Benralizumab (Fasenra) is a medicine your doctor can prescribe to treat eosinophilic asthma that other medications haven’t worked well enough to control. When you have this type of asthma, your blood and lungs have too many white blood cells called eosinophils. These cells inflame and narrow the airways of your lungs, which means you have trouble breathing.
How Does Benralizumab (Fasenra) Work?
Benralizumab is a type of drug called a monoclonal antibody. These are lab-made proteins that act like a protein your body makes as part of its immune response against harmful substances like viruses. This drug binds to interleukin-5, a substance that helps eosinophils multiply and survive. In doing so, it recruits natural killer cells to destroy eosinophils via antibody-dependent cell-mediated cytotoxicity (ADCC).
Without IL-5, eosinophils die. Benralizumab also kills eosinophils directly. When you have fewer of these white blood cells, you have less swelling in the airways of your lungs.
What Conditions Does Benralizumab (Fasenra) Treat?
This medicine treats serious eosinophilic asthma in people 12 and older. Doctors prescribe it as an add-on to other medicines like steroids and long-acting beta-agonists when they don’t work to control your asthma symptoms.
Benralizumab prevents asthma symptoms, but it doesn’t treat asthma attacks. Your doctor can prescribe other medicines like inhalers for you to use when your symptoms flare up.
How Do You Take Benralizumab (Fasenra)?
You take benralizumab in a shot. You’ll get it once every 4 weeks for your first three doses, then once every 8 weeks.
You can get the shot at your doctor's office or clinic. Your doctor or nurse will give you the injection under the skin of your upper arm, thigh, or belly. Afterward, they’ll watch you for symptoms of an allergic reaction.
If you feel comfortable giving yourself a shot, your doctor can show you how to inject benralizumab at home with a self-injector pen. You clean your skin with an alcohol wipe, then give yourself the shot in your thigh or lower belly. The pen or syringe stays in place until all the medicine has gone in.
Common Side Effects of Benralizumab (Fasenra)
Some of the more common side effects you could have when you take benralizumab are:
- Headache
- Fever
- Sore throat
These side effects may go away within a few weeks as your body adjusts to the drug. Talk to your doctor if they last a long time or get in the way of your daily life.
If you have an allergic reaction to benralizumab, you could have symptoms like these:
- Hives
- Rash
- Swelling
They can appear within a few hours after the injection. Or they might not show up until days later. If you have an allergic reaction to benralizumab, your doctor will tell you to stop taking this medicine.
Rarely, benralizumab can cause a severe and life-threatening allergic reaction called anaphylaxis. Get medical help right away for symptoms like these:
Warnings and Safety Issues With Benralizumab (Fasenra)
Before you take benralizumab, let your doctor know about any allergies you have to medicines or anything else. While doctors don’t know of any drugs that interact badly with benralizumab, make sure your doctor knows about all the other medications, vitamins, and supplements you take. And always tell other health care providers you use that you’re on benralizumab.
This medicine doesn't treat asthma attacks once they start. Tell your doctor if your asthma symptoms continue or get worse while you're taking benralizumab.
If you also use inhaled steroids or steroid pills, don't stop taking them unless your doctor tells you to. Stopping steroids quickly could cause an asthma flare or withdrawal symptoms like these:
- Appetite loss
- Body aches
- Fatigue or weakness
- Joint pain
- Mood swings
- Nausea
If you need to stop steroids, your doctor will help you lower your dose slowly to avoid these problems.
Tell your doctor before you take benralizumab if you have hookworm, roundworm, or whipworm. These parasites spread in some tropical countries. By reducing the eosinophils in your body, benralizumab might make it harder for your immune system to fight parasites. If you have one of these infections, your doctor will treat you for it before you start on benralizumab.
What Is the Long-Term Safety of Benralizumab (Fasenra)?
Benralizumab has been FDA-approved since 2017 to treat severe eosinophilic asthma.
A study called MELTEMI found that benralizumab was safe when people took it for up to 5 years. Very few people in the study had side effects from this medicine. The risk of side effects didn't increase after people had taken benralizumab for a few years.
Who Should Avoid Taking Benralizumab (Fasenra)?
Benralizumab isn't right for everyone. Scientists don't know whether it's safe for children under 12, so it's prescribed only to kids that age and older as well as adults.
Don't take benralizumab if you’re allergic to its active ingredient (benralizumab) or to any of the other ingredients in this medicine.
Doctors don't know whether benralizumab is safe to take during pregnancy or while breastfeeding. Monoclonal antibodies can cross the placenta and reach the baby. These medicines can also get into breast milk.
It's not clear how this medicine might affect a growing baby or infant. Because uncontrolled asthma also has risks, your doctor will weigh the pros and cons of keeping you on benralizumab when you’re pregnant or breastfeeding.
How Effective Is Benralizumab (Fasenra)?
Clinical studies compared benralizumab to a fake treatment (called a placebo) in people who had severe asthma symptoms while taking steroids plus a long-acting beta-agonist. In these trials, the group that added benralizumab:
- Had fewer asthma attacks
- Were able to lower their steroid dose
- Went to the hospital less often
- Had better lung function as measured on a forced expiratory volume (FEV1) test
- Said they had a better quality of life
In long-term studies, benralizumab continued to reduce asthma attacks in people with severe eosinophilic asthma for up to 5 years.
How Much Does Benralizumab (Fasenra) Cost?
No generic version is available for benralizumab. The brand-name medication costs $5,500 per injection before insurance, but you probably won’t pay that much. Your out-of-pocket cost depends on your health insurance coverage.
According to AstraZeneca, the drug’s maker, someone with an employer-sponsored or private insurance plan can expect to pay about $46 per dose out of pocket. With Medicare, the average cost is $90 per dose. Medicaid costs range from $2 to $9 per dose.
If you can't afford the cost of benralizumab, the drugmaker offers a Fasenra Savings Program that may help you pay for your medicine. The company also has other programs that can provide benralizumab free or at a reduced cost for people who’ve been denied coverage or don’t have insurance.
