New RAMPART trial results show combination immunotherapy significantly improves disease-free survival in kidney cancer patients after surgery

New RAMPART trial results show combination immunotherapy significantly improves disease-free survival in kidney cancer patients after surgery

(IN BRIEF) The Phase III RAMPART trial has demonstrated that combining the immunotherapy drugs durvalumab and tremelimumab after surgery significantly improves disease-free survival in patients with early-stage renal cell carcinoma (RCC). Led by the Medical Research Council Clinical Trials Unit at UCL and presented at the ESMO Congress 2025 by Professor James Larkin of The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust, the study found a 43% reduction in recurrence risk for high-risk patients receiving combination therapy. Three-year disease-free survival rates were 81% for those given both drugs compared to 73% under active monitoring. The trial, supported by AstraZeneca UK and The Royal Marsden Cancer Charity, marks a major advance in the use of immunotherapy to prevent kidney cancer relapse after surgery.

(PRESS RELEASE) LONDON, 21-Oct-2025 — /EuropaWire/ — A groundbreaking international study has revealed that combining two immunotherapy drugs can significantly extend disease-free survival for patients with the most common type of kidney cancer. Findings from the Phase III RAMPART trial show that treatment with durvalumab and tremelimumab after surgery substantially reduces the risk of cancer recurrence in patients with early-stage renal cell carcinoma (RCC). The results were presented at the European Society for Medical Oncology (ESMO) Congress 2025 by Professor James Larkin, Professor in the Division of Clinical Studies at The Institute of Cancer Research (ICR), London, and Consultant Medical Oncologist at The Royal Marsden NHS Foundation Trust.

The RAMPART trial, led by the Medical Research Council (MRC) Clinical Trials Unit at University College London (UCL), was designed to determine whether immunotherapy could help prevent relapse following surgery aimed at curing RCC. A total of 790 patients across 80 global sites were enrolled between October 2018 and June 2023 and randomly assigned to three groups: active monitoring, durvalumab alone, or a combination of durvalumab and tremelimumab. The current findings report results for the combination arm versus active monitoring, while data for durvalumab alone will follow in future analyses.

After three years, patients treated with both durvalumab and tremelimumab achieved an 81% disease-free survival rate, compared to 73% among those receiving no active treatment. The benefit was even more pronounced among high-risk patients, where disease-free survival reached 78% with immunotherapy versus 61% under active monitoring, representing a 43% relative reduction in recurrence risk.

Durvalumab and tremelimumab are immune checkpoint inhibitors that help the body’s immune system recognize and attack cancer cells. By targeting two distinct immune checkpoints, the combination therapy enhances and prolongs anti-tumour immune responses. Importantly, safety results from the trial were consistent with the known profiles of these drugs, suggesting the combination is both effective and manageable for patients.

Professor Larkin, Chief Investigator of the study, highlighted the clinical importance of the findings: “In a subgroup of patients facing a high risk of cancer returning after surgery, we saw a remarkable result, with over a 43 per cent relative reduction in the risk of recurrence. These are very promising findings that confirm the benefit of immunotherapy in the treatment of high-risk renal cell carcinoma.”

Professor Angela Meade, one of the international leads of the trial based at MRC CTU at UCL, added: “We are very pleased to see that this combination of immunotherapy drugs significantly reduces the risk of kidney cancer returning. Importantly, the greatest benefit was observed in participants who were at the highest risk of recurrence. As these treatments can cause serious side effects, it is important that we target their use to those most likely to benefit.”

Among the participants was Janet Middlehurst, a 69-year-old retired teacher from London, diagnosed with Stage 3 kidney cancer in 2019. After undergoing surgery at The Royal Marsden, she joined the RAMPART trial and received the combination therapy. “When I was diagnosed I didn’t even know if I’d see Christmas,” she shared. “I’ve been in remission ever since joining the trial, and I feel so lucky. I’ve been able to spend precious time with my grandchildren and will see my youngest son get married next year.”

The RAMPART trial was sponsored by UCL and conducted with financial support from AstraZeneca UK Limited. Immunotherapy research at The Royal Marsden is supported by The Royal Marsden Cancer Charity, which funds initiatives like the West Wing Clinical Research Centre — a hub for numerous clinical trials, including RAMPART.

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SOURCE: The Institute of Cancer Research