The epidermal growth factor receptor (EGFR) protein tyrosine kinase is one of the important kinases that play a fundamental role in signal transduction pathways.
Several human cancers overexpress Epidermal Growth Factor Receptors and the related human epidermal growth factor receptor (HER-2).
Gefitinib (Iressa), a compound that inhibits the kinase activity of EGFR and HER-2 after binding of their cognate ligand, have been used as new therapeutic antitumor agents.
Gefitinib, a potent and selective ATP-competitive inhibitor of EGFR and HER-2 kinases, is the first EGFR-targeting agent launched as an anti-cancer drug for the treatment of chemoresistant non-small cell lung cancer (NSCLC) patients.
In the pre-clinical studies, gefitinib has demonstrated antitumor activity against a variety of human cancer cell lines expressing EGFR, including lung, ovarian,breast, and colon. In human xenograft models, gefitinib in combination with standard cytotoxic agents resulted in both delayed tumor growth and tumor regression, leading to enhanced survival.
Gefitinib 250 mg is prescribed as monotherapy for the treatment of patients with locally advanced or metastatic NSCLC after failure of both platinum-based and docetaxel chemotherapies.
Side Effects of Gefitinib:
Gefitinib 250 mg is regarded as the safest agent, but sometimes some adverse reactions have been reported such as diarrhea and rash.
Some other side effects may also occur including nausea, vomiting, anorexia, stomatitis, dehydration, skin reactions, paronychia, asymptomatic elevations of liver enzymes, asthenia, conjunctivitis, blepharitis.
Discuss with your healthcare provider if any of the above-mentioned side effects happen to you. You may require further examinations or treatment.
Recommended Dosage: Gefitinib should be taken 250 mg orally. Should be taken once daily with or without meals until disease progression or unacceptable toxicity. Do not consume a missed dose within 12 hours of the upcoming dose.
This medication has been prescribed for you personally and you must not pass it on to anyone else. It may harm them, even if their signs and symptoms are identical as yours.
Dosage forms and Strength: This drug comes as strength of 250 mg in the form of tablets.
Conclusion:
As monotherapy or combination therapy, EGFR-targeted agents have demonstrated promise in the treatment of several tumor types.
The most extensive clinical experience has been with gefitinib and two large Phase II studies have demonstrated clinically relevant anti-tumour activity in patients with previously treated advanced NSCLC.
The EGFR agents discussed have favorable AE profiles and are not typically associated with the heavy toxicity burden of chemotherapy agents, allowing long-term treatment. The maximum efficacy for targeted agents occurs below toxic doses, allowing both gefitinib and cetuximab to be administered at doses lower than the MTD to maximize the benefit: risk ratio.
These novel therapies offer new treatment strategies to cancer patients with limited treatment options.
Gefitinib 250 mg tablet is effective, safe, and well-tolerated single-agent therapy in previously treated NSCLC. Despite the fact that there have been no direct comparisons, the small molecule inhibitors of EGFR gefitinib and erlotinib appear to have similar efficacy. Erlotinib has been shown to produce a survival advantage compared to best supportive care in an unselected group of previously treated patients with NSCLC.
Useful Term/Point Related To NSCLC: On the other hand, the NCCN (National Comprehensive Cancer Network) Drugs & Biologics Compendium has recommended erlotinib 150 mg either as a single agent or in combination with chemotherapy for patients with a known active EGFR mutation ( first-line treatment in NSCLC) or gene amplification who have never smoked.