Bristol-Myers Squibb (BMY) surged almost 9% in today's session after the company reported results from its phase 2 trial in patients with advanced squamous cell non-small cell lung cancer. Lung cancer occurs when cancer cells form on tissue cells of the lung. "Squamous cell" means that the lung cancer is initiated in the small cells of the lung, which are thin and flat. The trial results indicated that 41% of the patients taking nivolumab were still alive one year after treatment, which compares favorably to those taking placebo drugs, only 5%  to 18% of whom were still alive at the 1-year mark. 

Nivolumab is in a class of drugs known as PD-1 checkpoint inhibitors. This class of drugs are being developed as immunotherapy drugs which means that the cancers are being targeted by the patients' own immune system. The PD-1 drugs are responsible for disabling the stealth system of the immune system, leaving the cancerous cells vulnerable. Currently cancerous cells have a stealth mechanism that makes them invisible to the immune system, leading to the continuous spreading of the cancerous cells. PD-1 inhibitors stop the ability of these cancerous cells to become invisible, allowing the immune system to easily do its job of destroying these cancerous cells. 

Bristol-Myers intended to file for approval of Nivolumab in lung cancer earlier in the year, but it seems the company was waiting for the 12-month data to roll in before seeking approval from the FDA. Now the company believes that it can file for the non-small cell lung cancer indication to the FDA by the end of the year. The ability for the drug to allow 41% of patients to be alive after one year of taking the therapy is remarkable, especially with the excellent safety profile. There were some minor side effects like fatigue and diarrhea, but they were manageable and are nothing compared to survival. One thing to note is that Nivolumab achieved these great results in patients that had already failed two prior therapies. As more of these PD-1 checkpoint inhibitors are developed in the clinic, the survival rate for these patients with these advanced cancers will continue to climb.