SMAD4 Tailored Neoadjuvant Therapy for the Treatment of Resectable and Borderline Resectable Pancreatic Ductal Adenocarcinoma, SMART-PANC Trial

PRIMARY OBJECTIVE: I. To determine the R0/R1 surgical resection rate among patients with SMAD4-mutant pancreatic cancer treated with gemcitabine/nab-paclitaxel (Cohort A). SECONDARY OBJECTIVES: I. To estimate the trial participation rate among patients approached for enrollment, defined as the proportion of patients who consent and enroll among those approached, with a target participation rate of ≥ 70%, and to monitor this rate continuously during accrual. II. To estimate the R0/R1 surgical resection rate among SMAD4 wild-type patients treated with physician choice chemotherapy (Cohort B). III. To determine pathologic response rates, among the subset of patients who reach surgical resection. IV. To determine the progression free survival (PFS). V. To determine the overall survival (OS). EXPLORATORY OBJECTIVES: I. To estimate the proportion of R0 resections among patients with SMAD4-mutant pancreatic cancer treated with gemcitabine/nab-paclitaxel (Cohort A) who undergo surgical resection (R0/R1). II. To estimate the proportion of R0 resections among patients with SMAD4 wild-type patients treated with physician choice chemotherapy (Cohort B) who undergo surgical resection (R0/R1). III. To compare R0/R1 resection rates between Cohort A (SMAD4-mutant, gemcitabine/nab-paclitaxel) and Cohort B (SMAD4 wild-type, physician choice) in a descriptive, exploratory manner; the study is not powered for formal non-inferiority or superiority testing of this comparison. IV. To determine the preoperative/neoadjuvant ca19-9 dynamics in both cohorts. V. To determine the preoperative/neoadjuvant circulating tumor DNA (ctDNA) dynamics in both cohorts. VI. To assess reason for failure to reach surgical resection, categorized by clinical deterioration, patient withdrawal/refusal of surgery, metastatic progression, or local disease progression precluding surgery. OUTLINE: Patients with SMAD4 alterations are assigned to Cohort A and patients without SMAD4 mutations are assigned to Cohort B. COHORT A: Patients receive gemcitabine and nab-paclitaxel with or without radiation therapy per SOC. Treatment continues for 8 weeks in the absence of disease progression or unacceptable toxicity. After 8 week restaging, patients may continue to receive treatment for up to 16 or 24 weeks at the discretion of the multidisciplinary tumor board. Starting 21 days after last dose of chemotherapy, patients undergo surgical resection. Additionally, patients undergo blood sample collection and computed tomography (CT) or magnetic resonance imaging (MRI) as clinically indicated throughout the study. COHORT B: Patients receive either physicians choice of either fluorouracil, leucovorin, irinotecan, and oxaliplatin or gemcitabine and nab-paclitaxel with or without radiation therapy per SOC. Treatment continues for 8 weeks in the absence of disease progression or unacceptable toxicity. After 8 week restaging, patients may continue to receive treatment for up to 16 or 24 weeks at the discretion of the multidisciplinary tumor board. Starting 21 days after last dose of chemotherapy, patients undergo surgical resection. Additionally, patients undergo blood sample collection and CT or MRI as clinically indicated throughout the study. After completion of study treatment, patients are followed up at 30 days from surgical resection then every 3 months for up to 2 years from study enrollment.