NeuACT, a phase II, randomized, open-label trial of DN24-02: Updated analysis of HER2 expression, immune responses, product parameters, and safety in patients with surgically resected HER2+ urothelial cancer.

296^ Background: DN24-02 is an investigational autologous cellular immunotherapy (ACI) consisting of antigen presenting cells (APCs) cultured with BA7072, a recombinant HER2-derived antigen (HER500) linked to granulocyte-macrophage colony-stimulating factor. In the ongoing NeuACT (N10-1; NCT01353222) trial, patients (pts) with high-risk, HER2+ urothelial cancer (UC) are randomized 1:1 to either adjuvant DN24-02 or surveillance. Updated analyses are presented. Methods: Eligibility criteria include radical surgical resection of primary ≥pT2 or pN+ UC (bladder or upper tract) with HER2 expression ≥1+ by immunohistochemistry. Pts randomized to DN24-02 undergo 3 cycles of leukapheresis and infusion at 2-week intervals. Product potency is assessed at each infusion. Immune responses and adverse events (AEs) are measured at multiple time points. Results: By July 2013, tumor specimens from 226 pts had been screened. Of these, 75% (95% CI 69–81%) had HER2 expression of ≥1+ in the primary tumor, 32% had ≥2+ and 8% h...