18 and older, female only, with Advanced Breast Cancer Female. 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.
Number of Participants With All-causality Treatment-emergent Adverse Events (TEAEs)Primary· 3 years
An adverse event (AE) was any untoward medical occurrence in a clinical investigation participant administered a product; the event did not need to have a causal relationship with the treatment. All AEs reported after initiation of study drug treatment were considered as TEAE. AE severity was graded according to Common Terminology Criteria for AEs (CTCAE) version 4.03. Grade 1 AEs are mild AEs; Grade 2 AEs are moderate AEs; Grade 3 AEs are severe AEs, Grade 4 AEs are life-threatening consequences and Grade 5 AEs are deaths related to AEs. Each AE was counted once for the participant in the mos
Grade 1
Group
Value
95% CI
Palbociclib+Letrozole
0
Grade 2
Group
Value
95% CI
Palbociclib+Letrozole
17
Grade 3
Group
Value
95% CI
Palbociclib+Letrozole
82
Grade 4
Group
Value
95% CI
Palbociclib+Letrozole
23
Grade 5
Group
Value
95% CI
Palbociclib+Letrozole
7
Number of Participants With Palbociclib-related TEAEsPrimary· 3 years
An AE was any untoward medical occurrence in a clinical investigation participant administered a product; the event did not need to have a causal relationship with the treatment. All AEs reported after initiation of study drug treatment were considered as TEAE. AE severity was graded according to CTCAE version 4.03. Grade 1 AEs are mild AEs; Grade 2 AEs are moderate AEs; Grade 3 AEs are severe AEs, Grade 4 AEs are life-threatening consequences and Grade 5 AEs are deaths related to AEs. Palbociclib-related TEAEs were determined by the investigator.
Grade 1
Group
Value
95% CI
Palbociclib+Letrozole
2
Grade 2
Group
Value
95% CI
Palbociclib+Letrozole
25
Grade 3
Group
Value
95% CI
Palbociclib+Letrozole
81
Grade 4
Group
Value
95% CI
Palbociclib+Letrozole
20
Grade 5
Group
Value
95% CI
Palbociclib+Letrozole
0
Number of Participants With Serious Adverse Events (SAEs)Primary· 3 years
An SAE was any untoward medical occurrence at any dose that resulted in death; was life threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability/incapacity; resulted in congenital anomaly/birth defect. AEs included both SAEs and AEs. Palbociclib-related SAEs were determined by the investigator.
All-causality
Group
Value
95% CI
Palbociclib+Letrozole
32
Palbociclib-related
Group
Value
95% CI
Palbociclib+Letrozole
6
Number of Participants With DeathSecondary· 3 years
Death from any cause while on treatment and within 28 days of palbociclib discontinuation was only counted below.
Group
Value
95% CI
Palbociclib+Letrozole
5
The Objective Response Rate (ORR)Secondary· 3 years
The tumor response was based on the response reported by investigator per local practice. No response confirmation was applied. ORR was defined as the percentage of participants with complete response or partial response relative to all as-treated population.
Group
Value
95% CI
Palbociclib+Letrozole
24.8
17.6 – 33.2
Adverse events — posted to ClinicalTrials.gov
Time frame: 3 years.
Reporting threshold: 5%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
Palbociclib+Letrozole
Serious: 32/130 (25%)
Deaths: 10/130
Serious adverse events (36 terms)
Reaction
System
Palbociclib+Letrozole
Pneumonia
Infections and infestations
—
Disease progression
General disorders
—
Tuberculosis
Infections and infestations
—
Femur fracture
Injury, poisoning and procedural complications
—
Back pain
Musculoskeletal and connective tissue disorders
—
Deep vein thrombosis
Vascular disorders
—
Anaemia
Blood and lymphatic system disorders
—
Febrile neutropenia
Blood and lymphatic system disorders
—
Neutropenia
Blood and lymphatic system disorders
—
Pancytopenia
Blood and lymphatic system disorders
—
Arteriosclerosis coronary artery
Cardiac disorders
—
Ascites
Gastrointestinal disorders
—
Chest pain
General disorders
—
General physical health deterioration
General disorders
—
Cellulitis
Infections and infestations
—
Device related infection
Infections and infestations
—
Herpes virus infection
Infections and infestations
—
Urinary tract infection
Infections and infestations
—
Fractured ischium
Injury, poisoning and procedural complications
—
Road traffic accident
Injury, poisoning and procedural complications
—
Hypoglycaemia
Metabolism and nutrition disorders
—
Malignant neoplasm progression
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
—
Malignant pleural effusion
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
—
Neoplasm progression
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
—
Tumour flare
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
The purpose of this study is to provide access to palbociclib in Mexico and in selected Latin American countries before it becomes commercially available to patients with HR positive/HER2-negative ABC who are appropriate candidates for letrozole therapy.
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
NCT07405164 — Extension Study for Participants in Studies That Include Belzutifan (MK-6482-043/LITESPARK-043)
· Phase 3
· recruiting
NCT07347600 — A Study to Evaluate the Effectiveness and Safety of Inavolisib in Participants With Endocrine-resistant, PIK3CA-mutated,
· recruiting
NCT07123090 — A Study of Sasanlimab, Palbociclib and Axitinib in Metastatic Renal Cell Carcinoma
· Phase 2
· recruiting
NCT06997029 — A Phase 1 Study of BMS-986500 as Monotherapy or Combination Therapy in Advanced Solid Tumors
· Phase 1
· recruiting
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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 Pfizer
Last refreshed: 20 January 2022
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/NCT02600923.