ERBB2 and breast cancer: Active Immunotherapy PAClitaxel (AIPAC) is a double blind, placebo-controlled, randomized Phase IIb trial initiated in 2015, which enrolled 211 patients with metastatic hormone receptor-positive (HR+) breast cancer ineligible for HER-2/neu therapy to evaluate the safety and efficacy of IMP321 added to weekly paclitaxel as a first-line chemotherapy versus paclitaxel plus placebo (61) (clinicaltrials.gov trial no. NCT02614833).