An endemic challenge facing healthcare systems around the world is how to spread innovation more widely and sustainably. A common response to this challenge involves conducting pilot implementation studies to generate evidence of the innovation's benefits. However, despite the key role that such studies play in the local adoption of innovation, their contribution to the wider spread and sustainability of innovation is relatively under-researched and under-theorized. In this paper we examine this contribution through an empirical examination of the experiences of an innovation intermediary organization in the English NHS (National Health Service). We find that their work in mobilizing pilot-based evidence involves three main strands; configuring to context; transitioning evidence; and managing the transition. Through this analysis we contribute to theory by showing how the agency afforded by intermediary roles can support the effective transitioning of pilot-based evidence across different phases in the innovation journey, and across different occupational groups, and can thus help to create a positive feedback loop from localized early implementers of an innovation to later more widespread adoption and sustainability. Based on these findings, we develop insights on the reasons for the unnecessary repetition of pilots - so-called 'pilotitis'- and offer policy recommendations on how to enhance the role of pilots in the wider spread and sustainability of innovation.