At the 2017 ASCO meeting in Chicago, Dr. George Simon and Dr. David Carbone talk about news and progress in small cell lung cancer. Dr. Simon goes into detail on some new promising approaches and current studies for small cell lung cancer treatment, adding "these are some of the newer, in my opinion, more exciting approaches that are showing promise—though we'll have to validate this in larger, randomized trials." Dr. Carbone says in addition that immunotherapies may also show promise in small cell lung cancer as early phase studies have already produced good response rates. Dr. George Simon is a Professor in the Department of Thoracic/Head and Neck Medical Oncology in the Division of Cancer Medicine at MD Anderson Cancer Center and Dr. David Carbone is the Director of the James Thoracic Center at Ohio State University.
So, George, we've talked about progress in non-small cell lung cancer. We've heard a lot about that medicine. Small cell lung cancer, which I know is the minority but still people get so sick, where are we with that, with progress for that?
So we are starting to make some progress there too. For the last 40 years, the chemotherapy for small cell essentially hasn't changed. It consists of a platinum and a drug called etoposide (Toposar), and it's not for the lack of trying. For the last several decades, we have had many randomized studies looking at newer drugs, vaccines, all of which have come back negative.
But more recently, we have identified a marker called BLL3 against which we have an antibody-drug conjugate, an antibody that binds to this marker. And a chemotherapy drug is attached to the antibody, which then links to this marker. And a drug recently in a smaller Phase II study is showing promise with response rates of about 25 percent.
We've also gotten better, gotten a new drug called G1T28. G1T28 is a CDK4/6 inhibitor. What it does is it—one of the side effects of chemotherapy is it causes your blood counts to go down, your white cells and red cells, and so it limits our ability to give chemotherapy in the doses that we want to give. However, because of low counts sometimes we have to delay chemotherapy, sometimes we have to drop down the doses, and that could potentially affect its efficacy.
But this drug actually puts the hematopoietic cells, the blood bone marrow cells, into sort of a state of sleep, what we call G1 arrest. And when we come in with our chemotherapy then these cells, hematopoietic cells, are essentially resistant to the chemotherapy, so therefore we may not see the level of low counts or myelosuppression with this drug. So that may be a promising approach, which is showing some promise in early studies in this ASCO.
Another approach that's showing some promise which needs to be validated is a PARP inhibitor. One of the ways tumors become resistant to our chemotherapy is that it repairs the damage done by the chemotherapy, its ability to repair the DNA damage, and many of the drugs we give kills cancer by causing DNA damage. So if we are able to inhibit their ability to repair the damage, then we may enhance cell kill.
So these are some of the newer, in my opinion, more exciting approaches that are showing promise though we have to validate this in larger randomized trials.
There are also early signals that immunotherapies will work in small cell, and in fact there are very good response rates in early phase studies with that disease as well.
Published By :
Sep 25, 2017