Global Blood Therapeutics (GBT) announced that 2 novel treatments for sickle cell disease (SCD), inclacumab and GBT021601 (GBT601), were granted Orphan Drug and Rare Pediatric Disease designations by the US Food and Drug Administration (FDA).

Inclacumab, a novel P-selectin inhibitor, is being studied in 2 trials to assess its ability to reduce vaso-occlusive crises (VOCs) and hospital readmissions due to VOCs in patients with SCD. GBT601 is a next-generation sickle hemoglobin polymerization inhibitor that aims to achieve higher hemoglobin levels than voxelotor (Oxbryta®) at lower doses and with an acceptable safety profile.

“The FDA’s orphan drug and rare pediatric disease designations for both inclacumab and GBT601 are an acknowledgment of the critical and ongoing unmet need in sickle cell disease and the potential of GBT’s innovative pipeline of investigational medicines,” Kim Smith-Whitley, MD, executive vice president and head of research and development at GBT, said in a press release.

Read more about SCD experimental therapies

VOCs are a significant cause of hospital readmissions in patients with SCD. The two phase 3 clinical trials evaluating the safety and efficacy of inclacumab for VOC reduction are currently enrolling patients aged 12 or more years with SCD who have had 2 to 10 VOCs in the previous year. Inclacumab will be dosed quarterly.

GBT601 is being studied in a phase 1 clinical trial, which is expected to move to phase 2 by mid-2022.

“We believe that both inclacumab and GBT601 have the potential to be best-in-class therapeutic options for the treatment of this devasting disease,” Dr. Whitley said.


GBT’s inclacumab and GBT601 receive U.S. FDA Orphan Drug and Rare Pediatric Disease designations for the treatment of sickle cell disease. News release. Global Blood Therapeutics, Inc; June 6, 2022.