Samsung Bioepis said Friday that it has presented the three-year follow-up study comparing biosimilar Ontruzant (Ingredient: trastuzumab) and reference medicine trastuzumab in early or locally advanced HER2-positive breast cancer.

The company presented the data, which show comparable overall survival and cardiac safety, at the 16th St. Gallen International Breast Cancer Conference 2019 in Vienna.

Participants enrolled in an initial Phase 3 study received eight cycles of the Ontruzant or the reference medicine concurrently with chemotherapy in the neoadjuvant setting. Following surgery, they received an additional 10 cycles of the Ontruzant or the reference medicine.

After completion of the therapy, the company enrolled 367 of these participants -- 186 in the Ontruzant group and 181 in the reference medicine group -- in the follow-up study.

Median follow-up from initiation of study treatment was 40.8 months in the Ontruzant group and 40.5 months in the reference medicine group.

As a result, overall survival was 97 percent in the Ontruzant group and 93.6 percent in the reference medicine group, while event-free survival was 92.5 percent in the Ontruzant group and 86.3 percent in the reference medicine group. The incidence of cardiac events was rare for both treatment groups throughout the three-year follow-up period.

Also, there were two cases of asymptomatic significant left ventricular ejection fraction (LVEF) decrease in the Ontruzant group and one in the reference medicine group, with all patients recovering with LVEF of more than or equal to 50 percent.

There were no cases of symptomatic congestive heart failure, cardiac death or other significant cardiac conditions reported in either group.

“With the development of our biosimilar trastuzumab, we aimed to make one of the mainstays of modern cancer therapy more accessible for more people more quickly, and these long-term data underline the importance of that aim,” said Kim Chul, senior vice president and head of Clinical Sciences Division at Samsung Bioepis.

The company is committed to increasing access to high-quality, life-changing oncology medicines through the development of biosimilars to address some of the oncology’s most pressing challenges, Kim added.