STELLAR II
Preoperative short-course radiotherapy followed by chemotherapy with or without PD-1 inhibitor for locally advanced rectal cancer: a prospective, multicenter, randomized controlled, phase II/III study (STELLAR II)
Phase 2/3N = 218NCT05484024
- Population
- Patients with pMMR/MSS locally advanced rectal cancer
- Design
- Multicentre, randomised, seamless phase 2/3 trial in proficient mismatch repair (pMMR)/microsatellite stable (MSS) locally advanced rectal cancer. Participants were randomised 1:1 to short-course radiotherapy (5 Gy x 5) followed by 4 cycles of capecitabine and oxaliplatin or 6 cycles of leucovorin, oxaliplatin and fluorouracil, with (iTNT group) or without (TNT group) 4 cycles of sintilimab. After neoadjuvant therapy participants had surgery or a watch-and-wait strategy based on clinical complete response. Primary endpoints: complete response (CR) rate for phase 2 and 3-year disease-free survival for phase 3. The results here are from the phase 2 part only: 218 patients were randomised (110 iTNT, 108 TNT).
- Primary endpoint
- Complete response rate (clinical or pathological), DFS
- Arms
- Short-course radiotherapy-based TNT (TNT group) (control, n = 108): Short-course radiotherapy (5 Gy x 5) followed by 4 cycles of capecitabine and oxaliplatin or 6 cycles of leucovorin, oxaliplatin and fluorouracil
- Short-course radiotherapy-based TNT with sintilimab (iTNT group) (experimental, n = 110): Short-course radiotherapy (5 Gy x 5) followed by 4 cycles of capecitabine and oxaliplatin or 6 cycles of leucovorin, oxaliplatin and fluorouracil, with 4 cycles of sintilimab
- People
- Tang Y
Δ Complete response rate (clinical or pathological)+20.5 pointsΔ Grade 3-4 acute toxicity+15.1 points
Show the numbers
| Endpoint | Analysis | Short-course radiotherapy-based TNT with sintilimab (iTNT group) | Short-course radiotherapy-based TNT (TNT group) | Effect |
|---|---|---|---|---|
| Complete response rate (clinical or pathological)Randomised patients (218: 110 iTNT, 108 TNT); analysis population not stated in the abstractComplete response (CR) rate, the phase 2 primary endpoint; the abstract does not define CR in detail | interimTang 2025 | 45.5% | 25% | P=0.003Phase 2 results of a seamless phase 2/3 trial; the phase 3 primary endpoint (3-year disease-free survival) is not reported. Participants with clinical complete response could have a watch-and-wait strategy instead of surgery. |
| Grade 3-4 acute toxicityRandomised patients (218: 110 iTNT, 108 TNT); analysis population not stated in the abstractGrade 3-4 treatment-related adverse events | interimTang 2025 | 34.5% | 19.4% | P=0.012Thrombocytopenia, diarrhoea, leukopenia and neutropenia were the most frequent. Grade 3-4 immune-related adverse events occurred in 5.5% of patients in the iTNT group. |
| Endpoint | Analysis | Short-course radiotherapy-based TNT with sintilimab (iTNT group) | Short-course radiotherapy-based TNT (TNT group) | Effect |
|---|---|---|---|---|
| Complete response rate (clinical or pathological)Randomised patients (218: 110 iTNT, 108 TNT); analysis population not stated in the abstractComplete response (CR) rate, the phase 2 primary endpoint; the abstract does not define CR in detail | interimTang 2025 | 45.5% | 25% | P=0.003Phase 2 results of a seamless phase 2/3 trial; the phase 3 primary endpoint (3-year disease-free survival) is not reported. Participants with clinical complete response could have a watch-and-wait strategy instead of surgery. |
| Grade 3-4 acute toxicityRandomised patients (218: 110 iTNT, 108 TNT); analysis population not stated in the abstractGrade 3-4 treatment-related adverse events | interimTang 2025 | 34.5% | 19.4% | P=0.012Thrombocytopenia, diarrhoea, leukopenia and neutropenia were the most frequent. Grade 3-4 immune-related adverse events occurred in 5.5% of patients in the iTNT group. |