Panitumumab – Vectibix®

Panitumumab - Vectibix®

Usual Diluents

Dilution Data

Preparation and Administration
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Do not administer Vectibix as an intravenous push or bolus.

Preparation
Prepare the solution for infusion, using aseptic technique, as follows: Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration. Although Vectibix should be colorless, the solution may contain a small amount of visible translucent-to-white, amorphous, proteinaceous, panitumumab particulates (which will be removed by filtration; see below). Do not shake. Do not administer Vectibix if discoloration is observed. Withdraw the necessary amount of Vectibix for a dose of 6 mg/kg. Dilute to a total volume of 100 mL with 0.9% sodium chloride injection, USP. Doses higher than 1000 mg should be diluted to 150 mL with 0.9% sodium chloride injection, USP. Do not exceed a final concentration of 10 mg/mL. Mix diluted solution by gentle inversion. Do not shake
Administration
Administer using a low-protein-binding 0.2 µm or 0.22 µm in-line filter. Vectibix must be administered via infusion pump. Flush line before and after Vectibix administration with 0.9% sodium chloride injection, USP, to avoid mixing with other drug products or intravenous solutions. Do not mix Vectibix with, or administer as an infusion with, other medicinal products. Do not add other medications to solutions containing panitumumab. Infuse over 60 minutes through a peripheral intravenous line or indwelling intravenous catheter. Doses higher than 1000 mg should be infused over 90 minutes.
Use the diluted infusion solution of Vectibix within 6 hours of preparation if stored at room temperature, or within 24 hours of dilution if stored at 2° to 8°C (36° to 46°F). DO NOT FREEZE.   Discard any unused portion remaining in the vial.

DESCRIPTION
Vectibix (panitumumab) is a recombinant, human IgG2 kappa monoclonal antibody that binds specifically to the human epidermal growth factor receptor (EGFR). Panitumumab has an approximate molecular weight of 147 kDa. Panitumumab is produced in genetically engineered mammalian (Chinese hamster ovary) cells.

Vectibix is a sterile, colorless, pH 5.6 to 6.0 liquid for intravenous (IV) infusion, which may contain a small amount of visible translucent-to-white, amorphous, proteinaceous, panitumumab particulates. Each single-use 5 mL vial contains 100 mg of panitumumab, 29 mg sodium chloride, 34 mg sodium acetate, and Water for Injection, USP. Each single-use 10 mL vial contains 200 mg of panitumumab, 58 mg sodium chloride, 68 mg sodium acetate, and Water for Injection, USP. Each single-use 20 mL vial contains 400 mg of panitumumab, 117 mg sodium chloride, 136 mg sodium acetate, and Water for Injection, USP.

CLINICAL PHARMACOLOGY

Mechanism of Action
The EGFR is a transmembrane glycoprotein that is a member of a subfamily of type I receptor tyrosine kinases, including EGFR, HER2, HER3, and HER4. EGFR is constitutively expressed in normal epithelial tissues, including the skin and hair follicle. EGFR is over-expressed in certain human cancers, including colon and rectum cancers. Interaction of EGFR with its normal ligands (e.g., EGF, transforming growth factor-alpha) leads to phosphorylation and activation of a series of intracellular proteins, which in turn regulate transcription of genes involved with cellular growth and survival, motility, and proliferation. Signal transduction through the EGFR results in activation of the wild-type KRAS protein. However, in cells with activating KRAS somatic mutations, the mutant KRAS protein is continuously active and appears independent of EGFR regulation.

Panitumumab binds specifically to EGFR on both normal and tumor cells, and competitively inhibits the binding of ligands for EGFR. Nonclinical studies show that binding of panitumumab to the EGFR prevents ligand-induced receptor autophosphorylation and activation of receptor-associated kinases, resulting in inhibition of cell growth, induction of apoptosis, decreased proinflammatory cytokine and vascular growth factor production, and internalization of the EGFR. In vitro assays and in vivo animal studies demonstrate that panitumumab inhibits the growth and survival of selected human tumor cell lines expressing EGFR.

1. INDICATIONS AND USAGE
Vectibix is indicated as a single agent for the treatment of epidermal growth factor receptor (EGFR)-expressing, metastatic colorectal carcinoma (mCRC) with disease progression on or following fluoropyrimidine-, oxaliplatin-, and irinotecan-containing chemotherapy regimens [see PACKAGE INSERT FOR Clinical Studies (14)].

The effectiveness of Vectibix as a single agent for the treatment of EGFR-expressing, metastatic colorectal carcinoma is based on progression-free survival [see PACKAGE INSERT FOR Clinical Studies (14)]. Currently, no data demonstrate an improvement in disease-related symptoms or increased survival with Vectibix.

Retrospective subset analyses of metastatic colorectal cancer trials have not shown a treatment benefit for Vectibix in patients whose tumors had KRAS mutations in codon 12 or 13. Use of Vectibix is not recommended for the treatment of colorectal cancer with these mutations [see PACKAGE INSERT FOR Clinical Studies (14) and Clinical Pharmacology (12.1)].

2. DOSAGE AND ADMINISTRATION

2.1 Recommended Dose and Dose Modifications
The recommended dose of Vectibix is 6 mg/kg, administered as an intravenous infusion over 60 minutes, every 14 days. Doses higher than 1000 mg should be administered over 90 minutes [see Dosage and Adminsitration (2.2)].

Appropriate medical resources for the treatment of severe infusion reactions should be available during Vectibix infusions.

Dose Modifications for Infusion Reactions[see Boxed Warning, PACKAGE INSERT FOR Warnings and Precautions (5.2), and Adverse Reactions (6.1, 6.3)] Reduce infusion rate by 50% in patients experiencing a mild or moderate (grade 1 or 2) infusion reaction for the duration of that infusion.  Terminate the infusion in patients experiencing severe infusion reactions. Depending on the severity and/or persistence of the reaction, permanently discontinue Vectibix
Dose Modifications for Dermatologic Toxicity [see Boxed Warning, PACKAGE INSERT FOR Warnings and Precautions (5.1), and Adverse Reactions (6.1)] Withhold Vectibix for dermatologic toxicities that are grade 3 or higher or are considered intolerable. If toxicity does not improve to ≤ grade 2 within 1 month, permanently discontinue Vectibix. If dermatologic toxicity improves to ≤grade 2, and the patient is symptomatically improved after withholding no more than two doses of Vectibix, treatment may be resumed at 50% of the original dose. If toxicities recur, permanently discontinue Vectibix. If toxicities do not recur, subsequent doses of Vectibix may be increased by increments of 25% of the original dose until the recommended dose of 6 mg/kg is reached ------------------------------------------------------------------
2.2  Preparation and Administration
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Do not administer Vectibix as an intravenous push or bolus.

Preparation

Prepare the solution for infusion, using aseptic technique, as follows: Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration. Although Vectibix should be colorless, the solution may contain a small amount of visible translucent-to-white, amorphous, proteinaceous, panitumumab particulates (which will be removed by filtration; see below). Do not shake. Do not administer Vectibix if discoloration is observed. Withdraw the necessary amount of Vectibix for a dose of 6 mg/kg. Dilute to a total volume of 100 mL with 0.9% sodium chloride injection, USP. Doses higher than 1000 mg should be diluted to 150 mL with 0.9% sodium chloride injection, USP. Do not exceed a final concentration of 10 mg/mL. Mix diluted solution by gentle inversion. Do not shake
Administration Administer using a low-protein-binding 0.2 µm or 0.22 µm in-line filter. Vectibix must be administered via infusion pump. Flush line before and after Vectibix administration with 0.9% sodium chloride injection, USP, to avoid mixing with other drug products or intravenous solutions. Do not mix Vectibix with, or administer as an infusion with, other medicinal products. Do not add other medications to solutions containing panitumumab. Infuse over 60 minutes through a peripheral intravenous line or indwelling intravenous catheter. Doses higher than 1000 mg should be infused over 90 minutes.
Use the diluted infusion solution of Vectibix within 6 hours of preparation if stored at room temperature, or within 24 hours of dilution if stored at 2° to 8°C (36° to 46°F). DO NOT FREEZE.

Discard any unused portion remaining in the vial.

3. DOSAGE FORMS AND STRENGTHS
100 mg of panitumumab in 5 mL (20 mg/mL) single-use vial.

200 mg of panitumumab in 10 mL (20 mg/mL) single-use vial.

400 mg of panitumumab in 20 mL (20 mg/mL) single-use vial.

4. CONTRAINDICATIONS
None.

5. WARNINGS AND PRECAUTIONS

5.1 Dermatologic Toxicity
In Study 1, dermatologic toxicities occurred in 90% of patients and were severe (NCI-CTC grade 3 and higher) in 16% of patients with mCRC receiving Vectibix. The clinical manifestations included, but were not limited to, dermatitis acneiform, pruritus, erythema, rash, skin exfoliation, paronychia, dry skin, and skin fissures. Subsequent to the development of severe dermatologic toxicities, infectious complications, including sepsis, septic death, and abscesses requiring incisions and drainage were reported. Withhold Vectibix for severe or life-threatening dermatologic toxicity [see Boxed Warning, Adverse Reactions (6.1) and Dosage and Administration (2.1)].

5.2 Infusion Reactions
In Study 1, 4% of patients experienced infusion reactions and in 1% of patients, these reactions were graded as severe (NCI-CTC grade 3-4).

Infusion reactions, manifesting as anaphylactoid reactions, bronchospasm, and hypotension, can occur following Vectibix administration [see Boxed Warning, and Adverse Reactions (6.1, 6.3)]. In clinical studies, severe infusion reactions occurred with the administration of Vectibix in approximately 1% of patients. Fatal infusion reactions occurred in postmarketing experience. Terminate the infusion for severe infusion reactions [see Dosage and Administration (2.1)].

5.3 Increased Toxicity With Combination Chemotherapy
Vectibix is not indicated for use in combination with chemotherapy. In an interim analysis of Study 2, the addition of Vectibix to the combination of bevacizumab and chemotherapy resulted in decreased overall survival and increased incidence of NCI-CTC grade 3-5 (87% vs 72%) adverse reactions [see PACKAGE INSERT FOR Clinical Studies (14)]. NCI-CTC grade 3-4 adverse drug reactions occurring at a higher rate in Vectibix-treated patients included rash/dermatitis acneiform (26% vs 1%), diarrhea (23% vs 12%), dehydration (16% vs 5%), primarily occurring in patients with diarrhea, hypokalemia (10% vs 4%), stomatitis/mucositis (4% vs < 1%), and hypomagnesemia (4% vs 0). NCI-CTC grade 3-5 pulmonary embolism occurred at a higher rate in Vectibix-treated patients (7% vs 4%) and included fatal events in three (< 1%) Vectibix-treated patients.

As a result of the toxicities experienced, patients randomized to Vectibix, bevacizumab, and chemotherapy received a lower mean relative dose intensity of each chemotherapeutic agent (oxaliplatin, irinotecan, bolus 5-FU, and/or infusional 5-FU) over the first 24 weeks on study, compared with those randomized to bevacizumab and chemotherapy.

In a single-arm study of 19 patients receiving Vectibix in combination with IFL, the incidence of NCI-CTC grade 3-4 diarrhea was 58%; in addition, grade 5 diarrhea occurred in one patient. In a single-arm study of 24 patients receiving Vectibix plus FOLFIRI, the incidence of NCI-CTC grade 3 diarrhea was 25%.

Severe diarrhea and dehydration, which may lead to acute renal failure and other complications, have been observed in patients treated with Vectibix in combination with chemotherapy.

5.4 Pulmonary Fibrosis
Pulmonary fibrosis occurred in less than 1% (2/1467) of patients enrolled in clinical studies of Vectibix. Following the initial fatality described below, patients with a history of interstitial pneumonitis, pulmonary fibrosis, evidence of interstitial pneumonitis, or pulmonary fibrosis were excluded from clinical studies. Therefore, the estimated risk in a general population that may include such patients is uncertain.

One case occurred in a patient with underlying idiopathic pulmonary fibrosis who received Vectibix in combination with chemotherapy and resulted in death from worsening pulmonary fibrosis after four doses of Vectibix. The second case was characterized by cough and wheezing 8 days following the initial dose, exertional dyspnea on the day of the seventh dose, and persistent symptoms and CT evidence of pulmonary fibrosis following the 11th dose of Vectibix as monotherapy. An additional patient died with bilateral pulmonary infiltrates of uncertain etiology with hypoxia after 23 doses of Vectibix in combination with chemotherapy. Permanently discontinue Vectibix therapy in patients developing interstitial lung disease, pneumonitis, or lung infiltrates.

5.5 Electrolyte Depletion/Monitoring
In Study 1, median magnesium levels decreased by 0.1 mmol/L in the Vectibix arm; hypomagnesemia (NCI-CTC grade 3 or 4) requiring oral or intravenous electrolyte repletion occurred in 2% of patients. Hypomagnesemia occurred 6 weeks or longer after the initiation of Vectibix. In some patients, both hypomagnesemia and hypocalcemia occurred. Patients’ electrolytes should be periodically monitored during and for 8 weeks after the completion of Vectibix therapy. Institute appropriate treatment, e.g., oral or intravenous electrolyte repletion, as needed.

5.6 Photosensitivity
Exposure to sunlight can exacerbate dermatologic toxicity. Advise patients to wear sunscreen and hats and limit sun exposure while receiving Vectibix.

5.7 EGF Receptor Testing
Detection of EGFR protein expression is necessary for selection of patients appropriate for Vectibix therapy because these are the only patients studied and for whom benefit has been shown [see Indications and Usage (1) and Clinical Studies (14)]. Patients with colorectal cancer enrolled in Study 1 were required to have immunohistochemical evidence of EGFR expression using the Dako EGFR pharmDx® test kit.

Assessment for EGFR expression should be performed by laboratories with demonstrated proficiency in the specific technology being utilized. Improper assay performance, including use of suboptimally fixed tissue, failure to utilize specific reagents, deviation from specific assay instructions, and failure to include appropriate controls for assay validation can lead to unreliable results. Refer to the package insert for the Dako EGFR pharmDx® test kit, or other test kits approved by FDA, for identification of patients eligible for treatment with Vectibix and for full instructions on assay performance.

HOW SUPPLIED/STORAGE AND HANDLING
Vectibix is supplied as a sterile, colorless, preservative-free solution containing 20 mg/mL Vectibix (panitumumab) in a single-use vial.

Vectibix is provided as one vial per carton.

Each 5 mL single-use vial contains 100 mg of panitumumab in 5 mL (20 mg/mL) (NDC 55513-954-01).
Each 10 mL single-use vial contains 200 mg of panitumumab in 10 mL (20 mg/mL) (NDC 55513-955-01).
Each 20 mL single-use vial contains 400 mg of panitumumab in 20 mL (20 mg/mL) (NDC 55513-956-01).

Store vials in the original carton under refrigeration at 2° to 8°C (36° to 46°F) until time of use. Protect from direct sunlight. DO NOT FREEZE. Since Vectibix does not contain preservatives, any unused portion remaining in the vial must be discarded.

The diluted infusion solution of Vectibix should be used within 6 hours of preparation if stored at room temperature, or within 24 hours of dilution if stored at 2° to 8°C (36° to 46°F). DO NOT FREEZE

This product, its production, and/or its use may be covered by one or more US Patents, including US Patent No. 6,235,883, as well as other patents or patents pending.

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