Biopharmaceutical company CStone Pharmaceuticals said on Tuesday that it has received the first approval of investigational new drug (IND) application from the US Food and Drug Administration (FDA) for CS1001.

Following the IND approval in the US, the company expects to make further IND filings with the US FDA for other self-developed pipeline drug candidates.

CS1001, an investigational monoclonal antibody directed against PD-L1, is China's first fully human and full-length anti-PD-L1 monoclonal antibody. The US clinical trial is a bridging Phase I dose-escalation study, designed to confirm CS1001's recommended Phase II dosage (RP2D) in US patients with solid tumours.

In conjunction, the company has completed the CS1001 Phase I dose-escalation study in China, which showed the drug to be well-tolerated and produced sustained clinical benefit. Additionally, two pivotal Phase II studies have been initiated in China for natural killer cell/T-cell lymphoma (CS1001-201) and classical Hodgkin's lymphoma (CS1001-202). The Phase III studies are under way or being prepared both in China and globally for various serious tumour indications.