Sickle Cell Disease

SCD is a destructive disease with lifelong complications and debilitating symptoms.

Sickle Cell Disease (SCD) is a genetic blood disorder affecting hemoglobin, a protein in red blood cells that carries oxygen from the lungs to the body’s tissues and returns carbon dioxide from the tissues back to the lungs. SCD varies substantially in presentation and clinical course.

SCD is caused by an inherited mutation that results in substitution of the amino acid valine for glutamic acid in the sixth position of the beta globin chain. This causes the formation of HbS, an atypical form of hemoglobin that can cause red blood cells to change shape, or sickle. Most SCD is caused by having two copies of the HbS gene, but in some cases one HbS gene can cause the disease if it is combined with a another Hb gene mutation.

A Heterogenous Disease – Several Genotypes

There are several genotypes of SCD found globally with the following being most prevalent:

HbSS
Patients inherit two sickle cell genes (‘‘S’’); one from each parent. This is often referred to as ‘‘sickle cell anemia’’ and is usually the most severe form of SCD.

HbSC
Patients inherit a sickle cell gene (‘‘S’’) from one parent and an abnormal hemoglobin gene called ‘‘C’’ from the other parent. This is usually a milder form of the disease.

HbS/Beta thalassemia:
Patients inherit a sickle cell gene from one parent, and a gene for β thalassemia, another form of anemia, from the other parent. There are two types of beta thalassemia: ‘‘0’’ and ‘‘+’’. βthal0 is often a more severe form while βthal+ is a milder form.

STRONG-SCD Phase 2 Study

Following the completion of Phase 1 studies in healthy volunteers that demonstrated a well-tolerated dose range, dose-proportional pharmacokinetics and target engagement, we initiated our Phase 2 study in patients with SCD, the STRONG-SCD study.

The STRONG-SCD study is a randomized, placebo-controlled, dose-ranging Phase 2 study of 70 participants designed to evaluate safety, tolerability, and pharmacokinetics of olinciguat, compared to placebo, as well as to explore effects on daily symptoms and biomarkers of disease activity when dosed over a 12-week treatment period.

 

Dominique, Sickle Cell Disease Patient

Photo by Raimon Norris

SCD Facts & Figures

Most common hemoglobin disorder worldwide

Globally, affects an average of 300,000 children born annually

Affects approximately 100,000 patients in the US

Standard part of mandatory newborn screening in US

About one in every 365 African American births

About one in 16,300 Hispanic-American births

Most prevalent genetic disease in France and the UK

Frequency is steadily rising in many other countries in Northern, Central and Southern Europe

Average SCD patient is admitted to the hospital seven times per year

Average length of stay per visit is seven days

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