Orladeyo: An Expert’s Perspective

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

By Meng Chen, MD, as told to Sonya Collins

Meng Chen, MD, is an allergist and asthma specialist at Stanford Health Care and a clinical assistant professor of pulmonary, allergy, and critical care medicine at Stanford Medicine in Palo Alto, California. The information here represents her knowledge and experience as a medical professional.

Berotralstat (Orladeyo) is a once-daily oral medication used to prevent attacks of hereditary angioedema (HAE). It's FDA-approved for adults and children ages 2 and older with HAE. Unlike other long-term preventive treatments for HAE, which are given by injection or infusion, berotralstat is the first and only oral medication approved in the U.S. to prevent HAE attacks.

We asked Meng Chen, MD, an allergist and asthma specialist at Stanford Health Care and a clinical assistant professor of pulmonary, allergy, and critical care medicine at Stanford Medicine, to explain how berotralstat works, who may benefit from it, what side effects to expect, and what patients should consider when deciding whether it's right for them.

This medication is approved for a very small population of patients who have been diagnosed with hereditary angioedema (HAE), a rare genetic disorder in which your body has difficulty controlling swelling due to dysregulated blood proteins. For the small group eligible for this medication, it's very effective. There are no head-to-head trials that compare it to the other long-term preventive medications, but compared to placebo, it is effective. 

I would say its main selling point is that it's an oral medication. The other long-term preventive treatments for HAE are all injections — either IV or subcutaneous self-injections. So the really nice thing about this medication is that it's oral.

It does work well. It reduces the number of monthly attacks as well as the number of days with symptoms. People tend to see results within their first month of treatment. But if not, I would probably have the patient give it a few months. But this is not to be used as rescue medication taken when you're having an attack. There are patients who will still have attacks despite being on this medication, so we recommend that all patients still carry on-demand treatment or rescue medication for an acute attack.

It's generally safe and pretty well tolerated. But taking more than one daily dose can cause an abnormal heartbeat, a serious side effect called QTc interval prolongation.

I would describe the commonly reported side effects as mild. They are the same side effects that you can see with a lot of medications. Stomach discomfort, nausea, stomach pain, and other GI symptoms are the most common. These symptoms tend to get better over time. And berotralstat should be taken with food anyway, which helps with GI symptoms.

Some people also report headaches and just aches and pains, like back pain.

It's a once-daily oral medication. It comes in capsules for adults and pellets for children.

There's not so much toxicity that would warrant intense routine lab monitoring. But early on, we may keep an eye on your liver enzymes because there have been reports of patients who have had some elevation in them.

Other than that, it's critical for us to hear from the patient how often they're having attacks and if they're getting the disease control that allows them to have the quality of life that they want.

 

There aren't any absolute contraindications in terms of patients who absolutely can't take this medication. But there are some drug interactions, so it's always important for patients to make sure the doctor has a complete and up-to-date list of their medications. They might need to change a medication or adjust the dose or timing to avoid interactions.

A month's supply of the capsules, which are for patients ages 12 and older, retails for around $50,000 — about $600,000 a year. It is usually covered by health insurance, with a prior authorization, but it does depend on the specific insurance plan. I do find that the companies that produce these really specialized HAE medications often have patient assistance programs, which can be helpful. But I do know the cost can be really challenging for patients.

It really depends on patient preferences. One of the biggest determinants is if they want an oral medication or an injectable. If they are already on an injectable, before deciding to make a switch, they can ask themselves, "How well is this medication that I'm on controlling my disease?" "How bothersome are the injections?"

If a patient is newly diagnosed and hasn't started treatment yet, I present the options and try to understand what their preferences are. The biggest draw for this medication is that it's oral. But some patients may prefer injections because you don't have to get them as frequently as you have to take an oral medication. It all depends on the patient's values, goals, and preferences.

I always encourage patients to have an honest and open conversation with their physicians and to really advocate for themselves — to state what they need and what would help them live their best life.

In a large, international double-blind, placebo-controlled clinical trial called APeX-2, berotralstat was effective at reducing HAE attacks compared to placebo. Patients on placebo had an average of 2.35 attacks per month, and patients on berotralstat had 1.3 a month.

People taking berotralstat also had fewer days with symptoms than those on placebo during the 24-week clinical trial. Patients on berotralstat had an average of 19.4 days of symptoms, compared to those in the placebo group, who had an average of 29.2 days of symptoms. The statistical analysis looking at the proportion of days without symptoms showed about 13 fewer days of symptoms in patients who took berotralstat.

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