Galcanezumab (Emgality) is a drug your doctor can prescribe to prevent migraines or treat episodic cluster headaches. It’s the first medication the FDA has approved to treat cluster headaches. And it’s in a class of drugs that are the first treatments designed specially to prevent migraines (other medicines prescribed for this reason were originally used for different conditions).
With episodic cluster headaches, you have a series of short and very painful headaches over a stretch of 7 days to 1 year, with pain-free periods of 1 month or longer in between. Galcanezumab doesn’t treat chronic cluster headaches, which are attacks over a period of at least a year, with headache-free periods lasting less than a month.
How Does Galcanezumab (Emgality) Work?
Galcanezumab is a type of drug called a CGRP inhibitor. Calcitonin gene-related peptide, or CGRP, is a protein that nerves and blood vessels in your brain give off when you have a migraine. It helps send signals that cause pain and inflammation.
Galcanezumab can block the action of CGRP because it’s a monoclonal antibody. Monoclonal antibodies are lab-made versions of the antibodies your immune system makes to fight things like viruses and bacteria. They’re made to target a certain substance – in this case, CGRP.
Monoclonal antibodies are such large molecules that the only way to get them into your system is through an injection or IV.
What Can You Expect When You Take Galcanezumab (Emgality)?
You take galcanezumab as a shot just under your skin (called a subcutaneous injection). You take it once monthly, around the same day each month.
You might notice benefits after a week of starting galcanezumab. But for some people, it could take 2-3 months to work.
Before you begin treatment, your care team will tell you how to give yourself the shot. After that, you or a caregiver can do your injections at home.
There are three doses of galcanezumab:
- 120 milligrams per milliliter in a single-dose prefilled auto-injector pen
- 120 milligrams per milliliter in a single-dose prefilled syringe
- 100 milligrams per milliliter in a single-dose prefilled syringe
The doses for migraine are different from those for cluster headaches.
Prevention of migraines. Your first dose will be 240 milligrams, in two shots of 120 milligrams each. You’ll take the two injections at the same time, one right after the other. You may get these first doses at your doctor’s office. After that, you’ll give yourself a single shot of 120 milligrams every month. You can use either the injection pen or the syringe.
Treatment for episodic cluster headaches. You’ll begin with 300 milligrams of galcanezumab, in three shots of 100 milligrams each. You take all three shots back-to-back at the start of a cluster headache period. Then, you repeat this same dose once a month until the cluster period is over. You’ll use a syringe for your injections.
Before you inject yourself, wash your hands. Choose a fatty area of your body to inject the medication. This could be your thigh, butt, back of your upper arm, or stomach. Don’t inject in any place that your skin is tender, bruised, thick, hard, scaly, or red.
Common Side Effects of Galcanezumab (Emgality)
The most common side effect of galcanezumab is a reaction around the skin where it was injected. About 18% of those taking the drug had injection site reactions. They include:
- Bleeding
- Blistering
- Burning, stinging, or tingling
- Coldness or warmth
- Changes in skin color
- A feeling of pressure, pain, or soreness near the injection site
- Rash, redness, or hives
- Infection
- Inflammation
- Itching
- Lumps
- Numbness
- Scarring
A more serious side effect is an allergic reaction to the medication. You can get a reaction right away or days after you take the medicine.
If you have rashes, itching, hives, or trouble breathing, you might be allergic to galcanezumab. Call your doctor or 911 if you notice:
- Swelling in your face, tongue, mouth, or throat
- Trouble breathing or swallowing
Warnings and Safety Issues With Galcanezumab (Emgality)
Don’t take galcanezumab if you have an allergy to the drug or any of its ingredients.
If you have any kind of allergic reaction, stop the drug and get medical help right away.
Before you start galcanezumab, tell your doctor if you’re pregnant or plan to get pregnant. Also let them know if you breastfeed or plan to. We need more research into how CGRP might affect your baby.
Tell your doctor about all other drugs you take, including over-the-counter medications and supplements. While there are no drugs known to interact with galcanezumab, it’s smart to keep your doctor in the loop.
How Effective Is Galcanezumab (Emgality)?
Two 6-month studies looked at the effectiveness of galcanezumab for episodic migraines, which are when you have attacks on fewer than 15 days of every month. Study participants got either 120 milligrams of galcanezumab, 240 milligrams of galcanezumab, or a placebo shot (one that contained no medication).
The studies found that around 60% of those who took galcanezumab said the number of headache days they had each month went down by at least half during the study period. The effect was similar for both the 120- and 240-milligram doses. By comparison, less than 40% of those who took the placebo reported that level of improvement.
A 3-month study looked at adults with chronic migraines, which are migraines on 15 or more days out of the month. They also got either 120 or 240 milligrams of galcanezumab or a placebo. Some 28% of those on galcanezumab saw monthly headache days reduced by half, compared with 15% of those on the placebo. Results were similar for either dosage of galcanezumab.
In a study of people with cluster headaches, 71% of study participants reported that within 3 weeks of their first dose of galcanezumab, the number of their weekly headaches was cut in half.
What’s the Long-Term Safety of Galcanezumab (Emgality)?
Galcanezumab is considered a safe medication. The most common side effect people have reported is injection site reactions. But in clinical studies, very few people stopped treatment because of this.
A study that looked at the use of galcanezumab over 12 months found that the drug was effective, safe, and caused few side effects for people with chronic migraine.
Another study that followed people with cluster migraines had similar results.
Since there have been no major studies of this drug in children or people over 65, experts don’t know if it’s safe for people in these groups. Galcanezumab isn’t approved to treat children. If you’re over age 65, talk to your doctor before you start it.
