Edith A. Perez
CHICAGO — First-line therapy with ado-trastuzumab emtansine improved OS and reduced grade 3 and higher adverse events in patients with HER-2-positive advanced breast cancer, according to results from the MARIANNE trial presented at the ASCO Annual Meeting.
“In the primary analysis [of the MARIANNE trial], ado-trastuzumab emtansine-based treatment exhibited noninferior, but not superior, PFS relative to trastuzumab plus taxane,” the researchers wrote. “OS was similar between treatments in the first interim analysis. Here, we report OS from the final descriptive analysis.”
Edith A. Perez, MD, vice president and head of U.S. medical affairs for Genentech/Roche BioOncology, and colleagues enrolled patients with HER-2-positive, progressive or recurrent, locally advanced cancer or previously untreated metastatic breast cancer. Enrollment required an interval of six months or more since adjuvant or neoadjuvant treatment with taxanes or vinca alkaloids.
Perez and colleagues randomly assigned patients to first-line treatment with trastuzumab plus docetaxel or paclitaxel (n = 365), ado-trastuzumab emtansine plus placebo (n = 367), or ado-trastuzumab emtansine plus pertuzumab (n = 363).
At a median follow-up of 54 months, 512 patients had died. Median OS was 50.9 months in patients treated with trastuzumab plus docetaxel or paclitaxel, 53.7 months in patients treated with ado-trastuzumab emtansine and 51.8 months in patients treated with ado-trastuzumab emtansine plus pertuzumab.
The researchers also conducted a sensitivity analysis in which patients who received trastuzumab plus docetaxel or paclitaxel received ado-trastuzumab emtansine and/or pertuzumab following progression of disease. The analysis, which was censored before the treatment switch took place, demonstrated comparable outcomes between arms.
Ado-trastuzumab emtansine led to fewer grade 3 and higher adverse events than other regimens.
The extended follow-up results of the MARIANNE trial demonstrated that “the ado-trastuzumab emtansine safety profile was consistent with the primary analysis and prior experience,” the researchers wrote.
In addition, the median OS of 53.7 months and fewer adverse events equal to or less than grade 3 seen with ado-trastuzumab emtansine validate the agent “as an effective and tolerable alternative first-line treatment” for patients with HER-2-positive metastatic breast cancer. – by Julia Ernst, MS
Perez EA, et al. Abstract 1003. Presented at: ASCO Annual Meeting; June 2-6, 2017; Chicago.
Disclosures: Perez reports that she is an employee of and has stock and other ownership interests in Genentech/Roche. Please see the full study for a list of all other researchers’ relevant financial disclosures