- Dual blockade of HER2 protein with lapatinib (LAP) plus trastuzumab (TRAS) prolongs PFS compared with single blockade with TRAS in patients with HER2+ metastatic breast cancer.
- Both groups also received aromatase inhibitor (AI) according to updated results of phase 3 ALTERNATIVE trial.
Why this matters
- Dual HER2 blockade provides a safe and effective chemo-sparing option for HER2+ metastatic breast cancer.
- Phase 3 randomized controlled trial (N=355) comparing LAP (oral 1000 mg/day)+TRAS (6 mg/kg intravenous maintenance dose every 3 weeks)+AI (investigator choice) vs TRAS+AI in patients with HER2+ metastatic breast cancer.
- Funding: GlaxoSmithKline; Novartis; others.
- The dual-blockade group had longer PFS than the single-blockade group:
- Median PFS, 11 vs 5.6 months.
- HR, 0.62 (P=.0063).
- Dual blockade also yielded significantly better OS:
- Median, 46 vs 40.0 months with single blockade.
- HR, 0.60 (95% CI, 0.35-1.04).
- Serious adverse events were similar between groups.
- The dual-blockade group had fewer discontinuations.
- Open-label design.