Researchers report that two new cancer immunotherapy drugs in development by Bristol-Myers Squibb and Merck that free the immune system to fight cancer have shown excellent preliminary results in treating Hodgkin’s lymphoma. The drugs shrank tumors in more than 50% of patients who had exhausted many other cancer treatments.
The drugs have already generated a great deal of excitement for their strong early results on several “solid” tumors, especially melanoma but also kidney cancer, lung cancer and several other tumors, according to the New York Times. Researchers said the drugs, called PD-1 inhibitors, may also have promise for “liquid” tumors of the bone marrow and blood.
[quote text_size=”small” author=”– Craig Moskowitz” author_title=”Clinical director of hemotologic oncology at Memorial Sloan Kettering Cancer Center”]
They are both extremely active agents. These are the kind of numbers that have rarely been seen in patients.
The drugs work by releasing a natural immune system brake called PD-1 that some tumors use to evade an attack by the immune system, according to the Wall Street Journal. In previous studies, researchers suggested that the genetic makeup of Hodgkin’s lymphoma would make it vulnerable to PD-1 therapy.
A small study found that the drug Nivolumab from Bristol-Myers Squibb significantly shrank tumors in 87% of patients with Hodgkin’s lymphoma, or 20 out of 23. 17% of the patients had a complete response that resulted in total or almost complete disappearance of the tumors.
The Merck drug Pembrolizumab shrank tumors in 66% of patients with Hodgkin’s lymphoma, while 21% of patients had a complete response to the drug.
Both studies were Phase 1 trials to test safety. It is still too early to determine how effective the drugs will be and if they will help prolong the lives of patients. The results of the studies were impressive, however, as patients in both had failed many other treatment options, including stem cell transplants. In cancer drug studies, it is usually increasingly hard to find a benefit for patients who have failed other treatments.
A larger Phase II study is already underway for Nivolumab that will be used to confirm the results and seek FDA approval, according to Reuters.
There are about 9,200 new cases of Hodgkin’s lymphoma each year in the United States with about 1,200 deaths. The illness typically affects young adults and, while many are effectively cured, about 30% do not respond to the first treatment or relapse.