The phase III clinical trial of immunotherapy drug Nivolumab was extended as it was not equally effective in all the patients. The extension of the study focuses on the immune cells of the patients whether diverse immune system profiles is associated with the effectiveness of immunotherapy.

The study was headed by Dr. Robert Ferris. According to Science Daily, in some patients, nivolumab significantly increased the survival rate of cancer (head and neck) patients with fewer side effects. The researchers were able to discover that higher levels of tumor-associated immune cells (TAICs) were associated with longer overall survival and greater response to the drug nivolumab. Thus, the effectivity of the drug is associated with immune cells.

TAICs express PD-L1 and are also considered as immune cells that have infiltrated the tumor and are thought to be essential in cancer growth. Furthermore, in blood samples taken prior to the start of immunotherapy, the researchers found out that patient with higher levels of CD8 or cytotoxic T cells is associated with better response to the treatment.

The study shows that immune cells surrounding the tumor play essential role in how patients respond to immunotherapy as stated by Dr. Ferris. The determination of these cells including their mechanism on how they are affected by treatment led to the improvement of effective current therapy that is very helpful to certain patients.

According to Cancer.Net, immunotherapy is also called biologic therapy wherein the treatment is designed to boost the body's natural defenses in fighting cancer. Through the work of immune cells and some drugs, immunotherapy can improve and restore immune system function.

Immunotherapy works by stopping or slowing the growth of cancer cells thus, it could also stop the malignant cells from spreading to other parts of the body. Some drugs used in the biologic therapy helps the immune system to work better and destroying cancer cells. Immunotherapy includes monoclonal antibodies, T-cell therapy, and cancer vaccines.