Adults 18 to 100, female only, with Advanced, Metastatic Breast Cancer. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Progression Free Survival (PFS) by Investigator AssessmentPrimary· Up to 23 months
PFS was defined as the period starting from the date of randomization to the date of the first documented progression or death caused by any reason. In cases where patients did not experience an event, the PFS was censored at the date of the last adequate tumor assessment. Clinical deterioration without objective radiological evidence was not considered as documented disease progression.PFS was assessed by investigator assessment according to RECIST 1.1. The Kaplan-Meier method was used to estimate PFS, and the median PFS, along with 95% confidence intervals, was reported for each treatment gr
Group
Value
95% CI
Ribociclib + Letrozole
NA
19.3 – NA
Placebo + Letrozole
14.7
13.0 – 16.5
Overall Survival (OS)Secondary· Up to approximately 87 months
OS was defined as the time from the date of randomization to the date of death from any cause. In cases where the patient's death was not recorded, the OS value was censored at the date of the last known patient's survival status.OS was estimated using the Kaplan-Meier method. As per protocol, the final OS analysis was conducted after approximately 400 deaths were documented.
The median OS, along with 95% confidence intervals, was reported for each treatment group.The distribution of OS between the two treatment arms was compared using a log-rank test at one-sided cumulative 2.5% level of sig
Group
Value
95% CI
Ribociclib + Letrozole
63.9
52.4 – 71.0
Placebo + Letrozole
51.4
47.2 – 59.7
Overall Response Rate (ORR) by Investigator AssessmentSecondary· Up to 23 months
ORR is the percentage of participants with the best overall response of complete response (CR) or partial response (PR) according to RECIST 1.1 as per investigator assessment. . CR = Disappearance of all non-nodal target lesions. In addition, any pathological lymph nodes assigned as target lesions must have a reduction in short axis to \< 10 mm; PR = At least a 30% decrease in the sum of diameter of all target lesions, taking as reference the baseline sum of diameters.
Group
Value
95% CI
Ribociclib + Letrozole
40.7
35.4 – 46.0
Placebo + Letrozole
27.5
22.8 – 32.3
Clinical Benefit Rate (CBR) by Investigator AssessmentSecondary· Up to 23 months
Percentage of participants with complete response (CR) or partial response (PR) or stable disease (SD) lasting 24 weeks or longer as defined in RECIST 1.1 as per investigator assessment. CR = Disappearance of all non-nodal target lesions. In addition, any pathological lymph nodes assigned as target lesions must have a reduction in short axis to \< 10 mm; PR = At least a 30% decrease in the sum of diameter of all target lesions, taking as reference the baseline sum of diameters; SD = Neither sufficient shrinkage to qualify for PR or CR nor an increase in lesions which would qualify for progress
Group
Value
95% CI
Ribociclib + Letrozole
79.6
75.3 – 84.0
Placebo + Letrozole
72.8
68.0 – 77.5
Time to Definitive Deterioration of Eastern Cooperative Oncology Group Performance Status (ECOG PS) by at Least One Category of the ScoreSecondary· From baseline up to 23 months
ECOG PS categorized patients based on their ability to perform daily activities and self-care, with scores ranging from 0 to 5. A score of 0 indicated no restrictions in activity, while higher scores indicated increasing limitations. Time to definitive deterioration was defined as the time from the date of randomization to the date of the event, defined as experiencing an increase in ECOG PS by at least one category from the baseline or death. A deterioration was considered definitive if no improvements in the ECOG PS were observed at a subsequent time. The Kaplan-Meier method was used to esti
Group
Value
95% CI
Ribociclib + Letrozole
22.6
22.6 – NA
Placebo + Letrozole
NA
NA – NA
Time to Definitive 10% Deterioration in the Global Health Status/Quality of Life (GHS/QoL) Scale Score of the European Organization for Research and Treatment of Cancer's Core Quality of Life Questionnaire (EORTC QLQ-C30)Secondary· From baseline up to 23 months
The EORTC QLQ-C30 is a questionnaire that includes 5 functional scales, 3 symptom scales, 1 GHS/QoL scale, and 6 single items. GHS/QoL scale score ranges between 0 and 100. A high score for GHS/QoL represents better functioning or QoL.The time to definitive 10% deterioration is defined as the time from the date of randomization to the date of event, which is defined as at least 10% relative to baseline worsening of the QoL score (without further improvement above the threshold) or death due to any cause. The Kaplan-Meier method was used to estimate the distribution, and the median time to defi
Group
Value
95% CI
Ribociclib + Letrozole
19.3
16.6 – 22.1
Placebo + Letrozole
NA
14.8 – NA
Change From Baseline in the GHS/QoL Scale Score of the EORTC QLQ-C30Secondary· Baseline, every 2 cycles for 18 months, then every 3 cycles until last dose; at EOT (within 15 days from last dose);every 8 or 12 weeks post-treatment until progression (post-treatment efficacy visits), assessed up to 23 months. Cycle=28 days
The EORTC QLQ-C30 is a questionnaire that includes 5 functional scales, 3 symptom scales, 1 GHS/QoL scale, and 6 single items. GHS/QoL scale score ranges between 0 and 100. A high score for GHS/QoL represents better functioning or QoL.The change from baseline in the GHS/QoL score was assesed. A positive change from baseline indicated improvement.
For subjects who discontinued treatment earlier and without disease progression, post-treatment efficacy follow-up visits occurred every 8 weeks after End of treatment (EOT) during the initial 18 months since start of treatment, followed by visits ev
Cycle 3 Day 1
Group
Value
95% CI
Ribociclib + Letrozole
2.9
± 18.68
Placebo + Letrozole
4.9
± 19.14
Cycle 5 Day 1
Group
Value
95% CI
Ribociclib + Letrozole
4.6
± 19.86
Placebo + Letrozole
6.8
± 19.64
Cycle 7 Day 1
Group
Value
95% CI
Ribociclib + Letrozole
4.6
± 20.96
Placebo + Letrozole
6.0
± 20.19
Cycle 9 Day 1
Group
Value
95% CI
Ribociclib + Letrozole
5.1
± 21.95
Placebo + Letrozole
8.0
± 20.49
Cycle 11 Day 1
Group
Value
95% CI
Ribociclib + Letrozole
4.9
± 21.11
Placebo + Letrozole
7.0
± 20.45
Cycle 13 Day 1
Group
Value
95% CI
Ribociclib + Letrozole
5.3
± 22.37
Placebo + Letrozole
6.5
± 20.40
Cycle 15 Day 1
Group
Value
95% CI
Ribociclib + Letrozole
5.5
± 21.43
Placebo + Letrozole
8.7
± 21.23
Cycle 17 Day 1
Group
Value
95% CI
Ribociclib + Letrozole
4.6
± 22.85
Placebo + Letrozole
7.4
± 21.75
All Collected DeathsSecondary· Pre-treatment: Up to 21 days. On-treatment: Up to 99 months. Crossover on-treatment: Up to 12 months after crossing-over.Post-treatment survival FU: Up to 99 months.Crossover post-treatment survival FU: Up to 12 months after crossing-over
Pre-treatment deaths were collected from randomization to the day before first dose of study medication.
On-treatment deaths were collected from start of treatment to 30 days after last dose of treatment or one day before first administration of crossover treatment (for crossover participants), whichever came first Crossover on-treatment deaths were collected from start of crossover treatment up to 30 days after last dose of crossover treatment.
Post-treatment survival follow-up (FU) deaths were collected from day 31 after last dose of study treatment to end of study.
Crossover post-treatme
Pre-treatment
Group
Value
95% CI
Ribociclib + Letrozole
0
Placebo + Letrozole
0
On-treatment
Group
Value
95% CI
Ribociclib + Letrozole
8
Placebo + Letrozole
3
Crossover On-treatment
Group
Value
95% CI
Placebo + Letrozole
0
Post-treatment survival follow-up
Group
Value
95% CI
Ribociclib + Letrozole
178
Placebo + Letrozole
218
Crossover post-treatment survival follow-up
Group
Value
95% CI
Placebo + Letrozole
0
All deaths
Group
Value
95% CI
Ribociclib + Letrozole
186
Placebo + Letrozole
221
Adverse events — posted to ClinicalTrials.gov
Time frame: All-cause mortality (ACM): from randomization up to 99 months, including post-treatment survival follow-up (FU). If crossover, ACM also collected from start of crossover treatment to 12 months, including post-treatment survival FU. Serious and Other Adverse Events (AEs): from 1st dose of treatment to 30 days after last dose (or start of crossover treatment), up to 99 months. If crossover, AEs also collected from start of crossover treatment to 30 days post-crossover treatment, up to 12 months.
Reporting threshold: 5%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
The primary purpose of this study was to assess the efficacy of ribociclib, as measured by progression free survival (PFS), in postmenopausal women with hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer who received no prior treatment for advanced disease.
Publications & conference data
8 peer-reviewed publications reference this trial (live from Europe PMC):
NCT07492641 — BGB-43395 Plus Letrozole Versus CDK4/6i Plus Letrozole for Patients With Advanced or Metastatic HR+/HER2- Breast Cancer
· Phase 3
· not yet recruiting
NCT07405801 — A Phase II Study Evaluating the Efficacy and Safety of Inavolisib Plus Ribociclib Plus Fulvestrant Versus Placebo Plus R
· Phase 2
· recruiting
NCT06905301 — Implementation Study to Describe and Compare Retention Rate and Adherence to Adjuvant Therapy With Ribociclib With and W
· recruiting
NCT06930859 — Non-interventional Study to Assess the Effectiveness and Safety of Ribociclib in the Adjuvant Therapy of Hormone Recepto
· recruiting
NCT07054190 — A Study to Test Inavolisib Treatments in Participants With Early-Stage, PIK3CA-Mutated Breast Cancer
· Phase 2
· recruiting
Other Novartis Pharmaceuticals trials
Trials by the same sponsor.
NCT07498335 — Study to Assess the Efficacy, Pharmacokinetics, Safety and Tolerability of Atrasentan in Pediatric Patients With Primary
· Phase 3
· not yet recruiting
NCT07489573 — Study of Efficacy and Safety of Secukinumab in Chinese Adult Patients With Moderate to Severe Hidradenitis Suppurativa
· Phase 4
· not yet recruiting
NCT07484269 — PULSE Registry: for Patients Receiving Lutetium (177Lu) Vipivotide Tetraxetan
· not yet recruiting
NCT07416162 — A Study of Iptacopan in Korean Patients With Paroxysmal Nocturnal Hemoglobinuria or C3 Glomerulopathy
· not yet recruiting
NCT07387926 — Safety and Efficacy of Asciminib in Pediatrics and Young Adults With Relapse/Refractory (r/r) Philadelphia Positive (Ph+
· Phase 1, PHASE2
· not yet recruiting
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Novartis Pharmaceuticals
Last refreshed: 7 March 2025
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT01958021.