Reflections from Ranchi Cancer Summit 2.0 on dual immunotherapy, accurate biomarker testing and personalised treatment decisions
Scientific meetings become truly meaningful when research findings are translated into better decisions for patients. At the Ranchi Cancer Summit 2.0, I had the opportunity to participate in three scientific sessions—one as a speaker and two as a panelist. My speaker session focused on the important clinical outcomes and learnings from the phase III CheckMate 8HW trial in metastatic colorectal cancer.
Why CheckMate 8HW Is Important
The CheckMate 8HW trial, registered as NCT04008030, evaluated dual immunotherapy using nivolumab and ipilimumab in patients with microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer, commonly called MSI-H/dMMR mCRC.
These cancers have specific biological features that can make them more responsive to immunotherapy. The trial compared nivolumab plus ipilimumab with standard chemotherapy in the first-line setting and also compared the combination with nivolumab alone across different treatment lines.
A Major Improvement Over Chemotherapy
The results showed a 79% reduction in the risk of disease progression or death with nivolumab plus ipilimumab compared with chemotherapy, with or without targeted treatment.
At 24 months, approximately 72% of patients receiving dual immunotherapy remained progression-free, compared with only 14% of patients receiving chemotherapy.
Another encouraging finding was the lower rate of early disease progression. Earlier anti-PD-1 monotherapy studies reported early progression in a considerable number of patients. With the dual-immunotherapy approach, the rate of primary progression was reduced to approximately 10%.
Dual Immunotherapy Versus Nivolumab Alone
Nivolumab plus ipilimumab also provided better progression-free survival than nivolumab alone.
Progression-free survival rates with the combination were approximately:
- 76% at 12 months
- 71% at 24 months
- 68% at 36 months
For nivolumab alone, the corresponding rates were 63%, 56% and 51%.
The dual-immunotherapy group also achieved a higher overall response rate, approximately 71% versus 58%, with deeper complete responses.
Importantly, benefit was seen in difficult clinical subgroups, including patients with liver metastases and those with KRAS, NRAS or BRAF mutations.
Why Accurate MSI and MMR Testing Matters
One of the most practical lessons from CheckMate 8HW was the importance of correct biomarker testing.
Central laboratory review found that approximately 12–13% of patients initially classified as MSI-H/dMMR were actually microsatellite stable or mismatch repair-proficient. These patients received very limited benefit from immunotherapy, with progression-free survival of only around 1.9 months.
This highlights an important message: immunotherapy selection must begin with reliable MSI and MMR testing.
Balancing Effectiveness and Safety
Grade 3 or 4 treatment-related side effects occurred in approximately 22% of patients receiving nivolumab plus ipilimumab, compared with 14% receiving nivolumab alone. However, the immune-related side effects were consistent with the known safety profile and were generally manageable with established treatment protocols.
CheckMate 8HW represents an important step forward. It shows how biomarker-guided dual immunotherapy can provide deeper, longer-lasting disease control while reinforcing the need for accurate testing, careful patient selection and personalised cancer care.
