SYDNEY: An Australian cancer survivor Wednesday triumphed in a landmark challenge against biotech companies, with the country’s top court ruling they could not patent a gene linked to breast cancer. Yvonne D’Arcy took her case to the High Court of Australia, arguing that the so-called breast cancer gene BRCA1 — the mutation famously carried by Hollywood star Angelina Jolie — was a naturally occurring substance. Breast cancer is the leading cancer killer of women aged 20-59 worldwide, and supporters of the case had argued that patenting a gene could stymie medical research and testing. The High Court found that while isolating the gene required human activity that was not enough to classify it as a manufactured product and so make it patentable. D’Arcy’s case was previously dismissed by Australia’s Federal Court, which ruled in favor of the two medical research companies that hold the patent — US-based Myriad Genetics and Melbourne-based Genetic Technologies Ltd.