Andersson M, et al. - Researchers explored the efficacy and safety of pertuzumab and trastuzumab administered in a single infusion bag, followed by vinorelbine. Study outcomes supported the feasibility of pertuzumab and trastuzumab co-infusion from a safety perspective. In addition, vinorelbine offered an alternative chemotherapy companion for pertuzumab and trastuzumab.

Methods

• During cycle 1, loading doses of pertuzumab (840 mg) and trastuzumab (8 mg/kg) on consecutive days, followed by vinorelbine (25 mg/m2) on days two and nine had been administered to patients with HER2-positive locally advanced or MBC.
• Patients received a co-infusion of pertuzumab (420 mg) and trastuzumab (6 mg/kg) on day one, followed by vinorelbine (30–35 mg/m2) on days one and eight (or days two and nine), from cycle 2 onwards.
• Objective response rate (ORR) in patients with measurable disease, was the primary endpoint.
• Progression-free survival (PFS) and safety were secondary endpoints.

Results

• 107 patients were part of Cohort 2.
• In patients with measurable disease (91/107; 85.0%), the ORR was 63.7% (95% confidence interval [CI] 53.0–73.6).
• It was noted that median PFS was 11.5 months (95% CI 10.3–15.8).
• Diarrhea (57.9%), neutropenia (57.0%), and nausea (41.1%) were the most common adverse events [AEs].
• Results reported grade ≥3 AEs in 85 patients (79.4%) and serious AEs in 44 patients (41.1%).
• Data demonstrated AEs suggestive of congestive heart failure in eighteen patients (16.8%).