AbstractPurpose:Pancreatic ductal adenocarcinoma (PDAC) has limited treatment options. We compared the efficacy of comprehensive precision medicine against that of the conventional treatment in PDAC.Patients and Methods:We report a phase III trial of advanced PDAC in which patients were randomized (1:2) to a conventional treatment treated at physician’s discretion (arm A) or to precision medicine (arm B). Subjects randomized to arm B underwent a tumor biopsy for whole-exome sequencing and to generate avatar mouse models and patient-derived organoids for phenotypic drug screening, with final treatment recommended by the molecular tumor board. The primary objective was median overall survival (OS).Results:A total of 137 patients were enrolled with 125 randomized, 44 to arm A and 81 to arm B. Whole-exome sequencing was performed in 80.3% (65/81) patients of arm B, with potentially actionable mutations detected in 21.5% (14/65). Experimental models were generated in 16/81 patients (19.8%). Second-line treatment was administered to 39 patients in the experimental arm, but only four (10.2%) received personalized treatment, whereas 35 could not receive matched therapy because of rapid clinical deterioration, delays in obtaining study results, or the absence of actionable targets. The median OS was 8.7 and 8.6 months (P = 0.849) and the median progression-free survival was 3.8 and 4.3 months (P = 0.563) for the conventional and experimental arms, respectively. Notably, the four patients who received personalized treatment had a median OS of 19.3 months.Conclusions:Personalized medicine was challenging to implement in most patients with PDAC, limiting the interpretation of intention-to-treat analysis. Survival was improved in the subset of patients who did receive matched therapy.