Dana-Farber's Pasi Jänne, MD, PhD, reports on ctDNA with an EGFR mutation in FLAURA2 trial. The new data shows patients whose blood tested positive before therapy for tumor cell DNA with EGFR mutations stood to gain the most from combination therapy.
The data at A AC R will describe the findings from the circulating tumor DNA that was detected in patients treated on in the flora to clinical trial. Both the impact of what it means to have it at baseline and also what changes in circulating tumor DNA over over the course of treatment. And the first analysis is really looking at it, what does it mean as a prognostic indicator if you have it at baseline and so independent of which treatment you got having circulating tumor DNA at baseline is associated with a slightly worse prognosis compared to if you do not have circulating uh uh tumor DNA detected at baseline. Now, if we look at it within the treatment, arms patients who had detectable circulating tumor DNA, those who were treated with a combination oer and chemotherapy had a better outcome than those who treated with as Marna m alone in patients who did not have detectable circulating DNA at baseline patients did well with both the single agent osimertinib as well as the osimertinib chemotherapy treatment suggesting that its biomarker is more of a prognostic prior biomarker than actually predicting which therapy one should be treated with. Now, the final piece was looking at if you had circulating tumor DNA at baseline and three or six weeks into treatment that disappeared, what did that mean? And overall that was a good prognostic sign. So I think these studies highlight the utility of circulating tumor DNA in terms of providing prognostic information for patients. And to understand if you don't clear your circulating tumor DNA by a predefined time 0.3 or six weeks. Should that prompt the cha a change in therapy? And there are clinical trials that are asking that question. So I think it still remains a clinical trial question and a and a research question as opposed to established uh a clinical test. And so hopefully over the next several years, we'll see results from the approaches that like I mentioned uh and other studies to fully define how we study the dynamics of circulating DNA during the course of the treatment or where there are opportunities to adapt treatments uh moving forward.
