MK-3475, an experimental cancer drug, has shown early potential as an effective treatment for patients with non-small cell lung cancer ( NSCLC ).
Preliminary results of a phase 1B study of MK-3475 were presented at the World Conference on Lung Cancer in Sydney, Australia.

The detailed interim data on safety and activity came from a cohort of 38 patients with non-small cell lung cancer who were treated previously for the disease without positive results. For the study, the patients received MK-3475 every three weeks.

Among the participants, 24% responded to the drug, with their tumors shrinking, and the median overall survival rate was 51 weeks. For those who responded, the median response duration ( the average amount of time their tumors remained shrunk ) had not been reached at the time of this analysis, so it is at least 62 weeks.

Some cancer cells can evade detection by the immune system by expressing a protein called PD-L1, which interacts with the protein PD-1 to prevent the immune system from seeing the cancer as an invader.
MK-3475, an anti-PD-1 immunotherapy drug, allows the immune system to properly detect the cancer and to activate T cells to attack and kill cancer cells.

The most commonly reported drug-related side effects in the study were rash ( 21% ), skin itching ( 18% ), fatigue ( 16% ), diarrhea ( 13% ) and joint pain ( 11% ).
Most side effects, however, were of low grade.

According to the American Cancer Society, approximately 1.4 million people die from non-small cell lung cancer every year. It is the most common type of lung cancer, representing approximately 85% of all lung cancer diagnoses. ( Xagena )

Source: University of California - Los Angeles ( UCLA ), 2013