Bevacizumab

Approved Uses

Bevacizumab is primarily used to treat advanced or metastatic cancers. It is often prescribed in combination with chemotherapy or other targeted therapies. The specific conditions it is used for include:

• Colorectal Cancer: Used for cancer of the colon or rectum that has spread to other parts of the body.
• Lung Cancer: Used for specific types of non-small cell lung cancer that are advanced, metastatic, or recurrent.
• Glioblastoma: Used to treat this type of brain cancer in adults when the disease has returned after previous treatment.
• Kidney Cancer: Used for metastatic renal cell carcinoma in combination with other medications.
• Cervical Cancer: Used for persistent, recurrent, or metastatic cancer of the cervix.
• Ovarian, Fallopian Tube, and Primary Peritoneal Cancer: Used for advanced stages of these cancers, often after other treatments have been tried.
• Liver Cancer: Used to treat hepatocellular carcinoma that has spread or cannot be removed by surgery, typically in combination with other immunotherapy.

In many cases, bevacizumab is used when the cancer has not responded to other treatments or has returned after initial therapy.

Mechanism of Action

Bevacizumab belongs to a class of drugs known as angiogenesis inhibitors. It is a monoclonal antibody, which is a type of protein designed to recognize and bind to a specific target in the body.

The primary target of bevacizumab is a protein called vascular endothelial growth factor (VEGF). In a healthy body, VEGF helps create new blood vessels. However, many types of cancer cells produce high amounts of VEGF to encourage the growth of new blood vessels toward a tumor. This process, called angiogenesis, provides the tumor with the oxygen and nutrients it needs to grow and spread to other parts of the body.

How It Works Against Tumors

Bevacizumab works by interfering with the tumor's blood supply through the following steps:

• Binding to VEGF: The drug circulates in the bloodstream and attaches itself to the VEGF proteins.
• Blocking the Signal: By binding to VEGF, bevacizumab prevents the protein from connecting with the receptors on the surface of blood vessel cells.
• Starving the Tumor: When the VEGF signal is blocked, the growth of new blood vessels is inhibited. This can cause existing small blood vessels in the tumor to shrink or disappear, effectively starving the tumor of its nutrient supply.

By limiting the blood supply, bevacizumab helps to slow the growth of the cancer and may make the tumor more vulnerable to other treatments, such as chemotherapy.

Common Side Effects

• Nosebleeds
• Headache
• High blood pressure
• Back pain
• Dry or flaky skin
• Watery eyes
• Changes in the sense of taste
• Fatigue or feeling weak
• Diarrhea or loss of appetite
• Mouth sores

Serious Side Effects

While less common, some side effects can be severe and require immediate medical attention:

• Gastrointestinal complications: The development of holes in the stomach or intestines, known as perforation.
• Wound healing issues: Problems with surgical wounds healing properly or old wounds reopening.
• Severe bleeding: Serious internal bleeding, coughing up blood, or unusual vaginal bleeding.
• Blood clots: An increased risk of blood clots, which can lead to a stroke or heart attack.
• Kidney damage: High levels of protein in the urine or other signs of kidney dysfunction.
• Heart problems: New or worsening heart failure symptoms, such as shortness of breath or swelling.
• Neurological issues: A rare brain condition called posterior reversible encephalopathy syndrome (PRES), which may cause seizures, headache, confusion, or vision changes.
• Infusion reactions: Reactions occurring during or shortly after the injection, such as dizziness, nausea, or lightheadedness.

Serious Complications

Bevacizumab carries several significant warnings regarding life-threatening conditions. Healthcare providers monitor patients closely for the following:

• Gastrointestinal Perforation: This medication can cause holes to develop in the wall of the stomach or intestines. It may also lead to the formation of fistulas (abnormal connections between body parts).
• Hemorrhage: Severe and sometimes fatal bleeding can occur. This includes coughing up blood, nosebleeds, or gastrointestinal bleeding.
• Wound Healing Complications: Bevacizumab can interfere with the body's ability to heal wounds. It is generally not administered within 28 days of a major surgical procedure, and treatment is typically stopped if a surgical wound is not healing properly.

Cardiovascular and Kidney Risks

Treatment may affect the heart, blood vessels, and kidneys. Potential issues include:

• High Blood Pressure: New or worsening hypertension is a common side effect. Blood pressure should be monitored regularly during treatment.
• Blood Clots: There is an increased risk of blood clots in the arteries, which can lead to a stroke, heart attack, or chest pain.
• Kidney Function: This drug can cause protein to leak into the urine (proteinuria). In some cases, this may lead to kidney damage or nephrotic syndrome.
• Heart Failure: Some patients may develop congestive heart failure, especially if they have previously received certain types of chemotherapy.

Other Precautions

Additional considerations for those receiving bevacizumab include:

• Infusion Reactions: Some patients experience reactions during or shortly after the injection, such as shivering, chest pain, sweating, or dizziness.
• Ovarian Function: In women of childbearing age, this medication may cause the ovaries to stop working, which can affect fertility.
• Pregnancy and Breastfeeding: Bevacizumab can cause harm to an unborn baby. Effective birth control is necessary during treatment and for at least six months after the final dose. Breastfeeding is not recommended during therapy.

Pregnancy

Bevacizumab may cause birth defects or the loss of a pregnancy. Healthcare providers typically advise using effective birth control during treatment and for at least 6 months after the final dose. If a person becomes pregnant while using this medication, they should contact their doctor immediately to discuss the potential risks to the fetus.

Fertility

This medication may affect the function of the ovaries, which could impact a woman's ability to have children. It is not fully known if these effects on fertility are permanent.

Breastfeeding

It is not known whether bevacizumab passes into breast milk. Due to the risk of serious side effects in a nursing infant, breastfeeding is generally not recommended during treatment and for at least 6 months following the last dose.

Available Forms

Bevacizumab is available in the following form:

• Injectable solution: This medication is a sterile, preservative-free liquid solution. It is supplied in single-dose vials for intravenous use.

This medication is a concentrated solution that must be diluted by a healthcare provider before it is administered. It is given as an infusion into a vein and is not available in oral forms such as tablets or capsules.

FDA Approval and Indications

The U.S. Food and Drug Administration (FDA) has approved bevacizumab for the treatment of several specific conditions, typically in combination with other chemotherapy drugs. These include:

• Metastatic colorectal cancer
• Non-small cell lung cancer
• Glioblastoma (a type of brain cancer)
• Metastatic renal cell carcinoma (kidney cancer)
• Cervical cancer
• Epithelial ovarian, fallopian tube, or primary peritoneal cancer
• Hepatocellular carcinoma (liver cancer)

Boxed Warning

Bevacizumab carries a boxed warning, which is the FDA’s most serious warning for a medication. This warning highlights the following risks:

• Gastrointestinal Perforation: The drug can cause holes to develop in the stomach or intestines, which can be fatal.
• Surgery and Wound Healing Complications: Bevacizumab can interfere with the body's ability to heal wounds. It should not be used for a certain period before or after elective surgery.
• Hemorrhage: There is an increased risk of severe or fatal bleeding, including coughing up blood or bleeding in the brain.

Biosimilar Availability

The FDA has also approved several biosimilar versions of bevacizumab. A biosimilar is a biological product that is highly similar to and has no clinically meaningful differences from an existing FDA-approved reference product.

Factors Influencing Cost

Several factors determine the total expense of bevacizumab therapy:

• Product Selection: Bevacizumab is available as a reference biologic and as several biosimilars. Biosimilars are typically less expensive than the original brand-name medication.
• Dosage and Frequency: The amount of medication needed is often based on the patient's weight and the specific condition being treated, which directly impacts the price per session.
• Administration Fees: Since bevacizumab must be administered by a healthcare professional via intravenous (IV) infusion, the total cost includes charges for the clinical facility, medical supplies, and professional services.

Insurance and Financial Assistance

Most health insurance plans cover bevacizumab for FDA-approved indications, though many require prior authorization. Out-of-pocket costs such as deductibles, copayments, or coinsurance will vary depending on the individual's insurance policy.

For patients facing high costs, financial assistance may be available through manufacturer-sponsored programs or independent charitable foundations. These programs often help eligible patients with medication costs or insurance copays.