According to the Centers for Disease Control and Prevention, sickle cell disease (SCD) affects 100,000 individuals in the United States and the sickle cell gene is present in 1 in 13 African American newborns. If a newborn has sickle cell anemia, a type of SCD, the individual inherits a mutation in both of the hemoglobin subunit beta genes, leading to low blood count and increased infection that can be detected at birth. In individuals who have SCD, their red blood cells (RBCs) become stiff and easily adhere to the sides of blood vessels, preventing blood flow and the transport of oxygen to cells in the body. Sickle cell anemia can cause the early death of RBCs and periods of extreme pain when RBCs become stuck in blood vessels. Currently, individuals can receive a bone marrow transplant to cure SCD, but the method poses many risks. For instance, side effects from the transplant include the donor’s bone marrow attacking the recipient’s organs and the new bone marrow not producing ample RBCs.
Image of sickle cells (long, extended C-shaped cells) and healthy red blood cells (round, smooth cells) under a microscope.
Image Source: Cultura RM Exclusive/Michael J. Klein, M.D.
Because of the possible dangers of receiving a transplant, ongoing studies have tried to find more treatment options for SCD patients, such as a drug called crizanlizumab. The drug inhibits proteins that aid in the binding of molecules, so, when the drug binds to the proteins, it decreases the adhesion of RBCs to each other and the vessel lining. The Reprixys Pharmaceutical Corporation completed a clinical trial that showed the power crizanlizumab had in reducing pain crises in patients with SCD. The trial studied 198 patients in the United States for 52 weeks and measured the rate of hospital admittance or the frequency of receiving pain medication because of pain related to SCD. The trial results demonstrated that patients in the treatment group who took the drug had fewer instances of severe pain on average in the 52-week period compared to patients without the drug. The drug also delayed the time that patients had their first pain crisis as patients in the treatment group who received the drug did not have their first pain crisis until a median of 4.1 months into the study compared to a median of 1.4 months after the start of the study for the placebo group. In November 2019, the Food and Drug Administration approved the drug to be used alone or along with hydroxyurea, another drug that treats sickle cell anemia by enhancing the size of RBCs and preventing them from becoming an abnormal shape.
With the expanded distribution and use of crizanlizumab, there is hope that more patients with SCD can manage pain associated with the disease and get access to treatment and care.
Featured Image Source: Drobot Dean
