How Does Avastin (Bevacizumab) Treat Severe HHT?

Avastin (generically known as bevacizumab) has become a highly effective systemic treatment option for patients with Hereditary Hemorrhagic Telangiectasia (HHT) who experience severe, unmanageable bleeding. While local treatments like nasal cauterization or topical therapies are often the first line of defense, Avastin works throughout the entire body to target the root cause of HHT bleeding by preventing the growth of abnormal, fragile blood vessels ^[1][2]. It is generally reserved for severe cases, significantly reducing the frequency of nosebleeds, gastrointestinal bleeding, and the need for frequent blood or iron transfusions ^[3][4].

How Does Avastin Work for HHT?

In patients with HHT, the body overproduces a protein called Vascular Endothelial Growth Factor (VEGF). This protein acts as a signal that encourages the growth of new blood vessels ^[1]. Because HHT causes these new vessels to form improperly—resulting in fragile telangiectasias (small blood vessel malformations) and arteriovenous malformations (AVMs) that easily break and bleed—excess VEGF drives ongoing severe bleeding ^[2].

Avastin is an anti-angiogenic medication. It works by binding to VEGF and neutralizing it, effectively shutting off the signal that causes the abnormal, bleeding-prone vessels to grow ^[1][2].

Who Qualifies for This Treatment?

Because it is a powerful systemic medication, Avastin is not used for mild HHT symptoms. It is typically reserved for patients who fall into one of the following categories:

• Severe, Refractory Bleeding: Patients with debilitating, hours-long nosebleeds (epistaxis) or gastrointestinal (GI) bleeding that fail to respond to standard local treatments ^[3][5].
• High Transfusion Needs: Individuals whose bleeding is so severe they require regular iron infusions or red blood cell transfusions to treat chronic, draining anemia ^[4][6].
• Liver AVM Complications: Patients who have developed high-output heart failure as a result of abnormal blood flow through AVMs in the liver ^[7][8].

Note on “Off-Label” Use: Avastin was originally developed and FDA-approved as a cancer treatment. Its use in HHT is considered “off-label,” a common and legal medical practice where doctors prescribe a medication for an unapproved condition because strong evidence shows it is effective ^[2]. Because it is an expensive intravenous biologic drug used off-label, your doctor’s office will often need to navigate a prior-authorization process with your health insurance before you can begin treatment.

How is Avastin Administered?

For severe HHT, Avastin is administered directly into the bloodstream through an intravenous (IV) infusion ^[3]. (While intranasal or topical versions of the drug have been tested, studies show they do not significantly improve bleeding compared to placebos, making the IV route standard for severe disease ^[9].)

• Infusion Logistics: Infusions take place at a hospital or outpatient infusion center and typically last 30 to 90 minutes. Most patients can drive themselves home afterward, though you should verify your clinic’s specific policies.
• Initial Therapy (Induction): You will start with a series of infusions (often spaced about two weeks apart for the first few doses) to get severe bleeding under control.
• Maintenance Therapy: Once bleeding stabilizes, your treatment intervals will be spread much further apart—typically every one to three months, or even on an “as-needed” basis depending on when your symptoms return ^[10][11].
• Timeline for Relief: Relief is not instant, but it does not take years. Many patients begin to notice a meaningful reduction in the frequency and severity of their bleeding after the first few induction doses over the first couple of months.

Common Side Effects and Important Safety Warnings

While many HHT patients tolerate Avastin well, it alters how blood vessels behave body-wide and requires close monitoring by your care team:

• High Blood Pressure (Hypertension): One of the most frequent side effects. You will need regular blood pressure monitoring, and your doctor may prescribe medication to manage it ^[12][13].
• Protein in the Urine (Proteinuria): Avastin can affect the kidneys, causing protein to leak into the urine. Your care team will regularly test your urine to catch this early ^[12][13].
• Fatigue: The medication itself can make you feel unusually tired ^[12]. However, many patients eventually report an increase in their overall energy levels as their severe anemia resolves from bleeding less.

Critical Safety Warnings:

• Pregnancy Risks: Avastin can cause severe fetal harm and disrupt normal fetal development ^[13][14]. It is contraindicated during pregnancy. Women of childbearing age must use highly effective contraception during treatment and for a significant period (often up to 6 months) after the last dose.
• Impaired Wound Healing: Avastin reduces the body’s ability to heal surgical incisions and major wounds. (This applies to major surgeries, not everyday small cuts or the HHT bleeds the drug is designed to stop.) Your doctor will require you to pause treatment for at least several weeks before and after any planned surgeries or major dental work ^[13].
• Rare Complications: In rare cases, Avastin can cause abnormal growths on heart valves, blood clots, or gastrointestinal perforations ^[15][13]. Because of these risks, your doctor may perform baseline heart screenings (like an echocardiogram) and will closely monitor your overall health throughout treatment.