Atezolizumab for the treatment of breast cancer

ABSTRACT

Introduction: Breast cancer (BC) is the most common cancer diagnosed among women. The development of new personalized therapeutic strategies has reshaped the landscape in this field. However, BC is still the first cause of death among women. Interestingly, several preclinical studies and some clinical evidences are focused their attention on the role of immune system and immunotherapy on cancer control, also in BC.

Areas covered: Usually, BC has been considered a not immunogenic tumor for its low mutational load. However, recent studies have evidenced that some subtypes, triple negative and HER-2 positive BC, are ‘hot’ tumors, thus more immunogenic. Moreover, the presence of immune infiltrate is positively associated with favorable prognosis. Therefore, the use of immune-checkpoint inhibitors seems to be an encouraging treatment option also in BC. Among these drugs, atezolizumab is an anti-PD-L1 monoclonal antibody with a particular structure that reduce antibody-dependent cellular cytotoxicity against T cells, increasing quantitatively and qualitatively the effective response.

Expert opinion: The use of immunotherapy is a promising option for BC. However, at the same time it still raises many doubts. Surely, the research and the validation of immune biomarkers can permit to identify patients who more benefit from these drugs.

KEYWORDS:

• Breast cancer
• immunotherapy
• atezolizumab
• TILs

Box 1. Drug Summary Box

Article Highlights

• Breast cancer is the most common cancer in women. Although the new treatment options, BC is still the first cause of cancer-related death among women.

• Usually BC has been considered a cold tumor, but some subtypes have high mutational load and high immune infiltrate, thus they are immunogenic tumors.

• Immunotherapy has reshaped the landscape in many cancer type, being an encouraging treatment option. Data in BC are still few, but immunotherapy seems to be an encouraging therapy in this field.

• It is essential to validate and identify new potential predictive immune biomarkers to identify patients who may more benefit from these new drugs.

• Among immunotherapies, Atezolizumab is different for its structure that reduce ADCC against T cells, enhancing the effector response.

• Combination strategies could make the cold tumors more immunogenic and overcome immune resistances.

This box summarizes key points contained in the article.

Declaration of interest

F. Puglisi has acted as a consultant with compensation for Roche. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

This paper was not funded.