International Breast Cancer Study Group, Breast International Group and Merck Announce Opening of International PANACEA Study of Patients with HER2+ Breast Cancer

The gist: A new clinical trial will enroll patients to see whether combining the drug pembrolizumab (aka Keytruda) with trastuzumab (aka Herceptin) might help them overcome resistance to trastuzumab. Pembrolizumab is an immunotherapy, meaning it boosts a patient’s immune system to fight cancer. 

“The International Breast Cancer Study Group (IBCSG), Breast International Group (BIG), and Merck, known as MSD outside the United States and Canada, today announced the opening of the PANACEA study, a global collaborative study exploring a new way to treat HER2+ breast cancer that has become resistant to the current standard of care. The PANACEA study will investigate the use of pembrolizumab (KEYTRUDA®) in combination with trastuzumab to evaluate whether the addition of an anti-PD-1 therapy can reverse trastuzumab resistance in patients with HER2+ breast cancer whose cancer has spread while on trastuzumab therapy.

“Worldwide, breast cancer is the most common cancer among women.1 About one in five patients with breast cancer have too much of a growth-promoting protein known as HER2/neu (or just HER2) on the surface of cancer cells. Breast cancers with too much of this protein tend to grow and spread more aggressively.

“ ‘PANACEA is the first phase 2 immunotherapy trial not only in HER2+ breast cancer, but in the entire breast cancer field,’ said Sherene Loi, MD, PhD, study chair, division of cancer medicine, Peter MacCallum Cancer Centre, Australia. ‘If successful, this may herald a new treatment approach in certain types of breast cancer.’ ”