Immunotherapy works by harnessing the body's immune system to attack tumors.
A study involving people with advanced stage lung cancer found it nearly doubled their survival time, while another revealed that immunotherapy treatment shrank tumours before surgery.
Results were discussed Monday at an American Association for Cancer Research conference in Chicago and published by the New England Journal of Medicine.
Dr Roy Herbst, a lung cancer specialist at Yale Cancer Centre, who was not involved in the studies, said it could be the start of a fundamental change in treatment.
Hellmann's study, called CheckMate 227, found that advanced tumors that contain a lot of genetic mutations - often from smoking - respond particularly well to a combination of two immune therapy drugs, Yervoy and Opdivo, both from Bristol-Myers Squibb.
Pembrolizumab, sold under the brand name Keytruda, is an FDA-approved drug sold by a subsidiary of Merck & Company, Inc. that sponsored this study.
"I've been a doctor for 38 years, lung cancer, especially if it's spread - metastatic - is something that has been a devil to me, it's been a devil to my patients and the thought we have an exciting new therapy, I'm really pumped about it", LaPook said.
"The data show that treatment with pembrolizumab and chemotherapy together is more effective than chemotherapy alone", said lead investigator Leena Gandhi, director of the thoracic medical oncology program at Perlmutter Cancer Center at NYU Langone Health.
The estimated survival at 12 months was 69.2 percent in the group that received immunotherapy, and 49.4 percent in those who did not. Worldwide, lung cancer causes 1.69 million deaths annually. "This is really a pivotal study. a new standard of care", said Shaw, who has no ties to the drugmakers.
They cost more than $100,000 a year, can have serious side effects and help only some patients, generally fewer than half.
Dr. Jorge Gomez, a volunteer spokesperson for the American Lung Association and a medical oncologist and director of thoracic oncology at Mount Sinai Hospital in NY, explained that "about 220,000 patients are diagnosed with lung cancer a year in the United States".
Dr. Matthew Hellmann of Memorial Sloan Kettering Cancer Center in NY led a study testing the Opdivo-Yervoy combo versus chemo in a slightly different group of newly diagnosed advanced lung cancer patients.
Further trials will test the methods on patients with bowel and ovarian cancer. Medicare recently agreed to cover the $3,000 test for advanced cancers. In that group, survival without worsening of disease was 43 percent after one year for those on the immunotherapy drugs versus 13 percent of those on chemo. By killing some tumor cells, chemotherapy could pop open the bags, release the contents and help immune cells unleashed by the checkpoint drugs to identify their prey.
After a median followup of 10.5 months, those in the immunotherapy group were half as likely to die. Checkpoint inhibitors are one of two main types of immunotherapy. Details are expected in a couple months.