The background to the study is that there was a phase Ib dose escalation cohort expansion trial CA209003 that looked at nivolumab given once every two weeks in various different diseases. Today I’m going to be able to present the five year follow-up in the non-small cell lung cancer cohort.
How many patients were involved and what did you look at?
In this expansion cohort there were 129 patients with advanced non-small cell lung cancer who had been previously treated from one to up to five prior lines of therapy. They were randomised to three different doses of nivolumab given once every two weeks for up to two years. The previous efficacy safety and three year follow-up has been previously published and this presentation is based on a minimum follow-up of 58 months.
So what’s new is that the estimated five year overall survival for this group of patients is 16%. In the past, based on historical controls, what we typically say the five year overall survival for this group of patients would have been 4% but with immunotherapy, specifically nivolumab, we’re now seeing a 16% five year overall survival and a plateauing of this curve which is now typical of what we see with immunotherapy agents. Interestingly, we also looked at disease characteristics and there was no clear disease characteristics or patient characteristics that really stood out to be able to predict, ‘Oh, you’re going to be the one who lives five years and beyond.’ We did look at PD-L1 status of the tumour and approximately 50% of our patients had enough tumour to do PD-L1 staining, this was back when the biomarker wasn’t studied quite as much. In this about half of the patients, about 60 patients, patients who had PD-L1 negative or less than 1% staining the five year overall survival was approximately 20%. For patients with PD-L1 staining 1% or higher the five year overall survival was about 23%. If you looked at PD-L1 staining of high, using a 50% cut-off, the five year overall survival in thirteen patients in this subgroup was approximately 43%.
Also we looked at histology - there was really no difference and then we also looked at different patient characteristics again and there was really no difference between the five year survivor group versus the whole group who were treated.
Are patients in some cases being given drugs for the correct amount of time?
In this study we stopped at two years and we do have data from the 16 patients that if you do stop at two years, or even beforehand, the response can be durable for a very long period of time without needing further treatment. Certainly based on the nivolumab label or the pivotal phase III studies we continue to dose nivolumab until progression but based on this we can go back and look can we stop at two years. Most of the studies using nivolumab in lung cancer are now being amended to stop at two years and there is a study, CHECKMATE 153, that is looking at continuous dosing versus stopping at one year. Certainly with drugs like this and others that are very expensive it would be nice to be able to tell our patients we can feel safe of stopping at a period of time but we don’t have yet a biomarker or even patient characteristics to say that you can stop now versus someone that needs to continue to receive that therapy to keep their tumour in check.
What would be your take home message?
The take home message is that for your patients we can now quote five year survival of 16% in patients who have been previously treated with nivolumab and certainly this is something new. Again it brings hope for our patients that they too can be alive and well even five years from now.