Ribociclib plus endocrine therapy for premenopausal women with hormone-receptor-positive, advanced breast cancer (MONALEESA-7): a randomised phase 3 trial
A newer report of this study has been published: Overall Survival with Ribociclib plus Endocrine Therapy in Breast Cancer (2019)
- Study type
- Clinical trial
- Study name
- MONALEESA-7
- Phase
- Phase 3
- Design
- Multicentre, randomised, double-blind, placebo-controlled trial (188 centres in 30 countries)
- Sample size
- 672 patients (335 in the ribociclib group and 337 in the placebo group)
- Source
- The Lancet Oncology · 2018
- Trial registration
- NCT02278120
In plain words
This study was done in women before menopause who had advanced hormone receptor-positive breast cancer. Adding the oral drug ribociclib to hormone therapy lengthened the time without the disease getting worse, typically from 13 months to about 24 months. The most common serious side effect of this drug was a drop in white blood cells, which can be managed with regular blood tests. Whether this treatment is right for a given patient should be decided by the treating doctor, based on that patient's situation.
Key results
Treatment arms and regimens
Oral ribociclib 600 mg per day on a 3-weeks-on, 1-week-off schedule, plus one of two options: oral tamoxifen 20 mg daily, or a non-steroidal aromatase inhibitor, letrozole 2.5 mg or anastrozole 1 mg orally daily. All patients received goserelin 3.6 mg subcutaneously on day 1 of each 28-day cycle.
Matching placebo plus the same endocrine therapy (tamoxifen 20 mg daily or letrozole 2.5 mg or anastrozole 1 mg daily) and goserelin 3.6 mg subcutaneously on day 1 of each 28-day cycle.
Source of the regimen details: Abstract of the paper
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
Premenopausal women aged 18 to 59 years with histologically or cytologically confirmed hormone receptor (HR)-positive, HER2-negative advanced breast cancer. Other inclusion criteria: ECOG performance status 0 or 1; measurable disease by RECIST version 1.1 or at least one predominantly lytic bone lesion; and no prior treatment with cyclin-dependent kinase 4/6 (CDK4/6) inhibitors. Endocrine therapy and chemotherapy in the adjuvant or neoadjuvant setting, and up to one line of chemotherapy for advanced disease, were allowed.
Endpoints
Primary endpoint: investigator-assessed progression-free survival (PFS). Efficacy analyses were by intention to treat, and the safety analysis included all patients who received at least one dose of any study treatment.
Safety and side effects
Grade 3 or 4 adverse events reported in more than 10% of patients in either group were neutropenia (61% versus 4%) and leucopenia (14% versus 1%). Serious adverse events occurred in 18% of the ribociclib group and 12% of the placebo group; of these, 4% and 2% were attributed to the study regimen. Discontinuation due to adverse events occurred in 4% of the ribociclib group and 3% of the placebo group. There were no treatment-related deaths. A total of 11 deaths occurred during treatment or up to 30 days afterwards (5 [1%] in the ribociclib group and 6 [2%] in the placebo group), most due to progression of the underlying breast cancer (3 [1%] and 6 [2%]). The two remaining deaths in the ribociclib group were due to intracranial haemorrhage in a patient on anticoagulation and haemorrhage from a pre-existing wound in another patient.
Clinical significance and place in guidelines
Per the abstract's conclusion, ribociclib plus endocrine therapy may be a new first-line treatment option for premenopausal women with HR-positive, HER2-negative advanced breast cancer. The abstract gives no information on regulatory approvals or guideline recommendations; current guideline and approval status should be checked separately.
Limitations
The primary endpoint was investigator-assessed. Overall survival results are not reported in the abstract. The abstract does not report separate comparisons of the combination with tamoxifen and with an aromatase inhibitor. The study was funded by Novartis.
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.