Tan AR, Im SA, Mattar A, et al. - The US Food and Drug Administration (FDA) has approved a subcutaneous formulation of pertuzumab and trastuzumab with recombinant human hyaluronidase in one ready-to-use, fixed-dose combination vial (pertuzumab, trastuzumab, and hyaluronidase-zzxf), so researchers here present the primary analysis of the randomized, open-label, international, multicenter, non-inferiority, phase 3 FeDeriCa study, which assessed the pharmacokinetics, effectiveness, and safety of the fixed-dose subcutaneous formulation vs intravenous pertuzumab plus trastuzumab among patients suffering from HER2-positive early breast cancer in the neoadjuvant–adjuvant setting. A total of 252 eligible patients were randomized to the intravenous infusion group and 248 to the fixed-dose combination group. According to results, non-inferior cycle 7 pertuzumab serum C_trough (cycle 8 predose pertuzumab level) concentrations were conferred by the subcutaneous fixed-dose combination of pertuzumab and trastuzumab when compared to intravenous pertuzumab plus trastuzumab in the neoadjuvant setting; total pathological complete response rates were also comparable, and thus, FDA approval was supported. Similar safety was evident between treatment groups, and was in line with other pertuzumab, trastuzumab, and chemotherapy trials. For long-term results, including efficacy as well as long-term safety, the follow-up is ongoing.