You might have heard of biologics being used to treat conditions like lupus or inflammatory bowel disease (IBS). But they can also help with pulmonary arterial hypertension (PAH). Here’s what you need to know.
What Are Biologics?
The term “biologic” refers to medications with ingredients – like proteins, cells or genes – that come from a living organism, such as an animal, human, or a microorganism.
Also called biopharmaceuticals, examples include:
- Blood and blood products, like plasma
- Vaccines
- Insulin for diabetes
- Stem cell therapy for blood disorders or cancers
- Immunotherapy for cancer
- Certain immune-suppressing medications for autoimmune diseases and asthma
As you might’ve guessed, biologics are harder and more expensive to make than synthetic medications.
What Is Biologic Therapy for PAH?
The FDA has only approved one biologic, sotatercept-csrk (Winrevair), for the treatment of PAH.
To understand how this drug works, you first need to understand what happens in your pulmonary arteries when you have PAH.
The condition leads to high blood pressure in the arteries in your lungs and the right side of your heart. That’s because the blood vessels in your lungs have become too narrow for blood to flow easily. This happened because changes in the cells that line the arteries in your lungs caused the artery walls to get thick, stiff and narrow.
The high blood pressure in your lungs leads to shortness of breath and fatigue that can make it very hard or even impossible to do daily tasks like walking to the mailbox or just general housekeeping.
Sotatercept blocks a protein that fuels the growth of muscle around the blood vessels and the cells lining them. When cell and tissue growth in and around these blood vessels slows down, the walls of the blood vessels may thin out and loosen. This can help blood flow and lower blood pressure in the lung arteries.
Can Biologics Improve Daily Life With PAH?
The clinical trial that led to FDA approval of sotatercept included 323 people with PAH who had moderate or severe limitations in their ability to do light, day-to-day physical activity like climb stairs, make the bed, or go grocery shopping.
Half the people in the clinical trial got a shot of sotatercept every three weeks. The others got a placebo, or “fake,” treatment. Before everyone started the medication or placebo, they did a test to see how far they could walk in six minutes. They did the same six months later.
Those who took sotatercept could walk 111 feet farther than they could before starting the drug. Overall, light daily physical activity was easier. Those in the placebo group only managed to walk about three more feet in six minutes. They saw little or no change.
People who took sotatercept saw improvement in other markers of disease severity, too. Many had lower levels of NT-proBNP, a substance in the blood that can be a sign of heart failure. The same wasn’t true for those in the placebo group.
Most importantly, those who took sotatercept were significantly less likely to get worse or die during the six-month period than those in the placebo group.
How Do You Take Biologics?
Most biologics are given as an injection, or shot. Some you can inject yourself at home. Others may require you to go to a clinic for an IV infusion.
Sotatercept is a shot that you give yourself every three weeks in your belly, upper arm, or upper thigh. A health care provider will teach you how to do it and make sure you're comfortable doing it on your own.
Do Biologics Have Side Effects?
Biologics in general tend to be more likely than other drugs to trigger a bad reaction in your immune system. Because biologics contain ingredients from living organisms, your body may see them as a threat, like a virus, and attack. This could lead to feeling sick or flu-ish, or it could cause an allergic reaction. In some cases, the body’s attack against the drug could keep it from working.
Minor side effects of sotatercept may include:
- Headache
- Dizziness
- Nosebleeds
- Rash or skin redness
- Spider veins
- Diarrhea
In more rare cases, sotatercept can cause serious side effects such as:
- Severe allergic reaction
- Blood clots
- Internal bleeding
Are There Other Biologics for PAH?
Biologic medication for PAH is a growing area of research. While only one is on the market, many more are in the pipeline.
None of the drugs currently being researched work the way sotatercept does. Each one affects different biological processes in the body. Once more of these drugs are available, doctors may be able to predict which one might work best for a person with PAH based on their unique traits and symptoms.
Show Sources
Photo Credit: iStock/Getty Images
SOURCES:
FDA.gov: “What are Biologics – Questions and Answers.”
Cleveland Clinic: “Biologics (Biologic Medicine).”
Mayo Clinic: “Pulmonary Hypertension.”
Cytokine and Growth Factor Reviews: “Principles of the activin receptor signaling pathway and its inhibition.”
The New England Journal of Medicine: “Phase 3 Trial of Sotatercept for Treatment of Pulmonary Arterial Hypertension.”
PHA Europe: “Classification and WHO functional class.”
Merck: “Winrevair.”
UC Health: “Sotatercept.”
Journal of Drug Targeting: “Emerging biologics for the treatment of pulmonary arterial hypertension.”
