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 Study Of Pregabalin (Lyrica) In Patients With Painful Diabetic Peripheral Neuropathy (NCT01057693), a randomized phase 3 study. The primary outcome is Change From Single-Blind Baseline in Mean Pain Score at Week 19 During Double-Blind Phase.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01057693 |
| Phase | Phase 3 |
| Condition | Diabetic Neuropathy, Painful |
| Allocation | Randomized |
| Design model | Not Stated |
| Masking | Quadruple |
| Enrollment | 633 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Pfizer's Upjohn has merged with Mylan to form Viatris Inc. |
| Results posted | Yes |
2. Clinical Question
Population
Patients with inadequately treated painful diabetic peripheral neuropathy. The registry describes a full analysis set consisting of participants randomized to double-blind treatment who received at least 1 dose of that treatment.
Intervention
Pregabalin (Lyrica), after participants switched from their current medication for painful diabetic peripheral neuropathy. The study description states that all participants received pregabalin at some point.
Comparator
Placebo during the study. The registry description says half of participants received placebo at some point; it does not provide full arm descriptions or the detailed treatment sequence.
Primary question
How did mean pain score change from the single-blind baseline to Week 19 during the double-blind phase? The registry identifies this endpoint, but the result of the comparison is not reported in the registry record.
The clinical question is framed as a randomized-withdrawal comparison in patients with painful diabetic peripheral neuropathy whose current medication was to be switched. The study was designed to evaluate pregabalin against placebo, with treatment exposure described across single-blind and double-blind phases. The primary endpoint focuses on change in mean pain score between the single-blind baseline and Week 19 during the double-blind phase.
The score was based on participants’ daily ratings of their diabetic peripheral neuropathy pain over the past 24 hours. The registry defines the mean as the average of the last 7 daily diary ratings. Ratings used an 11-point numeric scale from 0 = no pain to 10 = worst possible pain. The record does not report the group-level endpoint estimates, their uncertainty, or a statistical test for the primary comparison. Therefore, the clinical question can be described, but the posted information does not establish the direction or size of any difference in pain-score change.
3. Trial Design
This was a Phase 3B, multicenter, double-blind, randomized-withdrawal study of pregabalin in patients with inadequately treated painful diabetic peripheral neuropathy. The registry records quadruple masking. It describes switching participants from their current medication and states that all participants received pregabalin, while half received placebo at some point during the study. The detailed sequence of treatment, the criteria for entering each phase, and the arm descriptions are not reported in the registry record.
The primary endpoint refers to a single-blind baseline and Week 19 during the double-blind phase. That wording indicates the assessment periods used for the endpoint, but it does not supply the full schedule of visits or explain how participants moved between phases. The study’s randomized-withdrawal designation and the brief description should therefore be read alongside the limited phase details: the record identifies a comparison with placebo, but does not specify the precise allocation sequence or treatment rules.
The registry records enrollment of 633 and lists the study as completed. The recorded study start was 2010-03-31, and primary completion was 2012-01-30. These dates describe the registered study timeline; they do not provide additional detail about recruitment duration, follow-up for individual participants, or the timing of analyses. The record names pregabalin (Lyrica) and placebo as drug interventions. The sponsor is identified as Pfizer's Upjohn, which merged with Mylan to form Viatris Inc.
For the primary endpoint, the stated analysis population was the full analysis set: participants randomized to double-blind treatment who received at least 1 dose of double-blind study treatment. Missing values were imputed using Last Observation Carried Forward (LOCF). The registry does not report a detailed statistical analysis plan, sample-size justification, or the number of participants contributing endpoint data in each group.
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.
Single-Blind Phase (Up to Week 6)
| Stage | Pregabalin SB | Pregabalin DB | Placebo |
|---|---|---|---|
| STARTED | 665 | 0 | 0 |
| COMPLETED | 566 | 0 | 0 |
| NOT COMPLETED | 99 | 0 | 0 |
Reasons for not completing this period:
| Reason | Pregabalin SB | Pregabalin DB | Placebo |
|---|---|---|---|
| Adverse Event | 45 | 0 | 0 |
| Lack of Efficacy | 7 | 0 | 0 |
| Lost to Follow-up | 14 | 0 | 0 |
| Protocol Violation | 9 | 0 | 0 |
| Withdrawal by Subject | 22 | 0 | 0 |
| Other | 2 | 0 | 0 |
Between Single-Blind and Double-Blind
| Stage | Pregabalin SB | Pregabalin DB | Placebo |
|---|---|---|---|
| STARTED | 566 | 0 | 0 |
| COMPLETED | 296 | 0 | 0 |
| NOT COMPLETED | 270 | 0 | 0 |
Reasons for not completing this period:
| Reason | Pregabalin SB | Pregabalin DB | Placebo |
|---|---|---|---|
| Adverse Event | 5 | 0 | 0 |
| Lack of Efficacy | 247 | 0 | 0 |
| Lost to Follow-up | 1 | 0 | 0 |
| Protocol Violation | 7 | 0 | 0 |
| Withdrawal by Subject | 4 | 0 | 0 |
| Other | 6 | 0 | 0 |
Double-Blind Phase (Week 7 to Week 19)
| Stage | Pregabalin SB | Pregabalin DB | Placebo |
|---|---|---|---|
| STARTED | 0 | 147 | 149 |
| Treated | 0 | 147 | 147 |
| COMPLETED | 0 | 125 | 113 |
| NOT COMPLETED | 0 | 22 | 36 |
Reasons for not completing this period:
| Reason | Pregabalin SB | Pregabalin DB | Placebo |
|---|---|---|---|
| Adverse Event | 0 | 8 | 11 |
| Lack of Efficacy | 0 | 3 | 8 |
| Lost to Follow-up | 0 | 2 | 5 |
| Protocol Violation | 0 | 0 | 4 |
| Withdrawal by Subject | 0 | 8 | 6 |
| Other | 0 | 1 | 0 |
| Randomized, Not Treated | 0 | 0 | 2 |
Analysis population for the primary outcome, as defined in the registry: Full analysis set (FAS) included all participants randomized to double-blind treatment who received at least 1 dose of double-blind study treatment. Missing data were imputed using Last Observation Carried Forward (LOCF).
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 | Pregabalin SB |
|---|---|---|
| Participants analysed | 665 | |
| Age, Customized: 18 to 44 Years | participants | 58 |
| Age, Customized: 45 to 64 Years | participants | 417 |
| Age, Customized: >=65 Years | participants | 190 |
| Sex: Female, Male: Female | Participants | 302 |
| Sex: Female, Male: Male | Participants | 363 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Single-Blind Baseline in Mean Pain Score at Week 19 During Double-Blind Phase, measured over SB Baseline, Week 19 (DB Phase).
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint was change from single-blind baseline in mean pain score at Week 19 during the double-blind phase. Pain was rated in daily diaries for diabetic peripheral neuropathy pain over the past 24 hours, using an 11-point numeric rating scale from 0 = no pain to 10 = worst possible pain. The endpoint’s mean pain score was defined as the mean of the last 7 daily ratings. The registry describes the single-blind baseline as the last 7 pain diary entries up to and including Day 1.
A change score is intended to describe how an outcome differs at a follow-up assessment from a defined starting point. In general, using a baseline can help put follow-up measurements in the context of participants’ initial scores. A diary-based mean also draws on repeated daily ratings rather than a single rating, although the registry does not report the completeness of the diaries or how many ratings were available for each participant.
The scale gives a common numeric framework for recording pain intensity. The registry categorizes ratings of 1-3 as mild, 4-6 as moderate, and 7-10 as severe; 0 is defined as no pain. These categories provide context for individual scale values, but the primary endpoint is described as a mean pain score and a change in that mean, not as a comparison of the proportions in each category.
The endpoint is clinically interpretable as a measure of reported pain intensity over time. However, the actual group changes, between-group contrast, confidence interval, and statistical test result are not reported in the registry record. Without those results, the endpoint definition alone cannot show the size, direction, or precision of the treatment comparison.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the primary comparison but does not report its numerical outcome. It gives no group-level mean change, between-group estimate, confidence interval, or p-value for change from single-blind baseline in mean pain score at Week 19 during the double-blind phase. As a result, the posted information does not permit a statistical assessment of the magnitude, direction, or precision of the primary comparison.
This absence matters because an endpoint definition is not itself an outcome. The description explains what was measured, when it was measured, and how the pain score was formed. It does not establish whether scores changed, whether changes differed between treatment groups, or whether any estimated difference was compatible with a range of effects. Those judgments require results and their uncertainty, neither of which is reported for the primary endpoint in the registry record.
The registry lists secondary outcomes that include time to loss of pain response, weekly mean pain scores, proportions with at least 30 percent and 50 percent reductions in mean pain score, and Patient Global Impression of Change. Several are specified separately for the single-blind and double-blind phases. Their inclusion shows that the study registered a range of pain-related assessments, but their results are not reported in the information available for this analysis. They cannot substitute for the missing primary comparison.
The safety information is more specific about counts. The registry lists serious adverse events for Pregabalin SB, Pregabalin DB, and placebo, along with counts of participants affected by other adverse events. For Pregabalin SB, the serious adverse-event count is 17 among 665 at risk, and the other adverse-event count is 331 among 665 at risk. For Pregabalin DB, the corresponding counts are 11 among 147 and 86 among 147. For placebo, they are 6 among 149 and 94 among 149. These are group-specific registry counts; they should not be combined, and they do not explain the difference between the recorded overall enrollment and the listed safety risk sets. The reason for that difference is not reported in the registry record.
The registry also lists myocardial infarction at 1.4%; acute coronary syndrome, angina pectoris, atrial fibrillation, chest pain, and non-cardiac chest pain are each listed at 0.7% among the top serious-event terms. The record does not state the denominator for these term percentages in the information, so they should be read as reported rather than recalculated. Death counts are not reported in the registry record.
Overall, the record supports a description of the trial question, endpoint, analysis population, and selected safety counts. It does not support a conclusion about the primary efficacy result because the relevant estimates and uncertainty are absent. The listed safety counts also do not, on their own, establish a comparative safety effect.
9. Statistical Methods Explained
What does a mean change measure?
In general, a mean summarizes the average value in a group. A mean change compares an outcome at follow-up with a defined baseline. The primary endpoint in this trial uses the mean of recent daily pain ratings at baseline and at Week 19 during the double-blind phase. This approach expresses the outcome on the pain-rating scale while focusing on change over the stated assessment period.
A mean can be useful when the research question concerns average symptom intensity, but it does not describe every participant’s experience. Participants may have different starting scores and different trajectories, and a group average can conceal that variation. The registry defines the pain-rating scale and the averaging window, but does not report the distribution of scores or individual changes. The primary result and its uncertainty would be needed to judge how precisely the group comparison was estimated.
Why does the analysis population matter?
The registry defines the full analysis set as participants randomized to double-blind treatment who received at least 1 dose of double-blind study treatment. This definition specifies who was included in the stated analysis population. It is not the same as a statement that every person enrolled contributed to the primary outcome analysis, and the record does not report the number analyzed in each group. The population definition should be considered when interpreting results because estimates apply to the participants included under that rule.
The criterion requiring at least 1 dose means the stated set is based on both randomization and treatment receipt. The registry does not explain whether other analysis populations were used, how participants who did not meet the criterion were handled, or whether analyses using alternative populations were performed. Those details are not reported in the registry record.
What does LOCF do?
The registry states that missing data were imputed using Last Observation Carried Forward. In general, LOCF fills a missing later measurement by carrying forward a participant’s last observed value. This produces a value for analysis where a later measurement is absent, but it relies on an assumption that the carried-forward value is an acceptable substitute for the missing value. If an outcome would have changed after the last observation, that imputed value may not represent the unobserved measurement.
LOCF does not remove uncertainty about why data are missing or whether missingness is related to participants’ outcomes. The registry does not report the amount or pattern of missing primary endpoint data, reasons for missingness, or sensitivity analyses using other approaches. Consequently, the effect of imputation on the reported estimate cannot be assessed from the registry information available.
What can randomization and masking contribute?
In general, random assignment is intended to make treatment groups comparable on average with respect to measured and unmeasured characteristics, subject to how the trial is conducted and analyzed. Masking is intended to reduce the influence of knowledge about treatment assignment on care, reporting, or outcome assessment. This trial is recorded as randomized and quadruple-masked, and its official title describes it as double-blind. The record does not specify which people were included in the quadruple-masking designation or provide enough detail to assess how allocation was implemented.
These design features do not replace the need for outcome estimates and uncertainty. Nor do they establish that all possible sources of bias were avoided. The registry does not report allocation concealment procedures, protocol deviations, or the detailed analysis plan.
How should planning illustrations be understood?
In general, a sample-size calculation estimates how many participants would be needed under chosen assumptions to detect a specified effect with a chosen statistical criterion. It is a planning exercise, not an observed trial result. The planning description associated with this study specifies a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect set to a stated fraction of the observed effect. It describes participant counts per arm for non-time-to-event outcomes.
Such illustrations depend on the assumptions used. Changing the target effect or statistical assumptions changes the planning estimate. A calculation based on an observed effect is not the trial’s original design justification, and it should not be interpreted as observed power. The registry record does not report the trial’s own sample-size justification or the numerical planning results in the information available for this analysis. The primary endpoint estimate needed to understand an effect-based illustration is also not reported in the registry record.
Why do confidence intervals matter?
In general, a confidence interval communicates the statistical uncertainty around an estimated effect under the method used to calculate it. It gives a range of values compatible with the data and model at the stated confidence level. A narrow interval indicates greater precision than a wide interval, while the interval’s location helps show which effect sizes remain compatible with the estimate. A p-value alone does not describe the range of plausible effect sizes.
No primary endpoint confidence interval or p-value is reported in the registry record. It is therefore not possible to describe the precision of the primary comparison, determine which effect sizes are compatible with the posted data, or assess the result against a statistical threshold.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists multiple secondary outcomes, including time to loss of pain response, pain-score changes and weekly mean scores, response thresholds of at least 30 percent and 50 percent reduction, and Patient Global Impression of Change. Several outcomes are specified separately for the single-blind and double-blind phases. These are distinct opportunities to examine treatment-related outcomes. When many outcomes or time points are tested, the chance of at least one apparently notable result can increase unless the statistical approach accounts for the multiplicity.
The registry record does not report a multiplicity adjustment, a hierarchy for testing outcomes, or a plan distinguishing confirmatory from exploratory analyses. It also does not report which secondary outcomes were analyzed or their results in the information available for this analysis. Therefore, no claim about control of the overall false-positive risk can be made from the posted record. This does not establish that no such plan existed; its details are not reported in the registry record.
Missing data were handled using LOCF for the stated full analysis set. In general, carrying a last observed value forward is one way to fill missing outcome measurements, but it may not reflect the value that would have been observed later. The amount, timing, and reasons for missing primary endpoint data are not reported. Nor are sensitivity analyses or alternative missing-data methods reported in the registry record.
The full analysis set included participants randomized to double-blind treatment who received at least 1 dose of double-blind study treatment. The record does not describe other analysis populations or provide group-specific counts for the primary endpoint. Because the primary result itself is not reported, it is not possible to compare how alternative population definitions or missing-data assumptions might affect the treatment estimate.
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 |
|---|---|---|---|
| Pregabalin SB | 17 | 665 | 2.6% |
| Pregabalin DB | 11 | 147 | 7.5% |
| Placebo | 6 | 149 | 4.0% |
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 |
|---|---|
| Pregabalin SB | 331 of 665 |
| Pregabalin DB | 86 of 147 |
| Placebo | 94 of 149 |
Most frequent serious adverse event terms
| Event term | Organ system | Pregabalin SB | Pregabalin DB | Placebo |
|---|---|---|---|---|
| Pneumonia | Infections and infestations | 3 of 665 | 1 of 147 | 0 of 149 |
| Myocardial infarction | Cardiac disorders | 0 of 665 | 2 of 147 | 0 of 149 |
| Chest pain | General disorders | 1 of 665 | 1 of 147 | 0 of 149 |
| Hypoglycaemia | Metabolism and nutrition disorders | 1 of 665 | 0 of 147 | 1 of 149 |
| Dyspnoea | Respiratory, thoracic and mediastinal disorders | 0 of 665 | 1 of 147 | 1 of 149 |
| Anaemia | Blood and lymphatic system disorders | 1 of 665 | 0 of 147 | 0 of 149 |
| Acute coronary syndrome | Cardiac disorders | 0 of 665 | 1 of 147 | 0 of 149 |
| Angina pectoris | Cardiac disorders | 0 of 665 | 1 of 147 | 0 of 149 |
| Atrial fibrillation | Cardiac disorders | 0 of 665 | 1 of 147 | 0 of 149 |
| Bradycardia | Cardiac disorders | 1 of 665 | 0 of 147 | 0 of 149 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Pregabalin SB | Pregabalin DB | Placebo |
|---|---|---|---|---|
| Oedema peripheral | General disorders | 53 of 665 | 20 of 147 | 16 of 149 |
| Dizziness | Nervous system disorders | 45 of 665 | 4 of 147 | 2 of 149 |
| Somnolence | Nervous system disorders | 38 of 665 | 6 of 147 | 5 of 149 |
| Headache | Nervous system disorders | 29 of 665 | 4 of 147 | 4 of 149 |
| Nausea | Gastrointestinal disorders | 22 of 665 | 4 of 147 | 5 of 149 |
| Pain in extremity | Musculoskeletal and connective tissue disorders | 19 of 665 | 3 of 147 | 8 of 149 |
| Diarrhoea | Gastrointestinal disorders | 15 of 665 | 5 of 147 | 6 of 149 |
| Fatigue | General disorders | 18 of 665 | 3 of 147 | 4 of 149 |
| Upper respiratory tract infection | Infections and infestations | 11 of 665 | 7 of 147 | 7 of 149 |
| Oedema | General disorders | 10 of 665 | 6 of 147 | 5 of 149 |
Serious events with the highest arm-level rate: myocardial infarction (1.4%), acute coronary syndrome (0.7%), angina pectoris (0.7%), atrial fibrillation (0.7%), chest pain (0.7%).
The registry reports serious adverse-event counts and counts of participants affected by other adverse events for Pregabalin SB, Pregabalin DB, and placebo. For Pregabalin SB, 17 participants were affected by serious adverse events among 665 at risk, and 331 were affected by other adverse events among 665 at risk. For Pregabalin DB, the respective counts were 11 among 147 and 86 among 147. For placebo, they were 6 among 149 and 94 among 149. These are the group labels and counts as recorded; the definitions of the two event groupings are not elaborated in the information available.
The registry lists myocardial infarction at 1.4% and acute coronary syndrome, angina pectoris, atrial fibrillation, chest pain, and non-cardiac chest pain at 0.7% each among the top serious-event terms. The denominator and group attribution for these term percentages are not reported in the registry record, so they should not be treated as independently recalculated group-specific rates. Death counts are not reported in the registry record.
The listed safety risk sets do not match the recorded enrollment of 633, and the record does not explain the relationship between them. These counts should be read separately rather than added or treated as a direct comparison of risk. In general, adverse-event counts alone do not establish whether a treatment caused an event or whether groups differ; interpretation also depends on definitions, exposure, follow-up, and the analysis approach.
12. What the Result Does, and Does Not, Mean
The registry record establishes what the trial set out to measure: change from single-blind baseline in mean pain score at Week 19 during the double-blind phase. It also defines the scale, the seven-day averaging approach, the full analysis set, and the use of LOCF for missing data. These details make the intended endpoint and analysis population understandable, but they are not a report of the primary outcome.
The primary group estimates, between-group contrast, confidence interval, and p-value are not reported in the registry record. Without those results, it is not possible to state whether mean pain scores changed, how the treatment groups compared, or how precisely any difference was estimated. The registered endpoint therefore does not by itself show that pregabalin was better, worse, or similar to placebo on the primary outcome.
The listed secondary outcomes broaden the set of registered questions, including response thresholds and patient global impressions. Their results are not reported in the information available for this analysis. They cannot be used to fill the gap in the primary endpoint results, and the record does not provide enough information to assess multiplicity or the relative confirmatory status of those outcomes.
The safety listings provide event counts for the named groups and some top serious-event terms with percentages. They are descriptive entries, not a complete causal analysis. The record does not report death counts, does not explain the safety risk sets in relation to the enrollment figure, and does not provide the denominator for the term percentages in the information available. These limitations prevent a full interpretation of comparative safety from these entries alone.
In general, a trial’s design features and its outcome estimates answer different questions. Randomization and masking describe aspects of how a comparison was planned; endpoint results show what was observed and with what precision. The registry record gives important design and measurement details, but without the primary result it cannot support a conclusion about the effect of pregabalin relative to placebo on the stated endpoint.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of why registered methods and posted results need to be read separately. The record specifies a randomized-withdrawal design, masking, a pain-rating scale, a defined baseline, a Week 19 assessment, and an analysis population. Those details help clarify the intended comparison and the meaning of the endpoint. However, they do not provide the estimated treatment contrast or its uncertainty.
The outcome is a mean derived from recent diary ratings and expressed as change from baseline. This makes the measurement window and baseline definition important to interpretation. The full analysis set is also defined by both randomization and receipt of at least 1 dose of double-blind treatment, while missing values were handled with LOCF. These choices affect which observations contribute and how missing measurements are represented. The registry does not report enough detail to assess the impact of those choices.
The registry also names several secondary measures and assessment periods. In general, a broad set of outcomes can be useful for describing different aspects of an illness, but it raises questions about how statistical multiplicity was managed and which analyses were intended to be confirmatory. That plan is not reported in the registry record.
Finally, the safety entries illustrate the need to preserve group labels, denominators, and definitions when interpreting counts. The safety risk sets differ from the enrollment figure, and their relationship is not explained. Counts and listed term percentages should therefore be treated as descriptive registry entries, not as a complete comparison. The record’s statistical value lies in its clearly stated measurement and analysis details, alongside the important limitation that the primary numerical result is not reported.
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 main limitation for interpreting efficacy is that the primary endpoint result is not reported in the registry record. There are no group-level changes, between-group estimate, confidence interval, or p-value in the information available. The record therefore supports description of the question and endpoint, but not an estimate of the comparative effect.
Important design details are also limited. The registry records a randomized-withdrawal study with single-blind and double-blind phases, but the arm descriptions are empty and the detailed treatment sequence is not reported. The criteria for moving between phases, allocation procedures, and the roles covered by quadruple masking are not described in the information available. These omissions constrain assessment of how the design was implemented.
The stated analysis population and missing-data method are identified, but the number analyzed in each group, amount and pattern of missing data, reasons for missingness, and sensitivity analyses are not reported. The record also does not report a detailed statistical analysis plan, multiplicity approach, or the trial’s own sample-size justification.
Safety counts are available, but the listed risk sets do not correspond to the recorded enrollment figure, and the relationship between those figures is not explained. The denominator and group attribution for the serious-event term percentages are not reported in the information available. Death counts are not reported in the registry record. These limitations make the safety entries difficult to interpret as a full comparative assessment.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study Of Pregabalin (Lyrica) In Patients With Painful Diabetic Peripheral Neuropathy — NCT01057693.
- Registry record last updated 2021-01-20; status last verified 2019-02.
- Results first posted 2013-02-22.
- 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
The registry describes a completed Phase 3B, multicenter, randomized-withdrawal study of pregabalin for inadequately treated painful diabetic peripheral neuropathy. It records quadruple masking and enrollment of 633. The study began on 2010-03-31, with primary completion on 2012-01-30. Its brief description states that participants switched from their current medication, all received pregabalin at some point, and half received placebo at some point.
The primary endpoint was change from single-blind baseline in mean pain score at Week 19 during the double-blind phase. Pain was rated on an 11-point scale, with the mean based on the last 7 daily diary ratings. The full analysis set included participants randomized to double-blind treatment who received at least 1 dose; missing data were imputed using LOCF. The primary numerical result is not reported in the registry record. Safety counts and selected serious-event terms are listed, but the relationship between the safety risk sets and recorded enrollment is not explained.