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 Phase II Study of Re-treatment of Myelofibrosis Patients With Ruxolitinib/Jakavi After Treatment Interruption Due to Loss of Response and/or Adverse Event (ReTreatment Trial) (NCT02091752), a na phase 2 study. The primary outcome is Proportion of Patients Achieving ≥20% Reduction From Baseline in Spleen Volume.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02091752 |
| Phase | Phase 2 |
| Condition | Primary Myelofibrosis |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 3 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Novartis Pharmaceuticals |
| Results posted | Yes |
2. Clinical Question
Population
People with myelofibrosis whose prior ruxolitinib treatment had been interrupted because of loss of response and/or an adverse event. The registry records primary myelofibrosis as the condition.
Intervention
Restarting ruxolitinib, also identified as Jakavi in the study title. All participants received ruxolitinib.
Comparator
There was no comparison group. The study was single-arm, with no randomized allocation.
Primary question
At week 24, what proportion of patients achieved at least a 20% reduction from baseline in spleen volume?
The study aimed to assess the efficacy and safety of restarting ruxolitinib after treatment interruption due to loss of response and/or adverse events. Its primary endpoint was a responder proportion: whether participants crossed a specified reduction threshold in spleen volume by the stated assessment time. That question is narrower than asking whether spleen volume changed on average, and it does not by itself establish what would have happened to comparable patients without restarting treatment.
The record reports enrollment of 3 and says the study was terminated early due to low enrollment. It also states that analysis of the primary endpoint was not done. Therefore, the registry record does not report an answer to the primary question: it gives no responder count or estimated proportion. The absence of an analysis is not evidence that nobody achieved the threshold, nor that anyone did. The record supports describing the planned question and the reason the analysis was not completed, but not estimating the endpoint or comparing outcomes across treatment strategies.
3. Trial Design
This was a phase II, open-label, single-arm study. The registry lists ruxolitinib as the intervention and states that all participants received it. There was no comparator arm, and allocation is recorded as not applicable. Masking is recorded as none, so the design was not blinded. The study title describes re-treatment after interruption due to loss of response and/or an adverse event; the brief summary gives the same general aim.
The registry records enrollment of 3. Its status is terminated, and the primary endpoint description says the study was terminated early due to low enrollment. The recorded study start is 2014-09, and the primary completion date is 2015-02. These dates do not establish the timing of individual participants’ treatment or assessments.
The primary outcome was the proportion of patients achieving at least a 20% reduction from baseline in spleen volume at week 24. The registry also lists secondary outcomes involving spleen volume and length, symptom scores, patient global impression of change, and health-related quality-of-life measures. It records 8 outcome measures. Listing an outcome does not mean that its analysis was completed.
The record does not report a sample-size justification, a detailed statistical analysis plan, or interim analyses. The reason for termination is reported as low enrollment; further operational details are not reported in the registry record. Since the study had no control group, its design could describe outcomes after re-treatment if analyses were available, but it could not directly estimate a contrast with an untreated or alternative-treatment group. Open-label conduct also means that participants and study personnel were not masked to treatment assignment.
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 | Ruxolitinib |
|---|---|
| STARTED | 3 |
| COMPLETED | 0 |
| NOT COMPLETED | 3 |
Reasons for not completing this period:
| Reason | Ruxolitinib |
|---|---|
| Study terminated by Sponsor | 2 |
| Adverse Event | 1 |
Analysis population for the primary outcome, as defined in the registry: The study was terminated early due to low enrollment. Analysis was not done.
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 | Ruxolitinib |
|---|---|---|
| Participants analysed | 3 | |
| Age, Continuous | Years | 68.00 (SD 9.165) |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Proportion of Patients Achieving ≥20% Reduction From Baseline in Spleen Volume, measured over Week 24.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was the proportion of patients achieving at least a 20% reduction from baseline in spleen volume at week 24. Each participant would be classified according to whether the specified reduction threshold was met, and the endpoint would express the share of the analyzed group classified as responders. The registry record does not report a responder count, a denominator for an endpoint analysis, or an estimated proportion.
Using a threshold converts a measurement of change into a responder status. As a general statistical matter, this can make an endpoint easier to express as the proportion meeting a predefined criterion, but it discards information about the size of changes on either side of the threshold. Participants with changes close to the threshold may be classified differently despite having similar measurements. The choice of the threshold and assessment time therefore defines what the endpoint captures; it is not interchangeable with mean change in spleen volume or with the other listed outcomes.
The registry identifies week 24 as the assessment time but does not report the endpoint analysis because the study was terminated early due to low enrollment. Consequently, the measure is identifiable as the planned primary outcome, but no result for it can be interpreted. The record does not establish whether assessments were obtained, how missing measurements would have been handled, or what analysis population would have been used.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central statistical fact is that the primary endpoint analysis was not done. The record reports the planned endpoint and its assessment time, but no estimate of the proportion achieving the threshold. It therefore provides no primary efficacy result to interpret. In particular, it does not report how many participants met the threshold, the denominator used for an analysis, or uncertainty around an estimate.
Enrollment was 3, and the study was terminated early due to low enrollment. Enrollment is not necessarily the same as the number with an eligible week 24 measurement or the analysis population. The registry does not report those details. It would be inappropriate to treat enrollment as an endpoint denominator or to infer a responder proportion from it.
There is no randomized or concurrent comparison group. Even if a within-group change had been reported, a single-arm result would describe the observed course among those analyzed after restarting treatment. It would not, on its own, distinguish changes associated with re-treatment from changes that might occur over time or for other reasons. Here, no primary endpoint result is reported, so even that descriptive estimate is unavailable.
Precision cannot be assessed from an endpoint estimate because the record reports no such estimate or confidence interval. In general, a confidence interval describes a range of values compatible with the data under the specified statistical method. It helps distinguish a precise estimate from one with substantial uncertainty; it cannot be reconstructed when the result and analysis details are absent. The registry also reports 0 analyses, consistent with the statement that the primary analysis was not done.
The listed secondary outcomes do not resolve this gap. They indicate outcomes of interest, including spleen measures, symptom measures, patient global impression, and quality-of-life scores, but the record does not report analyzed results for them. No interpretation of improvement, worsening, or between-outcome consistency is warranted from outcome names alone.
Safety information is recorded separately. The registry lists 2 participants affected by serious adverse events among 3 at risk in the ruxolitinib group, and it lists 2 affected by other adverse events among 3 at risk. The listed serious-event terms each have a reported frequency of 33.3%. These figures describe what the registry records; without further detail they do not establish causality, comparative risk, or a rate applicable to a broader population.
Any sample-size calculations should be understood as planning illustrations rather than evidence that the trial had a particular probability of detecting an effect. The record describes assumptions for such illustrations, but it does not report an observed primary endpoint effect or a completed primary analysis. The study’s status and missing endpoint result remain the main limits on statistical interpretation.
9. Statistical Methods Explained
The study’s design and absent endpoint analysis determine which statistical interpretations are possible. The primary outcome is a binary responder measure, but a planned measure is not an observed result. The registry states that analysis was not done after early termination due to low enrollment, and records 0 analyses. No estimated effect, uncertainty interval, or hypothesis test for the primary endpoint is reported.
What does a responder proportion represent?
For a threshold-based endpoint, an analysis would ordinarily identify the participants with an evaluable measurement at the specified time, determine which met the stated reduction criterion, and divide the responder count by the relevant analysis denominator. The resulting proportion describes the fraction classified as responders in that analysis population. The exact numerator and denominator matter: a proportion without them can obscure how much information supports the estimate. In this trial, the record reports neither an analyzed numerator nor an analyzed denominator. Enrollment alone cannot substitute for those quantities because the record does not state who had an evaluable week 24 assessment or which participants would be included in an analysis.
A confidence interval would ordinarily accompany a proportion to convey its statistical precision. In general, the interval reflects both the observed estimate and the amount of information available under the chosen method. Greater uncertainty is expected when information is sparse, but no interval can be interpreted or reconstructed without an analyzed estimate and its analysis details. The registry record reports no confidence interval for the primary endpoint.
Why does the single-arm design matter?
A single-arm analysis can describe outcomes within the treated group, but it does not provide a concurrent comparison of re-treatment with another strategy. Random allocation, when used, can support a more direct comparison by making treatment groups comparable in expectation. This study had no randomized comparison; allocation is recorded as not applicable. Consequently, an estimated within-group change, had one been available, would not be equivalent to an estimate of a treatment effect relative to a control group. Since the primary result is absent, the record supports no numerical estimate even of the within-group responder proportion.
The study was open-label, with masking recorded as none. In general, lack of masking can affect outcomes that rely on judgment or participant reporting, and can influence conduct of assessments. The listed outcomes include symptom scores, patient global impression, and quality-of-life measures, as well as spleen measures. The registry does not report analysis details that would allow assessment of how outcome measurement or open-label conduct was addressed.
What can be inferred from planning illustrations?
The registry describes planning illustrations based on a stated fraction of an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It specifies that the illustration assumes two arms, whereas the actual study was single-arm. Such outputs are hypothetical sample-size calculations under their stated assumptions; they are not observed power and do not show that this trial had adequate power. They also cannot replace the missing primary endpoint analysis. The record does not report the trial’s own sample-size justification, so the illustrations should not be treated as the original design rationale.
For time-to-event outcomes, the record’s general planning description refers to a total number of events using the Schoenfeld approach; other planning outputs are described in participants per arm. These are methodological conventions for the stated illustrations, not observed trial findings. The registry does not identify a time-to-event primary endpoint; the listed primary endpoint is a proportion assessed at week 24.
Why is multiplicity relevant?
The registry records 8 outcome measures, including one primary endpoint and several secondary outcomes. When multiple outcomes or comparisons are tested, the chance of at least one nominally notable result can increase unless the analysis plan addresses multiplicity. As a general concept, multiplicity procedures can control the interpretation of a family of tests, but they may affect the thresholds or uncertainty intervals used. The registry record does not report a multiplicity strategy, and no outcome analyses are reported. It is therefore not possible to assess whether multiplicity adjustments were planned or applied.
The record also does not report the statistical methods for missing data, the analysis population, or a detailed model for the primary endpoint. These omissions matter because endpoint results depend on which observations are included and how unavailable measurements are treated. They are especially consequential when an analysis has not been completed: no assumptions about missingness, exclusions, or model choice can be inferred from the endpoint title. The appropriate reading is limited to the endpoint that was planned and the registry’s explicit statement that its analysis was not done.
10. Multiplicity, Missing Data and Analysis Populations
The registry records 8 outcome measures: a primary endpoint and listed secondary outcomes covering spleen measures, symptoms, patient global impression, and quality of life. A multiplicity plan is not reported in the registry record. In general, testing multiple outcomes raises the possibility of chance findings across the set; an analysis plan may specify how those findings and their uncertainty are to be interpreted. Because the record reports 0 analyses and says the primary analysis was not done, there are no reported outcome tests to evaluate for multiplicity or adjust.
The record does not report how missing measurements would have been handled, what constituted an evaluable assessment, or which analysis population would have been used. Those choices can affect a responder proportion: the denominator depends on the analysis population, and unavailable week 24 measurements may affect the estimate depending on the handling rule. No rule can be inferred from the endpoint description.
Nor does the record report a detailed statistical analysis plan, an interim-analysis plan, or a sample-size justification. These absences should not be filled in with assumptions about common practice. The explicit account is that the study was terminated early due to low enrollment and the primary analysis was not done. Consequently, there is no basis for interpreting adjusted or unadjusted endpoint results, missing-data sensitivity analyses, or a prespecified analysis population.
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 |
|---|---|---|---|
| Ruxolitinib | 2 | 3 | 66.7% |
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 |
|---|---|
| Ruxolitinib | 2 of 3 |
Most frequent serious adverse event terms
| Event term | Organ system | Ruxolitinib |
|---|---|---|
| CONSTIPATION | Gastrointestinal disorders | 1 of 3 |
| CYTOKINE RELEASE SYNDROME | Immune system disorders | 1 of 3 |
| LISTERIOSIS | Infections and infestations | 1 of 3 |
| RENAL FAILURE | Renal and urinary disorders | 1 of 3 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Ruxolitinib |
|---|---|---|
| ANAEMIA | Blood and lymphatic system disorders | 1 of 3 |
| ANAL HAEMORRHAGE | Gastrointestinal disorders | 1 of 3 |
| ASCITES | Gastrointestinal disorders | 1 of 3 |
| CONSTIPATION | Gastrointestinal disorders | 1 of 3 |
| DIARRHOEA | Gastrointestinal disorders | 1 of 3 |
| VARICES OESOPHAGEAL | Gastrointestinal disorders | 1 of 3 |
| PORTAL VEIN THROMBOSIS | Hepatobiliary disorders | 1 of 3 |
| CYSTITIS | Infections and infestations | 1 of 3 |
| ALANINE AMINOTRANSFERASE INCREASED | Investigations | 1 of 3 |
| ASPARTATE AMINOTRANSFERASE INCREASED | Investigations | 1 of 3 |
Serious events with the highest arm-level rate: constipation (33.3%), cytokine release syndrome (33.3%), listeriosis (33.3%), renal failure (33.3%).
For the ruxolitinib group, the registry records 3 participants at risk for serious adverse events and 2 affected. It also records 3 at risk for other adverse events and 2 affected. These are separate registry categories; the record does not explain whether the same participants contributed to both categories. Deaths are not reported in the registry record.
The listed serious adverse-event terms are constipation, cytokine release syndrome, listeriosis, and renal failure, each with a reported frequency of 33.3%. These percentages should be read as the registry’s recorded frequencies for the listed terms. The record does not give further detail about event timing, severity, recurrence, or the denominator underlying each term’s percentage, so those details should not be inferred.
Adverse-event counts describe events recorded during the study; they do not by themselves show that the intervention caused an event. With no comparison group, these figures cannot provide a comparative risk estimate. The small enrollment and early termination also limit how much these observations can characterize safety beyond the participants recorded.
12. What the Result Does, and Does Not, Mean
The record establishes that the ReTreatment Trial was intended to examine restarting ruxolitinib after interruption due to loss of response and/or adverse events. It identifies a primary endpoint, a threshold reduction in spleen volume from baseline at week 24, and records that all participants received ruxolitinib. It also states that the study ended early due to low enrollment and that the primary analysis was not done.
What the record does not establish is whether the primary threshold was met by any participant, what the response proportion was, or how precise an estimate might have been. No primary result or uncertainty interval is reported. The endpoint’s absence is not equivalent to a result of no response; it is an absence of an analysis. The enrollment figure is not a substitute for the missing analysis population or outcome denominator.
The single-arm, open-label design also limits the kinds of conclusions that could follow even from an available within-group result. Without a comparator, observed changes could not be directly contrasted with outcomes under another treatment strategy. This design does not support a randomized treatment comparison. The registry provides no basis for attributing a change, had one been measured, to re-treatment alone.
The record lists several secondary outcome areas and safety counts, but listing outcomes is not the same as reporting analyzed results. Safety counts describe what was recorded in the group and should not be interpreted as comparative rates or proof of causation. The serious adverse-event terms and percentages are registry entries, not an estimate of risk for other patients.
In practical statistical terms, the trial’s record documents a research question and a planned endpoint, but does not answer that endpoint. The strongest interpretation is therefore about the limits of the available evidence: the primary response estimate is unavailable, precision cannot be assessed, and comparisons with other approaches are not supported by this design or record.
13. Why This Trial Matters Statistically
This trial is statistically informative in part because it illustrates the difference between a registered endpoint and an analyzed result. The registry clearly defines a primary question—a threshold reduction in spleen volume at week 24—but also states that the study was terminated early due to low enrollment and the analysis was not done. A named endpoint alone is not evidence about its outcome.
The distinction matters for evidence synthesis and clinical-trial interpretation. An absent result should not be encoded or discussed as a null effect, a failed response, or evidence of no change. There is no reported estimate to compare with another study or use as an observed effect. Keeping the missing result separate from a measured estimate prevents unsupported conclusions from entering summaries of trial evidence.
The single-arm structure adds a second statistical lesson. Within-group observations, if available, would not provide a randomized contrast. A comparator is needed for a direct estimate of how outcomes differ between treatment strategies, while a single group can at most describe outcomes among those analyzed. In this record, even the planned within-group primary estimate is unavailable.
Finally, the planning assumptions described in the record are not observed power. Sample-size illustrations rely on assumptions, and the record says the illustrations use equal allocation between two arms even though this was a single-arm study. They cannot compensate for the absence of an endpoint result or establish that the study was adequately powered. The record is useful for understanding the study’s design and why statistical conclusions are limited, not for estimating efficacy.
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 most direct limitation is that the study was terminated early due to low enrollment and the primary endpoint analysis was not done. Enrollment was 3, but the record does not identify how many participants had week 24 measurements or would have belonged to an analysis population. No response count, denominator, estimate, or confidence interval is reported.
The single-arm design provides no concurrent control group, and the study was open-label. Thus, even a reported within-group result would not constitute a randomized comparison, and outcomes involving participant report or judgment could be affected by lack of masking. The registry does not report methods addressing these design considerations.
The registry lists secondary outcomes but does not report their results or analyses. It also does not report missing-data methods, analysis populations, a detailed statistical plan, multiplicity handling, interim analyses, or the study’s sample-size justification. These omissions prevent assessment of how planned analyses would have addressed incomplete measurements or multiple outcomes. No assumptions about such procedures can be made from the outcome list.
The record’s safety entries are limited to the stated counts and listed serious-event terms. Further event details and a comparative group are not reported. Therefore, the entries cannot establish causality or characterize comparative safety. Taken together, early termination, the absent primary analysis, and the single-arm design sharply limit both efficacy interpretation and generalization beyond the registry’s descriptive record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Phase II Study of Re-treatment of Myelofibrosis Patients With Ruxolitinib/Jakavi After Treatment Interruption Due to Loss of Response and/or Adverse Event (ReTreatment Trial) — NCT02091752.
- Registry record last updated 2016-03-24; status last verified 2016-02.
- Results first posted 2016-02-10.
- 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
NCT02091752, the ReTreatment Trial, was a phase II, open-label, single-arm study of ruxolitinib re-treatment in myelofibrosis after interruption due to loss of response and/or an adverse event. The registry records primary myelofibrosis as the condition, enrollment of 3, and study status as terminated. The recorded start is 2014-09 and primary completion is 2015-02.
The primary endpoint was the proportion achieving at least a 20% reduction from baseline in spleen volume at week 24. The registry states that the study was terminated early due to low enrollment and that the primary analysis was not done. It records 8 outcome measures and 0 analyses. No primary response estimate or uncertainty interval is reported.
There was no comparator group. The safety record lists 2 participants affected by serious adverse events among 3 at risk, with four serious-event terms each recorded at 33.3%. These entries do not establish causation or comparative risk.