Bevacizumab (Avastin and biosimilars)

Bevacizumab at a glance

Bevacizumab blocks a protein called vascular endothelial growth factor, usually shortened to VEGF. Blocking VEGF interferes with the development of blood vessels that support cancer growth. It also affects normal blood vessels and healing, which explains several of its important precautions.

Avastin is the reference brand. Verified intravenous biosimilar brands include Mvasi, Zirabev, Alymsys, Vegzelma, Avzivi and Jobevne. Other verified names include Abevmy, Aybintio, Onbevzi, Oyavas and Equidacent. A biosimilar has been compared with the reference biological medicine for similarity in quality, safety and effectiveness. The pharmacy selects the appropriate prescribed product and records what you receive. These names do not establish local availability.

This article concerns intravenous cancer treatment. Bevacizumab-related eye injections, including the ophthalmic product Lytenava, have a different purpose, preparation and dose. Their instructions must not be substituted for an oncology infusion plan.

How bevacizumab works

A tumour needs oxygen and nutrients carried by blood. VEGF helps signal the formation of new blood vessels, a process called angiogenesis. Bevacizumab is a monoclonal antibody: a laboratory-made protein designed to attach to a particular target. It binds VEGF and reduces its activity.

Bevacizumab is classified as an anti-angiogenic targeted therapy. It is not conventional chemotherapy, and it is not a checkpoint immunotherapy. It may be prescribed alongside either of these treatment types, depending on the treatment plan. The medicines work differently, and each needs its own safety information.

Blocking a target does not guarantee that treatment will help. Your team assesses symptoms, scans and other relevant tests over time. Having few side effects does not show that it is ineffective; equally, difficult side effects do not prove that it is working.

How the team decides whether it is suitable

Your oncologist considers the diagnosis, previous treatment, relevant test results, overall health and the prescribing information for the proposed combination. Bevacizumab does not have one universal tumour-mutation test that everyone must pass before receiving it. Tests required for an accompanying targeted medicine still matter.

Bleeding risk, recent surgery, unhealed wounds, bowel problems, blood pressure, kidney health and previous blood clots are especially important. Explain any recent coughing up of blood, even if it stopped. Mention previous radiotherapy to the pelvis, bowel obstruction, inflammatory bowel symptoms, heart disease, stroke or an aneurysm, which is a weakened, enlarged blood vessel.

For a liver-cancer treatment plan involving bevacizumab, the team needs to assess varices: enlarged veins that can bleed, often in the food pipe or stomach. This may involve an endoscopy before treatment. The US label recommends assessment within six months of treatment initiation; the clinical study assessed patients within the preceding six months. High-risk or recently bleeding varices need particular specialist assessment. This precaution does not mean everyone receiving bevacizumab needs an endoscopy.

Before treatment starts

Your team will check blood pressure and urine protein, and arrange blood tests appropriate to the full treatment plan. These commonly include blood counts, kidney function, liver function and blood salts. Additional heart investigations depend on your symptoms, previous treatments and medical history.

Bring an up-to-date list of prescriptions, painkillers, vitamins and herbal products. Include blood thinners, aspirin, medicines for blood pressure and any previous bone-strengthening treatment. Explain any drug allergy or reaction to an earlier antibody infusion.

Surgery, procedures and dental care

Tell both the oncology team and the surgeon about any planned operation before dates are confirmed. The US Avastin label requires withholding treatment for at least 28 days before elective surgery. After major surgery, at least 28 days must pass and the wound must have healed adequately before treatment is given. Your clinicians may recommend a longer interval. Reaching day 28 is not automatic clearance to restart.

European information also requires withholding for elective surgery and addresses the interval after major surgery and full wound healing. The safest practical step is a written plan agreed between the treating teams. Smaller procedures, port insertion and dental extractions also need individual coordination; do not assume that one rule fits every procedure.

Discuss active dental problems before treatment, particularly if you receive or have received bisphosphonates. Damage to the jawbone has been reported, most often with additional risk factors. Tell the dentist about bevacizumab and ask them to contact oncology before invasive work.

How bevacizumab is given

The infusion appointment

Treatment is usually given in a hospital day unit. The dose is calculated using body weight and the prescribed regimen. Labelled schedules include 5 or 10 mg/kg every two weeks, or 7.5 or 15 mg/kg every three weeks. Your specialist selects the appropriate dose and interval together. These are examples, not a way to calculate your own appointment dates or dose.

The infusion enters a vein through a small cannula, a central line or an implanted port. Avastin's labelled first infusion takes 90 minutes. If tolerated, the second may take 60 minutes; later infusions may take 30 minutes if the 60-minute infusion was tolerated. Blood tests, preparation, other medicines and observation make the overall visit longer.

Routine preventive medicine is not required for bevacizumab alone in the European product information, but your team may prescribe it because of your regimen or a previous reaction. Chemotherapy or other partner medicines may also need anti-sickness medicines or other preparation. Follow the day unit's instructions; do not take an extra antihistamine or steroid yourself.

Symptoms during or after the infusion

Tell the nurse immediately about flushing, itching, shivering, rash, dizziness, wheezing, breathing difficulty or chest, back or abdominal pain. They can assess you, slow or interrupt the infusion and treat a reaction. A severe reaction can mean bevacizumab must be stopped permanently.

Report pain, redness, swelling or leaking around the line immediately. After discharge, contact the hospital promptly if reaction symptoms develop. Severe breathing difficulty, sudden face or throat swelling or collapse requires emergency help.

Delays and treatment length

If you miss an appointment, contact the day unit to rearrange it. There is no home catch-up dose. Vomiting after an infusion does not remove the medicine from your bloodstream and is not a reason for another dose. Report persistent vomiting so dehydration and its cause can be addressed.

The pharmacy prepares and stores the infusion. Unopened Avastin vials require refrigeration at 2–8°C (35.6–46.4°F), protection from light, and must not be frozen or shaken. If you must transport a supply, obtain product-specific cold-storage instructions rather than using a domestic bag or leaving it in a car. Do not prepare or inject it yourself.

The plan may involve treatment for a defined period or continuation while it is helpful and tolerable. Bevacizumab can sometimes continue after accompanying chemotherapy finishes. The labels manage important adverse effects mainly by withholding or stopping bevacizumab, rather than routine dose reductions. The approach to a partner medicine may be different.

Monitoring and checking treatment response

Blood pressure

Blood pressure can rise without causing symptoms. The US label specifies checks every two to three weeks during treatment. Your team may check more often or recommend a home monitor. Ask how to take a reading, where to record it and which results require a call. Do not wait for a headache before attending checks.

If prescribed blood-pressure tablets, take them consistently. Do not stop them on infusion days unless instructed. Uncontrolled high pressure can lead to a treatment pause; a severe blood-pressure emergency requires urgent treatment and stopping bevacizumab. Monitoring may continue after the course ends.

Urine and blood tests

Protein in urine can be an early sign that the kidney's filtering system is affected. A urine dipstick may be followed by a more detailed measurement, sometimes a 24-hour urine collection. This can be necessary even when you pass urine normally and feel well. Large protein losses can require withholding treatment, and nephrotic syndrome, a serious protein-leak problem, requires stopping it.

Blood tests help check kidney function, blood counts and effects of the overall regimen. Scans and clinical reviews assess benefit at intervals set by your team. Safety checks and response checks answer different questions: a normal blood test alone does not show that the cancer is responding.

Common side effects and practical care

The effects you notice depend on the complete regimen. Hair loss, low blood counts, tingling and digestive symptoms may be strongly influenced by accompanying chemotherapy. Side-effect percentages from combination trials cannot tell you the chance caused by bevacizumab alone.

Small nosebleeds and nasal irritation

Minor nosebleeds are common, but bleeding still deserves attention. Tell the team about new or repeated episodes and avoid vigorous nose blowing or picking. Ask which nasal moisturiser is suitable. Bleeding that is heavy, does not settle, or makes you dizzy requires urgent assessment. Coughing up blood must not be dismissed as a routine nosebleed.

Tiredness and weakness

Pace activities around your energy and allow rest after treatment. Gentle movement can be helpful when you feel able. Tell the team when tiredness limits normal activities or changes suddenly, because anaemia, infection and other treatable problems may contribute. Sudden weakness with chest pain, breathlessness or neurological symptoms needs urgent help.

Nausea, appetite, bowel and mouth changes

Take prescribed anti-sickness medicines as directed. Small meals and frequent sips may be easier when you feel nauseated. Report repeated vomiting, diarrhoea or inability to drink. If you have a stoma, pay attention to a change in output. Ask for an individual fluid target if you have kidney or heart problems rather than forcing a fixed amount.

Use the team's plan for diarrhoea or constipation. Severe or persistent tummy pain, blood in stools, abdominal swelling, or vomiting with inability to pass stool or wind must be assessed urgently. Do not repeatedly treat these symptoms at home as ordinary constipation or diarrhoea.

A soft toothbrush and gentle mouth care help when the mouth is sore. Report ulcers, white patches or pain that limits eating. Taste changes and poor appetite can make meals difficult; a dietitian can suggest manageable foods and supplements appropriate to your needs.

Skin, aches and watery eyes

Dry skin, itching, muscle or joint aches and watery eyes can occur. Use a gentle moisturiser and ask which pain relief or eye treatment is safe with your medicines. Report persistent headaches rather than repeatedly covering them with painkillers. A severe headache or sudden visual change needs urgent assessment.

Important side effects needing prompt assessment

Bleeding and blood clots

Bevacizumab can cause serious internal or external bleeding. Seek emergency help for heavy bleeding, vomiting blood, black tar-like stools, or significant coughing up of blood. Report smaller new bleeding promptly too. Bleeding can occur even when the platelet count is normal.

Clots may form in veins or arteries. A painful, swollen, warm limb needs urgent assessment. Sudden chest pain, unexplained breathlessness, collapse, facial drooping, one-sided weakness or difficulty speaking requires emergency help. Do not drive yourself. Previous arterial clots, diabetes and older age can increase arterial-clot risk.

Bowel perforation and fistulas

A perforation is a hole in the stomach or bowel wall. A fistula is an abnormal connection between organs or between an organ and the skin. Both can be serious. Severe abdominal pain, fever, persistent vomiting or unusual leakage of stool, urine or gas needs urgent assessment. Tell the team about new unusual vaginal discharge or passage of gas or stool through the vagina.

Wounds and severe tissue infection

Bevacizumab can delay wound healing. Contact the team for a wound opening, increasing redness, discharge or failure to heal. Rapidly spreading redness or swelling, severe pain around a wound, fever or feeling seriously unwell may indicate a dangerous infection and requires emergency assessment. A treatment pause may be needed; restarting after a wound complication needs an individual decision.

Kidney, heart and blood-vessel problems

Report foamy urine, reduced urine output, blood in urine, swollen ankles or sudden weight gain. Kidney injury does not always resolve promptly after treatment stops. Breathlessness on lying down, increasing swelling or reduced exercise tolerance can also indicate heart problems and needs prompt assessment. Severe symptoms require emergency care.

European information warns about aneurysms and tears in artery walls. Sudden severe chest, back or abdominal pain can be an emergency, especially with faintness. Tell the team beforehand if you have a known aneurysm or significant vascular disease.

PRES and infection

Posterior reversible encephalopathy syndrome, or PRES, is a rare brain condition. It can cause severe headache, seizures, confusion and visual disturbance. These symptoms require emergency assessment. Despite the word “reversible”, recovery must not be assumed; prompt treatment and stopping bevacizumab are important.

Infection risk depends particularly on accompanying treatment and blood counts. Contact your hospital urgently for fever, shaking chills or feeling suddenly unwell, using its temperature instructions. A serious infection can occur without a high temperature. Confusion, severe breathlessness or collapse needs emergency help.

Other medicines, supplements and vaccinations

Show the oncology pharmacist everything you take. Blood thinners and antiplatelet medicines need careful review because bleeding and clotting risks must be balanced. Do not independently stop a prescribed anticoagulant or aspirin, and do not add over-the-counter aspirin or anti-inflammatory painkillers without advice.

Tell other clinicians about bevacizumab before a new prescription or procedure. Some combinations, including particular cancer medicines, have additional heart, blood or kidney risks. A medicine being safe alone does not make it safe in every combination.

Bevacizumab infusions have no meal-timing requirement. However, tablets taken alongside them may have food or grapefruit restrictions. Check those instructions separately. Herbal or “immune-boosting” products are not automatically safe because they are described as natural.

Discuss vaccinations with the team. The timing of non-live vaccines and whether live vaccines must be avoided depend on the whole regimen and immune recovery. Do not adopt a fixed waiting period from someone else's treatment.

Everyday life during treatment

Many people adjust work and home activities around appointments and energy levels. Tell the team what matters most to you so practical support can be arranged. Take breaks during long periods sitting and discuss travel plans, particularly if you have clot risks or need frequent monitoring.

Eat what you can manage and keep fluids within your agreed plan. Avoid treating persistent appetite or weight changes as something you must tolerate silently. Dietetic, nursing and psychological support can help with the everyday burden of repeated treatment.

Do not drive or use machinery if you are sleepy, dizzy, have visual problems or cannot react normally. Arrange transport after an infusion if reaction medicines or other treatments could affect alertness. Carry an up-to-date medicine list when travelling and check where to seek urgent help.

Discuss sex and contraception without embarrassment. Pain, bleeding or fatigue may change what feels comfortable. Ask about any temporary barrier precautions required by accompanying chemotherapy. Dental treatment, operations and invasive cosmetic procedures need discussion because healing can remain affected after the last infusion.

Fertility, contraception, pregnancy and breastfeeding

Bevacizumab can harm a developing baby. Discuss pregnancy possibility before the first infusion and testing when appropriate. Patients who could become pregnant should use effective contraception during treatment and for six months after the final dose. Contact the team immediately if pregnancy occurs or is suspected.

Bevacizumab can affect ovarian function, causing periods to stop and potentially reducing fertility. Recovery is not guaranteed. Discuss fertility preservation before starting if having children in future matters to you. Absence of periods is not a reliable contraceptive method.

The reviewed Avastin labels do not specify a separate fixed male contraception interval. Patients with partners who could become pregnant should nevertheless obtain advice for the complete regimen, especially accompanying chemotherapy. A longer precaution period required by another medicine must not be shortened to bevacizumab's interval.

Do not breastfeed during treatment or for six months after the last dose. Discuss feeding alternatives and the timing required by every medicine in your plan.

After treatment stops or changes

Bevacizumab remains in the body for weeks. Continue the agreed monitoring, contraception and breastfeeding precautions, and tell surgeons or dentists when your last infusion was given. Do not assume that bleeding or wound-healing risks disappear on the day treatment stops.

If blood-pressure tablets were started during treatment, continue them until a clinician reviews your readings. Follow-up urine or kidney tests may still be needed. Report unresolved symptoms and ask which team now coordinates your care. A pause for safety is not automatically a permanent stop, but some serious reactions require permanent discontinuation.

Frequently asked questions