How Does Bevacizumab Work? — The Anti-VEGF Mechanism Explained

No. Bevacizumab is a monoclonal antibody, but it is classified as an anti-angiogenic or targeted therapy, not immunotherapy. Immunotherapy drugs — such as checkpoint inhibitors like pembrolizumab or nivolumab — work by releasing the brakes on your immune system so it can recognise cancer cells. Bevacizumab works on blood vessel growth and has no effect on immune checkpoints. The distinction matters because the eligibility testing, the side effects, and the monitoring are entirely different between the two drug classes.

Bevacizumab on its own does not cause hair loss. However, it is almost always given alongside chemotherapy, and many chemotherapy drugs do cause hair loss. Whether you lose hair depends on which other drugs are part of your regimen, not on bevacizumab itself. Ask your oncologist to go through each drug in your specific plan and what hair-related effects to expect — the answer varies considerably depending on the combination prescribed.

VEGF plays a role in keeping blood vessel walls relaxed. When bevacizumab blocks VEGF, blood vessels can tighten and blood pressure rises — this happens in a significant proportion of patients on the drug. High blood pressure that goes unmanaged over time can increase the risk of stroke or heart problems, which is why your team monitors it at every visit and often starts a blood pressure medicine during treatment. This is a manageable and expected effect, not a sign the drug is harming you, but it does need to be tracked consistently.

Yes, and this needs to be discussed with your oncologist before the surgical date is fixed. Bevacizumab impairs the process by which wounds grow new blood vessels to heal, and operating while the drug is active increases the risk of poor healing or infection. There is usually a gap between stopping bevacizumab and having surgery, and separately between surgery and restarting it. The right gap depends on the type of surgery and your individual situation. Tell both your oncologist and your surgeon about bevacizumab as early as possible so the timing can be planned safely.

No. Bevacizumab is indicated for specific cancers where VEGF-driven angiogenesis plays a significant role. NCCN and ASCO guidance supports its use in a range of cancers including colorectal, certain lung, ovarian, cervical, and kidney cancers, among others. Even within those cancer types, it is not suitable for every patient and is almost always used as part of a combination rather than alone. Whether it is appropriate for your specific cancer, stage, and overall health is a question your oncologist answers from your full clinical picture.

Avastin is the original brand name for bevacizumab, developed by Roche. Several biosimilar versions are now approved in India by CDSCO. A biosimilar is not a generic medicine in the conventional sense — it is a separately manufactured biologic that has been through regulatory comparison studies to demonstrate it works the same way, with the same safety profile, for the same indications. CDSCO approval means the biosimilar met those standards. If you have a question about which version has been prescribed for you and why, raise it directly with your oncologist rather than making any change on your own.