A 24-year-old twin given just six months to live after her leukaemia returned is attempting to raise £500,000 for potentially life-saving treatment abroad, saying the prospect of leaving her identical sister behind is 'unthinkable'.
Caitlin Leggett, from Cardiff, was diagnosed with acute myeloid leukaemia (AML) – 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 gruelling chemotherapy and a stem cell transplant in December 2025, Caitlin achieved complete remission. However, 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.
Desperate Search for a Cure
With just six months to live under her current treatment plan, she has resolved to seek potentially curative care overseas – most likely in the US – where treatment and associated expenses could amount to £500,000. Caitlin's twin sister Grace Leggett, who has given up her position 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 devastatingly difficult.
'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 told PA Real Life. 'It's unthinkable,' Caitlin added. 'We've gone through life together and I don't want our story to end here.'
From Army Aspirations to Cancer Battle
Caitlin and Grace have always shared an exceptionally close bond – even living together in a student house at the University of Bristol. Following her graduation in July 2024, Caitlin had set her sights on joining the Army, aspiring to train as an intelligence officer. She had her mandatory medical assessment scheduled for April 2025, but in March that year she developed a rash that persisted despite applying over-the-counter creams from the chemist. Several weeks later, she visited her GP, who suspected she might have a virus and requested blood tests, which were conducted on April 3 2025.
She was told to attend the Llewellyn Teenage Cancer Trust unit at University Hospital of Wales in Cardiff the next day, and instantly recognised it was serious. At the appointment on April 4, 2025, she received a diagnosis of acute myeloid leukaemia.
The Twin Twist: Identical but Incompatible
Upon discovering that treatment would require a stem cell transplant, the entire family underwent testing to find a suitable match. Both Caitlin and Grace had signed up as stem cell donors years earlier, with Grace initially told she would likely be a compatible match. However, genetic testing in June 2025 revealed they were monozygotic twins – identical. This proved to be a significant setback: because their DNA is nearly identical, Caitlin's body would not recognise Grace's stem cells as foreign, rendering the transplant ineffective. No other family members were a suitable match either.
While awaiting an alternative donor, Caitlin achieved remission in May 2025 after two months of chemotherapy. But in August 2025, the cancer returned to her skin. She participated in a menin inhibitors clinical trial in Manchester to eradicate the leukaemia in her skin, which proved successful and placed her back into complete remission. She received a stem cell transplant in December 2025 with a different donor, but the cancer reappeared in her skin a week before the procedure. Despite additional full-body radiotherapy, the transplant was considered successful, and she was in remission again in January 2026.
Recurrence and Limited Options
Caitlin was scheduled for monthly bone marrow monitoring for three months, then quarterly tests from March 2026. 'I didn't feel like it was safe to just go straight to three, so I persuaded my consultant to give me an extra one in May,' she said. 'On that extra one, they found that the leukaemia had come back. 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.'
Since May 2026, Caitlin has been participating in a further drug trial for Bleximenib and is awaiting news on whether her body will respond positively. Her medical team have confirmed there is an additional drug trial available should this prove unsuccessful – however, she has been warned that neither treatment offers a cure. She has also been informed that a second stem cell transplant cannot be carried out in the UK, with doctors estimating that her current treatment plan will extend her life by just six months.
Race Against Time to Raise Funds
As a result, she has resolved to seek curative treatment overseas – with specialised leukaemia care in America or CAR-T cell therapy, a form of immunotherapy, available in China or Singapore. Both options carry a price tag running into hundreds of thousands of pounds. Caitlin and Grace have launched a GoFundMe page entitled Saving Caitlin, aiming to raise £500,000 to fund the costly overseas treatment, along with travel, accommodation and living expenses for accompanying family members.
Without the necessary funds being raised, Caitlin faces the grim reality that she may not reach 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. Those are the things that matter most to me, and that's why I'm doing everything I can to find another treatment option. I don't want to miss out on the future we always thought we'd share together.'
