Novartis’ (VTX:NOVN) Phase III MONALEESA-3 trial is rational in combining Kisqali (ribociclib) with AstraZeneca’s (LON:AZN) Faslodex (fulvestrant) in first- and second-line HR+Her2-negative advanced metastatic breast cancer due to Faslodex’s efficacy advantage over aromatase inhibitors (AIs) that are commonly used in first-line disease, experts said. They added the trial is expected to be a positive study.
However, Faslodex’s intramuscular administration and well-established combinations with AIs like AstraZeneca’s Femara (letrozole) could diminish Kisqali/Faslodex’s first-line attractiveness relative to oral alternatives, some experts added.
Kisqali/Faslodex is expected to show improved clinical efficacy over Faslodex alone, having shown comparable efficacy to other CDK4/6 inhibitors like Pfizer’s (NYSE:PFE) Ibrance (palbociclib) and Eli Lilly’s (NYSE:LLY) Verzenio (abemaciclib) in pivotal studies, experts said. Clinical and trial experience with the three drugs in various settings led experts to suggest comparable efficacy between them to make a positive MONALEESA-3 result likely. Potential first-line Kisqali/Faslodex use – compared with Ibrance and Verzenio in first-line disease – would be a useful addition given recent evidence of Faslodex’s superior efficacy over Femara.
Positive results in the MONALEESA-3 study, leading to a regulatory filing in first- and second-line HR+Her2-negative advanced breast cancer are expected to boost Kisqali sales in 2019 and beyond, analysts said. Projected global revenues for Kisqali in 2024 are only USD 1.95bn compared to USD 8.4bn and USD 2.3bn with Ibrance and Verzenio respectively.