GBT440 increases haemoglobin oxygen affinity, reduces sickling and prolongs RBC half-life in a murine model of sickle cell disease.
Oksenberg, D., Dufu, K., Patel, M.P., Chuang, C., Li, Z., Xu, Q., Silva-Garcia, A., Zhou, C., Hutchaleelaha, A., Patskovska, L., Patskovsky, Y., Almo, S.C., Sinha, U., Metcalf, B.W., Archer, D.R.(2016) Br J Haematol 175: 141-153
- PubMed: 27378309 
- DOI: https://doi.org/10.1111/bjh.14214
- Primary Citation of Related Structures:  
5E83 - PubMed Abstract: 
A major driver of the pathophysiology of sickle cell disease (SCD) is polymerization of deoxygenated haemoglobin S (HbS), which leads to sickling and destruction of red blood cells (RBCs) and end-organ damage. Pharmacologically increasing the proportion of oxygenated HbS in RBCs may inhibit polymerization, prevent sickling and provide long term disease modification. We report that GBT440, a small molecule which binds to the N-terminal α chain of Hb, increases HbS affinity for oxygen, delays in vitro HbS polymerization and prevents sickling of RBCs. Moreover, in a murine model of SCD, GBT440 extends the half-life of RBCs, reduces reticulocyte counts and prevents ex vivo RBC sickling. Importantly, oral dosing of GBT440 in animals demonstrates suitability for once daily dosing in humans and a highly selective partitioning into RBCs, which is a key therapeutic safety attribute. Thus, GBT440 has the potential for clinical use as a disease-modifying agent in sickle cell patients.
Organizational Affiliation: 
Global Blood Therapeutics Inc., South San Francisco, CA, USA. doksenberg@globalbloodtx.com.