WO46063 (optINAVO): Inavolisib in breast cancer
Research type
Research Study
Full title
A PHASE II, RANDOMIZED, OPEN-LABEL STUDY EVALUATING TWO INAVOLISIB DOSE LEVELS IN COMBINATION WITH FULVESTRANT IN PARTICIPANTS WITH PIK3CA-MUTATED, HR-POSITIVE, HER2-NEGATIVE LOCALLY ADVANCED OR METASTATIC BREAST CANCER
IRAS ID
1013121
Contact name
n/a n/a
Contact email
Sponsor organisation
F. Hoffmann-La Roche AG
Research summary
Breast cancer is a leading cause of death in women. While current treatments for HR-positive, HER2-negative breast cancer are effective, there's a need for new options to prevent drug resistance.
The purpose of this study is to compare the effects, good or bad, of two drugs - inavolisib and fulvestrant. In this study, two dose levels of inavolisib are being explored.
Inavolisib is an experimental drug, which means health authorities have not approved inavolisib in combination with fulvestrant for the treatment of HR-positive, HER2-negative advanced or metastatic breast cancer, or for any other indication.
Who Can Join?
This study is for adults (18+) with advanced or metastatic HR-positive, HER2-negative breast cancer with a PIK3CA mutation. You must also meet specific health criteria.
You may not be able to join if you have certain health conditions, recent severe infections, serious heart or liver problems, or if you are pregnant or breastfeeding.
How the Study Works
You will be placed into one of two groups:
• Arm A: Inavolisib (9mg tablet daily) plus fulvestrant injections.
• Arm B: Inavolisib (6mg tablets daily) plus fulvestrant injections.
Both groups will receive the same amount of fulvestrant. You'll keep a daily diary of your medications.
You will continue to receive inavolisib and fulvestrant on a regular basis until your breast cancer worsens. Your total time in the study will depend on how your breast cancer responds to treatment but may be from 1 day to more than 2 years.
What We Are Measuring
The main goal is to measure how well inavolisib works and its safety. We'll look at how many participants respond positively to the treatment and track side effects like high blood sugar, mouth sores, or diarrhoea. We'll also measure how long the treatment works before the cancer progresses. The study medicine is experimental, and its full safety profile is not yet known
Approximately 80 people worldwide will participate, 8 from the UKREC name
South West - Central Bristol Research Ethics Committee
REC reference
25/SW/0130
Date of REC Opinion
18 Nov 2025
REC opinion
Further Information Favourable Opinion