Schmid P, Zaiss M, Harper-Wynne C, et al. - Researchers examined how the addition of vistusertib influence the progression-free survival and other measures of antitumor activity of fulvestrant in postmenopausal women with estrogen receptor–positive advanced or metastatic breast cancer that progressed after prior therapy with aromatase inhibitors. In the MANTA trial, an open-label, phase 2 randomized clinical trial, randomization of 333 patients with estrogen receptor–positive breast cancer progressing after prior aromatase inhibitor treatment (2:3:3:2) was done at 88 sites in 9 countries: 67 patients were assigned to receive fulvestrant, 103 fulvestrant plus vistusertib daily, 98 fulvestrant plus vistusertib intermittently, and 65 fulvestrant plus everolimus. As per outcomes, vistusertib plus fulvestrant vs fulvestrant alone resulted in no benefit. In addition, both vistusertib groups vs the group treated with fulvestrant plus everolimus had inferior outcomes.