I had the opportunity to present the results of IMpower 131. What this study was, it was a three arm study evaluating patients with squamous non-small cell lung cancer. It was a 1,000 patient study where patients were randomised one to one to one across three arms: Arm A evaluating carboplatinum and paclitaxel with atezolizumab immuno-oncologic agent; Arm B carboplatinum and nab paclitaxel and atezolizumab and then Arm C which was the control arm – carboplatinum and nab paclitaxel.
Any variation within the patients for each of those groups?
The patient populations were very well balanced across all the predetermined subgroups that oftentimes lead to changes in overall survival patterns based independent of treatment .So it was well balanced across both the two groups that we were analysing.
When it came to treatment tolerability were there any variations?
We saw typical toxicities that we’ve seen historically with the immuno-oncological agents but in this particular study we did not see any added toxicities when atezolizumab was added on to chemotherapy. So, typical toxicities that were seen were hypothyroidism, colitis but not at a higher rate than we’ve seen historically with the use of these agents.
When it came to the endpoints could you tell us about the trials and if they were met?
The primary endpoints in this particular study were investigator assessed progression free survival as well as overall survival. Then secondary endpoints were progression free survival and overall survival in the PD-L1 subgroups as well as duration of response and safety profile. In this particular trial the primary endpoint of investigator assessed progression free survival was met with a doubling of the progression free survival, the control group of 12%, progression free survival increased to 24.7% at twelve months. Some of the secondary endpoints that were exciting secondary endpoints that were met was evaluating the duration of response which was doubled in the intent to treat population as well as in the PD-L1 high and PD-L1 low populations. So very exciting data in the sense that we are starting to see greater response rates as well in those patients that have that PD-L1 high expression with a doubling of that response rate going from 30% to 60% in that patient subgroup.
There were some notes of concern about the effect of chemotherapy on just knocking down the immune system but that was found to not be a challenge?
While we did see some instances of neutropenia occurring, it did not appear to be a substantial increase in those patients that were receiving atezolizumab in combination with the cytotoxic chemotherapy.
Then the big question is where do we take this data next?
At this point right now in the study we are not seeing differences in overall survival in the intent to treat population. The take-home message at this point is, yes, we have further assessment to do of overall survival as the data matures as well as evaluating those subgroup populations of PD-L1, PDL low subpopulations in this study.