Results showed no significant difference in overall survival between the two groups in the intention-to-treat population, but that noticed that a subgroup of patients who were ctDNA positive showed a marked improvement when they were given atezolizumab.
These benefits included significantly higher disease-free survival, and significantly higher overall survival, than the observation group. This effect wasn’t seen in ctDNA negative patients.
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Researchers also found that patients that were ctDNA positive, but subsequently changed to became ctDNA negative after treatment with atezolizumab, ultimately had a particularly good prognosis.
Professor Gschwend, Chairman of the Department of Urology at the Technical University of Munich, said: “We already knew that patients who are ctDNA positive have a poor prognosis compared to those who are ctDNA negative. But this is the first time we’ve been able to show that with immunotherapy we can actually change the course of the disease depending on a patient’s ctDNA status.”
He continued: “If we can prove that consequent drug activity is linked to ctDNA status, and that high-risk patients will benefit, that could in time change the standard treatment pathway – and ultimately bring down the average cost of ctDNA analysis.”
Professor Morgan Roupret, Chairman of the European Section of Onco-Urology of the European Association of Urology, said: “The field of personalized medicine, using not only clinical but molecular indicators, is just around the corner. So, analyzing ctDNA is very interesting.”
It is easy to do with new technology and it means we can select a subset of patients who are likely to respond.”
The next step will be the upcoming IMvigor 011 study, which has been redesigned as a consequence of these results.
With 500 participants, the trial will evaluate the use of ctDNA sampling, and will compare atezolizumab against placebo in only ctDNA-positive patients, post-surgery.
Source: Medindia
