At ASCO, the Plenary Session is like the Valedictorian ceremony of oncology research. Held on the conference’s third day, it’s when the five most practice-changing phase 3 clinical trials are unveiled. On this stage, oncologists across specialties—GI, GU, breast, heme, head & neck—come together to celebrate breakthroughs that push cancer care forward. It’s fast‑paced, high‑energy, and reminds us why we do this work. I summarized the 5 studies below for healthcare provides and for patients. Hope it helps!
1. ATOMIC (Stage III dMMR Colon Cancer) presented by Dr Frank Sinicrope
For clinicians:
A global randomized Phase 3 trial comparing mFOLFOX chemotherapy alone vs. FOLFOX + immunotherapy using atezolizumab in stage III colon cancer with deficient mismatch repair (dMMR/MSI‑High). At 3 years, disease‑free survival (DFS) was 86.4% vs. 76.6%, a 50% reduction in relapse risk (HR 0.50; p < 0.0001). Grade 3–4 toxicity rose from 62% to 72%, but remained manageable. My only question in this is if the chemotherapy really matters or adds to PD1 monotherapy when we already know monotherapy is clearly better in the macroscopic setting compared to the chemotherapy. I have my doubts in the microscopic setting and perhaps (this is optimistic speculation on my part) using ctdna to guide therapy with immunotherapy alone or switch to chemotherapy in sequential fashion may be an interesting strategy.
For patients:
Combining chemotherapy with immunotherapy dramatically lowered the risk of cancer coming back after surgery. There were more, but expected, side effects like fatigue, low white cells and nausea. This combo now represents a new standard for tumors with this specific biomarker.
2. NIVOPOSTOP (High-Risk Head & Neck Cancer) presented by Dr John Bourhis Sr
For clinicians:
Phase 3 trial of adding nivolumab to cisplatin-based chemoradiation post-surgery in high‑risk locally advanced head and neck squamous cell carcinoma (extra‑capsular spread or close/positive margins). At 3 years, DFS improved 63.1% vs. 52.5% (HR ~0.76). Local-regional recurrence was also significant reduced and overall survival trended favorably in the chemo-immunotherapy-radiation arm.
For patients:
For those at higher risk of recurrence after surgery, adding the immunotherapy nivolumab helped prevent more patients from early relapse. Side effects were a bit more severe, but overall manageable. This is the first major treatment advance in 20+ years for this group.
3. VERIFY (Polycythemia Vera) presented by Dr Andrew Tucker KuyKendall
For clinicians:
A randomized, Phase 3 trial of the hepcidin-mimetic rusfertide vs. placebo in polycythemia vera (LBA3 plenary). Primary endpoint met: 76% achieved hematocrit < 45% without phlebotomy vs. 32% with placebo. There was less need for phlebotomy and better quality of life.
For patients:
Rusfertide, a once‑weekly injection, significantly reduced the need for phlebotomies and improved symptoms like fatigue and headache—making life easier for people living with polycythemia vera.
4. SERENA‑6 (HR+/HER2– Breast Cancer with Emerging ESR1 Mutations) presented by Dr Nicholas Turner
For clinicians:
A phase 3, double‑blind, ctDNA‑guided trial randomizing patients with newly detected ESR1 mutations while on first‑line endocrine + CDK4/6 inhibitor to continue standard therapy vs. switch to camizestrant (an oral SERD) + CDK4/6 inhibitor. At 12 months, PFS was 60.7% vs. 33.4%; at 24 months, 29.7% vs. 5.4% (HR ~0.44). Toxicity was similar. Again, I was impressed that ctdna was able to guide treatment in the adjuvant treatment prior to seeing radiographic disease progression.
For patients:
By using liquid biopsies to detect early mutations, we can preemptively switch therapy before visible tumor growth. This approach gave people a significant delay in cancer progression and maintained quality of life.
5. MATTERHORN (Resectable Gastric/GEJ Cancer) Dr Yelena Janjigian
For clinicians:
1584‑patient global, double‑blind Phase 3 trial testing perioperative FLOT (chemo) ± durvalumab. The primary endpoint, event‑free survival (EFS), favored the immunotherapy arm: at 2 years, 67.4% vs. 58.5% (HR ~0.71; p<0.001). No increase in perioperative toxicity.
For patients:
Adding durvalumab to chemo before and after surgery lowered the risk of relapse or death by about 9 more people per 100 at 2 years—with no added side effect risk. It sets a new approach for gastric cancer that can be fully removed surgically.
Final Takeaways
- Immunotherapy is truly everywhere—bolting onto surgery, chemo‑radiation, chemo, hormone therapy—and delivering big wins across cancer types.
- We’re pulling personalized medicine forward: genome-informed biomarker selection (dMMR, ESR1, high-risk features) is guiding who gets what.
- Patients see meaningful, real-world impacts: fewer relapses, fewer procedures, better quality of life.
Curious about what these findings mean for you or your loved ones? Drop your question below—whether you’re on the hunt for treatment options, thinking of clinical trials, or just want to learn more.
About the author
Dr. Sajeve Thomas is a distinguished medical professional and a compassionate guide in the field of oncology. With over a decade of dedicated experience as a board-certified medical oncologist/internal medicine specialist, Dr. Thomas has become a trusted expert in the treatment of melanoma, sarcoma, and gastrointestinal conditions. He brings a wealth of expertise to the complex and challenging world of oncology
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