The AVAiL trial in first-line advanced NSCLC, based in Europe, was designed to confirm the role of avastin with chemo using a different regimen of cisplatin and gemcitabine with a placebo or Avastin at 7.5 or 15 mg/mg every three weeks (the European trial was placebo-controlled, unlike the US-based Avastin trial with carbo/taxol). I described it in a prior post that described a glimpse of the results that were reported in a press release a few months ago, but we received more information at ASCO.

One of the themes that we've covered in some of the posts introducing the clinical entity of BAC is the variability in its natural history. In fact, much of what we've been learning about BAC has been in the last several years, and we're still learning more about it all the time. One of the things we've struggled with is the range of outcomes, that some patients can experience rapid deterioration and no response at all to EGFR inhibitors, while other patients can have a remarkably slow progression, and they sometimes will have an astounding regression of disease from EGFR inhibitors.

Inhibitors of the epidermal growth factor receptor (EGFR), such as Iressa (gefitinib) and Tarceva (erlotinib) are generally known for being often minimally toxic, oral, targeted therapies that can occasionally produce dramatic and long-lasting responses in a minority of patients and more modest, minor responses or prolonged disease stabilization in a larger proportion of patients. They are not widely considered as a treatment for brain metastases, but there are many reports that describe responses, including prolonged ones, of brain metastases to Iressa or Tarceva.

Celecoxib (Celebrex) has been studied in combination with chemo for NSCLC and has generated enough promising results to raise expectations but also enough negative data to produce disappointment. Dr.

We'll break from brain metastases for a while to talk about another potential avenue of targeted therapy in lung cancer: the cyclo-oxygenase, or COX, pathway.

Last week, Genentech had a press release in which they disclosed some potentially important information about a large randomized trial being done in Europe with Avastin. This study, known as the AVAIL trial, enrolled just over a thousand first-line patients with advanced NSCLC to receive their most common standard chemotherapy, cisplatin and gemcitabine, alone or in combination with Avastin at either of two dose levels, 7.5 mg/m2 and 15 mg/m2. The basic design is as shown in this figure:

The guidelines from the American Society for Clinical Oncology (ASCO) for NSCLC start the discussion on how long to continue first-line chemo as follows: "The optimal duration of chemotherapy remains a matter of debate." Just in case you thought it was only me saying that we don't know the exact answer for one issue or another, the evidence-based guidelines are filled with hedge comments like this.

We've come along way over the past decade. In the first half of the 1990s, the value of treating metastatic NSCLC was debated and not clear. A "meta-analysis" that pooled the results from 11 chemotherapy trials, 8 with cisplatin, and nearly 1200 patients demonstrated a modest but convincing improvement in survival compared to supportive care alone (article here). The figure summarizing the improvement by adding chemo is shown here:

In my last post, I described our evolving recognition in the lung cancer field that significant response as the threshold for clinical benefit is too high and that stable disease is likely a relative benefit as well. An important trial presented by Dr.

Most of the discussion with about inhibiting the EGFR axis in lung cancer has focused on the orally available tyrosine kinase inhibitors (TKIs) that work inside the cells. However, another way to inhibit the cells is by giving an IV "monoclonal antibody" which is a protein that attaches to the outside of the cell at the EGFR target and can block activity. A figure of the two approaches is shown here, with the antibody circled in red: