Six Months of Trastuzumab Just as Effective as One Year, Researchers Find

The standard treatment for women with human epidermal growth factor receptor 2 (HER2)-positive early-stage breast cancer has long been 12 months of trastuzumab therapy. However, a recent clinical trial, results of which will be presented at the upcoming American Society of Clinical Oncology (ASCO) 2018 Annual Meeting, sought to determine if a reduced treatment time of 6 months was as effective 12 months.

Researchers involved in the Persephone phase 3 randomized clinical trial of 4089 women with HER2-positive early breast cancer found that 6 months of trastuzumab treatment was not inferior to the current standard. Furthermore, the reduced treatment time was associated with fewer adverse events that are usually common with the treatment, such as headache, severe coughing, or heart problems, among other issues.

“We are confident that this will mark the first steps towards a reduction of the duration of trastuzumab treatment to 6 months in many women with HER2-positive breast cancer,” said lead study author, Helena Earl, MD, professor of clinical cancer medicine at the University of Cambridge, in a statement to the press.

Half of the women in the study were randomized to receive trastuzumab for 6 months, while the other half received the therapy for the standard period of 12 months. In addition, women also received anthracycline-based, taxane-based, or combination chemotherapy while participating in the trial.

Participants were followed for a median of 5 years. The disease-free survival rate at 4 years was 89.4% in the 6-month arm and 89.8% in the 12-month arm. Additionally, only 4% of women in the 6-month arm stopped therapy early due to cardiac problems, compared with 8% in the 12-month arm.

These results could provide women with HER2-positive breast cancer not only with the relief of fewer adverse events and shorter treatment time, but also less expensive treatment; 12-month trastuzumab costs approximately $55,000, based on Medicare estimates in 2017.

“This new trial shows that a shorter length of treatment can benefit patients just as much as a longer treatment, with less risk of cardiac side effects. This is a win-win for patients with breast cancer who are receiving this common treatment,” said American Society of Clinical Oncology’s (ASCOs) president, Bruce E. Johnson, MD, FASCO in a statement to the press.

The trial results will be presented at the ASCO’s meeting, held June 1 to 5, 2018, in Chicago, Illinois.

Reference

Earl H, Vallier AL, Dunn J, et al. Shorter trastuzumab treatment for HER2+ breast cancer can be as effective, with fewer cardiac side effects. Pesented at the American Society of Clinical Oncology’s 2018 Annual Meeting, June 1-5, 2018; Chicago, Illinois. Abstract 506. meetinglibrary.asco.org.