By Lauren Thayer from In The Cloud Copy
Sickle cell disease (SCD) is group of inherited red blood cell disorders. In a typical, healthy red blood cell, the cell is round and they carry oxygen through blood vessels throughout the body. In sickle cell disease, the healthy red blood cells become hard, sticky and “C” shaped. The sickled cells die early, meaning patients with sickle cell disease are constantly short on red blood cells. The sticky, hard cells may also clog small blood vessels, leading to more serious health problems.
Types of Sickle Cell Disease
There are a few different types of commonly recognized sickle cell disease. HbSS is usually the most severe form of the disease and occurs when the affected individual inherits two sickle cell genes – this is commonly called sickle cell anemia.
HbSC is a type of sickle cell in which the individual inherits a sickle cell gene from one parent and an abnormal hemoglobin gene from the other parent. This is typically a milder form of sickle cell disease.
HbS beta thalassemia individuals inherit a sickle cell gene from one parent and a beta thalassemia gene (another type of anemia) from the other parent.
Sickle cell trait or HbAs occurs when the patient inherits one sickle cell gene from one parent and one normal gene from the other parent. These individuals do not typically display any symptoms but can pass the disease on to their own children.
Finally, there are a few rare forms of SCD including HbSD, HbSE, and HbSO, in which the individual inherits one sickle cell gene and one gene of an abnormal type of hemoglobin, either D, E, or O.
Treatment with IMR-687
Biopharmaceutical company Imara Inc. has been working on a novel therapy for sickle cell disease called IMR-687. IMR-687 acts on the red and white blood cells, as well as adhesion mediators. It is highly selective and is a small molecule inhibitor of PDE9.
This once-a-day oral treatment that was given as a monotherapy, or in combination with hydroxyurea (HU), was well tolerated by clinical study participants and showed statistically significant increase in F-cells, which are red blood cells that contain fetal hemoglobin.
Compared with the placebo group, those treated with monotherapy IMR-687 saw a 18.1% increase in F-cells, which represents a mean increase from baseline of about 155%.
Patients in the clinical study tolerated the IMR-687 well, with reported mild-to-moderate GI events, and no reported hypotension or neutropenia. Patients also reported fewer vaso-occlusive crises, a dangerous event that occurs in SCD patients.
The clinical trial will now enter Phase 2b in which patients will be given higher doses of IMR-687 for up to one year.
IMR-687 seems to be a safer treatment option for sickle cell patients as it does not come with the limitations and safety concerns that current treatments present. The hope is that this once-daily medication can be taken alone or in combination with current therapies, resulting in better patient outcomes and higher quality of life for patients living with sickle cell disease.
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