Abstract P6-17-17: Pertuzumab, trastuzumab, and docetaxel for HER2-positive early or locally advanced breast cancer in the neoadjuvant setting: Efficacy and safety analysis of a randomized phase III study in Asian patients (PEONY)

Landscape of neoadjuvant therapy in HER2-positive breast cancer: a systematic review and network meta-analysis

BACKGROUND

The recommended preoperative approach for HER2-positive breast cancer is unclear. We aimed to investigate the following: i) what is the optimal neoadjuvant regimen and ii) whether anthracyclines could be excluded.

METHODS

A systematic literature search in Medline, Embase and Web of Science databases was performed. Studies had to satisfy the following criteria: i) randomised controlled trials (RCTs), ii) enroled patients treated preoperatively for HER2-positive BC (breast cancer), iii) at least one treatment group received an anti-HER2 agent, iv) available information of any efficacy end-point and v) published in English. A network meta-analysis with a frequentist framework using random-effects model was used to pool direct and indirect evidence. Pathologic complete response (pCR), event-free survival (EFS) and overall survival (OS) were the efficacy end-points of interest, and selected safety end-points were also analysed.

RESULTS

A total of 11,049 patients with HER2-positive BC (46 RCTs) were included in the network meta-analysis, and 32 different regimens were evaluated. Dual anti-HER2-therapy, with pertuzumab or tyrosine kinase inhibitors, combined with chemotherapy was significantly superior to trastuzumab and chemotherapy in terms of pCR, EFS and OS. However, a higher risk of cardiotoxicity was observed with dual anti-HER2-therapy. Anthracycline-based chemotherapy was not associated with better efficacy outcomes in comparison with non-anthracycline-based chemotherapy. In anthracycline-free regimens, the addition of carboplatin presented numerically better efficacy outcomes.

CONCLUSION

Dual HER2 blockade with chemotherapy is the recommended choice as neoadjuvant therapy for HER2-positive breast cancer, preferably by omitting anthracyclines in favour of carboplatin.

The efficacy and safety of pertuzumab plus trastuzumab and docetaxel as a first-line therapy in Japanese patients with inoperable or recurrent HER2-positive breast cancer: the COMACHI study

PURPOSE

In the CLEOPATRA study of patients with human epidermal growth factor receptor 2 (HER2)-positive recurrent or metastatic breast cancer, the Japanese patient subgroup did not demonstrate the improved progression-free survival (PFS) of pertuzumab plus trastuzumab and docetaxel vs. placebo that was seen in the overall population. Therefore, COMACHI was conducted to confirm the efficacy and safety of this treatment regimen in this patient subgroup.

METHODS

This was a phase IV study of pertuzumab plus trastuzumab and docetaxel in Japanese patients with histologically/cytologically confirmed inoperable or recurrent HER2-positive breast cancer. All patients received pertuzumab, trastuzumab, and docetaxel intravenously every 3 weeks until disease progression/unacceptable toxicity. The primary endpoint was investigator-assessed PFS. Secondary endpoints were overall survival (OS), investigator-assessed objective response rate, and duration of response (DoR). Safety was also assessed.

RESULTS

At final analysis, median investigator-assessed PFS was 22.8 months (95% CI 16.9-37.5). From first dose, OS rate at 1 year was 97.7%; and at 2 and 3 years were 88.5% and 79.1%, respectively. Of the 118 patients with measurable disease at baseline, response rate was 83.9% (95% CI 77.3-90.5) and median investigator-assessed DoR was 26.3 months (95% CI 17.1-not evaluable). Treatment was well tolerated, with no new safety signals detected.

CONCLUSIONS

Our results suggest similar efficacy and safety for pertuzumab plus trastuzumab and docetaxel in Japanese patients compared with the overall population of CLEOPATRA, providing further support for this combination therapy as standard of care for Japanese patients with inoperable or recurrent HER2-positive breast cancer.