Transcript
I'm David Carbone. I'm a thoracic medical oncologist and the Director of the Thoracic Oncology Center at Ohio State University in Columbus, Ohio. I would like to talk today a little bit about some of the recent progress in lung cancer.
I was also asked to look at another study that's specifically addressed PD-1 inhibitors in the brain. There are studies out there that show activity in the brain and activity is seen in clinic as well. First author is Tozuka from Japan; they had 197 patients analyzed in this study and 24 of them had active brain metastases.
First of all, patients with brain metastases had a significantly shorter overall survival than without. The intracranial response rate to PD-1 inhibitors was only 13%, which was half of the extracranial response rates, it was associated with poorer overall survival.
So really the initial hope that PD-1 inhibitors could be active on brain metastases has not been fully fulfilled, and the aggressive use of stereotactic radiation in that setting is useful.
And I know that there's at least 1 study looking at intrathecal administration of PD-1 inhibitors. Since they are large molecules, they don't tend to get into the CNS effectively.
I don't know any data from that study, but we do need additional studies on better treating brain metastases with or without ALK fusion mutations.
This latter study, I just wanted to emphasize is not in ALK fusion-positive patients.
With respect to brain metastases in ALK patients, there's a question as to whether there's intracranial benefit from an ALK inhibitor (but you have extracranial progression and you decided to start chemotherapy), whether you should continue the ALK inhibitor or discontinue it when you start chemotherapy.
I think that is an unanswered question as well, in other words, to maintain intracranial control of patients with known ALK-positive brain metastases by continuing, say, alectinib and treating the extracranial progression with chemotherapy.
