Dawnzera: An Expert’s Perspective

Medically Reviewed by Michelle Vermeulen, PharmD on September 24, 2026

By Timothy Craig, DO, as told to Rachel Reiff Ellis

Timothy Craig, DO, is an allergist and immunologist at Penn State College of Medicine and a member of the medical advisory board of the US Hereditary Angioedema Association in Hershey, Pennsylvania. The information here represents his knowledge and experience as a medical professional.

Donidalorsen (Dawnzera) is a preventive treatment for hereditary angioedema (HAE). You take it as a shot under the skin every four to eight weeks to help reduce the number of HAE attacks you have. Dawnzera was the first HAE treatment made with RNA-targeting technology. RNA is the genetic material your body uses to make proteins. 

The medicine suppresses messenger RNA (mRNA), which in turn slows production of a protein called plasma prekallikrein (PKK) in your liver. This stops a process that leads to the hallmark swelling of HAE. The FDA approved Dawnzera in August 2025. 

Timothy Craig, DO, an allergist and immunologist at Penn State and medical advisory board member at the US Hereditary Angioedema Association, explains more about how Dawnzera works and what else to know about this treatment.

Although mRNA technology is now many years old, it's a relatively new technology for bringing drugs to market. Dawnzera works by inhibiting the production of a specific protein, PKK, by inhibiting mRNA. When that happens, you don't make PKK in the liver, and then you don't get production of prekallikrein. And if you don't get production of prekallikrein, you don't get production of kallikrein, and then you can't make bradykinin, which is the protein responsible for the swelling. 

It's a subcutaneous medication, meaning you take it as a shot just under the skin. But unlike some of the other subcutaneous medications, it doesn't have citrate in it, so it doesn't burn when you get the injection. Also, right now, it is the preventive drug with the longest time from injection to injection — four to eight weeks.

If you compare Dawnzera to the subcutaneous C1 inhibitor Haegarda, or the monoclonal antibodies lanadelumab (Takhzyro), and garadacimab (Andembry), which were also approved within the last couple years, all of these drugs are right in the 85% range of effectiveness. And we judge this based on studies that look at reduction of attacks. But we also look at emergency room visits and the need for rescue medication, and moderate and severe attacks versus mild attacks. Obviously, none of these drugs are 100% effective, but even if we can't promise zero attacks, at least we want to make sure that anxiety levels about attacks, the need for ER care, and the ability to treat yourself easily with rescue are all there.

The most common adverse effects with Dawnzera, like all subcutaneous medications, are injection site reactions. You might have redness, swelling, bruising, or a rash where you get the shot. But again, compared to other subcutaneous medications that have citrate in them, Dawnzera has a lower risk of that side effect, around 24%. But in general, these drugs are pretty clean, fortunately, which is good.

It's an injection you take with a single-use autoinjector just under the skin, typically in the belly. You'll take it every four to eight weeks, depending on your doctor's direction. In studies, both a four-week and an eight-week therapy were effective, but I'm a little conservative and always start with four weeks. I don't want someone to be on it for only a month, decide it's working, and then jump to every eight weeks and have an attack. So if you're doing really well at four weeks, then you could probably try going out to six and then eight.

What I usually do is start someone on therapy, and then I meet with them online, so I can talk to them just like this, or I connect with them on the patient portal. And then I'll see people in person usually at about three or four months. After that, it's once a year. I know it sounds like a long time for a rare disease to see your doctor only once a year, but I do make special accommodations for people who have HAE. They usually have my cellphone or very easy access to me and the team that I work with.

Currently, Dawnzera is only approved for people 12 years old and older. Also, since the target is in the liver, we don't want to use it in someone who has significant liver disease. I think outside of that, it's OK for most people.

 

All of these drugs are expensive. Nobody can really pay for them. Private insurance will typically give copay assistance. I'm not aware of anybody in my patients who really have had to pay for the drug themselves. On the route of Medicare federal and Medicaid state, what we do is we help people get their medication through nonprofit copay assistance organizations. One of our main goals is to make sure cost is not a barrier to getting these drugs.

The pharmaceutical company that makes Dawnzera, Ionis Pharmaceuticals, has people who'll chat with you on the phone about the drug — the indications, how to get a start on therapy, etc. They can also help you prevent the financial burden. The Hereditary Angioedema Association (HAEA) is also a really great organization for information and guidance. I think you can make an informed decision based on what's available on the internet, provided you're careful with what you look at. Make sure you're referencing either the company or the HAEA — reliable sources that will provide sound information. And of course, talk to your doctor.

Add WebMD as a Preferred Source to see more of our trusted content across Google Search, AI Overviews, and AI Mode