>That won’t work unless the drugs are given to only the patients with the mutant EGFR. However, patients without the mutation do show some benefit from taking these drugs, so some of them will opt for treatment.<
Well, I was speaking to the argument around many parts (press / message boards) that testing for the mutation will decrease Iressa / Tarceva income. If a situation arises that it is only given to those with the mutation, then i think price will increase. If, as you suggest and i believe, that the drug will still be given to those without the EGF-R mutation, then i believe that the early forecasts of reduced usage are premature. Interestingly, if the degree of overexpression of EGF-R is a prognostic indicator, Tarceva may have an advantage over Iressa due to its higher affinity for the target... therefore greater chance to saturate the available targets.
>Iressa had two phase-3 trials: one in the second line and one in the third line. Tarceva had one trial with mixed second/third line. For all practical purposes, the two drugs were tested in the same setting.<
I should have indicated that I was confining my comments to Iressa's approved setting. Iressa's label indicates approval based on 216 patients split roughly evenly between 250 mg and 500 mg per day doses. More relevant for this discussion, the entry criteria underlying these data were "failure of both platinum-based and docetaxel chemotherapies". Therefore, these patients had gone through the carbo/taxol and then taxotere regimens, meaning that the minimum amount of prior treatments were 2. As you indicated, I believe that the Tarceva trial would accept those who had only failed one regimen.
AI
