The Food and Drug Administration on Thursday approved an innovative new treatment for patients with some types of lung cancer. This treatment is only used in patients who have exhausted all other options for treating small cell lung cancer and have 4 to 5 months to live.
The drug tarlatamab (also known as Imdeltra), made by Amgen, tripled the life expectancy of patients, with a median survival time of 14 months after taking the drug. 40% of people given the drug had a reaction.
After decades of no real progress in the treatment of small cell lung cancer, tarlatamab offers the first real hope, said a lung cancer expert at the federal National Cancer Institute who was involved in the trial. said Dr. Anish Thomas.
“It's been a long time since I felt light,'' he added.
Dr. Timothy Burns, a lung cancer specialist at the University of Pittsburgh, said the drug “will change the world of medicine.”
(Dr. Burns was not an investigator on this study, but served on Amgen's advisory board for another drug.)
However, this drug can have a serious side effect called cytokine release syndrome. This is an overreaction of the immune system and can cause symptoms such as a rash, increased heart rate, and decreased blood pressure.
Each year, approximately 35,000 Americans are diagnosed with small cell lung cancer and face a grim prognosis. Cancer usually has spread beyond the lungs by the time it is detected.
The standard treatment, unchanged for decades, is a combination of old-fashioned chemotherapy and immunotherapy that extends patients' lives by about two months. But almost inevitably, cancer resists treatment.
“There's a 95 percent chance it will come back, often within a few months,” Burns says. And when the disease relapses, patients have a harder time tolerating chemotherapy, making it even less effective, he added.
Most patients survive only 8 to 13 months after diagnosis, despite receiving chemotherapy and immunotherapy. Because the group of patients in the clinical trial had already received two or three rounds of chemotherapy, those who did not receive the drug had a much shorter life expectancy.
The dire prognosis of small cell lung cancer stands in stark contrast to the situation with the more common non-small cell lung cancer, which has become a triumph of the cancer treatment revolution. New targeted therapies seek out the molecules cancers need to grow and slow their spread.
As a result, many patients with this type of lung cancer live longer, making the disease “almost a chronic disease,” Dr. Thomas said.
There are several reasons why small cell lung cancer patients are left behind.
One is the type of genetic mutation that cancer growth depends on.
Dr. Jay Bradner, Amgen's chief scientific officer, explained that other cancers are also caused by abnormal genes being turned on. Treatments include drugs that turn off these genes.
However, small cell lung cancer is difficult to target because it is caused by genes that are turned off, Bradner explained. Another reason is the cancer's ability to block immune system cells that try to destroy it.
Tarlatamab is an antibody designed to overcome these obstacles. It has two arms, the first of which grabs a growth-promoting molecule that sticks out like a flag from the surface of a cancer cell. This acts as an identification tag for the drug, allowing tarlatamab to find cancer cells. The other arm grabs her T cells as they float through the bloodstream. Her T cells, which are white blood cells, can kill cancer if they can get close to it.
This drug connects T cells with cancer cells, creating holes in the cancer or activating genes that cause the cancer to self-destruct.
Patients who participated in clinical trials say they have gotten their lives back.
Martha Warren, 65, of Westerly, Rhode Island, was diagnosed last year with small cell lung cancer. She joined her Facebook group and she immediately saw the bad news. Most patients do not live long. Her best hope, she decided, was a clinical trial. After chemotherapy and immunotherapy, her cancer grew rapidly, so she was accepted into a study at Amgen and began attending Yale University to receive an infusion of her medication.
Almost immediately, her cancer began to shrink dramatically.
“I feel as normal as I did before I had cancer,” Warren said. “There's a lot of hope with this drug,” she added.
But Amgen's study and its approval included patients like Warren who had already received several treatments. Could tarlatamab help earlier?
Amgen is currently starting such a study, testing the drug immediately after the first round of chemotherapy.