CIRCULATE-US: What does participating involve for me?

Study design

CIRCULATE-US is an open-label study.

An open-label study means both the researcher and the participant will know the treatment they are receiving.

Participants in this study will be randomly assigned to get either FOLFOX/CAPOX or FOLFOXIRI, if they test positive for ctDNA. If they test negative for ctDNA, participants will be randomly assigned to get FOLFOX/CAPOX or no chemotherapy. All participants will receive regular monitoring.

5-fluorouracil, leucovorin, oxaliplatin, and irinotecan are commonly used in colorectal cancer treatment. They are all given intravenously, which means the medicine is delivered directly into your bloodstream through an IV or port. Capecitabine is also another common treatment, and is given in the form of tablets.

If you are in Group 1, you will receive:

  • Oxaliplatin IV
  • Leucovorin IV
  • 5-Fluorouracil (5-FU) bolus
  • 5-Fluorouracil (5-FU) IV continuous infusion over 46-48 hours (total dose) every 2 weeks for 6 to 12 cycles

OR

  • Oxaliplatin IV every 3 weeks
  • Capecitabine tablets by mouth days 1-14 every 3 weeks for 4 cycles

If you are in Group 2, you will receive regular ctDNA monitoring, but no treatment. If you test positive for ctDNA, you will be randomized into Group 3 or Group 4.

If you are in Group 3, you will receive:

  • Oxaliplatin IV
  • Leucovorin IV
  • 5-Fluorouracil (5-FU) bolus
  • 5-Fluorouracil (5-FU) IV continuous infusion over 46-48 hours (total dose) every 2 weeks for 12 cycles

OR

  • Oxaliplatin IV every 3 weeks
  • Capecitabine tablets by mouth days 1-14 every 3 weeks for 4 cycles

If you are in Group 4, you will receive: 

  • Oxaliplatin IV
  • Leucovorin IV
  • Irinotecan IV continuous infusion (30-90 minutes)
  • 5-Fluorouracil (5-FU) IV continuous infusion over 46-48 hours (total dose) every 2 weeks for 12 cycles

What happens after treatment?

After participants finish treatment, their doctors and the study team will watch for side effects. Participants will be checked every 6 months for four and a half years after treatment.

If a participant is ctDNA negative, and does not develop a positive ctDNA test, they will receive regular check-ups every 6 months for four and a half years after they join the study, without further treatment for colon cancer.

If a participant is ctDNA negative, and develops a positive ctDNA test during monitoring (and agrees to change to Group 3 or Group 4), their doctor and the study team will watch for side effects. They will receive regular check-ups every 6 months for four and a half years after treatment ends. It’s possible that participants could be in the study up to eight years.

Below are the standard NCCN surveillance guidelines for stage II and III patients. This is what patients receive outside of the study.