack pharmacokinetic data, or whether included participants differed from those not included. The recorded enrollment of 166 is not a substitute for the endpoint-specific analysis count.
Randomization is intended, in general, to balance treatment groups on average with respect to factors that could affect outcomes. The registry identifies the study as randomized, but does not describe the sequence generation or allocation concealment. No masking is listed. An unmasked design can matter for outcomes influenced by clinical judgment or reporting. The primary endpoint is a measured concentration-derived quantity, but the record does not describe how samples were collected, processed, or analyzed, or whether laboratory personnel were masked.
The broader outcome list covers pharmacodynamics, response, event-free survival, drug levels, asparagine concentrations, immunogenicity, and toxicities. These outcomes address different questions and should not be conflated with the primary pharmacokinetic endpoint. Their results, analysis populations, and uncertainty estimates are not reported in the registry record. The record lists 10 outcome measures and no analyses, so it does not allow a reader to determine which results were estimated or how they were evaluated.
The adverse-event record contains counts of participants at risk and affected in three groups, as well as serious-event term percentages. However, the group labels do not align clearly with the two treatment descriptions, and the record does not connect the listed serious-event percentages to individual groups. These data therefore should not be read as a clear comparative safety analysis.
Overall, the record establishes the trial’s stated design and endpoint, but not the observed treatment effects. It supports describing what the investigators planned to compare, not concluding that either regimen had a larger half-life, better clinical outcomes, or fewer adverse events.
9. Statistical Methods Explained
The registry record gives limited information about the statistical methods actually used. It states that the primary parameter is a mean, with standard deviation as the dispersion measure, and that the analysis is restricted to patients with pharmacokinetic data collected. It does not report the statistical test, model, adjustment variables, confidence intervals, or analysis results. The explanations below describe general statistical concepts, not methods confirmed as having been used for this trial.
What does a mean half-life represent?
In general, a mean summarizes the average of measured values in an analysis group. Here, the intended quantity is half-life in hours, derived from plasma asparaginase concentration. A group mean can describe a typical level, but does not show how widely individual measurements vary. The standard deviation describes spread around the mean; a larger standard deviation indicates more variability in the observations, in the same measurement units.
A comparison of group means would typically be presented as an estimated difference or another specified contrast, together with uncertainty. The registry record does not state which contrast was planned or report any estimate. It is therefore not possible to tell whether the comparison was framed as a difference in means, a ratio, or another measure.
What does a confidence interval communicate?
In general, a confidence interval gives a range of values compatible with the data and the assumptions of the statistical method. It communicates precision as well as the estimated direction and magnitude of an effect. A narrow interval indicates greater precision than a wide interval, while an interval spanning values that represent meaningfully different effects signals uncertainty about the effect’s size. No confidence interval for the primary endpoint is reported in the registry record.
A p-value, when used, measures how surprising data at least as incompatible with a specified null hypothesis would be if that hypothesis and the test assumptions were true. It is not the probability that a treatment works, nor does it communicate the magnitude or clinical importance of an effect. The registry record does not report a primary-outcome p-value or the test used.
Why does the analysis population matter?
The endpoint population is described as patients with pharmacokinetic data collected. In general, restricting an analysis to participants with observed measurements can affect interpretation if measurement availability is related to treatment, health status, or the measured outcome. An analysis based on available measurements may not represent everyone randomized. To assess this concern, readers would need information about missing measurements, reasons for missingness, and the handling of incomplete data. Those details are not reported in the registry record.
Randomization supports a fair comparison when outcomes are analyzed in a way that preserves the randomized groups and missing data are adequately addressed. The registry identifies random allocation, but does not specify an intention-to-treat analysis or another analysis population. It also does not report whether treatment changes, nonadherence, or protocol deviations were handled in a particular way.
How should the study design inform interpretation?
A parallel design assigns participants to treatment groups that are followed as separate groups. In general, this differs from a crossover design, in which participants receive multiple treatments in sequence. No masking is listed for this trial. Lack of masking can influence some aspects of care or outcome ascertainment, depending on how an outcome is measured. It does not by itself establish that an estimate is biased. For a pharmacokinetic endpoint, details of sample timing, laboratory procedures, and measurement quality would help assess possible sources of error; the registry record does not report these details.
The registry describes a randomized Phase 3 study, but does not report the method used to generate the allocation sequence, concealment procedures, stratification factors, or planned model. It is not appropriate to infer these features from the phase or randomization label.
What does over-dispersion mean in general?
Over-dispersion occurs when observed variation is greater than a statistical model expects. It is a concern in some count-data models, where failing to account for excess variation can make uncertainty appear too small. The primary endpoint is a continuous mean, and the registry does not report a count-data model. Over-dispersion is therefore a general concept, not a reported issue for this analysis. The registry also provides no model details that would support a more specific assessment of distributional assumptions.
How should planning calculations be read?
The registry’s planning assumptions describe an illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. Such calculations are planning illustrations, not evidence of an outcome and not observed power. The effect size and numerical planning results are not reported in the registry record. A planned sample size cannot demonstrate that a treatment effect was present, and a post hoc calculation based on an observed effect cannot replace an estimate with a confidence interval.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists secondary outcomes covering pharmacodynamics, minimal residual disease below 0.01% at the end of induction, complete remission at the end of induction, event-free survival, asparaginase level, plasma and cerebrospinal fluid asparagine concentrations, immunogenicity, and toxicities during post-induction intensification therapy. These outcomes do not all measure the same concept or use the same type of data. Their presence in the record does not indicate which were tested, how they were ordered, or which were considered confirmatory.
When many outcomes or multiple time points are examined, the chance of at least one apparently notable result can increase. In general, statistical plans may address this through a hierarchy of hypotheses, adjustment procedures, or clear designation of exploratory analyses. The registry record does not report a multiplicity strategy, an analysis hierarchy, or results for these outcomes. It also lists 10 outcome measures and no analyses, so the record does not establish how multiplicity was handled in the completed study.
The primary pharmacokinetic endpoint has measurements after Day 29 of induction and after Day 22 of consolidation. The record does not explain whether these were analyzed separately, combined, or treated as co-primary comparisons. It also does not report whether there were additional planned time points or how repeated measurements were handled.
Missing-data information is limited to the statement that the primary analysis was restricted to patients with pharmacokinetic data collected. The number with collected data, the reasons for missing measurements, and any imputation or sensitivity analyses are not reported in the registry record. The randomized analysis population, handling of participants who discontinued or changed treatment, and the populations used for secondary outcomes are also not reported. These omissions limit assessment of how representative each analysis population was and how robust results might be to missing observations.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Arm I (Calaspargase Pegol 2100) | 54 | 69 | 78.3% |
| Arm II (Calaspargase Pegol 2500) | 34 | 42 | 81.0% |
| Arm III (Pegaspargase 2500) | 32 | 54 | 59.3% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Arm I (Calaspargase Pegol 2100) | 64 of 69 |
| Arm II (Calaspargase Pegol 2500) | 40 of 42 |
| Arm III (Pegaspargase 2500) | 51 of 54 |
Most frequent serious adverse event terms
| Event term | Organ system | Arm I (Calaspargase Pegol 2100) | Arm II (Calaspargase Pegol 2500) | Arm III (Pegaspargase 2500) |
|---|---|---|---|---|
| Hyperglycemia | Metabolism and nutrition disorders | 21 of 69 | 14 of 42 | 12 of 54 |
| Anaphylaxis | Immune system disorders | 13 of 69 | 11 of 42 | 10 of 54 |
| Blood bilirubin increased | Investigations | 12 of 69 | 8 of 42 | 10 of 54 |
| Infections and infestations - Other, specify | Infections and infestations | 14 of 69 | 8 of 42 | 4 of 54 |
| Abdominal pain | Gastrointestinal disorders | 11 of 69 | 7 of 42 | 4 of 54 |
| Pancreatitis | Gastrointestinal disorders | 8 of 69 | 6 of 42 | 4 of 54 |
| Lipase increased | Investigations | 7 of 69 | 4 of 42 | 4 of 54 |
| Hypertriglyceridemia | Metabolism and nutrition disorders | 5 of 69 | 4 of 42 | 6 of 54 |
| Hypoxia | Respiratory, thoracic and mediastinal disorders | 6 of 69 | 3 of 42 | 3 of 54 |
| Alanine aminotransferase increased | Investigations | 4 of 69 | 2 of 42 | 5 of 54 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Arm I (Calaspargase Pegol 2100) | Arm II (Calaspargase Pegol 2500) | Arm III (Pegaspargase 2500) |
|---|---|---|---|---|
| Neutrophil count decreased | Investigations | 44 of 69 | 29 of 42 | 36 of 54 |
| Febrile neutropenia | Blood and lymphatic system disorders | 37 of 69 | 26 of 42 | 31 of 54 |
| Alanine aminotransferase increased | Investigations | 25 of 69 | 22 of 42 | 27 of 54 |
| Platelet count decreased | Investigations | 30 of 69 | 20 of 42 | 22 of 54 |
| Infections and infestations - Other, specify | Infections and infestations | 30 of 69 | 23 of 42 | 18 of 54 |
| Anemia | Blood and lymphatic system disorders | 18 of 69 | 16 of 42 | 23 of 54 |
| Hypokalemia | Metabolism and nutrition disorders | 25 of 69 | 15 of 42 | 14 of 54 |
| White blood cell decreased | Investigations | 19 of 69 | 16 of 42 | 18 of 54 |
| Hyperglycemia | Metabolism and nutrition disorders | 18 of 69 | 11 of 42 | 9 of 54 |
| Aspartate aminotransferase increased | Investigations | 10 of 69 | 11 of 42 | 14 of 54 |
Serious events with the highest arm-level rate: hyperglycemia (33.3%), anaphylaxis (26.2%), infections and infestations - other, specify (20.3%), blood bilirubin increased (19.0%), abdominal pain (16.7%).
The serious adverse-event listing gives participants at risk and affected in three groups: Arm I (Calaspargase Pegol 2100), Arm II (Calaspargase Pegol 2500), and Arm III (Pegaspargase 2500). The listed at-risk and affected counts are 69 and 54, 42 and 34, and 54 and 32, respectively. For other adverse events, the corresponding at-risk and affected counts are 69 and 64, 42 and 40, and 54 and 51. These are counts, not estimates of a treatment effect.
The serious-event terms with percentages listed are hyperglycemia (33.3%), anaphylaxis (26.2%), infections and infestations - Other, specify (20.3%), blood bilirubin increased (19.0%), abdominal pain (16.7%), and pancreatitis (14.3%). The registry record does not specify a group for each percentage in this listing, nor does it explain the denominator used for each term. The percentages should not be interpreted as comparative rates between the treatment descriptions.
The safety labels also do not align clearly with the trial’s two treatment descriptions, which compare calaspargase pegol with pegaspargase. The registry record does not clarify that discrepancy. Death counts are not reported in the registry record. The listing alone does not show whether participants experienced multiple events or provide a basis for causal attribution.
12. What the Result Does, and Does Not, Mean
The record describes a randomized comparison of calaspargase pegol and pegaspargase, each given with combination chemotherapy, and identifies mean plasma asparaginase half-life as the primary endpoint. It establishes the intended pharmacokinetic question and some timing and population details. It does not report the numerical primary result or the uncertainty around it. Consequently, the record does not show whether the mean half-life differed, how large any difference was, or how precisely it was estimated.
Half-life is a measure of the time course of drug concentration. In general, it helps characterize pharmacokinetics, but it is not itself a measure of remission, event-free survival, or toxicity. The registry lists those clinical and safety outcomes separately, but their numerical findings are not reported in the registry record. A pharmacokinetic comparison alone would not establish a difference in those other outcomes.
The record also does not report the number of participants contributing to the primary analysis, methods for handling missing measurements, or the statistical model and inferential procedure. The enrollment of 166 describes trial enrollment, not necessarily the population included in the pharmacokinetic analysis. The adverse-event group labels and the treatment descriptions do not match clearly, further limiting interpretation of the posted safety figures as a regimen-to-regimen comparison.
These limits do not mean that the trial produced no results. They mean that the results needed to evaluate the primary comparison are not reported in the registry record. Claims about which treatment has a longer half-life, whether any difference is statistically clear, or whether one treatment has better clinical outcomes would require results beyond those recorded.
13. Why This Trial Matters Statistically
This trial raises a useful statistical distinction between a pharmacokinetic endpoint and a clinical endpoint. Mean half-life describes how plasma drug concentration changes over time. Outcomes such as remission, event-free survival, and toxicity address different questions. Separating these endpoints prevents a concentration-based result from being mistaken for evidence about clinical response or safety.
The record also illustrates why analysis populations matter. The primary endpoint is restricted to patients with pharmacokinetic data collected, while the overall enrollment is 166. Without an endpoint-specific count and an account of missing measurements, the representativeness of the pharmacokinetic analysis cannot be judged from the registry record. Randomization is important to the study design, but analysis choices and missingness can affect how well a comparison reflects the randomized groups.
Another statistical issue is the relationship between the stated treatment arms and the safety labels. A clear mapping between treatment assignment and reported safety groups is necessary for interpreting comparative adverse-event data. The record’s labels identify three safety groups, while the treatment descriptions frame a comparison of calaspargase pegol and pegaspargase; the record does not explain how these relate.
Finally, the record lists several secondary outcomes but does not report analyses or a multiplicity approach. In general, evaluating multiple outcomes requires attention to which comparisons were planned and how uncertainty is interpreted across them. Since the numerical findings and analysis plan are not reported in the registry record, the statistical importance of the trial lies chiefly in the questions it set out to address and in recognizing what information is needed to assess its results.
14. 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 does not report numerical results for the primary endpoint. It gives no group means, standard deviations, treatment contrast, confidence interval, or p-value. The number of participants with pharmacokinetic data is not reported, although the primary analysis is restricted to that population. The record also does not explain missing measurements or their handling.
Details of the statistical analysis plan are not reported. The record does not specify the planned comparison measure, model, adjustment variables, assumptions, or whether the two stated measurement time points were analyzed separately. It does not describe the randomization sequence, allocation concealment, or an analysis population that preserves randomized assignment. These gaps prevent a detailed assessment of the planned or completed inferential approach.
The record’s naming is inconsistent. The official title calls the study a pilot study, while the listed phase is Phase 3. The treatment descriptions present calaspargase pegol and pegaspargase comparison arms, whereas the adverse-event group labels list three dose-named groups. The record does not reconcile these descriptions. Safety percentages are not mapped to the groups, and the denominator for each term is not specified in the listing. Death counts are not reported in the registry record.
The registry lists several secondary outcomes but does not report their numerical results, analysis populations, or a multiplicity strategy. It also does not provide details of pharmacokinetic sample collection or laboratory measurement. These limitations concern what can be assessed from the registry record; they do not establish that the information was absent from the trial’s full study documentation.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Calaspargase Pegol or Pegaspargase and Combination Chemotherapy in Treating Younger Patients With Newly Diagnosed High-Risk Acute Lymphoblastic Leukemia — NCT00671034.
- Registry record last updated 2021-04-27; status last verified 2021-04.
- Results first posted 2018-09-06.
- 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.
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18. Record Summary
NCT00671034 is listed as a completed, randomized, unmasked, parallel-group Phase 3 study sponsored by Children's Oncology Group. The record describes younger patients with newly diagnosed high-risk ALL receiving calaspargase pegol or pegaspargase with combination chemotherapy. Enrollment is 166. The recorded study start is 2008-07-21, and primary completion is 2011-02-01.
The primary endpoint is mean plasma asparaginase half-life in hours after Day 29 of induction and after Day 22 of consolidation. The primary analysis is restricted to patients with pharmacokinetic data collected. Numerical primary results, endpoint-specific sample counts, and details of the statistical analysis are not reported in the registry record.
Secondary outcomes include response, event-free survival, drug levels, immunogenicity, asparagine concentrations, and toxicity. Safety listings include counts in three labeled groups, but those labels are not reconciled with the two treatment descriptions. The registry record does not report analyses for the listed outcomes.