Safety of pertuzumab and trastuzumab administered in a single infusion bag in breast cancer

Purpose:Biophysical and analytical assays have demonstrated the physical and chemical stabilities of an admixture of pertuzumab and trastuzumab co-administered via a single infusion bag. Few data are available concerning the use of this practice in real life. We report the safety of pertuzumab and trastuzumab co-administered via a single infusion bag for first-line treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Methods: A cancer data registry was used to identify all patients with HER2-positive breast cancer. In cycle 1, patients received intravenous loading doses of pertuzumab and trastuzumab, and in cycle 2 and onward, patients received maintenance doses via a single infusion bag (cohort 1) or as separate infusions (cohort 2). Patients in cohort 3 received both regimens: separate infusions followed by a single infusion bag. Records were reviewed for general and cardiac safety Results: In total, 72 patients were eligible for analysis: 25 in cohort 1, 23 in cohort 2, and 24 in cohort 3. One patient (4%) in cohort 1 and 1 patient (4.3%) in cohort 2 had left ventricular dysfunction that led to treatment discontinuation, but this dysfunction was not observed in cohort 3. No significant differences in general or cardiac toxicities were observed between cohort 1 and cohort 2, or cohort 3 after switching to a single infusion bag. Conclusion: Pertuzumab and trastuzumab co-administered in a single infusion bag, in a non-clinical-trial setting, had acceptable general and cardiac tolerance profiles. This strategy could improve the comfort of patients while saving active healthcare professionals’ time. Implications for practice: Combined treatment of pertuzumab, trastuzumab, and a third chemotherapeutic agent is the standard of care for first-line HER2-positive locally advanced/metastatic breast cancer and can be used as (neo)adjuvant treatment for breast cancer. In practice, the 2 antibodies are administered separately, but this study supports co-administration of pertuzumab and trastuzumab via a single infusion bag. Co-administration has acceptable general and cardiac tolerances in a non-clinical-trial population. This strategy could improve the compliance and comfort of patients while saving active healthcare professionals’ time and medical resource utilization.