Gene therapies to fix failing hearts gain steam after years in the doldrums

Heart-muscle cells (in close-up, artificially coloured) do not normally proliferate in adult mammals, but scientists are trying to coax them into doing so. Credit: Medimage/SPL Scientists are developing a new wave of gene therapies to regenerate the heart — offering hope for treating heart failure , a debilitating and common condition. The first clinical trial aimed at growing new heart-muscle cells is now under way, and companies are developing at least four other regenerative gene therapies for heart conditions. “These are [the] first-in-human studies to take regeneration into the clinic,” says Andrew Baker, a gene-therapy researcher at the University of Edinburgh, UK, who is unaffiliated with the efforts. “It’s a very exciting time.” Ranking the risk of heart disease But the excitement is tempered with caution. The mammalian heart is bad at repairing itself and “is notoriously unwieldy when it comes to efforts to try to get it to regenerate”, says Sean Wu, a cardiologist at Stanford University in California. Some scientists are unconvinced that the data underpinning the existing clinical trial show true regeneration in the form of cell division. And efforts to regenerate the heart are still haunted by a controversy that led to the retraction of at least a dozen papers and the closure of a high-profile laboratory. Developing a gene therapy in this field will be difficult, says Antonio Abbate, a cardiologist at the University of Virginia in Charlottesville. …