Exciting Milestone Reached in Possible New Sickle Cell Disease Treatment
Do you know someone with Sickle Cell Disease (SCD)? There are millions of people worldwide suffering from SCD, including over 100,000 Americans, and that number is expected to grow exponentially by 2050.
While we’ve known about the disease for over 100 years, and have come to understand it much more over the past 50 years, major advances in treatment options are just coming along now (in the past ten years or so and right at this moment!). Let’s dig into what SCD is and some cutting-edge technology that is changing people’s lives!
What Is Sickle Cell Disease (SCD)?
SCD is a group of inherited diseases that affect your red blood cells (RBCs). Healthy RBCs are round and live 90 to 120 days on average. A protein called hemoglobin helps the RBCs deliver much-needed oxygen throughout the body. In SCD, hemoglobin doesn’t function correctly and deforms RBCs into sickle (“C”) shapes. This makes it much harder to carry oxygen, gums up the blood vessels and causes the RBCs to not live as long – only about 10 to 20 days.
What Does This Do to Patients?
Sick, sticky RBCs and lack of oxygen in the blood causes anemia and pain. The disease affects each patient differently and may change over time, but in general, symptoms related to disease complications include:
- Severe pain
- Signs of organ damage (e.g., yellowing of eyes due to jaundice)
Wow, sounds terrible, doesn’t it? It can be. And it affects many people around the world and in your community, maybe even yourself or your family members.
Who Is Affected and How?
Because SCD is an inherited disorder, it does affect some ethnic groups more than others. It is most common among those of African, South & Central American, and Middle-Eastern descent. In the U.S., most patients with SCD are black:
- About 1 in 13 African American babies are born with the trait
- About 1 in 365 African American babies are born with the disease
Remember learning about genes in science class? You get half your genes from your mom and half from your dad. If both parents carry the sickle cell trait, the child will have sickle cell disease.
A simple blood test, part of routine newborn screening at birth, can detect the disease. As with other genetic tests, if you’re thinking about having children, mom and dad can get tested to see what the likelihood of their child having SCD is.
How Is It Treated? Is There a Cure?
There is no single best treatment for all patients with SCD. Treatment is based on complications and symptoms the patient is experiencing. Some common treatments include:
- Pain relievers for acute and chronic pain (e.g., opioids)
- IV fluids
- Blood transfusions
- Antibiotics (for infections)
- Newer FDA-approved medications:
- L-Glutamine (Endari®) (FDA approved in 2017)
- Crizanlizumab (Adakevo®) (FDA approved in 2019)
The only known cure at this time is a bone marrow transplant. There are plenty of risks and benefits to consider, and this is not an option for everyone, unfortunately.
Hopefully, this will change soon as there are several exciting advancements on the horizon.
CRISPR Technology – Huh?
Time to go back to your science class yet again (dust off those cobwebs)! Our genes make us who we are. Genes are made up of DNA – deoxyribonucleic acid, which are long, double-stranded molecules that have a special sequence of repeated values (bases). Inherited diseases like SCD occur when there is an error in that sequence.
What if we could go in and fix that error?! This idea forms the basis of many genetic technologies being studied today. One of which is known as “CRISPR-Cas9”
CRISPR stands for clustered regularly interspaced short palindromic repeat – WHOA. I know. Stay with me. There are two components to the CRISPR-Cas9 technology:
- Guide RNA: identifies the relevant error in the DNA sequence
- Cas9 enzyme: cuts the DNA at the identified location for editing
Excitingly, this technology is being studied in several genetic diseases. For SCD, the editing phase includes inputting fetal hemoglobin (healthy hemoglobin) that then takes the place of the sickled cells. The first patient with SCD who received this treatment recently passed the one-year milestone and is doing great!
Over 1 Year and Counting!
Victoria Gray, a 34-year-old woman from Mississippi, was the first person to receive CRISPR-Cas9 treatment in the U.S. Both lab results and patient reports are promising. Gray reports markedly improved symptoms and quality of life, which is very exciting. Click here if you want to learn more about Gray’s journey.
Of course, this treatment is still in the very early stages of development and has a long way to go to be approved and available to all patients with SCD, but this is a great start.
Wow, I bet you didn’t expect quite the science lesson today! Thanks for sticking with me to learn about this very important disease. If you want to learn more, now is a great time because September is National Sickle Cell Awareness Month. Keep your eyes and ears open for more exciting advancements in the treatment of genetic diseases like SCD.
1. Sickle Cell Disease. MedlinePlus. Updated August 24, 2020. Accessed September 2, 2020. https://medlineplus.gov/sicklecelldisease.html
2. Salinas Cisneros G, Thein SL. Recent Advances in the Treatment of Sickle Cell Disease. Front Physiol. 2020;11:435. May 20, 2020. doi:10.3389/fphys.2020.00435
3. What is Sickle Cell Disease? Centers for Disease Control and Prevention. Updated October 21, 2019. Accessed September 2, 2020. https://www.cdc.gov/ncbddd/sicklecell/facts.html
4. CRISPR/Cas9. CRISPR Therapeutics. 2020. Accessed September 2, 2020. http://www.crisprtx.com/gene-editing/crispr-cas9
5. Questions and Answers About CRISPR. Broad Institute. 2020. Accessed September 2, 2020. https://www.broadinstitute.org/what-broad/areas-focus/project-spotlight/questions-and-answers-about-crispr
6. Stein R. A Year In, 1st Patient To Get Gene Editing For Sickle Cell Disease Is Thriving. National Public Radio. June 23, 20202. Accessed September 2, 2020. https://www.npr.org/sections/health-shots/2020/06/23/877543610/a-year-in-1st-patient-to-get-gene-editing-for-sickle-cell-disease-is-thriving
7. National Sickle Cell Awareness Month. Sickle Cell Disease Association of America. 2020. Accessed September 2, 2020. https://www.sicklecelldisease.org/get-involved/events/national-sickle-cell-awareness-month/