HER2+ metastatic breast cancer: closing CLEOPATRA results confirm pertuzumab survival benefit

  • Swain SM & al.
  • Lancet Oncol
  • 12 Mar 2020

  • curated by Miriam Davis, PhD
  • Univadis Clinical Summaries
Access to the full content of this site is available only to registered healthcare professionals. Access to the full content of this site is available only to registered healthcare professionals.

Takeaway

  • The end-of-study results of the CLEOPATRA phase 3 trial reveal that first-line treatment of HER2+ metastatic breast cancer (mBCa) with pertuzumab plus trastuzumab and docetaxel offers an OS advantage of 16.3 months vs placebo plus trastuzumab and docetaxel.

Why this matters

Study design

  • Double-blind, randomized, placebo-controlled phase 3 trial with pertuzumab (420 mg) plus trastuzumab (6 mg/kg) and docetaxel (up to 100 mg/m2; n=402) until disease progression vs placebo plus trastuzumab and docetaxel (n=406).
  • Funding: F Hoffmann-La Roche; Genentech.

Key results

  • Median follow-up: pertuzumab, 99.9 months; placebo, 98.7 months.
  • Pertuzumab group had longer OS:
    • 57.1 (95% CI, 50-72) months vs 40.8 (95% CI, 36-48) months with placebo.
    • Difference: 16.3 months.
    • HR, 0.69 (95% CI, 0.58-0.82).
  • 8-year landmark OS rates favored pertuzumab:
    • 37% (95% CI, 31%-42%) vs placebo, 23% (95% CI, 19%-28%).
  • Pertuzumab group had somewhat higher rates of grade 3-4 neutropenia (49% vs 46% of placebo patients), the most common adverse event.
  • Since the previous analysis, 1 new serious adverse event arose suggestive of congestive heart failure in the pertuzumab group.

Limitations

  • Analyses are descriptive.