Jeff Ryckman, Associate Professor of Radiation Oncology at WVU Medicine Camden Clark Medical Center, shared on X:
“UNION
3y EFS 91% vs 77% with SCRT/CAPOX/camrelizumab vs long-course CRT/CAPOX in rectal cancer. HR 0.33 (95% CI 0.15-0.71). Impressive signal. But RT schedule and IO both changed, so this doesn’t isolate the benefit of either.
Full UNION paper is out in Lancet Oncol. Supplement Table S4 caught my eye: median time from RT start to surgery was 72 vs 113 days (SCRT/IO vs control), yet pCR was 39.8% vs 15.3%.
I would’ve expected LOWER pCR with surgery that much sooner(!), as we’ve seen in past short-course RT trials. Makes that response signal even more interesting! Adding ICI in rectal cancer sure seems enticing! Are we entering a new frontier?!?
ASTRO26 – STELLAR II (Li)
Phase 2/3, 588 pts w/ pMMR LARC, SCRT 25/5 TO CAPOX x4 +/- sintilimab. Adding sintilimab increased CR (pCR + cCR) from 27% TO 52% (p<0.001). pCR among operated pts went from 19% TO 42%. G3-4 toxicity also went up, 20% TO 28%. Looking forward to the primary phase 3 endpoint, 3y DFS, which is still pending.
ASTRO26 – TORCH-iTNT (Wang) asks a different question:
Randomized phase II, pMMR LARC, CAPOX + toripalimab x6 w/ vs w/o SCRT 25/5. CR was 37% w/o RT TO 62% w/ SCRT. IO in both arms here.
Unlike UNION, both ASTRO trials allowed watch-and-wait / organ preservation, so CR includes cCR. These aren’t all pCR comparisons. Oh and of course standard caveat that cross trial comparisons are a sin.
UNION enrolled only surgery-intended pts, and both arms got just 2 cycles of consolidation chemo vs the 4-6 now recommended. I wonder how this compares w/ modern TNT, especially when organ preservation is the goal.”
Title: Neoadjuvant short-course radiotherapy followed by camrelizumab and chemotherapy versus standard of care for locally advanced rectal cancer (UNION): a prespecified interim analysis of a multicentre, open-label, randomised, phase 3 trial
Authors: Kaixiong Tao, Zhenyu Lin, Peng Zhang, Pan Chi, Yi Xiao, Zhiguo Hou, Ximing Xu, Aimin Zhang, Xingfeng Qiu, Junxin Wu, Ying Yuan, Zhenning Wang, Xiujuan Qu, Xin Li, Xiu Nie, Ming Yang, Kailin Cai, Zheng Wang, Weikang Zhang, Ying Huang, Zhen Sun, Rongrong Zheng, Feng Zhao, Chuyi Han, Tao Zhang
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