Rhapsido (remibrutinib) is a prescription medicine used to treat adults with chronic spontaneous urticaria (CSU). This is a condition that involves hives, causing you to feel very itchy and uncomfortable. Hives are itchy red bumps or welts on your skin that are often raised. They may feel warm to the touch and can be any size, big or small. The hives can last anywhere from 30 minutes to 24 hours. To be diagnosed with CSU, you have to have hives most days of the week for six or more weeks.
Many times there is no known trigger for hives, making it hard to prevent and treat. Some people with CSU also have angioedema. Anyone can have CSU at any age, but it usually starts in your 20s, 30s, or 40s. You may be more likely to have CSU if you have allergies, eczema, asthma, or food allergies.
Rhapsido is a tablet that you swallow. It is used to help adults with CSU when antihistamines are not able to fully control symptoms.
How Does Rhapsido Work for Chronic Spontaneous Urticaria?
Rhapsido is a kinase inhibitor. It works by calming down part of your immune system that can sometimes go into “overdrive.” It blocks a protein called Bruton’s tyrosine kinase (BTK) that helps certain immune cells, like mast cells, release chemicals such as histamine.
In people with chronic spontaneous urticaria (CSU), these immune cells can become too active, even when there is not a clear trigger like pollen or food. Immune cells release histamine and other substances that cause itching, redness, and hives.
By blocking BTK, Rhapsido helps quiet these immune cells, which may reduce the release of those irritating chemicals. Rhapsido may help ease itching, swelling, and the number of hives over time.
How Was Rhapsido Studied for Chronic Spontaneous Urticaria?
The effectiveness and safety of Rhapsido for chronic spontaneous urticaria (CSU) was studied in two studies called REMIX-1 and REMIX-2. Everyone in the studies had CSU that was not well controlled with antihistamines.
In the first study (REMIX-1), the average age of people was 45, most were female (68%), and races were White (58%), Asian (30%), and Black or African American (3%). In the second study (REMIX-2), the average age of people was 42 years, most were female (65%), and races were White (52%), Asian (45%), and Black or African American (2%).
The Urticaria Activity Score-7 (UAS7) is a tool used to define CSU disease activity and severity over a seven-day period. It combines information about hives (Hive Severity Score or HSS7) and itching (Itch Severity Score or ISS7). HSS7 and ISS7 scores each range from 0 to 21. These two scores are added together to make the UAS7 score. Different disease severities are represented by the following UAS7 scores.
- No hives or itching symptoms: 0
- Well-controlled symptoms : 1 to 6
- Mild symptoms: 7 to 15
- Moderate symptoms: 16 to 27
- Severe symptoms: 28 to 42
To be included in either of the REMIX studies, people needed to have a UAS7 score of 16 or higher (moderate or severe symptoms). Most people in REMIX-1 (65%) or REMIX-2 (60%) had a UAS7 score of at least 28, so they had severe symptoms.
Both itching and hives had to be present to be included in the studies. People needed a weekly score of at least 6 out of 21 right before starting the study for both the ISS7 and HSS7. For REMIX-1, the average ISS7 score was 15, and the average HSS7 score was 16. For REMIX-2, the average ISS7 score was 14, and the average HSS7 score was 16.
People in the study took either Rhapsido 25 milligrams twice daily or a matching placebo (a pill with no medicine in it) twice daily for 24 weeks. Neither the people in the study nor the study investigators knew who was taking Rhapsido and who was taking the placebo.
What Benefits of Rhapsido Were Seen?
To see if Rhapsido helped people with CSU, the study looked at how much the ISS7 (itching), HSS7 (hives), and UAS7 (itching + hives) scores changed after 12 weeks of Rhapsido or placebo. In both studies, Rhapsido improved itch and hives more than placebo among people with symptoms despite taking antihistamines.
The percentage of people who had either no symptoms or well-controlled symptoms at week 12 are shown in the table below.
REMIX-1 | REMIX-2 | |||
Rhapsido | Placebo | Rhapsido | Placebo | |
UAS7 = 6 or less at week 12 (well controlled) | 49.8% | 24.8% | 46.8% | 19.6% |
UAS7 = 0 at week 12 (no symptoms) | 31.1% | 10.5% | 27.9% | 6.5% |
To summarize, among patients with moderate to severe CSU, Rhapsido reduced itching (ISS7) and hives (HSS7) more than the placebo did by week 12. Almost half of the people taking Rhapsido had well-controlled symptoms as compared with about a quarter of the people who took the placebo.
Your results may differ from what was seen in these studies.
How Long Does It Take to Work?
In the REMIX studies, some people with chronic spontaneous urticaria (CSU) who took Rhapsido saw improvements in their symptoms (less itching and hives) as early as two weeks after the first dose. For example, across the two studies, about 30% of people taking Rhapsido had UAS7 scores of 6 or less (well controlled) compared to less than 6% of people taking placebo. It may have taken longer for other people to see improvements.
Do not stop taking Rhapsido for CSU without talking with your health care provider first, even if your symptoms have gotten better. It is important to track your progress and review with your health care provider. Contact your health care provider if you do not see improvements or your symptoms are getting worse.
Is Rhapsido Right for Me?
Rhapsido should not be used in people with hives for reasons other than CSU or in children. It has not been studied in these types of people, so we have no way of knowing if it works.
Rhapsido may not be right for you if you have bleeding problems, take other medicines that also increase your risk for bleeding, or have surgery. Before taking Rhapsido, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. Also, be sure to tell your health care provider about any upcoming surgeries or procedures. Follow any instructions that they give you.
Rhapsido should also not be used if your liver is not working well. This may be the case if you drink a lot of alcohol. Your liver helps your body process Rhapsido to get rid of it. If your liver is not working well enough, your levels of Rhapsido may get too high, increasing your risk of side effects. Your health care provider can check lab work to see if your liver is working well enough for you to take Rhapsido.
If you have questions about whether or not Rhapsido is an option for you, talk to your health care provider.
