Clinical Experience With the HER1/EGFR Tyrosine Kinase Inhibitor Erlotinib
November 02, 2003
In phase I trials in healthy volunteers and patients with refractorycancers, erlotinib (Tarceva) was well tolerated and showed activityagainst non–small-cell lung cancer and other tumors. The dose identifiedfor further clinical development was 150 mg/d; at this dose, erlotinibachieves high exposure, with maximum concentrations greater than2,000 ng/mL and 24-hour area under the concentration-time curvegreater than 35,000 ng
• h/L. In a phase II trial in 57 patients withpreviously treated advanced non–small-cell lung cancer, erlotinib treatmentproduced an objective response rate of 12.3% and a stable diseaserate of 38.6%, with median duration of response of 19.6 weeks;median overall survival was 8.4 months and 1-year survival was 40%,with 9 patients remaining alive over follow-up of greater than 18 months.No grade 4 toxicity was observed, and grade 3 toxicity was minimal. Inan ongoing phase II trial in bronchioloalveolar carcinoma, erlotinibtreatment has produced objective response in 26% of 50 evaluable patients,with median duration of response not yet having been reached.An ongoing phase II trial is examining the combination of erlotinibwith the angiogenesis inhibitor bevacizumab (Avastin) in previouslytreated non–small-cell lung cancer; phase I evaluation revealed no doselimitingtoxicities at tested doses and provided evidence of antitumoractivity. Two phase III trials are examining erlotinib in combinationwith carboplatin (Paraplatin)/paclitaxel (the TRIBUTE trial) orcisplatin/gemcitabine (Gemzar) (the TALENT trial) as first-line treatmentin advanced non–small-cell lung cancer. The phase III BR.21trial is assessing erlotinib monotherapy in advanced refractory non–small-cell lung cancer. Results of these phase II trials will soon beavailable.