Trial results
AI generated results summary. Written by an AI model from the official source data and checked on a sample basis. It can contain mistakes, so confirm anything important against the original source. How we use AI
According to the results reported on ClinicalTrials.gov, this trial (NCT01958021) enrolled 334 people in the ribociclib plus letrozole group and 334 people in the placebo plus letrozole group — 668 participants in total. The trial was measuring how long people lived without their cancer growing or spreading (called "progression-free survival"), as well as a range of secondary measures including how long people lived overall, how many people's tumours shrank, and how participants' daily functioning and quality of life changed over time. The reported data shows that for the main measure — time until cancer progression or death — the median figure for the placebo plus letrozole group was 14.7 months, while a median figure for the ribociclib plus letrozole group was not reported (listed as "NA" in the data, which can occur when more than half of participants in that group had not yet reached that point during follow-up). For overall survival, the reported median was 63.9 months in the ribociclib plus letrozole group and 51.4 months in the placebo plus letrozole group. When looking at tumour response, 40.7% of participants in the ribociclib plus letrozole group and 27.5% in the placebo plus letrozole group were reported to have their tumour shrink or disappear. A broader measure — including those whose disease stayed stable for at least 24 weeks — was reported at 79.6% and 72.8% respectively. The reported data also shows that for the time until participants' daily functioning noticeably declined (by at least one step on a standard scale), the ribociclib plus letrozole group had a reported median of 22.6 months, while a median for the placebo plus letrozole group was not reported. Similarly, the time until a meaningful drop in self-reported quality of life was recorded had a median of 19.3 months in the ribociclib plus letrozole group, while the figure for the placebo plus letrozole group was not reported in the data. These are the results as reported to ClinicalTrials.gov. They are not medical advice — always discuss what they mean for you with your doctor.
These are the results as reported to ClinicalTrials.gov, not medical advice. Verify independently with the trial site and discuss what they mean for you with your doctor.
Phase 3 Breast Cancer Trial, Completed
voxsanity.com.au · Eligibility summary from public government registries · 18 August 2026 · not medical advice
Who may and may not be able to join
AI generated eligibility summary. Written by an AI model from the official source data and checked on a sample basis. It can contain mistakes, so confirm anything important against the original source. How we use AI
Who may be able to join
- You are a woman with advanced breast cancer (either spread to other parts of the body, or returned in the local area) that cannot be cured.
- You have gone through menopause — either naturally (based on age or periods stopping for 12+ months), or because you had both ovaries surgically removed.
- You have not yet received any systemic (whole-body) treatment, such as chemotherapy or hormone therapy, for your advanced breast cancer.
- Your breast cancer has been confirmed by a lab test to be estrogen-receptor positive and/or progesterone-receptor positive.
- Your breast cancer has been confirmed by a lab test to be HER2-negative.
- You have at least one area of cancer that can be measured on a scan, or at least one bone lesion of a specific type (confirm with trial site).
- Your general health and ability to carry out daily activities is rated at a good level (ECOG score of 0 or 1 — confirm with trial site).
Who may not be able to join
Each point below is a reason the trial team may not be able to accept someone. It is not a list of requirements to meet.
- You have previously taken a CDK4/6 inhibitor medication (confirm with trial site for examples).
- You have already received systemic treatment (such as chemotherapy or hormone therapy) for your advanced breast cancer — though short-term use of certain hormone therapies (14 days or less) may be allowed (confirm with trial site).
- You are currently taking another anti-cancer treatment at the same time.
- You have had another cancer within the past 3 years, with some exceptions such as certain treated skin cancers or cervical cancer that was fully removed.
- You have active heart problems or a significant history of heart issues, including heart attacks, heart failure, irregular heartbeats, cardiomyopathy, low heart pumping function, or abnormal heart readings on a screening test.
- Your blood pressure at screening is too high (above 160) or too low (below 90) (confirm with trial site for units).
- You are currently taking certain medications that cannot be stopped at least 7 days before starting the trial, including some that affect how the body processes drugs, affect heart rhythm, or include herbal supplements (confirm with trial site for specific medications).
Important: Always verify eligibility with the trial site directly before applying.
Based on publicly available eligibility criteria from ClinicalTrials.gov. Verify directly with the trial site before acting. This is not medical advice.
GP referral letter
Print a one-page summary to share with your doctor.
Trial details
Where this trial was run
These are the locations recorded on the registry, including 3 in Australia. They are a historical record: this trial is not enrolling, so they are not places you can join it.
Primary endpoints
Progression Free Survival (PFS) by Investigator Assessment
Other options
Data last synced from ClinicalTrials.gov: 1 July 2026. Trial status can change. Always verify current status directly with the trial site before making any decision.