Dataset Information

Comparative effectiveness of first-line palbociclib plus letrozole versus letrozole alone for HR+/HER2- metastatic breast cancer in US real-world clinical practice.

ABSTRACT:

Background

Findings from randomized clinical trials may have limited generalizability to patients treated in routine clinical practice. This study examined the effectiveness of first-line palbociclib plus letrozole versus letrozole alone on survival outcomes in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor-negative (HER2-) metastatic breast cancer (MBC) treated in routine clinical practice in the USA.

Patients and methods

This was a retrospective observational analysis of electronic health records within the Flatiron Health Analytic Database. A total of 1430 patients with ≥ 3 months of follow-up received palbociclib plus letrozole or letrozole alone in the first-line setting between February 3, 2015, and February 28, 2019. Stabilized inverse probability treatment weighting (sIPTW) was used to balance baseline demographic and clinical characteristics. Real-world progression-free survival (rwPFS) and overall survival (OS) were analyzed.

Results

After sIPTW adjustment, median follow-up was 24.2 months (interquartile range [IQR], 14.2-34.9) in the palbociclib group and 23.3 months (IQR, 12.7-34.3) in those taking letrozole alone. Palbociclib combination treatment was associated with significantly longer median rwPFS compared to letrozole alone (20.0 vs 11.9 months; hazard ratio [HR], 0.58; 95% CI, 0.49-0.69; P < 0.0001). Median OS was not reached in the palbociclib group and was 43.1 months with letrozole alone (HR, 0.66; 95% CI, 0.53-0.82; P = 0.0002). The 2-year OS rate was 78.3% in the palbociclib group and 68.0% with letrozole alone. A propensity score matching analysis showed similar results.

Conclusions

In this "real-world" population of patients with HR+/HER2- MBC, palbociclib in combination with endocrine therapy was associated with improved survival outcomes compared with patients treated with letrozole alone in the first-line setting.

Trial registration

Clinicaltrials.gov; NCT04176354.

SUBMITTER: DeMichele A

PROVIDER: S-EPMC7989035 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundThe global burden of breast cancer (BC) is high, especially in advanced stages. CDK 4/6 inhibitors represent a paradigm shift in the treatment of advanced BC HR+/HER2-, given the clinically and statistically significant gain in overall survival associated with this new class of medications. Nevertheless, as an innovation, the incorporation of these drugs impacts healthcare budgets, requiring cost-effectiveness analyses for decision-making. The aim of this study was to evaluate the cost-effectiveness of ribociclib plus letrozole compared with palbociclib plus letrozole or letrozole as monotherapy for first-line treatment of postmenopausal women with HR+/HER2- locally advanced or metastatic BC (aBC) from a Brazilian private healthcare system perspective.MethodsA model including progression-free survival (PFS), progressed disease, and death health states was used to simulate lifetime costs and outcomes. PFS and overall survival were derived from the MONALEESA-2 trial (lifetime horizon). Healthcare costs included drug acquisition and monitoring, subsequent therapies, adverse events, and end-of-life costs. Effectiveness was measured in quality-adjusted life-years (QALYs). Deterministic and probabilistic sensitivity analyses were performed.ResultsThe total cost of treatment with ribociclib plus letrozole was USD 72,091.82 versus USD 92,749.64 for palbociclib plus letrozole. Total QALYs were 3.30 and 3.16, respectively. Base-case analysis showed ribociclib as dominant over palbociclib in first-line treatment of women with HR+/HER2- aBC, associated with cost savings and QALY gains. The total cost of treatment with ribociclib plus letrozole was USD 83,058.73 versus USD 29,215.10 for letrozole. Total QALYs were 3.84 and 2.61, respectively. Compared with letrozole, ribociclib plus letrozole was associated with an incremental cost of USD 53,843.64 and an incremental QALY gain of 1.23, with incremental cost-effectiveness ratio of USD 43,826.91 per QALY gained.ConclusionsAs demonstrated by the cost-effectiveness dominance over palbociclib, ribociclib results in savings when used as first-line treatment in postmenopausal women with HR+/HER2- aBC, warranting incorporation in the private healthcare system.