Skip to main content


Generic name: panitumumab [ pan-i-TUE-moo-mab ]
Brand name: Vectibix
Dosage form: intravenous solution (20 mg/mL)
Drug class: EGFR inhibitors

Medically reviewed by on Jul 26, 2022. Written by Cerner Multum.

What is panitumumab?

Panitumumab is used to treat a certain type of metastatic colorectal cancer that has progressed after treatment with other chemotherapy.

Panitumumab is used only if your tumor is a wild-type RAS tumor, for which your doctor will test.

Panitumumab may also be used for purposes not listed in this medication guide.


Panitumumab may cause severe skin problems that can lead to widespread infection and possibly death. Seek emergency medical attention at the first sign of any skin rash.

Before taking this medicine

You should not use panitumumab if you are allergic to it.

Tell your doctor if you have ever had:

  • lung disease, breathing problems;

  • an ulcer on the cornea of your eye (keratitis); or

  • an electrolyte imbalance (such as low levels of calcium, magnesium, or potassium in your blood).

Panitumumab may harm an unborn baby. Use effective birth control to prevent pregnancy while you are using panitumumab, and for at least 2 months after your last dose. Tell your doctor if you become pregnant.

You may have irregular menstrual periods while receiving panitumumab.

You should not breastfeed while using panitumumab.

How is panitumumab given?

Your doctor may perform a biopsy to make sure panitumumab is the right treatment for your cancer.

Panitumumab is given as an infusion into a vein. A healthcare provider will give you this injection.

Panitumumab must be given slowly, and the infusion can take up to 90 minutes to complete.

Panitumumab is usually given once every 2 weeks. Follow your doctor's instructions.

Call your doctor if you have ongoing vomiting or diarrhea, or if you are sweating more than usual. You can easily become dehydrated while using panitumumab. This can lead to very low blood pressure, electrolyte disorders, or kidney failure.

You may need frequent blood tests. Your skin and vision may also need to be checked.

Panitumumab can have long lasting effects on your body. You may need frequent medical tests for up to 8 weeks after you stop using this medicine.

What happens if I miss a dose?

Call your doctor for instructions if you miss an appointment for your panitumumab injection.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while receiving panitumumab?

Avoid exposure to sunlight or tanning beds. Panitumumab can make you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) during treatment and for at least 2 months you after stop receiving panitumumab

Panitumumab side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Some side effects may occur during the injection. Tell your caregiver right away if you feel dizzy, nauseated, light-headed, chilled, feverish, or have chest tightness or trouble breathing.

Seek emergency medical attention at the first sign of any skin rash. Panitumumab may cause severe skin problems that can lead to widespread infection and possibly death.

Panitumumab may cause serious side effects. Call your doctor at once if you have:

  • severe or ongoing diarrhea;

  • sudden chest pain or discomfort, wheezing, dry cough or hack, feeling short of breath;

  • redness, swelling, or irritation of your eyes or eyelids, vision changes;

  • swelling in your face;

  • low potassium level--leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling;

  • dehydration symptoms--feeling very thirsty or hot, being unable to urinate, heavy sweating, or hot and dry skin;

  • signs of a kidney problem--little or no urinating; painful or difficult urination; swelling in your feet or ankles; feeling tired or short of breath; or

  • skin problems--severe or worsening acne, swelling or infection around your fingernails or toenails, skin itching, redness, dryness, peeling, cracking, or oozing.

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common side effects of panitumumab may include:

  • acne, dry skin, rash, itching;

  • swelling or irritation around your fingernails or toenails;

  • loss of appetite, nausea, diarrhea;

  • blisters or ulcers in your mouth, red or swollen gums, trouble swallowing;

  • tired feeling, weakness; or

  • low potassium.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Panitumumab dosing information

Usual Adult Dose for Colorectal Cancer:

6 mg/kg IV over 60 minutes every 14 days; if the first infusion is tolerated, administer subsequent infusions over 30 to 60 minutes; administer doses higher than 1000 mg over 90 minutes

¬¬-Prior to initiation of therapy, assess RAS mutational status in colorectal tumors and confirm the absence of a RAS mutation in exon 2 (codons 12 and 13), exon 3 (codons 59 and 61), and exon 4 (codons 117 and 146) of both KRAS and NRAS.
-See Dose Adjustments for dosage modifications in patients experiencing infusion reactions or dermatologic toxicity.

Uses: For the treatment of wild-type RAS (defined as wild-type in both KRAS and NRAS as determined by an FDA-approved test for this use) metastatic colorectal cancer (mCRC):
-In combination with FOLFOX for first-line treatment.
-As monotherapy following disease progression after prior treatment with fluoropyrimidine, oxaliplatin, and irinotecan-containing chemotherapy.

What other drugs will affect panitumumab?

Other drugs may affect panitumumab, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.