Approximately 15% of the 67,000 women diagnosed with metastatic breast cancer (mBC) annually in the U.S. have mTNBC. Few effective treatment options for mTNBC patients have been identified in the past decade & outcomes are poor vs. other mBC subtypes. The objectives of this study were to quantify overall survival (OS) gains in mTNBC from 2010-2015 & project the potential magnitude of OS gains from new therapies approved by 2020.
We created a simulation model to estimate OS in mTNBC cohorts diagnosed from 2010-2020. OS data were derived from mTNBC clinical trials & were extrapolated to a lifetime horizon by fitting parametric curves. The distribution of 1L regimens used in each diagnosis year came from the IPSOS Global Oncology Monitor - a commercial registry. We projected 2020 OS assuming that 50% of patients receive newly approved therapies (e.g. immunotherapy) & those therapies have an average OS hazard ratio (HR) of 0.7 vs. docetaxel. Scenarios explored alternative HRs of 0.6 & 0.8. We estimated 5-year OS, mean OS & population life year (LY) gains assuming static mTNBC incidence (10,050 cases/year).
From 2010-2015, 5-year OS increased by 2.2% & mean OS increased 1.6 months. If new treatments meet projections for efficacy & market adoption, 5-year mTNBC OS could triple from 5.2% in 2010 to 15.6% in 2020. Over a lifetime horizon, mean per-patient OS could improve by 10.2 months (8,543 population LYs). The population survival gains from 2015-2020 (7,203 LYs) would be ∼5-fold greater vs. gains from 2010-2015 (1,340 LYs). Scenarios with average new treatment HRs of 0.6 & 0.8 resulted in population survival gains of 10,902 LYs & 6,763 LYs vs. 2010.Table: 347P
|Diagnosis Year||5-Year OS (%)||Mean OS (Months)||Population LYs|
We report modest mTNBC survival gains from 2010 to 2015, but show that clinically meaningful gains could be achieved if new treatments in development achieve realistic levels of effectiveness & are widely adopted. There is high unmet need in mTNBC & these new treatments offer hope for improved future outcomes.
Clinical trial identification
Legal entity responsible for the study
P. Bajaj A. Stein: Employee and stockholder: Genentech, Inc. / F. Hoffmann-La Roche AG. J.A. Roth: Consultant: Genentech; Research funding: Genentech. S.D. Sullivan: Research funding: Genentech, Inc. R. Mahtani: Advisor/consultant: Genentech and has received research support. S.D. Ramsey: Research funding from Genentech, Inc.