Hives, or what doctors call urticaria, are red, itchy, and sometimes painful welts that show up on your skin. If you have chronic spontaneous urticaria (CSU), your hives occur spontaneously and recur for more than 6 weeks. They could also stick around for months or years.
Hives aren’t life-threatening, but they can deeply affect your daily life. The itching may keep you awake at night or distract you during the day. You may be embarrassed or frustrated at how your skin looks. Feeling anxious and depressed are common when you live with CSU.
Because its cause is unclear, treating CSU is a challenge. Antihistamines are often tried, but they usually only work half the time.
Dupilumab (Dupixent), a medicine that you get as a shot, is the first new treatment for CSU in the U.S. in over a decade.
Here's the journey it took to FDA approval.
The Science Behind the Drug
Cytokines are proteins in your body that work as messengers for your immune system. They signal when it’s time to fight a threat like an infection. Normally, the inflammation that cytokines set into motion only lasts long enough to get rid of germs and start to repair damaged cells.
But if this process doesn’t work like it should, you end up with too many cytokines and inflammation that doesn’t go away. Doctors call this type 2 inflammation. It plays a big role in skin disorders like CSU.
So how does dupilumab help?
It’s a type of medicine known as a biologic. These treatments work on certain parts of your immune system. To break that down even more, dupilumab is a type of biologic called a human monoclonal IgG4 antibody. It contains lab-made proteins that work just like parts of your immune system called antibodies.
Dupilumab targets two specific cytokines — interleukin-4 (IL-4) and interleukin-13 (IL-13) — known to trigger skin issues. It stops them from talking to other cells, which then helps bring down inflammation inside your body.
If you think of IL-4 and IL-13 as keys that can turn on skin inflammation, dupilumab works by gumming up the lock.
Why Dupilumab as a CSU Treatment?
For years, scientists have known that this medication could help treat other conditions.
In 2017, the FDA approved dupilumab to treat dermatitis when prescription skin creams didn’t help.
In 2018, the FDA approved it to treat asthma in people aged 12 or older.
Researchers kept asking: What other conditions could dupilumab treat? It was tested as a treatment for kids with asthma as well as for babies, kids, and teens with dermatitis. Dupilumab was also tested on conditions like nasal polyps and alopecia.
This research led to it being approved to treat different type 2 inflammation conditions in the U.S. and around the world. The makers of dupilumab decided to see if it could also help CSU.
Getting FDA Approval for CSU
The steps to getting a drug approved by the FDA include:
Lab or animal tests. These help scientists understand how a drug works and how it might help people.
Clinical trials. Long-term studies rely on volunteers to try a medication. Clinical trials can confirm if a treatment is helpful and safe.
FDA review. Once clinical trials are over, the results are reviewed by a special group of scientists and doctors.
FDA approval means that all data about a drug has been carefully reviewed and that the benefits of its treatment outweigh its known risks.
Dupilumab has been studied in more than 60 clinical trials with over 10,000 patients. But to get approved by the FDA as a CSU treatment, new clinical trials were needed to show it could help people with chronic hives.
Clinical Trials
In 2020, dupilumab’s clinical trials began.
Study A
People who only took antihistamines were compared to another group who took dupilumab as well.
The dupilumab group showed:
- 63% less itching vs. 35% in the other group
- 65% reduction in itching and hives vs. 37% in the other group
Side effects between the two groups were about the same, with the most common complaint being pain from the shot.
Study B
Dupilumab was given to people with hard-to-treat CSU who hadn’t been helped by other medications. This trial ended early. Not because of safety issues, but because the scientists running it didn’t think they would get the results they were hoping for.
Because of these results, the FDA did not approve Dupixent. They asked to see more data.
Study C
This trial included 151 kids and adults with CSU. Thirty percent who took Dupixent and antihistamines saw their hives go away. It confirmed the results of study A. No new safety issues were found.
Based on the results of the studies, the FDA approved dupilumab for use in CSU.
Watching Over Time
Even after a drug is approved, FDA experts keep a close eye on it. Sometimes, new side effects show up.
For instance, after dupilumab was approved for conditions like dermatitis and asthma, some people reported:
- Rash
- Swelling
- Itching
- Bumps on their skin
- Burning
- Pain
But because these side effects were reported by random users, it’s hard to figure out if the drug itself is the cause. Many other things could also cause these issues.
Should You Try Dupilumab?
If you have CSU and other treatments haven’t helped, dupilumab might be a good fit.
It might not be right for you if you have any of the following:
- Eye issues
- Parasite infection
- You just got or are about to get a live vaccine
- You’re pregnant or want to get pregnant
- You’re nursing or plan to nurse soon
Talk to your doctor if any of these conditions apply to you. They should also know about any other medicines, vitamins, recreational drugs, or herbal supplements you take.
Recap
- Dupilumab (Dupixent), a medicine that you get as a shot, is the first new treatment for CSU in the U.S. in over a decade.
- It’s already used to treat different inflammation conditions in the U.S. and around the world.
- Dupilumab is a biologic treatment. It works by blocking certain pathways inside your immune system. That helps decrease inflammation.
- Clinical trials show that dupilumab works well and is safe, but it may not be for everyone. For instance, it’s unclear how it affects pregnant people, your fetus, or your breastmilk.
