Pertuzumab, trastuzumab, and docetaxel for HER2-positive metastatic breast cancer (CLEOPATRA): end-of-study results from a double-blind, randomised, placebo-controlled, phase 3 study

Median overall survival was 57.1 months (95% CI 50–72) in those treated with docetaxel/trastuzumab/pertuzumab and 40.8 months (36–48) in those treated with docetaxel/trastuzumab/placebo (HR 0.69, 95% CI 0.58–0.82); 8-year OS was 37% (95% CI 31–42) and 23% (19–28), respectively.

SPS commentary:

Since the publication of the first results of the CLEOPATRA trial in 2012, the pertuzumab-based regimen has become the new standard first-line treatment for patients with HER2-positive metastatic breast cancer. NICE recommends pertuzumab, in combination with trastuzumab and docetaxel, for the treatment of HER2‑positive metastatic or locally recurrent unresectable breast cancer, in adults who have not had previous anti‑HER2 therapy or chemotherapy for their metastatic disease (if the company provides pertuzumab within the agreed commercial access arrangement) [TA509; March 2018].


The authors of a related comment note that this is the fourth survival analysis published on this trial and it reports only exploratory results; however with a median follow-up of 8 years, it is an “extraordinary and unprecedented achievement”. Prior to the introduction of anti-HER2 targeted therapies, median overall survival for patients with HER2-positive metastatic breast cancer was less than two years; with the pertuzumab-based regimen however, more than a third of patients were alive 8 years after diagnosis. They go on to note however that 54% of enrolled patients had not received any previous adjuvant or neoadjuvant treatment, and only 11% were previously exposed to trastuzumab. The performance of the pertuzumab-based regimen in those previously exposed to adjuvant or neoadjuvant anti-HER2 therapy therefore remains to be clarified.


The Lancet Oncology

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