Abstract PO-055: Phase II clinical trial of subtype directed neoadjuvant therapy in patients with localized pancreatic cancer

Abstract

Abstract Background: Preoperative (neoadjuvant) therapy has become the preferred treatment sequencing strategy for patients with localized pancreatic cancer. During neoadjuvant therapy, approximately 30% of patients will experience metastatic disease progression while on treatment. Therefore, tools to aid clinicians to select efficacious first-line chemotherapeutic regimens is a critical unmet need. The most common neoadjuvant chemotherapy regimens used are 5-fluorouracil/irinotecan/oxaliplatin (mFOLFIRINOX) and gemcitabine/nab-paclitaxel (GnP). There is growing data to suggest an association of pancreatic cancer subtype (classical versus basal-like) with treatment response to therapy. Recently, the translation of tumor subtyping to the clinic has been successfully achieved using the Purity Independent Subtyping of Tumors (PurIST) single sample classifier. We aim to assess the clinical response to pancreatic cancer subtype-directed therapy in patients with localized pancreatic cancer. Methods: This is a phase II, multicenter, single-arm clinical trial for previously untreated patients with localized (resectable or borderline resectable) pancreatic cancer. Patients will undergo endoscopic ultrasound guided biopsy of the primary tumor and PurIST classifier to determine classical versus basal-like subtype. Patients with classical subtype will be assigned to mFOLFIRINOX and patients with basal-like tumors will be assigned to GnP. Following two months of therapy, patients will be restaged with a computed tomography scan, carbohydrate antigen (CA19-9) levels, performance status assessment, and a repeat endoscopic ultrasound guided biopsy for research. The primary endpoint is composite clinical response as measured by radiographic response, CA19-9 decline, and performance status following two months of treatment. Correlative endpoints include blood-based biomarkers for association with clinical response and stroma-specific response to therapy. The study has enrolled 4 of the anticipated 41 patients at the time of submission. Clinical Trial information: NCT 04683315. Citation Format: Susan Tsai, Erkut Borazanci, Margaret Gulley, Naim Rashid, Jason Merker, Abdul H. Khan, Phillip Chisholm, Bryan Hunt, Tamara Giorgadze, William Hall, Mandana Kamgar, Douglas B. Evans, Jen Jen Yeh. Phase II clinical trial of subtype directed neoadjuvant therapy in patients with localized pancreatic cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-055.