Roche Holding AG's Tecentriq improved survival in some patients with triple-negative breast cancer that has spread, making it the first immunotherapy to work in this type of cancer and heralding a new treatment option, according to late-breaking results at the European Society for Medical Oncology 2018 Congress in Munich.

Results from the much anticipated IMpassion130 phase 3 trial, a study of 902 patients with triple-negative breast cancer who had not received treatment for the disease spreading, found that the combination of standard chemotherapy and Tecentriq slowed the cancer growth — a measure called progression free survival – and prolonged life by 20% in all patients. In those patients that expressed PD-L1, the combination prolonged life by 38%.

Tecentriq, a monoclonal antibody that targets the PD-L1 protein, is currently being tested in seven different late-stage studies of both early and advanced triple-negative breast cancer.

These results will change the way triple-negative breast cancer is treated, according to Peter Schmid, Clinical Director of London's St. Bartholomew's Breast Cancer Centre and a professor at the Centre for Experimental Cancer Medicine, Barts Cancer Institute, Queen Mary University of London.

"It is also the first immune therapy to improve outcome in this cancer. Most of the survival benefit was in patients with PD-L1 positive tumors," he said.

Triple-negative breast cancer is the most aggressive and challenging type of breast cancer as it cannot be treated with either hormone therapy or drugs that target the HER2 protein. Affecting around 15% to 20% of women diagnosed with breast cancer, it often strikes younger women, most of whom become resistant to the chemotherapy after a few months of treatment, leading to an average survival rate of a year to 15 months.

"While the benefit in terms of progression-free survival was relatively small, around three months, the gain in overall survival in the PD-L1 positive subgroup was impressive with a 10-month benefit," said Marleen Kok, a cancer doctor at The Netherlands Cancer Institute in Amsterdam.

"Around 40% of the tumors were PD-L1 positive. The IMpassion 130 data will probably change the treatment landscape for our metastatic triple-negative breast cancer patients," she said, commenting on behalf of ESMO.

Schmid, the study lead, said that the combination therapy — which was compared with standard chemotherapy plus placebo — was well tolerated and most of the side effects observed were as a result of the chemotherapy and occurred at a similar rate in both treatment groups.

"These important results in people with metastatic triple-negative breast cancer whose disease expresses the PD-L1 protein are highly encouraging and represent a significant step forward in the treatment of this challenging disease," said Roche's Chief Medical officer and head of Global Product Development, Sandra Horning.

"We have shared the IMpassion130 results with global health authorities with the hope of bringing this Tecentriq combination to people with PD-L1- positive, metastatic triple-negative breast cancer as soon as possible."

The 2018 European Society for Medical Oncology meeting in Munich is expected to bring together 26,000 cancer professionals from all over the world to discuss the latest research. The conference ends Oct. 23.