- In both metastatic and early-stage HER2+ breast cancer treated with pertuzumab (Perjeta), the incidence of diarrhea is high (28%-72%), but dose-delays or discontinuations resulting from diarrhea are rare.
Why this matters
- This study gives clinicians and patients information about the frequency and severity of diarrhea as an adverse effect of pertuzumab.
- This study was a pooled analysis of a phase 3 trial of metastatic HER2+ cancer (CLEOPATRA, n=804) and 2 phase 2 trials (NeoSphere, n=416; TRYPHAENA, n=223).
- Funding: Genentech
- Pertuzumab-based treatment had a high incidence of diarrhea (from 28% to 72%; grade 1, 21%-54%; grade 2, 8%-37%; grade 3, 0%-12%; grade 4, 0%).
- The incidence was greatest during the first cycle, but decreased with later cycles.
- 0%-8% had dose delays or discontinuations from diarrhea.
- The most common treatment for pertuzumab-related diarrhea was loperamide.
- The highest incidence of all-grade diarrhea was seen in pertuzumab-treated Asian vs white patients with metastatic breast cancer (74% vs 63%) compared with 53% vs 45% of control patients.
- Lack of participation by patients with stage III tumors.