Phase III Randomized Study of Ribociclib and Fulvestrant in Hormone Receptor–Positive, Human Epidermal Growth Factor Receptor 2–Negative Advanced Breast Cancer: MONALEESA-3
- Study type
- Clinical trial
- Study name
- MONALEESA-3
- Phase
- Phase 3
- Design
- Randomised, placebo-controlled trial (2:1 randomisation)
- Sample size
- 726 postmenopausal women (484 in the ribociclib plus fulvestrant group and 242 in the placebo plus fulvestrant group)
- Source
- JCO · 2018
In plain words
In this study, women past menopause with advanced hormone-sensitive breast cancer (hormone receptor-positive and HER2-negative) received either the drug ribociclib with fulvestrant, or an inactive placebo with fulvestrant. Adding ribociclib lengthened the time the disease stayed under control without getting worse, from a typical 12.8 months to 20.5 months. The most common serious side effect was a drop in white blood cells (neutropenia), which was more frequent with this drug and needs regular blood tests.
Key results
Treatment arms and regimens
Ribociclib plus fulvestrant — 484 patients.
Ribociclib 600 mg orally daily, days 1 to 21 every 28 days + fulvestrant 500 mg intramuscularly on day 1 of each cycle and day 15 of cycle 1; until progression or unacceptable toxicity.
Placebo plus fulvestrant — 242 patients.
Placebo on days 1 to 21 every 28 days + fulvestrant 500 mg on the same schedule.
Source of the regimen details: ClinicalTrials.gov NCT02422615 and the FDA label for Kisqali (DailyMed, section 14)
Doses are given for the information of specialists, as in this study’s protocol, and are not a prescription. Every drug must be prescribed by the treating physician for the individual patient.
Study population
Patients with hormone receptor-positive, HER2-negative advanced breast cancer who were treatment-naïve in the advanced setting or had received up to one line of prior endocrine therapy for advanced disease. Enrolled patients were postmenopausal women.
Endpoints
Primary endpoint: locally assessed progression-free survival (PFS). Secondary endpoints: overall survival, overall response rate and safety.
Safety and side effects
Grade 3 adverse events with an incidence of ≥10% in either arm (ribociclib plus fulvestrant versus placebo plus fulvestrant): neutropenia 46.6% versus 0% and leucopenia 13.5% versus 0%. The only grade 4 adverse event with an incidence of ≥5% was neutropenia (6.8% versus 0%).
Clinical significance and place in guidelines
Based on the abstract, ribociclib plus fulvestrant may be a new first-line or second-line treatment option for hormone receptor-positive/HER2-negative advanced breast cancer, with a significant PFS improvement seen both in treatment-naïve patients and in those with up to one prior line of endocrine therapy. Regulatory approvals and guideline recommendations should be checked separately, as they are not mentioned in the abstract.
Limitations
The abstract covers only PFS and response results and reports no overall survival data. The study population was limited to postmenopausal women. The primary endpoint was assessed locally. Further details should be checked in the full text.
This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.