Avastin, known generically as bevacizumab, is a significant pharmaceutical advancement in the treatment of various cancers. It is a monoclonal antibody that interferes with the growth and spread of cancer cells in the body. Avastin is primarily used in the treatment of certain types of cancers, including brain, lung, colon, kidney, and ovarian cancers. Additionally, it has off-label use in treating wet age-related macular degeneration, a common cause of vision loss in older adults.
Its Role in Cancer Treatment and Macular Degeneration
In cancer treatment, Avastin is used to inhibit the growth of new blood vessels that tumors need to grow and spread. This process, known as antiangiogenesis, effectively starves the tumor of the necessary nutrients and oxygen. For macular degeneration, Avastin, though used off-label, helps in reducing the abnormal growth of blood vessels in the eye, which is a key factor in the progression of the disease.
What is Avastin?
Generic Name and Pronunciation
The generic name for Avastin is bevacizumab (pronounced bev-a-SIZ-oo-mab).
Description as an Antiangiogenic Agent
Avastin is classified as an antiangiogenic agent. It is specifically designed to bind to and inhibit a protein known as vascular endothelial growth factor (VEGF), which plays a crucial role in the formation of new blood vessels.
Mechanism of Action: How It Works by Inhibiting VEGF
Avastin’s mechanism of action involves the inhibition of VEGF. By binding to VEGF, Avastin prevents the interaction of VEGF with its receptors on the surface of blood vessel cells. This inhibition stops the formation of new blood vessels, cutting off the supply of oxygen and nutrients to tumors, thereby inhibiting tumor growth.
Detailed List of Conditions Treated by Avastin
Brain Cancer (Glioblastoma)
Avastin is used in the treatment of recurrent glioblastoma, a type of aggressive brain cancer. It is often used when standard therapy has not been effective.
Avastin is used in combination with chemotherapy for the treatment of persistent, recurrent, or metastatic cervical cancer.
Colon or Rectal Cancer (Colorectal Cancer)
Avastin is approved for the treatment of metastatic colorectal cancer, typically in combination with chemotherapy.
Epithelial Ovarian, Fallopian Tube, or Primary Peritoneal Cancer
It is used to treat advanced stages of ovarian, fallopian tube, or primary peritoneal cancer, often in conjunction with chemotherapy.
Kidney Cancer (Renal Cell Carcinoma)
Avastin, combined with interferon alfa, is used in the treatment of metastatic renal cell carcinoma.
Liver Cancer (Hepatocellular Carcinoma)
For the treatment of unresectable or metastatic hepatocellular carcinoma, Avastin is used in combination with atezolizumab.
Lung Cancer (Non-Squamous Non-Small Cell Lung Cancer)
Avastin is indicated for the first-line treatment of patients with unresectable, locally advanced, recurrent, or metastatic non-squamous non-small cell lung cancer, in combination with chemotherapy.
Off-Label Use for Wet Age-Related Macular Degeneration
Although not FDA-approved for this indication, Avastin is commonly used off-label to treat wet age-related macular degeneration by inhibiting abnormal blood vessel growth in the eye.
Dosage and Administration
- Avastin is administered as an intravenous (IV) infusion.
- It is not available in oral or injectable forms for patients to administer themselves.
Recommended Dosages for Different Conditions
- Glioblastoma: The typical dose is 10 mg/kg every two weeks.
- Metastatic Colorectal Cancer: 5 mg/kg every two weeks or 10 mg/kg every two weeks, depending on the treatment regimen.
- Non-Squamous Non-Small Cell Lung Cancer: 15 mg/kg every three weeks in combination with chemotherapy.
- Metastatic Renal Cell Carcinoma: 10 mg/kg every two weeks in combination with interferon alfa.
- Persistent, Recurrent, or Metastatic Cervical Cancer: 15 mg/kg every three weeks in combination with chemotherapy.
- Epithelial Ovarian, Fallopian Tube, or Primary Peritoneal Cancer: 15 mg/kg every three weeks as part of a combination therapy.
- Hepatocellular Carcinoma: 15 mg/kg every three weeks in combination with atezolizumab.
Instructions for Administration and Frequency of Doses
- Avastin infusions are administered by a healthcare professional in a clinical setting.
- The first dose is usually given over 90 minutes. If well-tolerated, subsequent doses may be given over a shorter period (30 to 60 minutes).
- The frequency of doses varies based on the condition being treated and the patient’s response to therapy.
Common Side Effects
- Nosebleeds, headaches, high blood pressure, and rhinitis.
- Other side effects include proteinuria, taste alteration, dry skin, and back pain.
- Some patients may experience minor bleeding or gastrointestinal discomfort.
Serious Side Effects and Allergic Reactions
- Severe side effects include gastrointestinal perforation, wound healing complications, and severe bleeding.
- Infusion reactions, which can be severe, include difficulty breathing, chest pain, and severe headaches.
- Allergic reactions may manifest as skin rashes, itching, or anaphylaxis in rare cases.
- Potential for kidney problems, including proteinuria and nephrotic syndrome.
- Increased risk of developing high blood pressure.
- Increased risk of arterial and venous thromboembolic events.
Warnings and Precautions
Risks Associated with Avastin
- Increased risk of gastrointestinal perforations and bleeding events.
- Risk of impaired wound healing and surgery complications.
- Potential for reversible posterior leukoencephalopathy syndrome (RPLS).
Conditions Under Which Avastin Should Not Be Used
- Should not be used in patients with hypersensitivity to bevacizumab or any of its components.
- Not recommended for patients with serious hemorrhage or recent history of hemoptysis.
- Should be avoided in patients with uncontrolled hypertension or congestive heart failure.
Necessary Medical Tests Before and During Treatment
- Regular monitoring of blood pressure and urine protein levels.
- Assessment for signs of bleeding or thromboembolic events.
- Monitoring for signs of infusion reactions during and after the administration of Avastin.
Interactions with Other Medications
Information on Drug Interactions
- Avastin can interact with various medications, potentially altering its effectiveness or increasing side effects.
- It is crucial to inform healthcare providers about all medications being taken, including over-the-counter drugs, prescriptions, and supplements.
Special Considerations for Use with Chemotherapy Drugs
- Avastin is often used in combination with chemotherapy drugs. However, it can enhance the toxic effects of chemotherapy, particularly those related to bleeding and gastrointestinal perforation.
- The use of Avastin with certain chemotherapy agents, such as anthracyclines, may increase the risk of congestive heart failure.
- Coordination between healthcare providers is essential to manage the timing and dosage of Avastin and chemotherapy drugs to minimize risks.
Use in Specific Populations
Considerations for Use in Children
- The safety and effectiveness of Avastin in pediatric patients have not been established.
- Clinical trials in children have shown unique risks, such as abnormal growth of bones and tissues.
Considerations for Use in the Elderly
- Elderly patients may have an increased risk of certain side effects, including arterial thromboembolic events.
- Dosing may need to be adjusted based on the patient’s overall health and other existing medical conditions.
Considerations for Use in Pregnant or Breastfeeding Women
- Avastin can cause harm to a developing fetus and should not be used during pregnancy.
- Women of childbearing potential should use effective contraception during treatment and for a period after the end of treatment.
- It is not recommended for breastfeeding women due to the potential for adverse effects in the nursing infant.
Storage and Handling
Proper Storage Conditions
- Avastin vials should be stored in a refrigerator at 2°C to 8°C (36°F to 46°F).
- The medication should be protected from light and not frozen.
- Once prepared, the infusion solution can be stored for a limited time under specific conditions as outlined in the product labeling.
Handling and Disposal of the Medication
- Avastin should be handled with care, and preparation should be done using aseptic techniques.
- Any unused or expired Avastin should be disposed of properly, following guidelines for hazardous medications.
- Needles, syringes, and materials used to prepare and administer Avastin should be placed in puncture-resistant containers and disposed of according to local regulations for biomedical waste.