Avastin (bevacizumab) is a cancer medication that works by cutting off the blood supply tumors need to grow. It is FDA-approved to treat seven types of cancer, including colorectal, lung, brain, kidney, cervical, ovarian, and liver cancers. It is also widely used off-label in ophthalmology to treat eye conditions involving abnormal blood vessel growth.
How Avastin Works
Tumors need a constant supply of new blood vessels to keep growing, a process called angiogenesis. Your body uses a signaling protein called VEGF to trigger the formation of these blood vessels. Avastin is an antibody that latches onto VEGF and neutralizes it before it can reach its receptors on blood vessel cells. Without that signal, the tumor’s blood supply stalls, slowing or stopping its growth.
This makes Avastin different from traditional chemotherapy, which attacks cancer cells directly. Avastin starves the tumor instead. In most cancers, it’s given alongside chemotherapy rather than on its own, with the combination proving more effective than either approach alone.
FDA-Approved Cancer Uses
Avastin is approved for the following cancers, nearly always in combination with other treatments:
- Metastatic colorectal cancer: Used with chemotherapy as a first- or second-line treatment. Notably, it is not approved for earlier-stage colon cancer after surgery (adjuvant use).
- Non-squamous non-small cell lung cancer: Used with chemotherapy as a first-line treatment for advanced or metastatic disease. It is not used in squamous cell lung cancer because of a significantly higher risk of serious bleeding in those patients.
- Recurrent glioblastoma: The only cancer for which Avastin can be used as a single agent. It is approved for adults whose glioblastoma has come back after initial treatment.
- Metastatic kidney cancer: Used in combination with an immune-stimulating drug for advanced disease.
- Cervical cancer: Used alongside chemotherapy for persistent, recurrent, or metastatic cervical cancer.
- Ovarian, fallopian tube, or primary peritoneal cancer: Approved for several scenarios, including after initial surgery for stage III or IV disease and for recurrent disease. In the post-surgery setting, treatment can extend up to 22 cycles total.
- Liver cancer (hepatocellular carcinoma): Used with the immunotherapy drug atezolizumab for patients with advanced liver cancer who haven’t received prior systemic treatment.
Off-Label Use for Eye Conditions
One of Avastin’s most common uses isn’t for cancer at all. Eye doctors routinely inject tiny doses of bevacizumab directly into the eye to treat wet age-related macular degeneration (AMD), a condition where abnormal blood vessels leak fluid beneath the retina and threaten vision. The same VEGF-blocking mechanism that starves tumors also shuts down these leaky vessels in the eye.
In clinical studies, about 43% of eyes treated with bevacizumab gained significant vision improvement at one year, and 92% of eyes were protected from major vision loss out to three years. Injections typically start monthly, then shift to every eight weeks. A single eye injection uses a fraction of a cancer dose, making it far less expensive per treatment. This off-label use has been practiced for nearly two decades, even though FDA-approved alternatives exist at higher cost.
What Treatment Looks Like
Avastin is given as an intravenous infusion, not a pill or injection into muscle. The first infusion takes about 90 minutes. If that goes well, the second drops to 60 minutes, and all sessions after that can be as short as 30 minutes. You’ll receive it at an infusion center or hospital outpatient clinic, typically every two or three weeks depending on the cancer being treated.
Doses are calculated by body weight, ranging from 5 mg/kg for some colorectal cancer regimens up to 15 mg/kg for lung and cervical cancers. Because it’s weight-based, the actual cost per infusion varies. Based on 2025 Medicare reimbursement rates, bevacizumab costs roughly $7.32 per milligram, which means a single infusion can run several thousand dollars before insurance.
Serious Risks
Because Avastin works on blood vessels throughout the body, not just in tumors, it carries some risks that are distinct from typical chemotherapy side effects.
Gastrointestinal perforation, where a hole develops in the wall of the stomach or intestines, occurs in about 1% to 2.4% of patients depending on the type of cancer being treated. This is a medical emergency. Symptoms include sudden severe abdominal pain, fever, nausea, and vomiting.
Bleeding is another concern. In lung cancer patients with squamous cell tumors (which is why Avastin isn’t approved for that subtype), the rate of serious or fatal pulmonary hemorrhage reached 31% in one study. In the approved non-squamous lung cancer population, the rate was about 2.3%, compared to 0.5% with chemotherapy alone.
Wound healing can be impaired. In one clinical trial, 15% of patients who had surgery after receiving Avastin experienced wound complications, compared to 4% in the chemotherapy-only group. For this reason, Avastin is typically stopped several weeks before any planned surgery.
Other notable side effects include high blood pressure, protein in the urine (which can signal kidney stress), fatigue, and an increased risk of blood clots.
Biosimilar Alternatives
Avastin’s patent exclusivity has expired, and five biosimilar versions of bevacizumab are now FDA-approved. Biosimilars are essentially the same drug, manufactured by different companies and typically available at lower cost. The approved options include Mvasi (2017), Zirabev (2019), Alymsys (2022), Avzivi (2022), and Jobevne (2025). All are approved for the same indications as the original Avastin and are considered equally safe and effective. Your oncologist or insurance plan may recommend one of these in place of brand-name Avastin to reduce treatment costs.