Efficacy and safety of neoadjuvant therapy with stereotactic body radiation therapy followed by nab-paclitaxel/gemcitabine plus camrelizumab for resectable, borderline resectable and locally advanced pancreatic cancer: Preliminary results.

Abstract

e16227 Background: Neoadjuvant therapy has been attempted to improve local control and prolong survival for pancreatic cancer patients. However, the standard treatment has not been defined. This trial was to evaluate the efficacy and safety of nab-paclitaxel/gemcitabine plus camrelizumab with or without stereotactic body radiation therapy (SBRT) in patients with resectable, borderline-resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC). Methods: This prospective clinical trial was designed to include patients pathologically confirmed and previously untreated resectable pancreatic cancer, BRPC and LAPC. Patients were randomized to receive either SBRT (5 Gy × 5), four courses of nab-paclitaxel 125 mg/m2, gemcitabine 1000 mg/m2 (administered intravenously on days 1, 8 of each 21-day cycle) plus Camrelizumab 200mg (every three weeks) followed by surgery (Arm A) or only four courses of nab-paclitaxel, gemcitabine and Camrelizumab followed by surgery (Arm B). The primary endpoint was objective response rate (ORR), and the second endpoints were disease control rate (DCR), margin-negative (R0) resection rate, progression-free survival (PFS), overall survival (OS) and toxicity. Results: From March 2021 to Jan 2022, 14 eligible patients were enrolled. Eight patients were randomly assigned to Arm A while 6 to Arm B. The median follow-up duration was 33 weeks. Overall, 9 patients completed preoperative therapy and were eligible for response assessment. Among the 9 patients, 4 (44.4%) had partial response (PR), 4 (44.4%) had stable disease (SD), while one had progressive disease (PD). The ORR was 44.4% (4/9), and DCR was 88.9% (8/9). Five of these 9 patients received pancreatectomy with a resection rate of 71.4% (5/7) and the R0 resection rate was 100% (5/5). The reasons why the other 4 patients did not undergo surgery were progression of disease (n = 1), refusal of surgery (n = 1), and still in the interval of neoadjuvant therapy to surgery (n = 2). The most common adverse events of grade 3 or higher were neutropenia (22.2%), neuropathy (11.1%) and thrombocytopenia (11.1%). Median CA 19-9 level was 116U/ml (2 to 12000) in baseline while decreased to 69U/ml (2 to 4832) before surgery. The median OS or PFS has not been reached yet. Conclusions: The neoadjuvant therapy of nab-paclitaxel/gemcitabine plus camrelizumab with or without SBRT had a good safety and efficacy in patients with resectable pancreatic cancer, BRPC and LAPC. Clinical trial information: ChiCTR2100042415. [Table: see text]