Innovent Biologics Inc. said blood cancer patients treated with its experimental drug IBI-308 showed a high response rate in a mid-stage study.

In the phase 2 trial, dubbed Orient-1, the drug now known as sintilimab was given to 96 patients with difficult-to-treat classical Hodgkin lymphoma — a type of blood cancer that affects part of the immune system.

Treatment with the drug led to 79.2% of patients experiencing a reduction in cancer growth and about 97.9% of patients saw their disease regress or stabilize.

The Suzhou, China-based private company is expected to present the updated and final analysis of the drug's overall response rate at the American Society of Clinical Oncology in June.

Sintilimab is part of a class of anticancer drugs that interfere with the interaction between certain proteins on the surface of immune cells and cancer cells. Blocking these interactions — such as the pairing of PD-1 proteins on immune cells with PD-L1 proteins on tumor cells — enable the immune system to target cancer.

In the race to be the first drug of its class to reach the Chinese market, the company is one of few domestic manufacturers to have filed a drug approval application with the China Food and Drug Administration.

Innovent's drug targets the PD-1 protein and is being jointly developed with Eli Lilly and Co. to treat a number of solid tumor cancers such as lung, kidney and gastric cancer, in addition to skin cancer.