CLB-505

CLB-505 is a recombinant, modified Hepatitis B surface antigen (HBsAg) protein designed as part of a bivalent subunit therapeutic vaccine for chronic hepatitis B. It is one of two engineered antigens (the other being CLB-405) included in the investigational vaccine candidate CLB-3000, which aims to drive functional cure in patients with chronic hepatitis B infection. Both proteins were designed to display clearance profile-associated epitopes identified from anti-HBs responses of functionally cured patients. The proteins are expressed in Pichia pastoris yeast and adjuvanted with Alhydrogel for enhanced immunogenicity[3][6]. The primary developer is ClearB Therapeutics, and the product is currently under clinical investigation. CLB-505 itself is not marketed as a standalone drug but as a component of the bivalent therapeutic vaccine candidate CLB-3000 for chronic hepatitis B. Its mechanism involves eliciting an immune response against hepatitis B virus by presenting specific viral epitopes associated with viral clearance[3][6].