Washington: Scientists have found that rare and aggressive neuroendocrine tumours shrink through a combination of two common immunotherapy drugs.
The research results were presented at the American Association for Cancer Research Annual Meeting 2019.
Results show a significant clinical benefit for patients with high-grade neuroendocrine carcinoma, a cancer of the neuroendocrine cells that often form tumours in the lungs and along the digestive tract.
This cancer is rare, about 12,000 people in the United States are diagnosed each year, but the general prevalence of the disease grew six-fold between 1973 and 2012. Patients with the high-grade, or rapidly growing, form have few treatment options.
“We saw a benefit in patients with high-grade carcinoma, which is the population that really needs an effective treatment option,” said Sandip Patel, MD, The SWOG Cancer Research Network trial known as DART, clinical study chair.
“These early results are really encouraging and intriguing. We found a clear difference in response to treatment between the high-grade and low-grade forms of this cancer type,” said Patel.
“So tumour biology makes a difference. We don’t yet know why, but we’ve opened another treatment arm of the trial to patients with just high-grade neuroendocrine carcinoma to see if we find the same response to the immunotherapy combination,” Patel added.
DART features an innovative ‘basket’ design which allows the testing of a single drug or drug combination in a variety of tumour types. DART, currently tests the immunotherapy combination of ipilimumab and nivolumab in patients with 37 types of rare cancers, which together make up almost a quarter of all cancers diagnosed worldwide.
Researchers enrolled 33 patients with neuroendocrine tumours. Of those 33 patients, 19 had high-grade disease. Most patients’ tumours were located in the gastrointestinal tract or the lungs.
All patients received doses of ipilimumab every six weeks and doses of nivolumab every two weeks and continue on the treatment for as long as their bodies respond to the drugs.
Results showed that 42 per cent of patients with the high-grade form of neuroendocrine carcinomas saw their tumours shrink partially or completely after treatment, while none of the low-grade patients did.
For all the patients, 70 per cent saw their cancer spread within six months. Patients survived a median of at least 11 months after treatment. Some patients are alive more than a year after treatment, and doctors continue to track their progress.
“There’s a myth that you can’t successfully complete clinical trials in rare cancers. Researchers think it’s too hard to find patients. But DART shows us that we can run rare cancer trials, and enroll patients quickly and learn if therapies are effective in rare diseases,” he said.
“We can also offer investigational drugs to patients’ right in their communities. They don’t necessarily need to travel to a cancer centre to get enrolled in a clinical trial.”