(Reuters) – Eighty-seven percent of Hodgkin lymphoma patients responded to a Bristol-Myers Squibb drug that helps the immune system fight the blood cancer, according to data from a small, early stage trial released on Saturday.
The study of Bristol-Myers’ immunotherapy drug nivolumab involved 23 patients whose lymphoma had progressed after numerous prior treatments, including chemotherapy, stem cell transplants and the Seattle Genetics drug Adcetris.
Of the 23, 16 saw their tumors shrink by at least half and four had a complete response, meaning no detectable sign of the cancer, generating excitement among researchers. The remaining three patients had stable disease.
“What makes these results especially encouraging is that they were achieved in patients who had exhausted other treatment options,” said Dr. Margaret Shipp, co-lead investigator of the Checkmate-039 study from Dana-Farber Cancer Institute in Boston.
“We’re also excited by the duration of responses to the drug,” she said. “The majority of patients who had a response are still doing well more than a year after their treatment.”
The results were being presented at the American Society of Hematology meeting in San Francisco.
A larger Phase II study is underway, the company said, one that will be used to confirm the results and to seek approval.
Nivolumab belongs to a new class of drugs called PD-1 inhibitors that work by blocking cancer cells’ ability to camouflage themselves from the immune system, allowing it to recognize and attack the cancer.
The drug received a breakthrough designation for Hodgkin lymphoma from U.S. health regulators, given to medicines seen as a potentially important advance. It is awaiting U.S. and European approval decisions for melanoma and lung cancer.
Merck & Co this year became the first company to receive U.S. approval for a PD-1 drug. It was for advanced melanoma, the deadliest form of skin cancer. Bristol’s drug is approved in Japan for melanoma under the brand name Opdivo.
Hodgkin lymphoma is one of the most frequent cancers in children and young adults. More than 9,000 cases are estimated to be diagnosed in the United States this year, according to the Leukemia and Lymphoma Society. About a quarter of all patients eventually relapse, creating a need for new treatments.
The most common side effects reported in the nivolumab study were rash and decreased blood platelet count.
(Reporting by Bill Berkrot in New York; Editing by David Gregorio)