["Sociology of Health & Illness, EarlyView. ", "\nAbstract\nThis article analyses patient advocacy for ovarian cancer patients' access to a group of new targeted cancer treatments, so‐called poly (adenosine diphosphate ribose) polymerase (PARP) inhibitors. Ovarian cancer is often detected in its advanced stages and has relatively poor survival rates. Based on ethnographic fieldwork with the Gynae Cancer Group, a Swedish patients' group, this article examines ovarian cancer patient advocates' engagement with biomedicine as a rarely considered topic in the social sciences. Adopting a modified version of the science and technology studies perspective on evidence‐based activism, I analyse how ovarian cancer patient advocates engage in the ‘epistemic activities’ of framing, producing and mobilising ‘credentialed’ and ‘experiential’ knowledge. I show how patient advocates, alone and together with professionals and the media, engage in epistemic activities to ‘act upon’ ovarian cancer patients' anticipated limited time and poor prognosis: patient advocates mobilise around PARP inhibitors as offering hope, access to these drugs as an urgent matter and ovarian cancer care as unequal. The article contributes to the sociological literature on novel cancer treatments and patient advocacy through its ethnographic tracing of cancer advocacy tropes and knowledge practices, centred on the temporal figure of ‘the patient running out of time’.\n"]