Metastatic colorectal cancer refers to cancer cells that have broken off and spread to other parts of the body.3
Some tumor types may respond to certain treatments, while others do not.4 It’s important that your doctor does biomarker testing to find out which type of mCRC you have before choosing an appropriate treatment.
Vectibix should not be used to treat patients with mutant RAS, or whose RAS status is not known.
References: 1. Vectibix® (panitumumab) prescribing information, Amgen. 2. Kim ST, Lee S, Lee J, et al. The impact of microsatellite instability status and sidedness of the primary tumor on the effect of cetuximab-containing chemotherapy in patients with metastatic colorectal cancer. J Cancer. 2017;8(14):2809-2815. doi:10.7150/jca.18286. 3. American Cancer Society. https://www.cancer.org/treatment/understanding-your-diagnosis/advanced-cancer/what-is.html. Accessed October 4, 2021. 4. Boeckx N, Koukakis R, Op de Beeck K, et al. Primary tumor sidedness has an impact on prognosis and treatment outcome in metastatic colorectal cancer: results from two randomized first-line panitumumab studies. Ann Oncol. 2017;28:1862-1868. doi:10.1093/annonc/mdx119. 5. Allegra CJ, Rumble RB, Hamilton SR, et al. Extended RAS gene mutation testing in metastatic colorectal carcinoma to predict response to anti–epidermal growth factor receptor monoclonal antibody therapy: American Society of Clinical Oncology provisional clinical opinion update 2015. J Clin Oncol. 2016;34:179-185. 6. National Cancer Institute. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/wild-type-gene. Accessed October 4, 2021. 7. Zhao B, Wang L, Qiu H, et al. Mechanisms of resistance to anti-EGFR therapy in colorectal cancer. Oncotarget. 2016;8(3):3980-4000.
In a clinical study, nearly all patients (90%) taking Vectibix® experienced skin rash or other skin reactions. Skin reactions included but were not limited to:
Of these patients, 15% had severe skin reactions that involved, for some, pain, disfigurement, ulceration, or loss of outer layers of skin when receiving Vectibix® alone. Some patients who developed severe skin reactions also developed infections in the blood, skin, fat, or tissue that sometimes resulted in death.
Your doctor may need to make changes to your dose to address your side effects or, in the event of severe or life-threatening side effects, stop Vectibix® treatment. It is important that you tell your doctor right away if you have any skin reactions or any signs of infection (such as chills, fever, or increased redness or swelling of an existing skin reaction).
Patients who have metastatic colorectal cancer with RAS-mutant tumors should not receive Vectibix®. Several clinical trials have been done evaluating treatments that block part of the pathway that increases tumor cell growth (anti-epidermal growth factor receptor [EGFR]). Anti-EGFR treatments include Vectibix® and Erbitux® (cetuximab). In studies of these medicines, patients with RAS-mutant tumors experienced serious side effects without any benefit from the treatment. In one study, patients with RAS-mutant tumors who received Vectibix® + FOLFOX did not live as long as patients who received FOLFOX alone.
Some patients who were taking Vectibix® developed low levels of certain electrolytes, including:
Your doctor may check the levels of these electrolytes in your blood while you are on treatment and for up to 2 months after you finish treatment. Your doctor may add other oral or intravenous medications to your Vectibix® treatment.
Vectibix® is given by infusion into a vein. Some patients may develop an infusion reaction, which can be severe and in rare cases has resulted in death. In one clinical study, infusion reactions developed in 4% of patients, and 1% of patients experienced serious infusion reactions. Infusion reactions included:
Depending on how severe the reaction is, your doctor may decide to slow the rate of the infusion, stop the infusion, or stop your Vectibix® treatment completely.
Tell your doctor right away if you experience severe diarrhea or dehydration. Some patients treated with Vectibix® and chemotherapy developed kidney failure and other complications because of severe diarrhea and dehydration.
Lung disease, including fatal lung disease, occurred in 1% or less of patients who had taken Vectibix®. Tell your doctor if you have problems breathing, wheezing, or a cough that doesn’t go away or keeps coming back. If you have had lung problems in the past, be sure to tell your doctor. Your doctor may decide to stop Vectibix® treatment.
Being in the sun may make skin reactions worse. Wear sunscreen and protective clothing (such as a hat) and avoid direct sunlight while you are on treatment with Vectibix®. Tell your doctor if you have new or worsening skin reactions.
Inflammation of the eye and injury to the cornea have been reported. Tell your doctor if you have any vision changes or eye problems. If you experience any of these side effects or they worsen, your doctor should interrupt or discontinue Vectibix®.
In a study of patients treated for mCRC, the addition of Vectibix® to the combination of Avastin® (bevacizumab) and chemotherapy caused patients to experience severe side effects and to not live as long as patients receiving only Avastin® and chemotherapy. Do not take Avastin® with Vectibix®.
Vectibix® can cause harm to an unborn child. Use effective birth control to avoid pregnancy while taking Vectibix® and for at least 2 months after the last dose.
In patients who received Vectibix® alone, the most commonly reported side effects (experienced by 20% or more of patients) were different types of skin rash, infections at the side of the nail beds of the fingers or toes, fatigue (extreme tiredness), nausea, and diarrhea.
In patients who received Vectibix® + FOLFOX, the most commonly reported side effects (experienced by 20% or more of patients) were diarrhea, sore mouth, inflammation of mucous membranes, weakness, infection of the nail beds, loss of appetite, low magnesium, low potassium, rash, acne-like skin rash, itching, and dry skin. The most common serious side effects were diarrhea and dehydration.
Please read the full Prescribing Information and discuss it with your doctor.
Vectibix® (panitumumab) is for treating patients with wild-type RAS metastatic colorectal cancer (cancer that has spread outside of the colon and rectum). RAS status is determined by an FDA-approved test. Wild-type RAS is a cancer without mutations in the KRAS and NRAS genes.
Vectibix® can be used:
Vectibix® is not to be used to treat patients with tumors that have mutations in the RAS gene (called RAS mutant), or when the RAS mutation status is unknown. Talk to your doctor about your RAS status.