It is used to treat several cancers, mostly non-small cell lung cancer and pancreatic cancer. It is most effective in cancers with EGFR mutation, but it has been shown to have some benefit even with EGFR negative cancers. Cancers with a KRAS mutation are usually EGFR negative. In patients with the EGFR mutation, the response rate is about 60%. In trials, the addition of Tarceva to chemo regimens extended the average overall survival by 3.3 months. A test for the EGFR mutation is available through Genzyme.
Tarceva is taken daily in pill form.
Tarceva can he used for a limited time as the cancer develops resistance, usually within 8-12 months.
The most common side effect is an acne type rash. This is usually restricted to the head, face and neck areas. Studies have hinted at a correlation between the strength of the rash and the response. The stronger the rash, the better the prognosis. The rash should resolve itself even with continued use.
Other side effects include diarrhoea, loss of appetite, fatigue and partial hair loss. The more rare side effects include hearing loss and interstitial pneumonitis.
I have been prescribed Tarceva for my colorectal cancer. This is an off-label use of the drug as it has not been approved for CRC. Unfortunately I am KRAS positive, so Erlotinib will most likely be less effective.
Five days after starting Tarceva I developed the rash. The rash resembles small, puss filed boils, mostly around the nose area. They are slow to heal. They are quite painful and the rash is getting worse. That should be a good thing. I have also developed sores on the edges of my tongue.