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Multiple Myeloma Phase 2 Non-Randomized NCT02336815

STORM: Complete Statistical Analysis of Selinexor in Multiple Myeloma

An independent statistical review of the STORM phase 2 trial of selinexor and dexamethasone in multiple myeloma, focusing on its non-randomized parallel design, overall response rate endpoint, statistical interpretation, and reported safety information.

Trial status: COMPLETED  ·  Enrollment: 202  ·  Sponsor: Karyopharm Therapeutics Inc
Scope of this record

This page separates information reported in the ClinicalTrials.gov record from statistical interpretation. The registry identifies results as posted, but the ClinicalTrials.gov record contains no formal statistical analysis records. Accordingly, numerical treatment-effect estimates, confidence intervals, and p-values are not reported here.

Registry note: This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record.

1. Trial at a Glance

STORM was a completed phase 2 oncology trial in multiple myeloma evaluating selinexor and dexamethasone. The ClinicalTrials.gov record describes a non-randomized, parallel design with no masking and a treatment purpose, enrolling 202 participants across two parts.

202
Enrollment
Participants
2
Arms
Selinexor and dexamethasone interventions
2
Phase
Phase 2
1
Primary endpoint
Binary ORR endpoint
FeatureSTORM
Trial nameSTORM
NCT identifierNCT02336815
Brief titleSelinexor Treatment of Refractory Myeloma
ConditionMultiple Myeloma
PhasePhase 2
StatusCOMPLETED
AllocationNON_RANDOMIZED
Design modelPARALLEL
MaskingNONE
Primary purposeTREATMENT
Enrollment202
InterventionsSelinexor; Dexamethasone
Lead sponsorKaryopharm Therapeutics Inc
Sponsor typeINDUSTRY

2. Clinical Question

The registered primary question centers on the proportion of participants achieving an overall response according to International Myeloma Working Group criteria, with assessment performed by an Independent Review Committee.

Population

Participants enrolled in the STORM phase 2 trial for multiple myeloma.

Intervention

The ClinicalTrials.gov record identifies selinexor and dexamethasone as the study interventions.

Comparator

The trial is registered as non-randomized. The ClinicalTrials.gov record does not identify a randomized comparator regimen.

Primary question

What percentage of participants experienced an overall response according to the registered IMWG-based definition and independent review?

3. Trial Design

01
Enrollment202 participants
02
Study partsPart 1 and Part 2
03
InterventionSelinexor + dexamethasone
04
AssessmentIRC-assessed ORR
05
Follow-upUntil progression, discontinuation, or death
Allocation
NON-RANDOMIZED
Design model
PARALLEL
Masking
NONE
Primary purpose
TREATMENT

The distinction between a randomized and non-randomized design is central to interpreting STORM statistically. Randomization creates a mechanism for balancing both measured and unmeasured prognostic factors in expectation. Because this registry identifies STORM as non-randomized, an observed response proportion is principally a description of the enrolled population rather than a randomized estimate of a treatment effect against a concurrent control group.

4. Study Parts and Safety Population

The ClinicalTrials.gov record reports two parts and provide serious adverse-event counts separately for each part. They do not provide the treatment assignment structure or intervention-specific enrollment counts for the two parts, so the safety figures should be retained in their registry form rather than re-labeled as randomized treatment-arm comparisons.

Study componentSerious adverse eventsAt risk
Part 14579
Part 278123
Interpretation: The reported serious-adverse-event figures are counts of affected participants over the reported numbers at risk. They are not formal comparative risk estimates, and the ClinicalTrials.gov record does not provide a p-value, confidence interval, relative risk, odds ratio, or hazard ratio for serious adverse events.

5. Primary Endpoint

EndpointRegistered definitionEndpoint type
Part 2: Percentage of Participants With Overall Response Rate (ORR) Per International Myeloma Working Group (IMWG) as Assessed by an Independent Review Committee (IRC) IRC assessed ORR per 2016 IMWG criteria. The registry definition states that participants were classified according to response categories including Partial Response (PR), defined as greater than or equal to 50% reduction of serum M-Protein and reduction in 24-hour urinary M-protein by greater than or equal to 90% or to less than 200 mg per 24 hours, with additional response definitions continuing in the registry record. Binary

The registered time frame is Baseline until disease progression/discontinuation from the study, or death, whichever occurred first, with the registry text ending before the maximum duration is specified.

Endpoint-definition limitation: The ClinicalTrials.gov record contains only a partial text extraction of the full IMWG response definition. This page therefore does not reconstruct the omitted portions of the registry wording.

6. Results

Results are posted for the primary endpoint in the ClinicalTrials.gov record. However, no formal statistical analyses were posted. No numerical estimate, confidence interval, p-value, or formal comparative statistical analysis for the primary endpoint is provided in the ClinicalTrials.gov record.

Primary endpoint: IRC-assessed ORR

Results posted

Formal statistical analysis records reported: none

No ORR estimate, confidence interval, or p-value is included in the ClinicalTrials.gov record.

Clinical Biostats interpretation

The primary endpoint is a binary response outcome: each participant is classified according to whether the registered response criteria were met. The natural descriptive quantity is therefore the proportion of participants with an overall response.

Because STORM is registered as non-randomized, an observed ORR would not by itself establish that selinexor and dexamethasone caused the observed response rate. Without a randomized comparator, differences from historical response experience can be affected by patient selection, eligibility criteria, disease characteristics, assessment procedures, and other differences between populations.

A confidence interval around an ORR would quantify statistical precision around the estimated response proportion. It would not describe the range of responses that an individual participant could experience, and it would not by itself remove the design limitations created by non-randomized allocation.

A p-value, if one were reported against a prespecified reference value, would quantify evidence against that statistical null hypothesis under the specified analysis. It would not measure the size or clinical importance of the response rate.

7. What Analysis Would Normally Be Used for a Binary ORR Endpoint?

For a binary endpoint such as ORR, the first statistical quantity is the observed response proportion:

Binary response proportion
p = number of responders / number of evaluable participants

A confidence interval for p can then be calculated using an appropriate binomial method. If a prespecified benchmark response rate exists, a one-sample hypothesis test can compare the observed response proportion with that benchmark.

For a randomized two-group trial, investigators could compare response proportions between treatment groups using a method appropriate to the analysis plan, such as a test of two proportions or a regression model for a binary outcome. That framework is different from STORM's registered non-randomized design.

What an ORR estimate tells you

It describes the proportion of participants meeting the prespecified response criteria within the defined assessment framework.

What an ORR estimate does not tell you

It does not by itself establish causality, durability of benefit, or comparative treatment efficacy.

What a confidence interval tells you

It describes statistical uncertainty around an estimated response proportion under the selected interval method.

What a p-value tells you

It quantifies evidence against a specified null hypothesis; it is not a measure of effect size.

8. Statistical Methodology

Binary endpoint analysis

The primary endpoint is registered as binary. Binary outcomes reduce each participant's endpoint status to one of two outcome categories for the purpose of the primary analysis. For ORR, those categories are response versus no response under the prespecified response-assessment rules.

Independent review

The registered endpoint specifies assessment by an Independent Review Committee (IRC). Independent assessment can reduce the possibility that investigators' knowledge of treatment or other clinical information influences response classification. The ClinicalTrials.gov record does not specify the statistical adjudication procedure used by the IRC.

Time-to-event follow-up in the endpoint definition

Although the primary endpoint itself is binary, the registry defines its assessment window from baseline until disease progression, discontinuation, or death, whichever occurs first. This makes the timing of assessment relevant to determining whether a participant has an opportunity to meet the response criteria.

Non-randomized analysis

Because allocation is registered as non-randomized, a simple response proportion is primarily descriptive. Statistical adjustment can sometimes be used in non-randomized research, but the ClinicalTrials.gov record does not identify an adjustment model, covariates, propensity method, or other causal-inference procedure.

Core distinction
Observed ORR ≠ randomized treatment effect

An observed response proportion describes outcomes among the participants studied. A causal treatment-effect estimate requires additional design or modeling assumptions, particularly when there is no randomized concurrent comparator.

9. Statistical Methods Explained

Why is ORR a binary endpoint?

Overall response rate is based on whether an individual participant meets the prespecified response criteria. The final endpoint therefore has a yes/no structure even though the underlying clinical assessments used to determine response can involve multiple measurements.

Why use an Independent Review Committee?

The registry specifies IRC assessment for the primary endpoint. Independent review provides a standardized assessment mechanism separate from the treating investigator's assessment. This is particularly relevant when tumor response classification determines the endpoint.

How would an ORR normally be summarized?

The basic summary is the number of responders divided by the number of participants included in the relevant analysis population. The result is expressed as a proportion or percentage, accompanied by an appropriate confidence interval when statistical precision is being reported.

Why does non-randomization matter?

Without random assignment, treatment exposure can be associated with baseline characteristics or clinical-selection factors. Consequently, an observed response rate cannot automatically be interpreted as the response rate that would have occurred under a different treatment in the same participants.

What does a confidence interval around ORR mean?

A confidence interval quantifies uncertainty arising from sampling and the selected statistical model or interval procedure. A narrower interval generally indicates greater statistical precision than a wider interval, but neither interval width nor point estimate addresses systematic bias caused by non-randomized treatment allocation.

Why is the assessment time frame important?

The registered endpoint is assessed from baseline until progression, discontinuation, or death. Participants therefore have an assessment history that can end for different reasons. The definition of the analysis population and rules for participants without an evaluable response are important components of any final ORR analysis, but those rules are not reported in the available statistical-analysis data.

10. Analysis Population and Missing Data

The ClinicalTrials.gov record does not provide a statistical-analysis record specifying the primary analysis population, handling of participants who discontinue before response assessment, treatment of unevaluable participants, or missing-data rules.

Analysis issueWhat the ClinicalTrials.gov record establishesStatistical implication
Primary endpointBinary IRC-assessed ORRResponse proportions are the natural descriptive measure
AllocationNon-randomizedObserved response cannot automatically be interpreted causally
Missing response assessmentNot specified in the ClinicalTrials.gov recordDenominator and missing-data handling can affect ORR estimation
Analysis populationNot specified in the ClinicalTrials.gov recordExact responder proportion cannot be reconstructed from the ClinicalTrials.gov record
ImputationNot specifiedNo imputation method should be inferred
Why this matters: For a binary endpoint, the definition of the denominator can materially change the reported response proportion. A statistically careful analysis therefore identifies the evaluable population and the rules for participants without a response assessment before interpreting the percentage.

11. Multiplicity, Interim Analysis, and Bayesian Methods

The ClinicalTrials.gov record does not report a multiplicity-adjustment procedure, alpha-spending strategy, interim-analysis framework, or Bayesian analysis method.

Design topicInformation in the ClinicalTrials.gov record
MultiplicityNo procedure reported
Interim analysisNo statistical interim-analysis method reported
Alpha spendingNot reported
Bayesian methodsNot reported
Non-inferiority marginNot applicable to the registry-reported primary endpoint description
CrossoverNot reported
Factorial designNot reported
Missing-data imputationNot reported

These omissions should not be filled with assumptions. In a statistical review, an unreported method is different from a method that was not used.

12. Safety Results

The ClinicalTrials.gov record provides serious adverse-event counts separately for Part 1 and Part 2. They do not provide a statistical comparison of serious adverse events between interventions.

Study partAffected by serious adverse eventsAt risk
Part 14579
Part 278123

These figures indicate the number of participants affected by serious adverse events and the corresponding number at risk as reported in the ClinicalTrials.gov record. Because the registry information does not identify these counts as randomized treatment-group comparisons, they should not be interpreted as evidence that one intervention has a higher or lower serious-adverse-event rate than another.

Statistical interpretation

A safety comparison would normally begin with event counts and denominators for clearly defined analysis populations. Depending on the design and endpoint definition, investigators could report risks, risk differences, relative risks, odds ratios, incidence rates, or time-to-first-event analyses. None of those formal comparative estimates is included in the ClinicalTrials.gov record.

13. Trial Timeline

2015-05-26

Trial start

The registry identifies May 26, 2015 as the study start date.

2019-07-26

Primary completion

The registry identifies July 26, 2019 as the primary completion date.

Completed

Current registry status in the ClinicalTrials.gov record

The trial is listed as COMPLETED, with 202 participants enrolled.

14. What the Primary Endpoint Does — and Does Not — Mean

Response rate is a proportion

The registered ORR endpoint is the percentage of participants meeting the specified IMWG response criteria. It is therefore a measure of how frequently the prespecified response state was observed within the analyzed population.

Response rate is not survival

ORR does not directly measure how long participants remain alive or free of progression. A response endpoint and a time-to-event endpoint answer different clinical questions and should not be treated as interchangeable.

Response rate is not automatically causal

Because the registry design is non-randomized, the observed response proportion cannot by itself establish the causal effect of selinexor or dexamethasone compared with another treatment.

Precision and validity are different

A very precise response estimate can still be affected by selection bias or other systematic limitations. Confidence intervals address statistical uncertainty; they do not automatically correct for non-randomized treatment allocation.

15. Limitations

16. Why This Trial Matters Statistically

STORM is useful as a teaching example because it illustrates a statistical problem that differs from the more familiar randomized phase 3 setting: how to interpret a clinically important binary response endpoint when treatment allocation is non-randomized and the available registry record does not provide the underlying formal analysis.

ConceptHow it appears in STORM
Binary endpointPrimary endpoint is IRC-assessed overall response rate.
Response criteriaORR is defined according to 2016 IMWG criteria in the registry.
Independent reviewThe primary endpoint specifies assessment by an Independent Review Committee.
Non-randomized designAllocation is registered as NON-RANDOMIZED.
Parallel designThe design model is registered as PARALLEL.
Statistical estimandThe primary registered quantity is the percentage of participants with overall response.
Confidence intervalsWould quantify precision around an estimated response proportion if reported.
Missing dataDenominator and handling rules are not provided in the ClinicalTrials.gov record.
Safety analysisSerious adverse events are reported as affected/at-risk counts by study part.
Causal inferenceNon-randomization limits direct causal interpretation of observed response rates.

17. Related Tutorials

Learn more about the methods used to understand this trial:

18. Related Calculators

19. Sources

Continue through the Clinical Biostats statistical library

Explore tutorials and calculators for binary endpoints, clinical-trial methodology, confidence intervals, and other statistical methods.

20. Record Summary

STORM is a completed phase 2, non-randomized, parallel oncology trial in multiple myeloma with 202 participants and two registered interventions: selinexor and dexamethasone. Its primary registered endpoint is the percentage of participants with an overall response according to 2016 IMWG criteria as assessed by an Independent Review Committee, measured from baseline until disease progression, discontinuation, or death, whichever occurred first.

The key statistical issue is the distinction between describing response and estimating a causal treatment effect. A binary ORR endpoint can be summarized with a response proportion and, when appropriate, a confidence interval. However, the non-randomized design limits causal interpretation, and the ClinicalTrials.gov record does not contain the formal statistical-analysis record needed to report an ORR estimate, confidence interval, or p-value.

The safety information reported with the record consists of serious-adverse-event counts of 45/79 for Part 1 and 78/123 for Part 2. Those figures should be interpreted as registry-reported affected/at-risk counts rather than as a randomized comparative safety analysis.

Clinical Biostats methodology: A rigorous trial-results page should distinguish the endpoint that was registered, the design that generated the data, the statistical analysis actually documented, and the additional interpretation that can reasonably be made from those facts.