Ribociclib / Ansastrozole / Letrozole · Phase 3 Trial

Phase IIIb Study of Ribociclib + ET in Early Breast Cancer

ClinicalTrials.gov · August 18, 2026

Preliminary Why this matters to you Expert discussion

Early or partial results. Treat as a signal, not a conclusion.

AI Summary

This is a clinical trial registry record for a phase IIIb, open-label, single-arm study of ribociclib combined with endocrine therapy in early breast cancer. No results have been posted to the registry; the study is currently recruiting. Any judgment of efficacy or safety is premature.

What was studied

Phase 3, Interventional, Single Group, Open label, Treatment purpose. Early Breast Cancer; age from 18 Years; to 100 Years. Intervention: Ribociclib + endocrine therapy. n = 1,400. 228 sites across 16 countries.

Key findings

Safety

Safety was not reported in the material analysed. Check the source before drawing any conclusion about harm.

Who this may help

The source did not state who this applies to in practice.

Plain-language summary

This is a trial registration with no posted results; the study is actively recruiting and outcome data are not yet available for assessment.

Study design

As stated by the source record.

MethodsPrimary outcome measure: Invasive Breast Cancer Free Survival (iBCFS) rate at 3 years (assessed at At 3 years)

DesignPhase 3, Interventional, Single Group, Open label, Treatment purpose

PopulationEarly Breast Cancer; age from 18 Years; to 100 Years

Sample size1,400

InterventionRibociclib + endocrine therapy

Setting228 sites across 16 countries

Reported figures

Quoted from the source exactly as published.

Planned enrollment1400

Primary outcome measureInvasive Breast Cancer Free Survival (iBCFS) rate at 3 years

Study phasePhase IIIb

Caveats

Registry record contains no outcome data; results are not yet reported.
Single-arm design without control group limits interpretation of efficacy.
Study is open-label, introducing bias risk.
Recruitment status is active; final data unavailable.

Evidence assessment

Graded across the dimensions that decide whether you should act, each from what the source actually supports. There is no single score, and where a dimension was not assessed it says so.

Study design

moderate

Open-label, multicenter, phase IIIb, single-arm design; lacks control arm.

Directness

moderate

Hard clinical endpoint (invasive breast cancer-free survival); pragmatic population described as close to clinical practice.

Consistency

insufficient

No results posted; consistency cannot be assessed against other trials or this trial's own data.

Risk of bias

limited

Open-label design without control arm introduces bias risk; no blinding reported.

Sample adequacy

moderate

Estimated 1400 participants enrolled; sample size appears adequate for phase IIIb, but recruitment ongoing.

What is missing. This record has no key findings. That is a gap in the analysis, not a judgement about the study.

Source abstract

Registry record from ClinicalTrials.gov (NCT05827081). This is a study registration, not published results. Lead sponsor: Novartis Pharmaceuticals. Recruitment status: RECRUITING. Phase: PHASE3. Study type: INTERVENTIONAL. Enrollment: 1400 participants (ESTIMATED). Conditions: Early Breast Cancer. Interventions: DRUG: Ribociclib; DRUG: Letrozole; DRUG: Ansastrozole; DRUG: Goserelin; DRUG: Leuprolide; DRUG: Exemestane. Primary outcome measures: Invasive Breast Cancer Free Survival (iBCFS) rate at 3 years , At 3 years. Brief summary: The purpose of this open-label, multicenter, phase IIIb, single-arm study is to characterize the efficacy and safety of the combination of ribociclib and standard adjuvant endocrine therapy (ET) on invasive breast cancer-free survival (iBCFS), in a close to clinical practice patient population with HR-positive (HR+), HER2-negative (HER2-), Anatomic Stage Group III, IIB, and a subset of Stage IIA Early Breast Cancer (EBC).

Follow from this

Taken from the source record, never inferred. Follow any of these and new work involving them reaches your briefing.

NCT05827081RibociclibAnsastrozoleLetrozoleEarly Breast CancerGoserelinNovartis Pharmaceuticals