iwCLL 2025 | The impact of testing for genetic markers on clinical outcomes among patients with CLL

Thank you for the question about testing before treatment. And this has been one of the cornerstones of my efforts on behalf of the CLL Society to ensure that all patients are tested before treatment. And because we know that testing, especially FISH testing, fluorescent in situ hybridization testing, looking for 17p aberrations through genetic sequencing and looking at IGHV status, are not only prognostic but also predictive of what therapies can work. 

It’s always been important to me, but what I was able to do was look back at some real-world data and access some de-identified information using Flatiron Health Resource Database. And we looked at patients between 2020 and 2024. There was a total of almost 5,500 patients. And I was pleased to see that almost 82% of those patients had FISH testing, but just a little over a quarter had been tested for 17p aberrations, and just a little over half for IGHV mutations. Who got tested was determined by a number of factors. Patients that were tested tended to be a little bit younger. They were more likely to be male. They were more likely to have commercial insurance. The testing for FISH was done more in the community setting, while the next-gen sequencing testing was done more in the academic setting. 

But the really important part of this was that, when we looked at real-world time to next treatment or death, there was a significant difference between the patients who were tested and not tested. For example, median real-world time to next treatment was 30 months for patients without 17p deletion/TP53 testing versus 41 months for those who were tested. This is a very significant difference. Similar significant differences were found in people tested for IGHV. While there was no significant difference in overall survival, perhaps because of the length of time people were followed in this, there was, if you normalize the groups for demographic and clinical factors, including prognostic markers, there was a 27 and 28 percent higher hazard ratio for patients who did not have the appropriate testing, IGHV and 17p/TP53, respectively. What this says to me is that testing can serve as a proxy for how well patients will do and how well their management is. We also found, not surprisingly, that patients who weren’t tested were more likely to receive chemoimmunotherapy, which is generally not a preferred approach. They were less likely to be followed on NCCN guidelines. So this may explain why time to next treatment was shortened in these patients.

This transcript is AI-generated. While we strive for accuracy, please verify this copy with the video.