Background Pertuzumab, in combination with trastuzumab and docetaxel, is indicated for use in adult patients with HER2 positive metastatic or locally recurrent unresectable breast cancer, who have not received previous anti-HER2 therapy or chemotherapy for their metastatic disease. Pertuzumab is available in vials of 420 mg and the typical dose is 840 mg intravenously initially, followed by 420 mg every 3 weeks. Common side effects include diarrhoea, nausea, fatigue, rash, abdominal pain and cardiac dysfunction.

Purpose To evaluate the effectiveness and safety of pertuzumab in patients with HER2 positive metastatic breast cancer.

Material and methods Retrospective descriptive study of patients who have received pertuzumab since November 2014. Data were collected from the oncologic electronic prescription programme and by reviewing the patients’ medical histories. Variables examined: age, ECOG performance status, hormone receptor status, HER2 in situ hybridisation, cycles received, progression free survival (PFS) and adverse drug reactions (ADRs).

Results Since November 2014, pertuzumab has been administered to 15 women (median age 54.2 years). Approximately 90% of patients had an ECOG performance status of 0–1. The hormone receptor status was positive in 33.3% of patients and HER2 in situ hybridisation was performed in 46.6% of cases. The median number of pertuzumab cycles received was 7 and the median PFS was 198 days (range 63–324 days). Only 3 of the 15 patients progressed and 2 patients switched to treatment with trastuzumab-emtansine. 12 patients currently continue treatment with pertuzumab, and thus the median PFS will increase. The median follow-up is 2 months at the time of writing, and ADRs were mild and as described in the literature.

Conclusion Our patients responded well to the treatment. Although more data are needed, previous studies suggest that pertuzumab, in combination with trastuzumab and docetaxel, significantly improves the treatment of HER2 positive metastatic breast cancer. The median PFS is significantly increased with no increase in toxic effects.

References and/or Acknowledgements

1. Assessment Report for Perjeta (Pertuzumab). Available at http://www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Product_Information/human/002547/WC500140980.pdf (accessed October 2015)

2. Baselga J, Cortés J, Kim SB, et al. CLEOPATRA Study Group. Pertuzumab plus trastuzumab plus docetaxel for metastatic breast cancer. N Engl J Med 2012;366:109-19

References and/or AcknowledgementsNo conflict of interest.