One of my good friends in the lung cancer community, Dr. Ed Kim from MD Anderson, was in town tonight and gave a talk that I attended. He's one of the emerging real leaders in the field, and last week had published in Lancet one of the largest trials in advanced lung cancer, the INTEREST trial (see prior post describing it, and the link to the summary of the published article). The trial compared the EGFR inhibitor iressa (gefitinib) to standard chemo taxotere (docetaxel) and reported that the two approaches produced identical survival results. (click to enlarge) This is interesting (excuse the pun) in its own right, because some oncologists hold on to a belief that chemo is the treatment that really works and that EGFR inhibitors are a late consolation prize to offer. Even a less effective EGFR inhibitor like iressa (compared with tarceva (erlotinib)) was absolutely comparable, truly equivalent to a chemo approach that was less well tolerated. But we'll cover the full results of the INTEREST trial in more detail separately. Dr. Kim mentioned in passing that he wanted to see iressa return to the US market.

Some people here may recall my comments about how I saw no need for iressa here, now that we have a more effective EGFR inhibitor in tarceva, so I asked him why we should want it when we could get the same effect by just breaking a tarceva pill in half. He agreed that the idea that iressa is basically remarkably similar to just a lower dose of tarceva, but he raised a very good point about why it would be good to have iressa back on the market, which is as a cost competitor. As he pointed out, iressa sold for about $1800-2000/month, whereas tarceva started out more expensive and has increased in cost every year, now over $3500/month. If you have even a 10% copay, that's a significant amount of money, but it's really a challenge if you're responsible for more. Now, if iressa were simply ineffective, it wouldn't be worth it even at a much lower price than tarceva. But iressa is still widely used in Asia and other parts of the world, and the avialable evidence is quite convincing in demonstrating that the patients with EGFR mutations get the same remarkable benefit with iressa that they do with tarceva, and with less intense side effects (the same ones for both agents, but less severe with iressa at the standard dose of 250 mg by mouth daily, compared with the standard tarceva dose of 150 mg by mouth daily). The difference appears to be that iressa is less effective in the patients who don't have extreme sensitivity to EGFR inhibitors, largely the patients with EGFR mutations, in whom tarceva still appears to produce a modest but real survival benefit despite a very, very low rate of significant objective responses in this population. This doesn't mean that iressa would be an appealing option for patients who have progressed on tarceva: we both agree that they're remarkably similar drugs, kind of like iressa being the junior size version of tarceva. For people who need the full version, tarceva would be the clear way to go. But for patients with extreme sensitivity to the side effects and/or efficacy of EGFR inhibitors, such as those with a known activating mutation, iressa may be all that is needed and could provide a much less expensive alternative that is also associated with less significant side effects. And it would keep the cost of tarceva from rising higher and higher, because you could potentially just escalate the dose of iressa, and even at a higher cost you could still come out ahead. We haven't yet approved treatments just to provide alternatives to facilitate competitive pricing, but Dr. Kim made a strong point that one more equivalent option has its merits, if it can prevent a monopoly on the oral EGFR inhibitor market.