Removing ‘invisibility cloaks’ and safely skipping chemo: new weapons in war on cancer shared at US conference

By Andrew Gregory Health editor • June 6, 2026 • Science

Drug that stops cancer cells hiding and a breakthrough pill for pancreatic cancer among highlights from Asco conference – but there were also notes of caution

Doctors, scientists and researchers shared new research about ways to tackle cancer at the 2026 American Society of Clinical Oncology (Asco) annual meeting, the world’s largest cancer conference. The event in Chicago, attended by 40,000 health professionals, featured more than 200 sessions and 2,700 poster presentations on this year’s theme, “the science and practice of translation: improving cancer outcomes worldwide”. Here are the five biggest takeaways. Smart drugs can help patients kill off their own tumours Immunotherapy drugs, which harness the body’s immune system to attack tumours, have revolutionised cancer treatment over the last decade. But they don’t work in every patient. Their effectiveness can falter or fail when cancer cells hide. Now researchers have developed a smart drug that stops cancer cells hiding. The experimental tablet, GRWD5769, can help shrink tumours by at least 30% in six of the world’s most common forms of the disease, delegates in Chicago were told. All of the patients in a trial spanning the UK, France, Spain and Australia had previously failed to respond to treatment. Most had no options left when they joined the study. Crucially, immunotherapy had not worked or had stopped working. The smart drug was able to remove “invisibility cloaks” from tumour cells, exposing them to the parts of the immune system that attack infections and diseases. This enabled an immunotherapy drug, cemiplimab, to detect and then destroy the cancer. Researchers led by the Christie NHS foundation trust in Manchester, England, found tumours shrank in 26 of 83 patients with cervical, bladder, liver, bowel, lung or head and neck cancers who were given GRWD5769 alongside cemiplimab. Of the 26, 15 had tumour reductions of at least 30%. Speaking to the Guardian in Chicago, the trial’s principal investigator, Prof Fiona Thistlethwaite, said: “For a drug that is given as a tablet, this is very impressive. It’s early days, and we need further studies, but this is a new drug with a new mechanism that clearly helps immunotherapy perform more effectively.” A second trial presented at Asco showed that combining another smart drug with chemotherapy helped people with lung cancer live 15% longer on average. Cancer Research UK called the discovery of this novel drug a “promising step forward”. Like GRWD5769, ivonescimab blocks the “off” switch used by tumours to evade the immune system, exposing cancer cells and allowing the body to recognise and fight the disease. Trial results of a third smart drug, ozekibart, found it was able to mimic a natural protein in the body to bind to specific receptors on cancer cells, triggering their “death” while minimising harm to healthy tissue. Showing promise in bowel cancer patients, the drug shrank tumours in some patients and stopped cancer progressing in others. One patient said the therapy had given her a “new lease of life”. A daily pill can tackle the world’s deadliest cancer Drawing a standing ovation in Chicago, delegates were told about a pill that doubles survival time in patients with pancreatic cancer. The discovery was hailed as a gamechanger and one of the biggest breakthroughs in decades. Until now, there were few treatments for the world’s deadliest common cancer, and most of these did little or nothing to help. In a trial of 500 patients, all of whom had pancreatic cancer that had spread, the pill, daraxonrasib, doubled survival time, with fewer side-effects compared with chemotherapy. Patients who took the drug lived substantially longer, for an average of 13.2 months, compared with 6.6 to 6.7 months for patients who had chemotherapy. “These results are landscape-changing,” said Dr Rachna Shroff, the chief of oncology at the University of Arizona Cancer Center and an Asco expert in gastrointestinal cancers, who was not involved with the study. “We are seeing unprecedented survival.” When Shroff first read the results of the trial, which was led by the Dana-Farber Cancer Institute in Boston, she wept, she said. Cancer charities worldwide welcomed the findings, although one, Pancreatic Cancer UK, said access to trials for patients was still “appallingly low”. It said too many people were still being denied the possibility of more precious time with their loved ones. The conference in Chicago heard about a second pill that, when added to existing treatments, could help patients with an incurable blood cancer live longer without the disease getting worse. Patients on the triple therapy, which included the new treatment mezigdomide, lived more than twice as long without their cancer progressing, delegates were told. Mezigdomide worked by attaching to a specific protein in the body. It acted like a magnet, attracting disease-causing proteins that were vital for survival of multiple myeloma cells and degrading them. By wiping out these cancer-promoting proteins, the drug also stimulated the immune system to attack and kill remaining cancer cells. Some patients can safely skip some treatments While most headlines from the conference were about the discovery of new weapons in the war on cancer, there were also surprising findings about which treatments might now safely be avoided. Millions of women with breast cancer could be spared chemotherapy with a groundbreaking genomic test, according to the results of one trial that could transform guidelines worldwide. The breakthrough enables doctors to determine which patients can safely skip chemotherapy, paving the way for a new era of personalised medicine. The Optima trial, led by University College London, followed 4,000 patients with newly diagnosed breast cancer in the UK, Norway, Sweden, Australia, New Zealand and Thailand. Those with a low score on the genomic test could be treated safely with hormone therapy alone, it found. One woman involved in the trial told the Guardian that being able to skip chemotherapy felt “like Christmas”. Nine years after being diagnosed, taking the test and avoiding chemotherapy, she is healthy and enjoying a full and active life. Doctors also welcomed a drug that spares bladder cancer patients “life-changing” surgery and stops tumours coming back. Researchers led by the Institute of Cancer Research, London found adding the immunotherapy drug durvalumab to chemotherapy and radiotherapy reduced the risk of the disease coming back while avoiding the need for surgery. Urgent action is required to cope with rising cancer cases If most of the news in Chicago was positive, there were some notes of caution. A blood test for more than 50 types of cancer that was billed as the holy grail of oncology failed to achieve its main objective in a major clinical trial, according to data presented at the conference. The goal of the study involving 142,000 NHS patients in the UK was to assess whether adding the multi-cancer early detection test Galleri to standard screening could shift diagnoses to earlier, more treatable stages. Results from the trial showed it failed to meet its primary endpoint, which was to reduce late-stage cancer diagnoses. “The trial flopped,” one delegate told the Guardian. “Clear and simple.” And while treatment advances are keeping patients alive for longer, an expanding and ageing population means more cancer cases are being diagnosed than ever before. As a result, the world faces a cancer workforce crisis, experts said, with a shortage of 100 million staff expected by 2050 when 100,000 people will be being diagnosed every day. Patients could face much longer waits to be diagnosed and treated as the cancer burden grows and threatens to overwhelm healthcare systems, the experts said. A 21% increase in cancer incidence is predicted, according to a report presented at the conference. The rate is set to rise from 165 per 100,000 people in 2025 to 200 per 100,000 in 2050. Globally, about 20 million people a year are diagnosed with cancer. By 2050 that figure could top 35.3 million, the report said, equivalent to 100,000 diagnoses a day. One of the report’s co-authors, Dr Peter Kingham, the director of Memorial Sloan Kettering’s global cancer research and training programme, said a focus on cancer prevention was key, such as promoting healthier diets and countering sedentary lifestyles. But urgent action to tackle the workforce crisis was also essential, given the growing and ageing global population meant more people would develop cancer in future. “Cancer is fundamentally a disease of ageing,” he told the Guardian. “As global life expectancy rises and conditions such as HIV are managed as chronic rather than terminal illnesses, more people worldwide are living long enough to face a cancer risk. “This demographic shift is not a failure – it reflects remarkable progress in global health, but it demands an equally ambitious response in cancer care.” Lifestyle changes can make a significant difference As Kingham noted, lifestyle changes can make a significant difference to your risk of developing or dying from cancer. Two large studies presented in Chicago suggest poor sleep may be fuelling the global rise in under-50s being diagnosed with cancer. The number of younger people diagnosed with the disease has risen by almost 80% in three decades, a trend that was hotly debated by oncologists at this year’s Asco. Worldwide cases of early-onset cancer increased from 1.82m in 1990 to 3.26m in 2019, while cancer deaths among people in their 40s, 30s or younger rose by 27%. Experts are still trying to understand the reasons behind the increase, but research presented in Chicago suggested irregular sleeping patterns in younger people may be a contributing factor. Two studies analysed data for 18 million adults in the US aged between 18 and 50. Researchers found that people with poor sleeping patterns were more likely to develop early-onset bowel, breast, uterine or ovarian cancer. In some cases, under-50s with insomnia were three times more likely to develop cancer within five years. Lifestyle changes can also have a positive impact even after cancer patients have been diagnosed and treated, delegates heard. One study presented in Chicago found yoga could reduce emotional distress, anxiety, fatigue and insomnia in people living with cancer. Up to 95% of cancer survivors experience sleep disturbances or insomnia at some point during or after their treatment, and more than half experience mood disturbances, anxiety or fatigue. Trial results showed regular gentle hatha and restorative yoga could help improve those side-effects without the need for medication.

Source: The Guardian