“A neoadjuvant regimen combining the CDK4/6 inhibitor abemaciclib with anastrozole induced a response rate of 54.7% in patients with HR+/HER2-negative early-stage breast cancer, according to findings from the phase II neoMONARCH trial presented at the 2016 San Antonio Breast Cancer Symposium.
“The study also met its primary endpoint of reduction in Ki67 expression level at week 2. The abemaciclib combination yielded a geometric mean change in Ki67 from baseline to day 15 of -92.6%.”
“Neoadjuvant abemaciclib with or without anastrozole led to significantly greater reductions in tissue Ki67 after 2 weeks of treatment than anastrozole alone among postmenopausal women with hormone receptor–positive, HER-2–negative breast cancer, according to interim phase 2 study results presented at the European Society for Medical Oncology Congress.”
“Premenopausal women whose invasive breast cancers were of the luminal A subtype had comparable 10-year disease-free survival rates regardless of whether or not they received adjuvant chemotherapy, according to data from the phase III DBCG77B clinical trial presented at the 2015 San Antonio Breast Cancer Symposium, held Dec. 8-12.
” ‘Luminal A is a relatively common subtype of breast cancer, and is defined by high expression of hormone receptors [estrogen receptor (ER) and progesterone receptor (PR)], and low expression of the cell-growth marker Ki67 and the oncoprotein HER2. It is the form of breast cancer with the best prognosis,’ said Torsten Nielsen, MD, PhD, professor of pathology at the University of British Columbia in Vancouver, Canada.
” ‘We wanted to address the clinical question of whether or not women with molecularly low-risk luminal A breast cancer actually benefit from chemotherapy,’ added Nielsen. ‘Instead of starting a new trial and waiting for 10 years to find answers, we used an older, completed trial that had saved tissue samples for future studies.’ “
The gist: The drug pictilisib might improve response to treatment with the drug anastrozole for patients with early-stage, ER-positive, HER2-negative, luminal B breast cancer. In a clinical trial, patients who took pictilisib with anastrozole had better responses than patients who took anastrozole alone.
“The addition of pictilisib to anastrozole improved anti-proliferative response through the reduction of Ki67 in patients with early-stage breast cancer and particularly among those with luminal B tumors, according to study results presented at the San Antonio Breast Cancer Symposium…
“Schmid and colleagues evaluated data from 73 post-menopausal women with newly diagnosed breast cancer. All women had ER-positive, HER-2–negative disease. Fifty-three percent of the women had luminal A tumors, and 47% had luminal B tumors.
“Researchers randomly assigned patients 2:1 to the PI3K inhibitor pictilisib (GCD-0941, Genentech) plus 1 mg anastrozole (n=50) or anastrozole alone (n=23) for 2 weeks prior to surgery. The dose of pictilisib was reduced from 340 mg to 260 mg due to a concern for side effects demonstrated on other studies…
“ ‘The data presented show that the addition of the PI3 kinase inhibitor pictilisib significantly increases the anti-proliferative response of anastrozole in ER-positive breast cancer,’ Schmid said. ‘Subsequent analyses suggest increased benefit of pictilisib for patients with luminal B and highly proliferative tumors.’ ”