- Pertuzumab plus trastuzumab was well-tolerated and produced objective responses in patients with human epidermal growth factor receptor 2 (HER2)-amplified metastatic colorectal cancer (mCRC).
Why this matters
- Results come from the MyPathway basket clinical trial, which is evaluating 6 different treatment regimens in a range of solid tumors.
- Subset analysis of MyPathway including 57 patients with HER2-amplified mCRC treated with pertuzumab + trastuzumab.
- Funding: F Hoffmann-La Roche/Genentech.
- Median treatment duration, 2.1 months.
- Disease control rate, 44%.
- 18 patients had objective response (32%; 95% CI, 20%-45%), with 1 complete response.
- Median response duration, 5.9 months. 4 patients had responses >1 year.
- Median PFS, 2.9 months. Median OS, 11.5 months.
- Outcome differences (KRAS wild-type vs mutated):
- median PFS, 5.3 vs 1.4 months;
- median OS, 14.0 vs 8.5 months;
- objective response rate 40% vs 8%.
- Treatment-emergent adverse events (AEs) included diarrhea (33%), fatigue (32%), and nausea (30%).
- 37% of patients experienced grade 3-4 AEs, most commonly hypokalemia (5%) and abdominal pain (5%).
- 10 patients (18%) had serious AEs, 2 of which were considered treatment-related (chills and infusion-related reaction).
- Small sample size.