Charu Aggarwal, M.D., MPH: I wanted to close this topic by asking you your preference on rebiopsying after progression. Could you talk about what your pathway or algorithm is for patients who are on targeted agents and patients who aren’t, as well as in terms of tissue vs plasma?

Hossein Borghaei, DO, MS: Sure. For patients who are on targeted therapy, particularly EGFR and ALK, we favor rebiopsying at time of progression. We are using more liquid biopsies. As I said, we’re slightly late comers to this, but because of the improvement in the accuracy of the tests and the availability of more data, we’re using that at the time of progression. We do that particularly for our EGFR-mutated patient population. There’s always this bit of an issue of small cell transformation for patients with an EGFR mutation. That was more common with the earlier generation of TKIs [tyrosine kinase inhibitors] that we were using. We always felt that a tumor biopsy to confirm histology at the time of progression was an important component, and we’ve continued along those lines.

For monitoring patients’ response to treatment, sometimes liquid panels are used and can be very helpful, and also for identification of resistance mechanisms at the time of disease progression. And in the world of EGFR, and to some extent in the world of ALK translocation-positive lung cancer, there are data that you can have an impact on patient care by identifying potential resistance mechanisms. For patients who don’t have a molecular driver, in the absence of a clinical trial that requires rebiopsy and confirmation, or for translational projects where we want to know what’s happening at the level of tumor microenvironment post–frontline therapy, I don’t necessarily go to a rebiopsy. But we’re definitely doing a lot more rebiopsies than we did before because we’re using the information quite successfully in terms of deciding what the next line of treatment should be for our patients. It’s definitely something we use.

Transcript edited for clarity.