Utility of ctDNA to Manage Adjuvant Therapy in CRC Based on Results of the GALAXY Study - Episode 9

Ongoing Trials and Future Directions in CRC


Drs. Cohen and Lewis close by outlining ongoing clinical trials in CRC and hopes for the future of care.


Mark Lewis, MD: The prospect of randomized studies, we talked about VEGA, we talked about ALTAIR. I think to round out the landscape, it’s important to mention some others in development. There’s the COBRA or NRG-GI005, which is fascinating to me. This is stage IIA patients who will either go to active surveillance or they’ll go to assay-directed therapy. There’s CIRCULATE-US, which is really interesting and is asking 2 things. It’s taking the ctDNA [circulating tumor DNA]-positive stage II [patients] and stage III [patients] as well, and it’s deescalating chemotherapy in patients who are ctDNA-negative, but potentially escalating to a FOLFOXIRI [folinic acid, fluorouracil, oxaliplatin, irinotecan] triplet above cFOLFOX [colorectal-oxaliplatin, folinic acid, fluorouracil] or CAPOX [capecitabine, oxaliplatin], in the ctDNA-positive group. Then finally there’s a Stand Up to Cancer ACT3 study, which is also trying to match patients to the right therapies. I believe there’s a FOLFIRI [folinic acid, fluorouracil, irinotecan] arm for patients with persistent ctDNA positivity. So again, there’s going to be so much happening in this space the next couple years, it’s going to be really exciting to watch.

I think we’re in the infancy of understanding how to use this, which means in turn then we are in the early stages of knowing how to counsel our patients about what these values mean. The tumor-informed aspect does feel to me like we’re getting 1 step closer to truly personalized medicine, but you’ve also very astutely pointed out that not all these assays are created equally. So we really need to pay attention to the operating characteristics of what is giving us the ctDNA signal. I have referenced the fact that there are tumor-agnostic, plasma-only approaches. As we move forward, I think we have to be very careful that we understand the clinical context, we understand the patients in which these are being used, we understand where these assays are being drawn in the longitudinal treatment course, and precisely which assay is being deployed and what are its features.

With that, Dr Cohen, I think it’s been a great discussion about a really thoughtful abstract that is going to set the stage for many studies like it to come, and hopefully allow us to take better, more refined care of our patients. So thank you. I thank our audience, and I hope that they found this discussion illuminating, and I hope that it will help them think about this topic. Thank you very much.

Stacey A. Cohen, MD: Thanks.

Transcript edited for clarity.