What is Erbitux?
Erbitux is a solution for infusion (drip into a vein) containing the active substance cetuximab.
What is Erbitux used for?
Erbitux is used to treat the following types of tumors:
- metastatic tumor of the colon or rectum (large intestine). "Metastatic" means that the tumor has spread to other parts of the body. Erbitux is used in patients whose tumor cells have a protein called epidermal growth factor receptor (EGFR) on their surface and contain a "wild type" (unmutated) gene called "KRAS". Erbitux is indicated in combination with other anticancer drugs or on its own if previous antitumour treatment with oxaliplatin and irinotecan has not responded and the patient is unable to receive irinotecan;
- "squamous cell" carcinomas of the head and neck. These types of carcinomas affect cells in the tissue that lines the mouth or throat or other organs, such as the larynx. In locally advanced carcinoma (when the tumor has grown but has not spread), Erbitux is given in combination with radiotherapy (radiation therapy). In relapsing tumors (which reappear following previous treatment) or metastatic, Erbitux is indicated in combination with a combination of "platinum-based" anticancer drugs (including drugs such as cisplatin or carboplatin).
The medicine can only be obtained with a prescription.
How is Erbitux used?
Erbitux should only be administered by doctors experienced in the use of anticancer drugs. Before the administration of Erbitux for the first time, the patient must receive an antihistamine and a corticosteroid to avoid allergic reactions. This is also recommended for all subsequent infusions.
Erbitux is given once a week. The first infusion is administered at a dose of 400 mg per square meter of body surface (calculated according to the patient's height and weight) and lasts two hours. The following infusions are 250 mg / m2 and last one hour each. In monotherapy or in combination with other anticancer drugs, treatment with Erbitux should be continued for as long as necessary depending on the therapeutic response. When Erbitux is
given concomitantly with radiotherapy, treatment with Erbitux should start a week before the start of radiotherapy and should be continued until the end of radiotherapy.
How does Erbitux work?
The active substance in Erbitux is cetuximab, a monoclonal antibody, or an antibody (a type of protein) designed to recognize a specific structure (antigen) present on some cells of the body and bind to it. Cetuximab was designed to bind to the epidermal growth factor receptor (EGFR), which may be present on the surface of some tumor cells. As a result, cancer cells can no longer receive the messages needed to grow, progress and spread. Between 79 and 89% of colorectal cancers and more than 90% of head and neck squamous cell tumors express EGFR on the surface of their cells.
What studies have been carried out on Erbitux?
For cases of metastatic colon or rectal cancer, Erbitux has been studied in five main studies:
- two studies involved 1, 535 patients, who had not previously received chemotherapy, and analyzed the effects of adding Erbitux to combination therapy based on irinotecan or oxaliplatin;
- three studies involved 2 199 patients whose disease had worsened during a previous treatment including irinotecan, oxaliplatin or both, or to whom these medicines could not be given.
For cases of head and neck cancer, Erbitux has been studied in two main studies:
- the first study involved 424 patients with locally advanced cancer and analyzed the effects of adding Erbitux to radiotherapy;
- the second study involved 442 patients with relapsed or metastatic cancer and analyzed the effects of adding Erbitux to the combination of platinum-based anticancer drugs.
All studies examined the duration of the life period without worsening the cancer or the survival time of the patients. Most studies evaluated the results separately in patients with wild-type KRAS tumor cancer compared to patients with mutated gene tumors. In tumor cells the KRAS gene stimulates tumor growth when it is mutated.
What benefit has Erbitux shown during the studies?
In studies related to colon or rectal cancer, patients whose tumors had the wild-type KRAS gene and who took Erbitux survived longer without their disease getting worse:
- in patients who had never had chemotherapy before, patients had survived longer without their disease getting worse when they were treated with Erbitux in addition to chemotherapy. This included chemotherapy with irinotecan (the mean interval was 9.9 months compared to 8.7 months) and with oxaliplatin (the average interval was 7.7 months compared to 7.2 months);
- the first study in patients who had already undergone chemotherapy did not examine KRAS gene mutations, while in the other two studies, patients with wild-type KRAS tumor survived longer without worsening the disease when Erbitux was administered in association with their own therapy. Patients who had not responded to treatment with either oxaliplatin or irinotecan survived on average 3.6 months with Erbituxil until their disease worsened, compared with 1.9 months for patients treated only with the best supportive therapy (treatment of symptoms but not of the tumor itself). Patients who did not respond to oxaliplatin treatment survived on average 4.0 months with Erbitux and irinotecan until their disease worsened, compared with 2.6 months with irinotecan alone.
With regard to locally advanced head and neck cancer, patients survived longer until the disease got worse by adding Erbitux to radiotherapy (on average 24.4 months compared to 14.9 months). In relapsed or metastatic head and neck cancer, survival was greater by adding Erbitux to the combination of platinum-based anticancer drugs (on average 10.1 months compared to 7.4 months).
What is the risk associated with Erbitux?
The most common side effects associated with Erbitux (seen in more than 1 patient in 10) are skin reactions such as rashes, hypomagnesemia (low magnesium levels in the blood), infusion-related reactions (including fever, chills, dizziness and difficulty breathe), mucositis (inflammation of the mucous membrane of the oral cavity) and high values of certain liver enzymes. Skin rashes occur in over 80% of patients. For the full list of all side effects reported with Erbitux, see the Package Leaflet.
Erbitux should not be used in people who are hypersensitive (allergic) to cetuximab.
Serious reactions are possible during the infusion, so that at this stage the patient should be closely monitored.
Why has Erbitux been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that the benefits of Erbitux are greater than its risks in the treatment of patients with metastatic colorectal cancer with EGFR expression, with wild-type KRAS gene and cell tumor patients scaly head and neck. The committee recommended the granting of a marketing authorization for Erbitux.
More information on Erbitux:
On 29 June 2004, the European Commission granted a marketing authorization valid for Erbitux, valid throughout the European Union, to Merck KGaA. The marketing authorization was renewed on 29 June 2009.
For the full EPAR for Erbitux, click here.
Last update of this summary: 06-2009.
