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 A Study to Evaluate IGSC 20% Biweekly Dosing in Treatment-Experienced Participants and Loading/Maintenance Dosing in Treatment-Naïve Participants With Primary Immunodeficiency (NCT04566692), a non-randomized phase 4 study. The primary outcome is Treatment-experienced Cohort: AUC of IGSC 20% Administered Weekly Assessed as: Steady-State AUC of Total IgG Over a Regular Dosing Interval (τ).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04566692 |
| Phase | Phase 4 |
| Condition | Primary Immunodeficiency |
| Allocation | Non-Randomized |
| Design model | Crossover |
| Masking | None (open label) |
| Enrollment | 33 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Grifols Therapeutics LLC |
| Results posted | Yes |
2. Clinical Question
The study asks whether biweekly IGSC 20% dosing in treatment-experienced participants produces steady-state total IgG exposure, measured by area under the concentration-versus-time curve, that is non-inferior to exposure with weekly dosing. The registry also describes a treatment-naïve cohort receiving a loading regimen followed by weekly maintenance dosing. These are distinct clinical pathways, not a randomized comparison between treatment-experienced and treatment-naïve participants.
Population
Participants with primary immunodeficiency. The study included treatment-experienced and treatment-naïve cohorts; the total enrollment was 33.
Intervention
IGSC 20%. Treatment-experienced participants received weekly dosing before the study’s biweekly dosing evaluation. Treatment-naïve participants received a loading dose followed by weekly maintenance infusions.
Comparator
For the treatment-experienced question, weekly IGSC 20% dosing is the comparison for biweekly dosing. The registry describes a non-randomized, single-sequence, open-label study.
Primary question
Is steady-state total IgG AUC with biweekly dosing non-inferior to AUC with weekly dosing in the treatment-experienced cohort? The non-inferiority margin and numerical comparison result are not reported in the registry record.
The treatment-naïve cohort addresses a dosing regimen that begins with a loading phase and continues with weekly maintenance. It does not answer the same weekly-versus-biweekly question. The registry lists additional outcomes, including IgG concentration measures and infection outcomes, but their numerical results are not reported in the registry record. The clinical question can therefore be described, but the direction and precision of the primary comparison cannot be determined from the available result details.
3. Trial Design
This is a phase 4, multicenter study described in its official title as single-sequence and open-label. The registry classifies allocation as non-randomized and the model as crossover. Enrollment was 33, and the study status is completed. The listed study dates are 2020-11-24 for start and 2022-07-18 for primary completion.
The treatment-experienced cohort received 16 weekly doses of IGSC 20% using a subcutaneous infusion pump from Week 0 to Week 15. The stated primary endpoint concerns weekly dosing at steady state, and the study purpose is to compare that exposure with biweekly dosing in this cohort. The full dosing details for the treatment-experienced cohort’s earlier therapy are incomplete in the registry record. The timing and complete sequence of its biweekly phase are not reported in the registry record.
Treatment-naïve participants received 150 mg/kg/day for 5 consecutive days during Week 0, Days 1 to 5, followed by weekly maintenance infusions of 150 mg/kg starting Week 1 (Day 8) through Week 32. The registry describes infusion by subcutaneous pump.
Because allocation was non-randomized and masking was absent, this is not a blinded randomized comparison. The sequential structure means the weekly and biweekly observations in the treatment-experienced cohort are not equivalent to measurements from independently randomized groups. The registry record does not report a protocol rationale for the sequence, a sample-size justification, or details sufficient to reconstruct the full comparison model. The 33 participants enrolled should not be assumed to be the number contributing data to every endpoint; endpoint-specific analysis counts 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 | IGSC 20%: Treatment-experienced Cohort | IGSC 20%: Treatment-naïve Cohort |
|---|---|---|
| STARTED | 27 | 6 |
| Safety Population | 27 | 6 |
| Efficacy Evaluable Population | 27 | 6 |
| IgG Population | 27 | 6 |
| Pharmacokinetic (PK) Population | 25 | 0 |
| COMPLETED | 24 | 5 |
| NOT COMPLETED | 3 | 1 |
Reasons for not completing this period:
| Reason | IGSC 20%: Treatment-experienced Cohort | IGSC 20%: Treatment-naïve Cohort |
|---|---|---|
| Adverse Event | 2 | 0 |
| Withdrawal by Subject | 1 | 1 |
Analysis population for the primary outcome, as defined in the registry: PK population included all the participants who had sufficient PK concentration data to have at least one of the PK parameters AUC (0-7 days), Cmax, or Tmax. Overall number analyzed is the number of participants with data available for analysis.
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: Safety population included all participants who received at least 1 dose of IGSC 20%.
| Characteristic | Unit | IGSC 20%: Treatment-experienced Cohort | IGSC 20%: Treatment-naïve Cohort | Total |
|---|---|---|---|---|
| Participants analysed | 27 | 6 | 33 | |
| Age, Continuous | years | 51.7 (SD 12.06) | 56.0 (SD 8.25) | 52.5 (SD 11.47) |
| Sex: Female, Male: Female | Participants | 16 | 4 | 20 |
| Sex: Female, Male: Male | Participants | 11 | 2 | 13 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 0 | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 27 | 6 | 33 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 27 | 6 | 33 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Treatment-experienced Cohort: AUC of IGSC 20% Administered Weekly Assessed as: Steady-State AUC of Total IgG Over a Regular Dosing Interval (τ), measured over Predose and post dose at multiple time points after end of infusion up to Week 15.
| Element | Registry entry |
|---|---|
| Result type | Geometric Mean |
| Measure of spread | Geometric Coefficient of Variation |
| Unit | hours*milligrams per deciliter (h*mg/dL) |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the steady-state area under the total IgG concentration-versus-time curve over a regular weekly dosing interval, expressed in h*mg/dL. In this measure, concentrations collected across the interval are integrated to represent total exposure over time, rather than relying on a single measurement such as a trough or peak concentration. The registry describes the endpoint for participants receiving weekly IGSC 20%, with predose and post-dose sampling at multiple time points after infusion through Week 15.
The record says AUC was calculated using linear and logarithmic trapezoidal methods: linear trapezoids for increasing concentrations and logarithmic trapezoids for decreasing concentrations. The interval, denoted τ, was 7 days for weekly dosing. The endpoint is reported as a geometric mean with geometric coefficient of variation as its dispersion measure. The number analyzed is defined as participants with data available for analysis in the pharmacokinetic population.
General explanation: AUC is useful when the question concerns overall exposure across a dosing interval, because it incorporates measurements throughout that interval. In a non-inferiority question, the intended interpretation is whether the new schedule preserves exposure within an acceptable prespecified bound. That bound is essential to interpreting non-inferiority, but the margin is not reported in the registry record. Neither the numerical weekly AUC result nor the numerical comparison with biweekly dosing is reported in the registry record. Thus, the endpoint’s meaning is clear, but the result cannot be assessed for magnitude or precision from these details.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinically relevant pharmacokinetic question: whether biweekly dosing in treatment-experienced participants gives steady-state total IgG exposure that is non-inferior to weekly dosing. It describes the primary endpoint and the calculation approach, but the numerical endpoint estimates and comparison results are not reported in the registry record. There is therefore no basis in these details to say how similar or different the schedules were, or how precisely any difference was estimated.
Non-inferiority is not established simply because a comparison is non-significant or because two point estimates appear close. General explanation: A non-inferiority conclusion depends on the estimated contrast and its uncertainty relative to a prespecified margin. The margin, estimate, confidence interval, and statistical test result are not reported in the registry record. The registry summary states the intended question but does not provide enough numerical information to evaluate whether its criterion was met.
The study’s design also shapes interpretation. It is non-randomized, open-label, and described as single-sequence, with a crossover model. For the treatment-experienced cohort, weekly dosing is described before the biweekly evaluation. This sequence does not provide the same protection against time-related changes or sequence effects as a randomized, counterbalanced design. The record does not report details of any adjustments or analyses addressing such effects, so their handling cannot be assessed.
The treatment-naïve cohort followed a loading and weekly maintenance regimen. Its measurements should not be treated as a randomized control for the treatment-experienced cohort. The registry lists outcomes for both cohorts, including infection and IgG measures, but does not provide their numerical results. The overall enrollment of 33 also does not establish how many participants contributed to each endpoint; the primary population definition requires sufficient pharmacokinetic data, and the analysis count is not reported in the registry record.
The calculated tables, plots, and planning section can organize results and illustrate assumptions, but they do not replace absent trial estimates. Any planning figures are illustrations based on an observed effect, not observed power. Since the underlying numerical comparison is not available in this record summary, no quantitative conclusion about the primary endpoint or its precision is justified. The appropriate reading is that the registry describes the question and methods, while the result needed to answer that question is not reported in the registry record.
9. Statistical Methods Explained
The main analysis concept is pharmacokinetic exposure. Total IgG concentration is measured at multiple times, and AUC summarizes the concentration profile across a dosing interval. The primary endpoint is steady-state AUC over the weekly interval, with τ defined as 7 days for participants on weekly dosing. The record identifies measurements before dosing and at multiple post-dose times through Week 15. It does not give the actual collection schedule or the numerical concentration data in this summary.
The registry states that AUC was calculated with a combination of trapezoidal methods. General explanation: A trapezoidal calculation approximates the area under a curve by dividing it into sections between observed time points. When concentrations increase between observations, the record says the linear trapezoidal method was used. For decreasing concentrations, it says the logarithmic trapezoidal method was used. These methods provide a way to estimate the integrated exposure from sampled concentrations; the accuracy still depends on the sampling and the underlying concentration profile.
The endpoint is summarized using a geometric mean and geometric coefficient of variation. General explanation: A geometric mean is often used for positive measurements that may be right-skewed, since it summarizes values on a multiplicative scale. A geometric coefficient of variation describes relative variability on that scale. It is not the same as a standard deviation on the original scale. The registry record does not provide the estimates or variability values here, so readers cannot judge the observed level or spread of AUC.
How does the design affect the comparison?
The treatment-experienced cohort is described as receiving weekly dosing before the biweekly evaluation, within a non-randomized, single-sequence, open-label study classified as a crossover model. General explanation: Crossover comparisons can use measurements from the same participants under different regimens, which can reduce some between-person variability. However, the sequence, timing, and potential period or carryover effects matter. Randomization of treatment order can help balance systematic time trends, but allocation is explicitly non-randomized. The registry record does not report enough detail to determine how the analysis handled period, sequence, or carryover effects, or whether any washout was used.
The stated objective is non-inferiority. General explanation: A non-inferiority analysis asks whether the result rules out a loss greater than a clinically acceptable margin. That interpretation depends on the margin, the direction of the contrast, and the confidence interval or test result. The margin, comparison estimate, confidence interval, and test result are not reported in the registry record. A statement of the objective alone is not evidence that the non-inferiority criterion was satisfied.
Which participants contribute to the endpoint?
The primary pharmacokinetic population includes participants with sufficient concentration data to have at least one of AUC (0-7 days), Cmax, or Tmax. The record says the overall number analyzed is the number with data available for analysis. This is an endpoint-specific population definition, not necessarily all enrolled participants. The number meeting this definition and the number contributing specifically to the primary AUC analysis are not reported in the registry record. General explanation: When participants lack enough measurements to calculate an endpoint, the analysis population may differ from enrollment. Readers need both the population definition and the actual analysis count to understand how much information supports an estimate.
The registry lists 12 outcome measures and 2 analyses. This indicates that the record covers multiple outcomes, but it does not state how statistical testing was organized across them. General explanation: When many outcomes or comparisons are tested, the chance of at least one apparently notable result can increase if each is assessed without adjustment. Whether multiplicity matters depends on which outcomes are confirmatory, how hypotheses are arranged, and whether an adjustment or hierarchy is prespecified. Those details are not reported in the registry record.
How should uncertainty and planning be read?
A confidence interval, when reported, shows a range of effect estimates compatible with the data under the analysis assumptions. Its width communicates precision; it does not by itself address bias from design or missing data. No confidence interval for the primary comparison is reported in the registry record. General explanation: An interval that is wide may leave materially different interpretations plausible, while a narrow interval can still be affected by limitations in the design or analysis.
The sample-size section is described as a planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation; its effect targets are stated as fractions of the observed effect. For time-to-event tables, the illustration uses total events; other illustrations use participants per arm. These are planning assumptions, not the trial’s own design justification and not observed power. The registry record does not report the trial’s sample-size justification. Since numerical planning rows and the underlying observed effect are not stated, they cannot be interpreted quantitatively in this explanation.
Finally, over-dispersion can matter for count outcomes. General explanation: It occurs when observed variability exceeds what a simple count model assumes, potentially making standard errors too small if ignored. The registry lists infection rates per participant per year among secondary outcomes, but the analysis model and any assessment or treatment of over-dispersion are not reported in the registry record. It is therefore not possible to judge that modeling choice from this record summary.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 12 outcome measures and 2 analyses, including pharmacokinetic outcomes and infection-related outcomes. The number of listed outcomes alone does not establish how many formal hypotheses were tested, which were considered primary or confirmatory, or whether testing followed a prespecified hierarchy. Any multiplicity adjustment, alpha allocation, or strategy for controlling the overall false-positive rate is not reported in the registry record.
This matters because general explanation multiple statistical tests can make isolated findings more likely even when no true effect exists. The implications depend on the analysis plan and on whether outcomes are exploratory, supportive, or part of a confirmatory family. The primary endpoint is identified, but the registry entries do not show how it was protected from or related to testing across other endpoints. Interim analyses and any associated statistical rules are not reported in the registry record.
The pharmacokinetic population includes participants with sufficient concentration data for at least one of AUC (0-7 days), Cmax, or Tmax. The record defines the analyzed count as participants with data available for analysis, but the actual count for the primary endpoint is not reported in the registry record. The approach to missing concentration measurements, incomplete profiles, withdrawal, or other missing outcome data is not reported in the registry record. Nor is there information about imputation, sensitivity analyses, or whether all participants were analyzed according to a particular population principle.
General explanation: Missingness can affect both precision and validity, especially if the reasons for missing observations are related to participant characteristics or outcomes. Reporting the number included, the reasons for exclusions, and sensitivity analyses helps readers assess that risk. Without those details, the effect of missing data cannot be evaluated. The planned and actual analysis populations, and the handling of deviations from the intended dosing sequence, are not reported in the registry record.
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 |
|---|---|---|---|
| IGSC 20%: Weekly Dosing | 1 | 27 | 3.7% |
| IGSC 20%: Bi-weekly Dosing | 2 | 25 | 8.0% |
| IGSC 20%: Treatment-naïve Cohort | 1 | 6 | 16.7% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| IGSC 20%: Weekly Dosing | 0 of 27 |
| IGSC 20%: Bi-weekly Dosing | 0 of 25 |
| IGSC 20%: Treatment-naïve Cohort | 0 of 6 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| IGSC 20%: Weekly Dosing | 4 of 27 |
| IGSC 20%: Bi-weekly Dosing | 1 of 25 |
| IGSC 20%: Treatment-naïve Cohort | 3 of 6 |
Most frequent serious adverse event terms
| Event term | Organ system | IGSC 20%: Weekly Dosing | IGSC 20%: Bi-weekly Dosing | IGSC 20%: Treatment-naïve Cohort |
|---|---|---|---|---|
| Barrett's oesophagus | Gastrointestinal disorders | 1 of 27 | 0 of 25 | 0 of 6 |
| Pancreatitis acute | Gastrointestinal disorders | 0 of 27 | 1 of 25 | 0 of 6 |
| Compression fracture | Injury, poisoning and procedural complications | 0 of 27 | 0 of 25 | 1 of 6 |
| Dehydration | Metabolism and nutrition disorders | 0 of 27 | 1 of 25 | 0 of 6 |
| Back Pain | Musculoskeletal and connective tissue disorders | 0 of 27 | 0 of 25 | 1 of 6 |
Most frequent non-serious adverse event terms
| Event term | Organ system | IGSC 20%: Weekly Dosing | IGSC 20%: Bi-weekly Dosing | IGSC 20%: Treatment-naïve Cohort |
|---|---|---|---|---|
| Headache | Nervous system disorders | 3 of 27 | 0 of 25 | 1 of 6 |
| Procedural pain | Injury, poisoning and procedural complications | 1 of 27 | 1 of 25 | 1 of 6 |
| Contusion | Injury, poisoning and procedural complications | 0 of 27 | 0 of 25 | 1 of 6 |
| Upper limb fracture | Injury, poisoning and procedural complications | 0 of 27 | 0 of 25 | 1 of 6 |
| Plantar fasciitis | Musculoskeletal and connective tissue disorders | 0 of 27 | 0 of 25 | 1 of 6 |
| Infusion site reaction | General disorders | 0 of 27 | 0 of 25 | 1 of 6 |
| Infusion site scab | General disorders | 0 of 27 | 0 of 25 | 1 of 6 |
| Vitamin B12 deficiency | Metabolism and nutrition disorders | 0 of 27 | 0 of 25 | 1 of 6 |
| Skin mass | Skin and subcutaneous tissue disorders | 0 of 27 | 0 of 25 | 1 of 6 |
| Bartholin's cyst | Reproductive system and breast disorders | 0 of 27 | 0 of 25 | 1 of 6 |
Serious events with the highest arm-level rate: compression fracture (16.7%), back pain (16.7%), pancreatitis acute (4.0%), dehydration (4.0%), barrett's oesophagus (3.7%).
The registry presents safety counts separately for weekly dosing, biweekly dosing, and the treatment-naïve cohort. In the weekly group, 27 participants were at risk for serious adverse events and 1 was affected; 27 were at risk for other adverse events and 4 were affected. In the biweekly group, 25 were at risk for serious adverse events and 2 were affected; 25 were at risk for other adverse events and 1 was affected. In the treatment-naïve cohort, 6 were at risk for serious adverse events and 1 was affected; 6 were at risk for other adverse events and 3 were affected. Deaths are listed as 0 in each group.
These are group-level counts, not a randomized head-to-head safety comparison. The study is non-randomized and includes a treatment-experienced sequence, so the groups should not be treated as independent, like-for-like control arms. The record summary does not establish whether participants could contribute to more than one dosing group, nor does it provide exposure-adjusted comparisons or the time at risk for each group. The counts therefore describe what the registry lists, not comparative safety rates.
The listed top serious-event terms include Compression fracture (16.7%), Back Pain (16.7%), Pancreatitis acute (4.0%), Dehydration (4.0%), and Barrett's oesophagus (3.7%). The record summary does not provide enough context to reconstruct the denominator or explain the relationship between these term percentages and the group counts. These figures should be read as reported event information, not as evidence that a particular regimen caused an event or as a complete account of all safety findings.
12. What the Result Does, and Does Not, Mean
The record establishes that the study was designed to examine a dosing-frequency question using a pharmacokinetic endpoint in treatment-experienced participants with primary immunodeficiency. It also documents a separate loading-and-maintenance regimen for treatment-naïve participants. The primary measure, steady-state total IgG AUC, is an integrated exposure measure, and the registry states how it was calculated and summarized.
However, the numerical primary result is not reported in the registry record. The record summary does not provide the weekly and biweekly AUC estimates, the contrast, a confidence interval, a p-value, or the non-inferiority margin. Without those elements, it is not possible to determine whether the posted data support the stated non-inferiority objective or how precise the comparison is. The study’s stated purpose should not be mistaken for a reported finding.
The design also limits what can be inferred from simple differences between groups or phases. Allocation was non-randomized, masking was absent, and the treatment-experienced cohort is described as single-sequence. These features do not make the study uninformative, but they mean that time effects, sequence effects, and other differences need to be considered. The registry information does not describe whether or how such issues were addressed in the analysis.
The safety counts offer descriptive information for the listed groups, including the number affected by serious and other adverse events and deaths listed as 0 in each group. They do not, on their own, establish comparative risk. The listed infection outcomes and other secondary measures likewise cannot be interpreted quantitatively from this record summary because numerical outcome results are not reported.
General explanation: A result can be statistically precise yet still require careful consideration of study design, population, and endpoint relevance. Conversely, a study description without numerical results does not permit a judgment about the size or uncertainty of an effect. The appropriate conclusion from the available record is limited: the research question and key design features are documented, but the primary comparison and its uncertainty cannot be evaluated from the results.
13. Why This Trial Matters Statistically
This trial raises a useful statistical question about comparing dosing schedules through pharmacokinetic exposure rather than through a single concentration measurement. AUC integrates measurements across an interval, and the registry specifies steady-state total IgG exposure as the primary measure for weekly dosing. This makes the analysis depend not only on the endpoint definition but also on sampling over time and how the concentration curve is summarized.
The study also illustrates why design labels need to be read together. The record identifies a crossover model, but also describes the study as single-sequence, non-randomized, and open-label. General explanation: Crossover designs can be efficient when participants are observed under more than one regimen, yet inference depends on treatment order and temporal effects. Randomization and adequate reporting of sequence and period handling are important for judging whether a within-participant contrast has a straightforward interpretation. Here, those analytical details are not reported in the registry record.
The non-inferiority objective makes the distinction between a stated aim and an evaluated result especially important. The margin and estimate’s uncertainty are necessary to interpret whether any loss in exposure was ruled out. Those numerical details are not reported in the registry record. This highlights a broader reporting lesson: endpoint definitions and analysis methods provide context, but they cannot substitute for results and uncertainty estimates.
The separate treatment-naïve cohort further demonstrates that a study can contain more than one clinical pathway without those pathways forming direct control groups. Its loading and weekly maintenance schedule answers a different descriptive question from the treatment-experienced weekly-versus-biweekly comparison. Keeping those populations and questions distinct helps prevent misleading comparisons.
Finally, the record lists multiple outcomes and safety summaries. Without analysis counts, missing-data methods, multiplicity details, and numerical estimates, readers cannot fully assess precision or robustness. The trial is therefore statistically instructive not because a conclusion can be recovered from the available summary, but because it shows which design and reporting details are needed to interpret a non-inferiority pharmacokinetic comparison.
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 primary limitation for interpreting the posted results is that the numerical primary endpoint and weekly-versus-biweekly comparison are not reported in the registry record. The non-inferiority margin, effect estimate, confidence interval, and test result are also not reported. Consequently, neither the magnitude nor the precision of the primary comparison can be assessed from this summary.
The design is non-randomized, open-label, and described as single-sequence, while the registry also classifies it as crossover. Treatment-experienced participants are described as receiving weekly dosing before the biweekly evaluation. The complete sequence and timing of the biweekly phase, any washout, and the analysis of period or carryover effects are not reported in the registry record. This prevents a detailed assessment of how the within-participant comparison was constructed.
The registry describes 33 enrolled participants but does not report the actual primary analysis count in this summary. The pharmacokinetic population requires sufficient data for at least one listed PK parameter, which may differ from enrollment. The handling of missing measurements and exclusions is not reported in the registry record. The sample-size justification and the reason for the selected enrollment are also not reported in the registry record.
The treatment-naïve cohort follows a distinct regimen and is not a randomized comparator for the treatment-experienced cohort. The registry’s adverse-event groups likewise should not be interpreted as like-for-like randomized arms. The record summary does not clarify participant overlap across those groups or provide exposure-adjusted safety comparisons. Details of multiplicity control, interim analyses, and the analysis models for secondary outcomes are not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study to Evaluate IGSC 20% Biweekly Dosing in Treatment-Experienced Participants and Loading/Maintenance Dosing in Treatment-Naïve Participants With Primary Immunodeficiency — NCT04566692.
- Registry record last updated 2023-09-29; status last verified 2023-09.
- Results first posted 2023-08-07.
- 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
This completed phase 4 study enrolled 33 participants with primary immunodeficiency. It is described as multicenter, single-sequence, open-label, non-randomized, and crossover. The primary question concerns whether biweekly IGSC 20% dosing in treatment-experienced participants provides non-inferior steady-state total IgG AUC compared with weekly dosing.
Treatment-experienced participants received 16 weekly doses from Week 0 to Week 15 before the biweekly evaluation. Treatment-naïve participants received a loading regimen of 150 mg/kg/day for 5 consecutive days, followed by weekly maintenance infusions of 150 mg/kg through Week 32. The primary endpoint uses a geometric mean and geometric coefficient of variation, with AUC calculated by linear and logarithmic trapezoidal methods.
The registry lists 12 outcome measures and 2 analyses, plus safety counts for the dosing groups. The primary comparison’s numerical result, non-inferiority margin, uncertainty estimate, analysis count, missing-data methods, and multiplicity strategy are not reported in the registry record. The posted details therefore describe the study question and methods but do not permit evaluation of the primary result.