Erlotinib HCl (OSI-744) is an EGFR inhibitor with IC50 of 2 nM, >1000-fold more sensitive for EGFR than human c-Src or v-Abl. Phase 3.
ChEBI: A quinazoline hydrochloride compound having a (3-ethynylphenyl)amino group at the 4-position and two 2-methoxyethoxy groups at the 6- and 7-positions.
Mechanisms of Action
The small molecular compound erlotinib is a tyrosine kinase receptor inhibitor which inhibits the proliferation of tumor cells by inhibiting phosphorylation, binding to the intracellular catalytic domain of tyrosine kinase in competition with ATP, thus blocking downstream signal transduction and inhibiting activity of tumor cell ligand dependent HER-1/EGFR.
Selective epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor. Antineoplastic
Erlotinib HCl is an HER1/EGFR inhibitor with IC50 of 2 nM.
Phase I clinical trials showed that the main toxicities and side effects of erlotinib were dose-dependent rashes and diarrhea. Other rare side effects included headaches, nausea, and vomiting. Phase II trials used erlotinib as a second-line anticancer drug, with efficacy matching second-line chemotherapy drug docetaxel. Phase III randomized control trials (BR21) mainly focused on NSCLC patients (locally advanced and distant metastasis) after the failure of first- or second-line chemotherapy. The treatment group, with 488 cases in total, took 150mg of erlotinib daily. The control group (243 cases) took a placebo. The study showed:
Median survival rate: 6.7 months for the treatment group, 4.7 months for the control (P<0.001, hazard ratio HR=0.73)
1 year survival rate: 31.2% for the treatment group, 21.5% for the control
Median time of no progression: 9.9 weeks for the treatment group, 7.9 weeks for the control
Meanwhile, symptomatic improvement in the treatment group was more pronounced.
Based on the results of the BR21 study, several further phase III clinical trials were conducted. The TRIBUTE trial combined erlotinib with chemotherapy. The treatment group used chemotherapy (carboplatin + paclitaxel) + erlotinib, while the control used the same chemotherapy alone, with a total of 1,059 late-stage NSCLC patients. The effectiveness of the treatment group was 21.5%, and the control group 19.3%; median survival times were 10.8 and 10.6 months, respectively, and the times of tumor progression (TTP) were 5.1 and 5.0 months. Meanwhile, TALENT trials, with 1,172 NSCLC patients, also investigated the effects of adding erlotinib to chemotherapy (gemcitabine + cisplatin), and also failed to show that erlotinib significantly increased its effects.
Indications and Usage
Erlotinib hydrochlorate is a small molecule tyrosine kinase inhibitor which acts reversibly on epidermal growth factor receptors, a hydrochloride of erlotinib, a molecular-targeted drug. The US Food and Drug Administration (FDA) has approved erlotinib (Tarceva) combined with gemcitabine as a first-line treatment for locally advanced and metastatic pancreatic cancer.
It is mainly used as a second- or third-line treatment for locally advanced or metstatic non-small cell lung cancer (NSCLC) and as a treatment for pancreatic cancer. It is used as a tyrosine inhibitor for NSCLC treatment.