Reduction in length of immunotherapy treatment for hard-to-treat melanoma shows promise in clinical trial

Technician in face mask with tray of samples
  • Reducing the length of immunotherapy treatment for an advanced skin cancer did not significantly diminish disease control when compared to giving treatments over a longer period
  • Results from the five-year trial revealed that 80.2 per cent of patients who discontinued immunotherapy after 12 months continued to maintain disease control after a further 12 months
  • Since joining the trial patient Jackie Summers, 77, has seen her tumour shrink to about half its size - despite receiving only 50 per cent of standard treatment
  • Melanoma is the fifth most common skin cancer. Immunotherapy treatments have transformed the outlook for patients with inoperable late-stage melanoma – which was considered untreatable just 10 years ago

Reducing the length of immunotherapy treatment for an advanced skin cancer did not significantly diminish disease control when compared to giving treatments over a longer period, according to breakthrough research led by the Universities of Sheffield and Leeds and Sheffield Teaching Hospitals NHS Foundation Trust.

The findings from the UK DANTE phase III trial were presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago today (3 June 2025).

The trial, which was funded by a National Institute for Health and Care Research (NIHR) Health Technology Assessment grant, is the largest prospective trial to date to evaluate the best duration to treat inoperable late-stage melanoma with immunotherapy.

Results from the five-year trial, conducted between September 2018 and March 2023, revealed that 80.2 per cent of patients who discontinued immunotherapy after 12 months continued to maintain disease control after a further 12 months. This was comparable to the 87.6 per cent of patients who maintained disease control after taking the drugs for two years or more, when considering a pre-defined margin of disease worsening.

Analyses of secondary endpoints showed little difference in quality of life between patients receiving the different treatment durations.  Further work is underway to explore the cost-effectiveness of the reduced treatment duration.

Melanoma is the fifth most common skin cancer, with immunotherapy treatments transforming the outlook for patients with inoperable late-stage melanoma – which was considered untreatable just 10 years ago.

Current standard first-line treatment is to use immunotherapy drugs, such as pembrolizumab and nivolumab, for at least two years, or for as long as the drugs continue to help patients. This has significantly improved survival rates, but there is no strong evidence that two years is the best duration for controlling or shrinking tumours in patients with inoperable stage 3 and stage 4 metastatic melanoma. Patients can also experience severe side effects, needing more tests and hospital visits and sometimes inpatient admissions. 

In the trial, 415 patients from 36 UK hospitals were recruited during their first 12 months of treatment. Upon reaching 12 months, 166 patients whose disease had not progressed were randomly assigned to stop immunotherapy treatment or continue with the treatment for a further 12 months or longer, providing the treatment and toxicity of treatments was manageable.

Although the findings represent a significant contribution to understanding future treatment strategies for metastatic melanoma, challenges with recruitment, arising from the pandemic, led to early closure of the trial before the full sample size could be recruited. This meant the trial was underpowered and continuing immunotherapy for at least two years should remain as standard treatment.

The trial was sponsored by Sheffield Teaching Hospitals NHS Foundation Trust and conducted by the Leeds Cancer Research UK Clinical Trials Unit at the University of Leeds.

Chief Investigator of the DANTE trial Professor Sarah Danson, Professor of Medical Oncology at the University of Sheffield and Honorary Consultant in Medical Oncology at Weston Park Cancer Centre, at Sheffield Teaching Hospitals NHS Foundation Trust, said: “Reducing the amount of treatment is one of the hardest things to do because patients and clinical teams worry that ‘more is best’. 

“However, more treatment may mean more side-effects, which can be a burden to patients. Through this trial, we have gained a wealth of information and important evidence on the way advanced melanoma is treated. We will now be looking at this in more detail to see if certain patients benefited more than others.”

Michelle Collinson, Associate Professor in Clinical Trials at the Leeds Cancer Research UK Clinical Trials Unit, University of Leeds, said: “Clinical trials research is essential to improve the care and outcomes for patients globally. At the University of Leeds, we are committed to finding the best ways to treat cancer and this would not be possible without the patients who take part in research. We are proud to have led delivery of the DANTE trial and hope the promising findings will inform further research into immunotherapy treatment for melanoma patients.”

One patient who has benefited from the trial is Jackie Summers, 77, who lives near Lincoln. She was diagnosed with inoperable stage 3 melanoma in 2018 after noticing swelling and lack of strength in her right arm and was initially told she would have immunotherapy infusions for two years.

Once she had been on the treatment for a year, however, she was asked if she wanted to join the DANTE trial – something she didn’t hesitate to agree to.

“Immunotherapy had only been around seven years before I was diagnosed with advanced skin cancer, and I truly believe that if you are on the receiving end of something so fantastic – the people, the nurses and the huge team that surround you – you need to give back,” said Jackie.  

“It was all about the people that had gone before me on the research trials; I wanted to tap into that and help thousands of people on the same drug as I was on.”
Since having the treatment Jackie’s tumour has shrunk to about half its size. She's also seen a slow reduction in her swelling although she still wears a compression sleeve to help with the discomfort.

“I know the tumour is there but don’t often think about it. I’ve only had 50% of the standard treatment but I’m glad I am as bolshy as I am as there’s so much to be gained from research, not just for yourself but for the information that is recouped by the hospital, and that’s so important as it will help the next cohort of people who unfortunately will have cancer like me. The staff have been absolutely wonderful.”

The ‘Comparison of 1 year versus minimum 2 years of anti-PD1-immunotherapy as first-line treatment for metastatic melanoma: Results of the DANTE phase III trial’ abstract, will be included in the 2025 Best of ASCO programme, an educational meeting which will be held in the summer following the ASCO meeting.

The ASCO Annual Meeting is the world’s largest cancer conference, bringing together advances in the field that will improve outcomes for all people with cancer.

The DANTE trial was designed with patients, through the Melanoma Focus Charity.

“My thanks go to all patients who signed up to the trial and to everyone else who contributed,” Professor Danson added.


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