VECTIBIX

What it is

VECTIBIX (panitumumab) is a concentrated injection for intravenous infusion. Panitumumab is a fully human IgG2 monoclonal antibody that binds with high affinity and specifically to the human epidermal growth factor receptor (EGFR). Each vial contains either 100 mg of panitumumab in 5 mL, or 400 mg of panitumumab in 20 mL.

Approved indications

— VECTIBIX monotherapy is indicated for the treatment of patients with wild-type RAS metastatic colorectal cancer (mCRC) after the failure of standard chemotherapy. — VECTIBIX in combination with FOLFOX is indicated as first-line therapy for the treatment of patients with wild-type RAS metastatic colorectal cancer (mCRC). — VECTIBIX in combination with FOLFIRI is indicated as second-line therapy for patients who have received first-line fluoropyrimidine-based chemotherapy (excluding irinotecan).

Dosing overview

The recommended dose of VECTIBIX is 6 mg/kg given once every 2 weeks. It is recommended that VECTIBIX treatment be continued until progression of the underlying disease or unacceptable toxicity. VECTIBIX must be administered by IV infusion pump. Infusions should occur over approximately 60 minutes through a peripheral line or indwelling catheter, and if the first infusion is tolerated, then subsequent infusions may be administered over 30 to 60 minutes.

Key safety warnings

Dermatologic related reactions, a pharmacological effect observed with EGFR inhibitors, were reported in approximately 93% of patients with mCRC receiving panitumumab monotherapy in clinical trials. Life-threatening and fatal infectious complications including events of necrotising fasciitis and/or sepsis have been observed in patients treated with panitumumab. Rare cases of Stevens-Johnson syndrome and toxic epidermal necrolysis have been reported in patients treated with panitumumab in the post marketing setting. Infusion reactions, including anaphylactic reactions, bronchospasm and hypotension, have been reported in clinical trials and in the post marketing setting. Cases of fatal and non-fatal interstitial lung disease (ILD) have been observed in patients treated with EGFR inhibitors, including panitumumab. In the event of acute onset or worsening of pulmonary symptoms, panitumumab therapy should be interrupted and a prompt investigation of these symptoms should occur. If ILD is confirmed, panitumumab should be permanently discontinued and the patient should be treated appropriately. Progressively decreasing serum magnesium levels leading to severe hypomagnesaemia have been observed in some patients. Patients should be monitored for hypomagnesaemia, and accompanying hypocalcaemia, prior to initiating panitumumab treatment, and periodically during and for up to eight weeks after the completion of panitumumab treatment.

Contraindications

VECTIBIX is contraindicated in patients with a history of life-threatening hypersensitivity reactions to panitumumab, or any product excipients. VECTIBIX in combination with oxaliplatin-based chemotherapy is contraindicated in patients with mutant RAS mCRC or for whom RAS status is unknown.

PBS listing

VECTIBIX is listed on the PBS in a solution concentrate for intravenous infusion 100 mg in 5 mL across 4 items with streamlined restriction, with an ex-manufacturer price of A$450.42 as of 2026-05-01.

Regulatory history

VECTIBIX panitumumab was first listed on the ARTG on 2008-05-14, with registrations for both the 100 mg/5 mL and 400 mg/20 mL concentrated injection vial presentations. An AusPAR was approved on 2011-12-21, with the TGA approving VECTIBIX for the treatment of patients with wild-type KRAS metastatic colorectal cancer as first-line therapy in combination with FOLFOX, as second-line therapy in combination with FOLFIRI, and as monotherapy after the failure of standard chemotherapy.