Every rectal cancer patient in the trial saw their tumor vanish on immunotherapy
Published · Researched 2026-09-22
What happened (dated facts)
In an updated analysis presented at ASCO 2024 from Memorial Sloan Kettering's Phase 2 study, the immunotherapy dostarlimab (Jemperli) produced a 100% clinical complete response rate in 42 patients with mismatch repair–deficient (dMMR) locally advanced rectal cancer who completed treatment — defined as no evidence of tumor on MRI, endoscopy, and digital rectal exam, with no surgery, radiation, or chemotherapy needed. In the first 24 patients evaluated, the complete response was sustained with a median follow-up of 26.3 months. An even later update (AACR 2025, published in NEJM) extended the rectal cohort to 49 patients, all with complete clinical response at a median follow-up of 30.2 months and a 2-year recurrence-free survival of 96%.
Why it is genuinely positive
Standard rectal cancer treatment means chemoradiation plus surgery that can leave patients with a permanent colostomy and lasting quality-of-life damage. In this trial, every patient avoided all of that: the tumors disappeared on a drug alone, and stayed gone. It is one of the most striking complete-response results ever reported in a solid tumor.
Social pulse
Strong oncology-press circulation of the 100% complete-response results (ASCO 2024, AACR 2025). Targeted Threads searches did not return direct posts about dostarlimab in this session. The social layer here is oncology media rather than viral patient posts.
Verified quotes
None captured.
Verification
- Tier: 2
- Primary source: GSK regulatory announcement of the ASCO 2024 update (https://www.lse.co.uk/rns/unprecedented-results-in-jemperli-trial-continue-9gnrxy8jiw1obtt.html?mobile_view=desktop), June 3, 2024; extended results via OncLive/AACR 2025 (https://www.onclive.com/view/neoadjuvant-dostarlimab-eradicates-disease-in-82-of-mismatch-repair-deficient-solid-tumors). Proves: 100% cCR in 42 patients; sustained response at 26.3-month median follow-up; later 49-patient cohort, 96% 2-year RFS.
- Social sources: health-press layer + targeted Threads searches (direct story posts not captured — noted honestly). Proves: sustained coverage and community relevance via health media.
- Positivity check: complete, durable tumor eradication without surgery in every treated patient — an extraordinary genuine outcome.
Key facts
| Fact | Value | Source | Date |
|---|---|---|---|
| Trial | MSK Phase 2, dMMR locally advanced rectal cancer, neoadjuvant dostarlimab | GSK / OncLive | 2024 |
| Complete response (ASCO 2024) | 100% in 42 patients completing treatment | GSK RNS | 2024-06-03 |
| Durability | First 24 patients: sustained cCR, median follow-up 26.3 months | GSK RNS | 2024-06-03 |
| Extended cohort (AACR 2025) | 49 rectal patients, 100% cCR, median follow-up 30.2 months, 2-yr RFS 96% | OncLive | 2025 |
| Treatment avoided | No surgery, radiotherapy, or chemotherapy required | GSK RNS | 2024-06-03 |
UNVERIFIED points
- Social-layer posts about dostarlimab were not yet observed; tier cannot be finalized until they are.
Sources
- Primary source: GSK regulatory announcement of the ASCO 2024 update ( — retrieval date not recorded
- Primary source: GSK regulatory announcement of the ASCO 2024 update (https://www.lse.co.uk/rns/unprecedented-results-in-jemperli-trial-co… — retrieval date not recorded