Vectibix 20 mg/mL concentrate for solution for infusion – panitumumab for metastatic colorectal cancer

Vectibix is an infusion medicine containing panitumumab – a human monoclonal antibody that binds to the epidermal growth factor receptor (EGFR) on the surface of certain tumour cells and so blocks the signal they need to grow and divide.

It is used in adults with metastatic colorectal cancer (cancer of the large bowel) whose tumour has a wild-type (non-mutated) RAS gene. One vial contains 100 mg panitumumab in 5 mL of concentrate (20 mg/mL), and the medicine is given only in hospital under the supervision of a doctor experienced in cancer therapy.

What is Vectibix used for and how is it given?

Key facts about the medicine

What is Vectibix used for?

According to the Summary of Product Characteristics, Vectibix is indicated for adult patients with RAS wild-type metastatic colorectal cancer:

• as first-line treatment in combination with FOLFOX or FOLFIRI chemotherapy;
• as second-line treatment in combination with FOLFIRI in patients who received first-line fluoropyrimidine-based chemotherapy (excluding irinotecan);
• as monotherapy after failure of chemotherapy regimens containing fluoropyrimidine, oxaliplatin and irinotecan.

The mutation status of the KRAS and NRAS genes (exons 2, 3 and 4) is determined in a laboratory with a validated method before treatment starts.

How is it given and dosed?

• The recommended dose is 6 mg per kilogram of body weight once every two weeks.
• The medicine is diluted in 0.9% sodium chloride solution (to a total of 100 mL; final concentration not above 10 mg/mL) and given as an intravenous infusion using an infusion pump with a 0.2 or 0.22 micrometre in-line filter.
• The first infusion lasts about 60 minutes; if well tolerated, later infusions may take 30–60 minutes. Doses above 1000 mg are given over about 90 minutes.
• It must not be given as a rapid intravenous (bolus) injection.
• In severe skin reactions (grade 3 or higher) the doctor withholds 1–2 doses and, after improvement, continues at 100%, 80% or 60% of the dose (depending on which occurrence it is); at the fourth occurrence treatment is stopped.

Treatment is carried out by an oncologist in hospital; the dose and duration are set individually.

Special patient groups

• Children and adolescents: there are no relevant data for use in colorectal cancer.
• Elderly patients: no data indicate a need for dose adjustment; in patients over 65 years the doctor assesses whether they can tolerate Vectibix together with the prescribed chemotherapy.
• Impaired kidney or liver function: safety and efficacy have not been studied.

Contraindications – when the medicine must not be used

Vectibix must not be given:

• in allergy to panitumumab or any of the excipients;
• in previous or existing interstitial pneumonitis or pulmonary fibrosis;
• in combination with oxaliplatin-containing chemotherapy if the tumour has a mutated RAS gene or RAS status is unknown.

Warnings and precautions

• Skin reactions (acne-like rash, redness, itching, flaking, dry and cracked skin, inflammation around the nails) are very common and can worsen in the sun. Limiting sun exposure, sunscreen and a hat are recommended; the doctor may recommend moisturisers, sunscreens (SPF > 15), topical steroids and/or oral antibiotics.
• Magnesium and calcium levels (and potassium before the start) are checked before and during treatment and for up to 8 weeks after it ends; if levels are low the doctor may prescribe supplements.
• Severe diarrhoea can lead to dehydration and kidney damage – tell the doctor or nurse immediately.
• Tell the doctor if you wear contact lenses or have had severe eye problems (marked dryness, inflammation or ulcer of the cornea); acute redness and pain in the eye, watering, blurred vision or sensitivity to light need urgent examination.
• The medicine contains 3.45 mg sodium per 1 mL of concentrate – relevant for a controlled sodium diet.

Interactions with other medicines, food and drink

Tell the doctor about all medicines you take, including non-prescription and herbal medicines.

• Vectibix is not used in combination with bevacizumab.
• It is not used in combination with the chemotherapy regimen known as "IFL".
• With oxaliplatin only if wild-type RAS status is confirmed.

Pregnancy and breast-feeding

Vectibix has not been studied in pregnant women and may affect the unborn baby or the ability to become pregnant. Women of childbearing potential must use effective contraception during treatment and for two months after the last dose. Breast-feeding is not recommended during treatment and for two months after the last dose.

Driving and using machines

Talk to your doctor before driving or using machines, because some side effects (e.g. tiredness, dizziness, eye problems) may affect this ability.

Possible side effects

The most important side effects according to the leaflet:

• infusion reactions (headache, rash, itching, flushing, swelling of the face and throat, fast pulse, nausea, difficulty breathing, fall in blood pressure) – mild to moderate in about 5 in 100, severe in about 1 in 100 patients;
• skin reactions in about 94 in 100 patients, usually mild to moderate; rarely severe skin infections, Stevens-Johnson syndrome or toxic epidermal necrolysis;
• severe allergic reactions, very rarely and even more than 24 hours after the infusion.

Also very common: anaemia, low potassium and magnesium, conjunctivitis, hair loss, mouth sores, diarrhoea, nausea, vomiting, abdominal pain, constipation, decreased appetite and weight loss, extreme tiredness, fever, swelling of the legs, back pain, insomnia, cough and shortness of breath.

Common, among others: low white blood cell count, low calcium and phosphate, eyelash growth, watery and dry eyes, eyelid inflammation, nail changes and breakage, hand-foot syndrome, dehydration, dry mouth, rectal bleeding, blood clots (pulmonary embolism, deep vein thrombosis), high blood pressure and fast heartbeat. Uncommon: inflammation and ulcer of the cornea, skin necrosis and interstitial lung disease.

Skin reactions resolve when treatment is stopped. Report suspected side effects to your doctor or ALIMS.

Overdose, missed dose and stopping treatment

• Overdose: the medicine is given by healthcare staff; doses up to 9 mg/kg were used in studies, and with overdoses of about 12 mg/kg skin toxicity, diarrhoea, dehydration and tiredness were seen.
• Missed dose: the infusion appointment is arranged by the oncologist – it is not made up on your own.
• Stopping treatment: decided by the doctor, e.g. in severe skin reactions, serious infection or lung problems.

Related information

For questions about skin care, diet and support during treatment, contact the oncologist or pharmacist at the healthcare institution where you are treated.

Composition, pack and manufacturer

• Active substance: panitumumab – 20 mg in 1 mL; one vial contains 100 mg in 5 mL.
• Excipients: sodium chloride, sodium acetate trihydrate, glacial acetic acid, water for injections.
• Pack: type I glass vial with elastomeric stopper, aluminium seal and flip-off cap; carton with 1 vial.
• Marketing authorisation holder: AMICUS SRB D.O.O., Milorada Jovanovića 9, Belgrade. Manufacturer: AMGEN EUROPE B.V., Minervum 7061, Breda, Netherlands. Leaflet approved December 2020.

Storage

• Stored in the healthcare facility in a refrigerator (2–8 °C), in the original package to protect from light; do not freeze.
• Shelf life of the unopened vial: 3 years. Use the diluted solution immediately, and no longer than 24 hours at 2–8 °C; do not freeze.
• The vial is for single use only; any remaining medicine is discarded.

Frequently asked questions

Why is a RAS test needed before treatment?

Vectibix is approved only for tumours with a wild-type (non-mutated) RAS gene. With oxaliplatin-containing chemotherapy it must not be given if RAS is mutated or unknown, so the KRAS and NRAS genes are tested before treatment.

How often is Vectibix given?

Once every two weeks at a dose of 6 mg/kg body weight, as an intravenous infusion that lasts about 60 minutes the first time and 30–60 minutes later if well tolerated.

Is an acne-like rash normal?

Skin reactions occur in about 94 out of 100 patients and are usually mild to moderate. However, report blisters, infected wounds or fever with the rash to your doctor immediately – in severe reactions the dose is changed or treatment is paused.

Why is magnesium checked during treatment?

Panitumumab can lower magnesium, calcium and potassium in the blood. Levels are checked before and during treatment and for up to 8 weeks afterwards, and the doctor prescribes supplements if needed.

Sources

• ALIMS – Summary of Product Characteristics Vectibix®, 20 mg/mL, concentrate for solution for infusion (Serbian)
• ALIMS – Patient leaflet Vectibix®, 20 mg/mL, concentrate for solution for infusion (December 2020, Serbian)

Sources checked on: 25 October 2026.