PANITUMUMAB

PANITUMUMAB
(pan-i-tu-mu'mab)
Vectibix
Classifications: antineoplastic agent; biologic response modifier; monoclonal antibody; epidermal growth factor receptor (egfr) inhibitor;
Therapeutic:antineoplastic; monoclonal antibody; egfr inhibitor
Pregnancy Category: C

Availability

20 mg/mL solution for injection in 5 mL, 10 mL, and 20 mL vials

Action

Overexpression of epidermal growth factor receptors (EGFRs) occurs in many human cancers, including those of the colon and rectum. EGFRs control the activity of intracellular tyrosine kinases that regulate transcription of DNA molecules involved in cellular growth, survival, motility, proliferation, and transformation.

Therapeutic Effect

Panitumumab inhibits upregulation or overexpression of EGFR in cancer cells, decreasing their capacity for cell proliferation, cell survival, and decreasing their invasive capacity and metastases.

Uses

Treatment of EGFR-expressing metastatic colorectal carcinoma in patients with disease progression on or following fluoropyrimidine-, oxaliplatin-, and irinotecan-containing chemotherapy regimens.

Contraindications

Pulmonary fibrosis; interstitial lung disease. Use contraception for females of childbearing age; pregnancy (category C); lactation. Safe use in children not established.

Cautious Use

Photosensitivity with drug use; electrolyte imbalances, especially hypomagnesemia, and hypocalcemia; lung disorders.

Route & Dosage

Metastatic Colorectal Carcinoma
Adult: IV 6 mg/kg q14d

Dosage Adjustments for Infusion Reactions and Dermatologic Reactions
Mild or moderate infusion reactions (Grade 1 or 2): Reduce infusion rate by 50%
Severe infusion reactions (Grade 3 or 4): DC permanently
Intolerable or severe dermatologic toxicity (greater than Grade 3): Withhold drug. If toxicity does not improve to at least grade 2 within 1 mo, permanently DC. If toxicity improves to at least grade 2 and patient is symptomatically improved after withholding no more than 2 doses, resume at 50% of original dose. If toxicities recur, DC permanently. If toxicities do not recur, subsequent doses may be increased by increments of 25% of original dose until 6 mg/kg is reached.

Administration

Intravenous

PREPARE: IV Infusion: Dilute doses up to 1000 mg with NS to a total volume of 100 mL. Dilute higher doses with NS to a total volume of 150 mL. Final concentration should not exceed 10 mg/mL. Mix by gentle inversion and do not shake. Solution will contain small translucent particles that will be removed by filtration during infusion.

ADMINISTER: IV Infusion: Infuse doses <1000 mg over 60 min. Infuse doses >1000 mg over 90 min. Use an infusion pump and a 0.2 or 0.22 micron in-line filter. Flush the line before/after infusion with NS. Discontinue infusion immediately if an anaphylactic reaction is suspected (i.e., bronchospasm, fever, chills, hypotension).

Store unopened vials at 2°–8° C (36°–46° F). Protect vials from direct sunlight. Use diluted infusion solution within 6 h if stored at room temperature, or within 24 h if stored at 2°–8° C (36°– 46° F).

Adverse Effects (≥1%)

Body as a Whole: Fatigue, infectious sequelae and septic death, infusion reactions, peripheral edema. GI: Abdominal pain, constipation, diarrhea, mucosal inflammation, nausea, stomatitis, vomiting. Metabolic: Hypomagnesemia. Respiratory: Cough, pulmonary fibrosis. Skin: Acneiform dermatitis, dry skin, erythema, pruritus, skin exfoliation, skin fissures, nail disorders, paronychia. Special Senses: Conjunctivitis, eye/eyelid irritation, increased lacrimation, ocular hyperemia.

Pharmacokinetics

Half-Life: 7.5 d.

Nursing Implications

Assessment & Drug Effects

Monitor for S&S of a severe infusion reaction; check vital signs q30min during infusion and 30 min post-infusion.
Monitor for and report S&S of dermatologic toxicity such as acne-like dermatitis, pruritus, erythema, rash, skin exfoliation, dry skin, and skin fissures; inflammatory or infectious sequelae in those who experience severe dermatologic toxicities.
Withhold drug and notify physician for any signs of drug toxicity.
Lab tests: Periodic serum electrolytes during and for 8 wk following completion of therapy.

Patient & Family Education

Immediately report any discomfort experienced during and shortly after drug infusion.
Wear sunscreen and limit sun exposure while receiving panitumumab.
Report any of the following to a health care provider: any signs of irritation, inflammation, or infection of the skin, nails, or eyes; shortness of breath or any other breathing difficulty.
Women of childbearing age should use reliable means of contraception during and for 6 mo after the last dose of panitumumab.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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