PRIME-ROSE: A blueprint for implementing precision cancer medicine in Europe.

11086 Background: Precision Cancer Medicine (PCM) is limited by increasingly small patient subgroups defined by tumor type and biomarker, producing rare cohorts even within common cancers. This is demonstrated by several European national PCM platform trials like DRUP (NL), IMPRESS-Norway (NO) and ProTarget (DK). From our experiences, we identify four essential requirements for successful, scalable PCM implementation: i) integration of platform trials with national healthcare systems via molecular tumor boards for efficient screening by comprehensive molecular profiling and accrual; ii) cross-national data merging; iii) scalable networks to onboard new countries; and iv) clear decision pathways linked to outcome data for reimbursement. Methods: PRIME-ROSE links national PCM implementation platforms through a robust data sharing framework that retains national/regional data governance while enabling harmonised statistical analyses and standardised endpoints for decision-makers. Predictable implementation pathways provide multiple, pre-defined decision points for industry, health technology assessment (HTA) bodies and payers, and integrate risk-sharing and responder-only reimbursement options with existing data collection. A scalable, transparent network facilitates rapid expansion to additional European partners. Results: We have developed and tested an operational data-sharing framework, with defined protocols for minimal datasets and harmonised merging procedures. Patient-level data from multiple national cohorts (1100 patients in 400 cohorts) have been aggregated, and analyses of five filled cohorts are in progress. PRIME-ROSE uses a staged implementation model to detect initial efficacy signals (industry-financed drugs) to confirm and expand on prior evidence, facilitating predictable scale-up. Risk-sharing is operationalised via responder-only reimbursement after 16 weeks of treatment and a defined transition from trial to commercial supply. In 2025, PRIME-ROSE expanded partnerships, secured the first and second multi-trial industry access contracts, and expanded payer commitment to make reimbursement decisions after Stage III. Conclusions: PRIME-ROSE translates lessons from platform trials into a practical, scalable blueprint that preserves national governance, accelerates evidence generation and reduces payer uncertainty – thereby lowering barriers to equitable, continent-wide PCM adoption. Aligned with initiatives such as Basket of Baskets and ROME, PRIME-ROSE is positioned for further scale-up through member state collaboration under the Joint Action on Personalised Cancer Medicine.