What Are Angiogenesis Inhibitors?

What is angiogenesis?

Angiogenesis refers to the generation of new blood vessels in your body that support the growth and repair of tissue. It’s a process that’s controlled by chemical signaling between your cells.

Typically, angiogenesis is important at certain points in time. Examples include when you’re still growing or when you’re in the process of healing from an injury or a surgery.

In cancer, solid tumors need a steady supply of blood to continue to grow and spread. In order to achieve this, tumors can send signals that promote the process of angiogenesis. As new blood vessels form around the tumor, they provide it with oxygen and nutrients that allow it to thrive.

Angiogenesis can also contribute to metastasis, when tumor cells break off and spread to more distant parts of your body via the bloodstream.

How do angiogenesis inhibitors work?

Angiogenesis inhibitors work by blocking the formation of new blood vessels around your tumor. When this happens, it can prevent your tumor from continuing to grow and thrive.

Typically, angiogenesis is initiated when a chemical signal called vascular endothelial growth factor (VEGF) binds to its receptor on a cell type called an endothelial cell.

Endothelial cells line the walls of your blood vessels. When VEGF binds to its receptor, a chain of signaling happens within the endothelial cell that promotes the formation of new blood vessels.

Angiogenesis inhibitors can interfere with this process in a variety of ways, including:

• blocking the binding of VEGF to its receptor (bevacizumab and ramucirumab)
• inhibiting VEGF’s receptor from signaling into the endothelial cell (axitinib and sorafenib)
• impacting signaling pathways between cells, which can work to block angiogenesis (lenalidomide and thalidomide)

What types of cancers are angiogenesis inhibitors being used for?

Angiogenesis inhibitors can be used in the treatment of many different types of cancers, including:

• brain cancer
• breast cancer
• cervical cancer
• colorectal cancer
• endometrial cancer
• gastrointestinal cancer
• liver cancer
• lung cancer
• kidney cancer
• lymphoma
• multiple myeloma
• ovarian cancer
• pancreatic cancer
• soft tissue carcinoma
• stomach cancer
• thyroid cancer

Whether or not angiogenesis inhibitors are recommended as a part of your cancer treatment will depend on several factors, including:

• the specific type of cancer you have
• the stage of your cancer
• the molecular characteristics of your cancer
• which treatments have been used already, if any
• your age and overall health
• your personal preference

How effective are angiogenesis inhibitors at fighting cancer?

Angiogenesis inhibitors can be used alone or in combination with other cancer drugs. When used as a part of combination therapy, angiogenesis inhibitors are often used with chemotherapy or with other targeted therapy drugs.

Generally speaking, research has found that angiogenesis inhibitors used alone or in combination can help to improve the outlook for people with cancer. But they’re also often associated with an increase in side effects.

A look at the research

A 2016 study analyzed five clinical trials comparing angiogenesis inhibitors with a placebo in the treatment of advanced thyroid cancer. Angiogenesis inhibitors were associated with increased treatment response rate and progression-free survival.

But compared with the placebo, angiogenesis inhibitors were also associated with a significantly increased risk of study participants discontinuing treatment as well as experiencing severe side effects.

Another 2016 study looked into 10 clinical trials of the use of angiogenesis inhibitors in the treatment of advanced stomach cancer. Compared with regimens that didn’t contain angiogenesis inhibitors, those that did were associated with a significant increase in overall and progression-free survival.

The researchers also found that angiogenesis inhibitors were associated with a higher number of side effects, some of which could be severe. But they also noted that many of these were both predictable and manageable.

Combination therapy, particularly when tailored to an individual’s specific cancer, can also lead to improved outcomes. A 2021 study of 60 people with solid tumors found that, compared with when angiogenesis inhibitors were used alone, combination therapy with other cancer drugs led to improved outcomes.

What are the known side effects of angiogenesis inhibitors?

As with any drug, angiogenesis inhibitors have some side effects. While the exact side effects that you may experience can vary based on the specific drug, some of the common ones include:

• high blood pressure
• fatigue
• body aches and pains
• fever
• headache
• diarrhea
• nausea or vomiting
• lowered appetite
• abdominal pain
• constipation
• weight loss
• changes to your skin and hair color
• dry skin
• rash

Other potential side effects that may happen are:

• slow wound healing
• bleeding events
• blood clots
• increased protein in your urine
• thyroid problems
• hand-foot syndrome
• reversible posterior leukoencephalopathy syndrome, a type of brain condition

Before you start taking an angiogenesis inhibitor, you’ll want to go over the potential side effects with a doctor or oncology care team. While you’re on treatment, never hesitate to let them know if you begin to have concerning side effects.

What angiogenesis inhibitor products have been approved for use?

There are several angiogenesis inhibitors that have been approved by the Food and Drug Administration (FDA) to treat cancer.

The table below lists these drugs alphabetically as well as the types of cancers that they’re used for.

Takeaway

Angiogenesis inhibitors are a type of targeted therapy for cancer. They work by blocking the formation of new blood vessels that can provide your tumor with vital oxygen and nutrients.

Angiogenesis inhibitors can be used in the treatment of many different types of cancer, including but not limited to, colorectal, kidney, and thyroid cancers. They may be given alone or as a part of combination therapy.

Angiogenesis inhibitors are associated with several side effects, some of which can be severe. Before starting on angiogenesis inhibitors, your care team will let you know about any specific side effects that you may experience.