More cancer success with drugs that enlist immune system
May. 29, 2015
CHICAGO (AP) — For the first time, a major study shows that a drug targeting the body's disease-fighting immune system may improve survival for the most common form of lung cancer.
These newer kinds of drugs have transformed treatment of melanoma, the deadliest kind of skin cancer. Studies presented at a conference Friday suggest these "immune therapies" can play a broader role in more common cancers, including lung, liver, colon and head and neck.
Doctors also may have found a way to help predict which patients would respond best to one of these newer treatments, according to research presented at the Chicago meeting. Immune therapy drugs are aimed at helping the body's immune system recognize and attack cancer.
The lung cancer study tested Bristol-Myers Squibb's Opdivo (op-DEE-voh), which blocks a protein that prevents the immune system from attacking cancer cells. It worked better than chemotherapy for patients with a form of non-small cell lung cancer that is diagnosed in more than 120,000 people nationwide each year.
Opdivo, also called nivolumab, was approved in March for a less common form of lung cancer, and late last year for melanoma. Two other immunotherapies are approved for melanoma — Keytruda and Yervoy.
"These drugs are among the most promising drugs that have come along" in many years, said Dr. Richard Schilsky, chief medical officer for the American Society of Clinical Oncology, the meeting's organizer.
"What we're seeing is ... a broader scope of activity for these drugs," Schilsky said.
Any success against lung cancer is considered welcome. Patients are often diagnosed when the disease is advanced. It's the No. 1 cancer killer in the country — about 220,000 men and women are expected to be diagnosed this year and nearly 160,000 people will die of the disease, the American Cancer Society estimates.
In the new study, almost 600 patients were randomly assigned to receive infusions of Opdivo or the chemotherapy drug docetaxel every two weeks. Median survival was just over 12 months for Opdivo patients versus about nine months for chemo patients. That difference might seem unremarkable, but long-term survival chances are generally slim for these patients.
Tumors shrank in almost 20 percent of Opdivo patients versus about 12 percent of the others.
"This is a huge step forward for treatment but we have a long way to go to be able to personalize this type of therapy for all lung cancer patients," said senior author Dr. Julie Brahmer of Johns Hopkins University. She is an unpaid consultant for the drug's maker.
Study participant John Ryan of Aldie, Virginia, was diagnosed with incurable lung cancer two years ago and figured he would not live to see his son's college graduation. Standard treatments left him exhausted, prone to infections and did little to shrink the tumor. He joined the study in October 2013 and was assigned to get Opdivo. Three months later his tumor had been reduced by about two-thirds and he felt well enough to help his son cut down a large tree for firewood.
Now he walks two miles most days, and best of all, just watched his 23-year-old son graduate from Virginia Tech.
"I'm out there whistling with the birds and feeling pretty good about life," said Ryan, who is 70. He's still on Opdivo and is due to get it again Monday.
Other research presented Friday at the meeting:
— A study of about 70 patients with advanced cancer suggested a potential way to predict who may respond best to immunotherapy. It found that Merck's drug Keytruda worked better for patients whose cancers lacked an effective way to repair DNA mutations. That repair defect can be detected ahead of treatment. Larger studies are needed to confirm the results.
Dr. Lynn Schuchter, a University of Pennsylvania melanoma expert who has been involved in other Keytruda research, said it works in about 40 percent of melanoma patients and that "we would rather not give it to patients who are not going to benefit."
— Opdivo shrank tumors in almost 20 percent of patients with advanced liver cancer and several survived more than a year, in a small, early study.
— Keytruda shrank tumors substantially in 25 percent of head and neck cancer patients whose disease had recurred or spread, in a preliminary study with about 130 patients. The results suggest the drug might be more effective than Erbitux, a drug that can improve survival for these patients.
AP Chief Medical Writer Marilynn Marchione in Milwaukee contributed to this report.
Cancer information: http://www.cancer.net
AP Medical Writer Lindsey Tanner can be reached at http://www.twitter.com/LindseyTanner