On 1 September, Spain authorised the treatment for eligible adults with metastatic colorectal cancer whose tumours carry dMMR/MSI-H alterations. The combination of nivolumab and ipilimumab is the first dual immunotherapy financed for first-line treatment of this disease. The trial compared it with conventional chemotherapy and nivolumab alone.
The decision also fits within a wider European regulatory structure. Bristol Myers Squibb reports that the European Commission approved the combination for first-line treatment of adults with unresectable or metastatic MSI-H/dMMR colorectal cancer across the European Union, as well as Iceland, Liechtenstein and Norway.
The two-year result is stark: 74% of patients who received the combination remained free of disease progression, compared with 11% of those given standard chemotherapy. The phase III CheckMate 8HW trial also found a 79% reduction in the risk of progression or death compared with chemotherapy and a 38% reduction compared with nivolumab monotherapy.
Nivolumab acts on PD-1, while ipilimumab blocks CTLA-4. Together, the drugs target both immune-system brakes. Rocío García Carbonero says the combined effect is stronger because the two pathways are blocked together. European approval provides the regulatory basis for first-line use, while national health systems decide when treatment is financed and how it reaches patients.
Hospital público 12 de Octubre helped produce the trial evidence. Rocío García Carbonero coordinates the Digestive Tumours Unit within the hospital's Oncology Service. She was an investigator and co-author of the international trial, and enrolled the centre's first patient in 2020.
Patients treated there received the strategy six years before it entered Spain's national public health system. The first patient in the trial achieved a complete response after two years of therapy and remained in sustained complete response several years after treatment ended.
For metastatic disease, this is a major change. Patients have traditionally relied on continuous conventional treatment; the new approach can produce deep responses and long periods without therapy.
The trial results appeared in The New England Journal of Medicine. In first-line treatment, the combination produced an objective response rate of 73%, with complete responses in 35% of patients. A complete response means no detectable lesions remained.
Materials prepared for ESMO 2026 also identify final overall-survival results from CheckMate 8HW. The analysis compares nivolumab plus ipilimumab with nivolumab or chemotherapy in patients with MSI-H/dMMR metastatic colorectal cancer, providing a longer-term view alongside the progression-free survival findings.
The biology helps explain the result. dMMR/MSI-H tumours fail to repair errors made during DNA replication and accumulate thousands of mutations. This can make them resistant to traditional chemotherapy but especially sensitive to immunotherapy.
This subtype accounts for between 4% and 7% of metastatic colorectal cancer cases and may be linked to hereditary conditions such as Lynch syndrome. The group is small, but the treatment difference is clear.
Colorectal cancer also affects the wider population. It is the most frequently diagnosed cancer in Spain when both sexes are counted together and the second leading cause of cancer death worldwide. Some dMMR/MSI-H cases affect patients considerably younger than those with other colorectal cancers.
Practical information on how public healthcare brings new treatments to patients appears in earlier coverage of changes in access to medical care.
The funding decision adds a treatment for a clearly identified group to Spain's public system. Results against chemotherapy and nivolumab show why dual immune blockade has changed the first-line standard for these patients.
The 12 de Octubre's role also matters: research carried out in Spain's public hospitals helped bring the treatment to patients in the trial. Coverage of fast-track cancer research in Spain has made the wider point that regulatory registration is only one stage. Later financing decisions and the rules for inclusion in the public health system determine when patients can actually receive a new treatment.
