SAN FRANCISCO (TheStreet) -- The new class of cancer immunotherapy drugs led by Merck's (MRK) Keytruda and Bristol-Myers Squibb's (BMY) Opdivo have already generated tremendous excitement for their ability to shrink solid tumors. Now, the drugs are also demonstrating equal promise in blood-related cancers.
Patients with very advanced Hodgkin lymphoma unresponsive to any currently approved medicines were able to achieve complete remissions of their disease following treatment with Merck's Keytruda and Bristol's Opdivo, according to results from separate, early-stage studies being presented for the first time at the American Society of Hematology (ASH) annual meeting here.
These studies demonstrate that so-called checkpoint inhibitors can prime a patient's own immune system to identify and kill certain types of blood cancer cells just like they do with solid tumors such as melanoma and lung cancer.
Based on the early data from these studies, Merck and Bristol-Myers are moving ahead with larger studies necessary to get their respective drugs approved as new treatments for blood-related cancers.
The Merck study enrolled 29 patients with relapsed/refractory Hodgkin lymphoma, meaning their cancer had returned and was growing despite treatment with Seattle Genetics' (SGEN) Adcetris, the only drug currently approved for such advanced disease. Twenty patients enrolled in the study failed a prior stem cell transplant, while the remaining nine patients were either ineligible or refused a stem cell transplant.
Six of the 29 patients (21%) treated with Merck's Keytruda achieved a complete remission, meaning there was no evidence of disease in their bodies. Another 13 patients achieved partial remission, for an overall response rate to Keytruda of 66%.
At the time of the analysis, 17 of the 19 patients with either a complete or partial remission were still responding to Keytruda. The median duration of response has not yet been reached in the study.
In all, 27 of the 29 Hodgkin lymphoma patients treated with Keytruda showed some level of response or tumor shrinkage in the study.