Letrozole / Inavolisib / Breast Cancer · Phase 3 Trial

A Study Evaluating the Efficacy and Safety of Inavolisib Plus CDK4/6 Inhibitor and Letrozole vs Placebo + CDK4/6i and Letrozole in Participants With Endocrine-Sensitive PIK3CA-Mutated, Hormone Receptor-Positive, HER2-Negative Advanced Breast Cancer

ClinicalTrials.gov · August 5, 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 Phase 3 randomized trial registration evaluating inavolisib (a PI3K inhibitor) combined with CDK4/6 inhibitor and letrozole versus placebo plus CDK4/6 inhibitor and letrozole in first-line PIK3CA-mutated, HR+/HER2− advanced breast cancer. No efficacy or safety results are reported in this registry record; the trial is currently recruiting.

What was studied

Phase 3, Interventional, Randomized, Parallel, Double masking, Treatment purpose. Breast Cancer; age from 18 Years. Intervention: Inavolisib + Letrozole + CDK4/6i. Compared with: Placebo + Letrozole + CDK4/6i — Placebo Comparator. n = 450. 239 sites across 20 countries.

Key findings

Safety

This registry record reports no study results; efficacy, safety, and benefit cannot be assessed.

Who this may help

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

Plain-language summary

This is a Phase 3 trial registration with no posted results; efficacy and safety cannot be assessed from registry data alone.

Study design

As stated by the source record.

MethodsPrimary outcome measure: Progression-Free Survival (PFS) (assessed at From randomization to the first occurrence of disease progression or death from…)

DesignPhase 3, Interventional, Randomized, Parallel, Double masking, Treatment purpose

PopulationBreast Cancer; age from 18 Years

Sample size450

InterventionInavolisib + Letrozole + CDK4/6i

ComparatorPlacebo + Letrozole + CDK4/6i — Placebo Comparator

Setting239 sites across 20 countries

Reported figures

Quoted from the source exactly as published.

Planned enrollment450

PhasePhase 3

Primary outcome measureProgression-Free Survival (PFS), from randomization to first occurrence of disease progression or death from any cause, whichever occurs first (up to 7 years)

Caveats

This registry record reports no study results; efficacy, safety, and benefit cannot be assessed.
Recruitment status is active; trial is not complete.
Blinding strategy not specified in registry text.
Follow-up duration specified for primary outcome (up to 7 years) but study completion timeline not stated.

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

strong

Phase 3 randomized controlled trial with placebo comparator reported.

Directness

strong

First-line advanced breast cancer with PIK3CA mutation; directly addresses clinical population.

Consistency

insufficient

Registry record only; no results posted for consistency assessment.

Risk of bias

insufficient

Randomized and placebo-controlled design suggested; blinding not stated in registry.

Sample adequacy

moderate

Estimated 450 participants planned; sample size adequate for Phase 3 but enrollment 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 (NCT06790693). This is a study registration, not published results. Lead sponsor: Hoffmann-La Roche. Recruitment status: RECRUITING. Phase: PHASE3. Study type: INTERVENTIONAL. Enrollment: 450 participants (ESTIMATED). Conditions: Breast Cancer. Interventions: DRUG: Inavolisib; DRUG: Placebo; DRUG: CDK4/6i; DRUG: Letrozole. Primary outcome measures: Progression-Free Survival (PFS) , From randomization to the first occurrence of disease progression or death from any cause, whichever occurs first (up to 7 years). Brief summary: This study will evaluate the efficacy and safety of the combination of inavolisib plus a cyclin-dependent kinase 4 and 6 inhibitor (CDK4/6i) and letrozole versus placebo plus a CDK4/6i and letrozole in the first-line setting in participants with endocrine-sensitive PIK3CA-mutated hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-), advanced breast cancer (ABC).

Follow from this

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

NCT06790693LetrozoleInavolisibBreast CancerCDK4/6iHoffmann-La Roche