The IPASS trial that randomized Asian never-smoking or light previously smoking patients with previously untreated advanced NSCLC to either standard chemo or the epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) inhibitor Iressa (gefitinib) is widely considered among the most important and standard-changing trials of the last few years in the field of lung cancer. Nevertheless, it’s important to bear in mind that patients were identified for enrollment on that trial based on clinical factors, with about a third of the 1217 enrolled patients having their tumors analyzed for EGFR mutation status. The post-hoc results for that molecularly defined subset was the most interesting component of the trial, demonstrating that the patients with an EGFR mutation had a very significantly longer progression-free survival (PFS) with Iressa than with the standard chemo combination of carbo/taxol (paclitaxel). In contrast, the exact opposite was true for patients who were Asian never-smokers with an adenocarcinoma but didn’t have an EGFR mutation.

That comparison of chemo vs. an EGFR inhibitor in a clinically selected population was a perfectly appropriate question when the study was designed and enrolled, since we didn’t have evidence that one approach was superior to another in clinically or molecularly selected populations. This line of inquiry has been taken one step further by work from the North East Japan Gefitinib Study Group from Kobayashi and colleagues that tested Iressa against chemo in 200 previously untreated patients with advanced NSCLC who were prospectively selected for having an EGFR mutation. It was designed to enroll 160 patients per arm, but an interim analysis showed that the results were so overwhelmingly more favorable for recipients of Iressa that the trial was closed early because it was felt to be unethical to continue to randomize patients if the answer to the question was already clear. Although overall survival was not mature and wasn't shown, preliminary results of this trial presented at ASCO 2009 revealed that the patients on the Iressa arm had a far superior response rate (74.5% vs 29%, p < 0.001) as well as PFS (10.4 vs. 5.4 months, p < 0.001). The curves for the latter are shown below.

(click on image to enlarge)

Along with this trial, a remarkably similar European trial is being completed that randomizes a population of previously untreated patients with an EGFR mutation to either erlotinib or cisplatin/docetaxel.

Between the recently closed Japanese trial and the ongoing European trial with a very similar design, I would say that there's no more need for a new trial comparing an EGFR inhibitor to chemo in patients with an EGFR mutation. Still, there's a new one recently activated, this time with a new agent known as BIBW 2992, or "Tovok", from the large German pharmaceutical company Boehringer Ingelheim. BIBW 2992 has been hailed as a next generation targeted agent because it inhibits both EGFR (also known as HER-1) and another sibling receptor called HER-2 or HER2/neu, which is a very important target in breast cancer). Last year, some data emerged from a single arm trial of BIBW 2992 in patients with an EGFR mutation, and this showed that patients in this small trial had responses about half the time, which is similar to the results we've seen with the currently widely used EGFR TKIs Iressa and Tarceva, or perhaps less impressive. Still, the company wasn't aiming high, and they achieved their modest goal of ballpark comparability with our currently available agents when the dice were loaded in their favor.

(this is how I think of this work)

Now, Boehringer Ingelheim is trying to run a trial called LUX-Lung 3, in which 330 patients with a lung adenocarcinoma and a proven EGFR will now be randomized 2:1 to their oral EGFR/pan-ERB inhibitor BIBW 2992 or cisplatin/alimta (pemetrexed). In a not very shocking turn of events, they’re having trouble getting patients enrolled globally, but especially in the US. After all, this is very similar to a trial that was closed in Japan because it was felt unethical to continue to randomize EGFR mutation positive patients to standard chemo.

While I can see why this trial would be helpful to the sponsor company, I can’t imagine a patient sending their tissue, learning that they have an EGFR mutation, hearing the rationale for giving a first line EGFR inhibitor and then willingly signing up to get chemo. What oncologist would feel comfortable randomizing such a selected patient to this? Even more impressive to me is that the principal investigator in the US is Mark Kris, Chief of the Thoracic Oncology Division at Memorial Sloan Kettering Cancer Center and one of the strongest proponents for aggressive EGFR mutation testing and first line use in the population of patients with an EGFR mutation. I believe that Dr. Kris is more likely to spontaneously burst into flames than to publicly declare that feels comfortable with the randomization in this trial and thinks it’s a perfectly great idea for previously untreated patients with advanced NSCLC who have an EGFR mutation to then knowingly have an EGFR inhibitor withheld. Tellingly, he hasn’t enrolled a patient of his own…

This is a trial that does not answer a relevant scientific question anymore. The proper trial for today would be one in which BIBW 2992 is directly compared to one of the more established EGFR TKIs to see whether it provides any improved outcomes, or if it happens to have activity in patients who have already received and progressed on gefitinib or erlotinib. But that trial isn't being done, and instead the company is trying to get a drug approved by doing a trial that has essentially already been done and is known to subject some of the patients to a suboptimal treatment. Thankfully, doctors and patients are voting with their feet.