Gefitinib: a key drug for targeted treatment of non-small cell lung cancer

Gefitinib is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor mainly used to treat EGFR mutation-positive locally advanced or metastatic non-small cell lung cancer (NSCLC). This article will start with its mechanism of action, clinical application, manufacturer and precautions to help readers fully understand this important anti-tumor drug.

Paragraph 2: Mechanism of action and core indications

Gefitinib blocks tumor cell proliferation signaling pathways by selectively inhibiting EGFR tyrosine kinase activity. Its key target is EGFR exon 19 deletion mutation or exon 21 (L858R) point mutation. Clinical studies have shown that gefitinib has significantly better progression-free survival (PFS) than traditional chemotherapy for NSCLC patients carrying these mutations. According to IPASS data from the international multi-center clinical trial, the positive rate of EGFR mutations in the Asian population is about 30%, and these patients are the main beneficiary group of gefitinib.

Paragraph 3: Usage and adverse reaction management

The standard dose of gefitinib is 250 mg orally once daily, which needs to be taken on an empty stomach (1 hour before a meal or 2 hours after a meal). Common adverse reactions included rash (44%), diarrhea (29%), and elevated liver enzymes (18%), most of which were grade 1-2. Liver function needs to be monitored regularly during clinical use. If interstitial lung disease occurs (the incidence is about 1%), the drug should be discontinued immediately. It is worth noting that smoking may reduce the efficacy of the drug, and patients are advised to avoid smoking during treatment.

Paragraph 4: Drug R&D and market status

Gefitinib was developed by AstraZeneca and was first approved in Japan in 2003 under the trade nameIressa. At present, in addition to original drugs, there are many domestic companies producing generic drugs, including Qilu Pharmaceutical, Zhengda Tianqing, etc. In 2021, gefitinib passed national medical insurance negotiations, and the price dropped from 2,280 yuan to 547 yuan per box, greatly improving drug accessibility. According to data from the National Cancer Center, there are approximately 787,000 new NSCLC cases in my country every year, of which approximately 250,000 may benefit from EGFR-TKI treatment.

Paragraph 5: Treatment status and prospects

As the first approved EGFR-TKI drug, gefitinib has opened an era of precision treatment for non-small cell lung cancer. Although the third-generation drug osimertinib has become a new first-line treatment option, gefitinib still plays an important role in clinical practice because of its accurate efficacy and affordable price. In the future, with the popularization of genetic testing and optimization of combination treatment strategies, gefitinib will continue to provide survival benefits for specific patient groups.

Quote sources:
1. National Medical Products Administration Drug Instructions (Gefitinib Tablets)
2. "Chinese Society of Clinical Oncology (CSCO) Guidelines for the Diagnosis and Treatment of Non-Small Cell Lung Cancer" 2023 Edition
3. AstraZeneca Iressa product instructions
4. Mok TS et al. N Engl J Med 2009;361:947-57 (IPASS Research)