ESMO 2019: Dr. Rugo Highlights Progress in Breast Cancer

Hope S. Rugo, MD, a professor in the Department of Medicine and director of Breast Oncology and Clinical Trials Education at University of California, San Francisco, discusses updates in breast cancer presented at the 2019 ESMO Congress.

At data cutoff of the phase III MONALEESA-7 trial, which evaluated the addition of ribociclib (Kisqali) plus endocrine therapy in peri- or premenopausal women with advanced hormone receptor (HR)—positive, HER2-negative breast cancer, 37.1% of patients on the ribociclib arm and 18.6% on the placebo arm remained on treatment. Overall survival (OS) was not reached for the patients on ribociclib compared with 40.7 months for the patients on placebo (HR, 0.699; 95% CI, 0.501-0.976). Additionally, the time to 10% deterioration was 34.2 months versus 23.3 months in the ribociclib and placebo arms, respectively (HR, 0.69; 95% CI, 0.52-0.91).

The MONARCH 2 trial (NCT02107703), examining abemaciclib (Verzenio) combined with fulvestrant (Faslodex) in patients with HR—positive, HER2-negative advanced breast cancer, showed a median OS of 46.7 months for abemaciclib plus fulvestrant versus 37.3 months for placebo plus fulvestrant (HR, 0.757; 95% CI, 0.606, 0.945; P = 0.0137); these results were very promising, says Rugo.

The IMpassion130 trial, the first phase III trial to demonstrate clinical benefit of immunotherapy in patients with PD-L1-positive triple-negative breast cancer (TNBC), showed clinical activity of atezolizumab (Tecentriq) and nab-paclitaxel (Abraxane) in a subgroup of patients with TNBC who had immune cell PD-L1 expression by the SP142 immunohistochemistry assay, regardless of the site of the tumor sample. Median OS in PD-L1—positive patients was an improvement of 7 months (HR, 0.71; 95% CI, 0.54-0.93); however, there was no impact on progression-free survival (PFS) or OS in patients with PD-L1–negative disease using the assay. According to Rugo, questions still remain regarding how to best identify patients who can benefit from this combination.

The phase III KEYNOTE-522 trial, which enrolled over 1100 randomized patients, examined chemotherapy combined with either pembrolizumab (Keytruda) or placebo in patients with early TNBC. The data showed that the neoadjuvant pembrolizumab/chemotherapy combination extended pathological complete response rates in patients with early TNBC.