Palbociclib is a selective cyclin-dependent kinase ( CDK ) 4/6 inhibitor used in combination with aromatase inhibitors or fulvestrant for patients with hormone receptor-positive ( HR+ ) human epidermal growth factor receptor 2 (HER2)-negative advanced/metastatic breast cancer ( ABC/MBC ) .
Real-World Palbociclib Use in HR+/HER2- Advanced Breast Cancer in Canada: The IRIS Study.  Palbociclib is a selective cyclin-dependent kinase ( CDK ) 4/6 inhibitor used in combination with aromatase inhibitors or fulvestrant for patients with hormone receptor-positive ( HR+ ) human epidermal growth factor receptor 2 (HER2)-negative advanced/metastatic breast cancer ( ABC/MBC ) . palbociclib was the first CDK 4/6 inhibitor approved for HR+/HER2- ABC/MBC treatment in Canada in combination with letrozole (P+L) as an initial endocrine-based therapy (approved March 2016), or with fulvestrant (P+F) following disease progression after prior endocrine therapy (approved May 2017). The Ibrance Real World Insights (IRIS) study (NCT03159195) collected real-world outcomes data for palbociclib-treated patients in several countries, including Canada. ### methods This retrospective chart review included women with HR+/HER2- ABC/MBC receiving P+L or P+F in Canada. Physicians reviewed medical records for up to 14 patients, abstracting demographic and clinical characteristics, treatment patterns, and clinical outcomes. Progression-free rates (PFRs) and survival rates (SRs) at 6, 12, 18, and 24 months were estimated via Kaplan-Meier analysis. ### results Thirty-three physicians examined medical records for 247 patients (P+L, ### conclusions Dose reduction rates were low and PFR and SR were high in this Canadian real-world assessment of P+L and P+F treatments, suggesting that palbociclib combinations are well tolerated and effective.
### Instruction:
            Given the context about compound efficacy for the given treatment mentioned within the input, mentioned the compounds 
            that can co-occur for the mentioned treatment

            ### Input:
            Real-World Palbociclib Use in HR+/HER2- Advanced Breast Cancer in Canada: The IRIS Study.  Palbociclib is a selective cyclin-dependent kinase ( CDK ) 4/6 inhibitor used in combination with aromatase inhibitors or fulvestrant for patients with hormone receptor-positive ( HR+ ) human epidermal growth factor receptor 2 (HER2)-negative advanced/metastatic breast cancer ( ABC/MBC ) . palbociclib was the first CDK 4/6 inhibitor approved for HR+/HER2- ABC/MBC treatment in Canada in combination with letrozole (P+L) as an initial endocrine-based therapy (approved March 2016), or with fulvestrant (P+F) following disease progression after prior endocrine therapy (approved May 2017). The Ibrance Real World Insights (IRIS) study (NCT03159195) collected real-world outcomes data for palbociclib-treated patients in several countries, including Canada. ### methods This retrospective chart review included women with HR+/HER2- ABC/MBC receiving P+L or P+F in Canada. Physicians reviewed medical records for up to 14 patients, abstracting demographic and clinical characteristics, treatment patterns, and clinical outcomes. Progression-free rates (PFRs) and survival rates (SRs) at 6, 12, 18, and 24 months were estimated via Kaplan-Meier analysis. ### results Thirty-three physicians examined medical records for 247 patients (P+L, ### conclusions Dose reduction rates were low and PFR and SR were high in this Canadian real-world assessment of P+L and P+F treatments, suggesting that palbociclib combinations are well tolerated and effective.

            ### Response:
            Palbociclib, fulvestrant
            