A 24-year-old twin given just six months to live after her leukaemia came back is attempting to raise £500,000 for potentially life-saving treatment abroad, saying the prospect of leaving her identical sister behind is 'unthinkable'.
Diagnosis and Initial Treatment
Caitlin Leggett, from Cardiff, was diagnosed with acute myeloid leukaemia – an aggressive cancer of the white blood cells – in April 2025, with a persistent rash being the only indication that something was seriously wrong. Following months of chemotherapy and a stem cell transplant in December 2025, Caitlin achieved complete remission. But in May 2026, doctors discovered the cancer had returned and the treatment options available to her on the NHS were unlikely to offer a cure.
Seeking Overseas Treatment
With only six months to live on her current treatment plan, she has chosen to seek potentially curative care overseas – most likely in the US – where treatment and related costs could amount to £500,000. Caitlin's twin sister Grace Leggett, who has given up her job as a complex care personal assistant in Bristol to return to Cardiff to be closer to her family, said witnessing Caitlin's ordeal while facing the possibility of losing her sister within six months was devastating.
'We're only 24 – nobody expects this to happen... Being twins as well, you're not supposed to have one twin not be there,' Grace said. 'It's unthinkable,' Caitlin added. 'We've gone through life together and I don't want our story to end here.'
Close Bond and Unexpected Discovery
Caitlin and Grace have always been incredibly close – even sharing a student house together at the University of Bristol. Following graduation in July 2024, Caitlin had intended to enlist in the Army, aspiring to train as an intelligence officer. She had her mandatory medical assessment scheduled for April 2025, but in March of that year she developed a rash that wouldn't disappear despite using over-the-counter creams. After visiting her GP, blood tests were taken on April 3, 2025, and she was diagnosed with AML the next day.
Throughout their lives, they had believed themselves to be fraternal twins, meaning there was a strong possibility that Grace's stem cells would be accepted by Caitlin's body. However, genetic testing in June 2025 revealed they were actually identical twins. This discovery proved to be a significant setback – due to their near-identical DNA, the transplant wouldn't work as the body must recognise the stem cells as foreign.
Setbacks and Clinical Trials
While awaiting an alternative donor, Caitlin achieved remission in May 2025 following chemotherapy, but the cancer returned to her skin in August 2025. She participated in a menin inhibitors clinical trial in Manchester, which proved successful and placed her into complete remission. She underwent a stem cell transplant in December 2025 with a different donor, but the cancer reappeared in her skin a week prior. The transplant was considered successful, and she was in remission again in January 2026.
Caitlin was scheduled for monthly bone marrow monitoring, but persuaded her consultant to add an extra test in May 2026, which found the leukaemia had returned. 'Initially, the blast count came back at 5.7%, just over remission, but then about a week later it went up to 37%. So it's quite fast-growing,' she said.
Fundraising Campaign
From May 2026, Caitlin has been participating in a drug trial for Bleximenib and is awaiting news. Her medical team say there is another drug trial option should it prove unsuccessful, but these treatments are not curative. She has been informed that a second stem cell transplant cannot be carried out in the UK, and doctors have predicted six more months on her current plan.
As a result, she has chosen to seek curative treatment overseas – weighing up specialised leukaemia treatment in America or CAR-T cell therapy in China or Singapore. Caitlin and Grace have launched a GoFundMe page entitled 'Saving Caitlin' in a bid to raise £500,000 to meet the cost of treatment, transport, accommodation and sustenance for accompanying family members.
Should the twins fail to raise the necessary funds, it is unlikely that Caitlin will survive to celebrate her 25th birthday. 'It's incredibly difficult to think about,' Caitlin said. 'At 24, I always assumed I had my whole life ahead of me. There are so many things I still want to do, places I want to see, and memories I want to make with the people I love. What I would miss most isn't one particular event, it's the chance to keep living an ordinary life with the people I love and growing older alongside my twin sister.'
