Solid Tumors CNS Tumors Phase 1/2 NCT02650401

STARTRK-NG: Complete Statistical Analysis of Entrectinib in Pediatric Solid and CNS Tumors

An independent statistical review of STARTRK-NG, a phase 1/2 single-group study evaluating entrectinib in children and adolescents with locally advanced or metastatic solid tumors and/or primary CNS tumors who have no satisfactory treatment options.

Scope of this record

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

69
Enrollment
1
Treatment Group
7
Arms
1/2
Phase
FeatureSTARTRK-NG
InterventionEntrectinib
DesignNon-randomized, single-group
MaskingNone
Primary purposeTreatment
StatusActive, not recruiting
SponsorHoffmann-La Roche
Start date2016-05-03
Primary completion date2026-06-30

2. Clinical Question

Population

Children and adolescents with locally advanced or metastatic solid tumors and/or primary CNS tumors and no satisfactory treatment options.

Intervention

Entrectinib.

Comparator

No comparator arm. The study uses a single-group design.

Primary question

What dose levels and recommended phase 2 doses can be identified, and what objective response rates are observed in specified cohorts?

3. Trial Design

STARTRK-NG is a phase 1/2, non-randomized, open-label, single-group treatment study. The registry reports 69 participants and seven arms evaluating different pediatric formulations and dosing approaches of entrectinib.

Design elementDescription
AllocationNon-randomized
ModelSingle group
MaskingNone
Arms7

4. Endpoints

EndpointTime frameAssessment
Maximum Tolerated Dose (MTD)Approximately 6 monthsNCI CTCAE v4.03
RP2D of F1 formulation in pediatric participants able to swallow intact capsulesApproximately 6 monthsNCI CTCAE v4.03
RP2D of F06 formulation in pediatric participants able to swallow intact capsulesApproximately 6 monthsNCI CTCAE v4.03
RP2D of F06 formulation in pediatric participants dosed via feeding tubeApproximately 6 monthsNCI CTCAE v4.03
RP2D of Minitablets/F15 formulationApproximately 6 monthsNCI CTCAE v4.03
Cohort B Objective Response RateApproximately 6 monthsRANO per BICR
Cohort D Objective Response RateApproximately 6 monthsRECIST v1.1 per BICR

5. Planned Analysis

The ClinicalTrials.gov record lists primary endpoints but does not report posted statistical analyses or outcome results.

For dose-finding endpoints such as Maximum Tolerated Dose and Recommended Phase 2 Dose, analysis generally focuses on observed adverse events, dose-limiting toxicities, and tolerability patterns assessed using predefined toxicity criteria.

For objective response rate, analysis typically summarizes the proportion of participants achieving a complete or partial response according to the specified response assessment framework. Confidence intervals may be used to describe precision around the estimated response proportion.

6. Statistical Methodology

Dose escalation and tolerability assessment

Phase 1 oncology studies commonly use structured dose evaluation approaches to identify doses that provide acceptable tolerability. The key statistical challenge is balancing limited participant numbers with the need to characterize toxicity across dose levels.

Objective response rate analysis

Objective response rate is a binary endpoint: each participant is classified according to whether a prespecified response criterion is achieved. Unlike time-to-event endpoints, ORR does not directly describe duration of benefit.

Clinical Biostats interpretation

A response proportion answers the question of how many evaluated participants met the response definition. It does not by itself measure survival, durability, comparative benefit, or superiority versus another treatment because STARTRK-NG does not include a randomized comparator.

7. Statistical Methods Explained

Why is this trial not analyzed like a randomized phase 3 trial?

The study uses a single-group design, so treatment comparisons between randomized groups are not available. Interpretation focuses on dose selection, safety, and observed activity within defined cohorts.

What does Maximum Tolerated Dose measure?

MTD summarizes the highest evaluated dose considered tolerable under the study's toxicity assessment framework. It is a dose-selection endpoint rather than an efficacy endpoint.

Why is Objective Response Rate different from survival?

ORR measures tumor response status at assessment points, whereas survival endpoints measure time until an event such as death. They describe different aspects of treatment effect.

Why are confidence intervals important for response rates?

A confidence interval describes uncertainty around an estimated response proportion. Small studies can produce imprecise estimates even when the observed response proportion appears notable.

8. Limitations

9. Why This Trial Matters Statistically

STARTRK-NG illustrates several important concepts in early-phase clinical trial statistics.

ConceptApplication
Early-phase designDose selection and tolerability assessment
Single-group analysisInterpretation without randomized comparison
Safety endpointsUse of standardized toxicity criteria
Response endpointsAssessment using RANO and RECIST frameworks

10. Sources