Combined recombinant humanized anti-PD-1 monoclonal antibody (JS001) and nab-paclitaxel/gemcitabine (AG) as the first-line therapy for patients with advanced pancreatic adenocarcinoma: Preliminary results of an open-label, phase Ib/II clinical study.

Abstract

e16792 Background: To determine evaluate the safety and efficacy of nab-paclitaxe, gemcitabine (AG) and Recombinant Humanized Anti-PD-1 Monoclonal Antibody (JS001) for patients with advanced pancreatic ductal adenocarcinoma (PDAC). Methods: This was a single-arm, open-label, phase 1b/2 clinical trial of nab-paclitaxel plus gemcitabine plus Anti-PD-1 Monoclonal Antibody in which 11 patients with previously untreated advanced PDAC were enrolled from December 2018. Patients were treated with nab-paclitaxel 125 mg/m2 on days 1 and 8 plus gemcitabine 1000 mg/m2 on days 1 and 8 plus fixed dose of JS001 240mg on day 1 of a 21-day cycle until progression or toxicity or receiving maintance therapy. Safety monitoring, RECIST 1.1, and irRECIST assessments were conducted. Results: 11 chemotherapy naïve PDAC patients with a median age of 52 years old were treated. 5 were men and all patients had an ECOG of 0 or 1. Grade 3/4 events were observed in 27.3% of patients (2 patients presented hematological toxicity ), and JS001 was discontinued because of asymptomatic elevated cardiac biomarkers and hypothyroidism as immunotherapy-related toxicities in a female patient, no patient was discontinued AG therapy because of chemotherapy-related adverse events. Of the 11 evaluable patients, the disease control rate (partial response [PR] + stable disease[SD]) was 81.8%. There were 2 patients with PR and 1 patient with complete response respectively, and overall response rate (ORR) was 27.3%. The median progression-free survival (PFS) was 7 months and all patients survive at the last following-up in Jan-2020. All patients were proficient mismatch repair (pMMR) status. Whole-exome sequencing was performed on 7 patients, no immunotherapy-associated gene was detected, and next comprehensive analysis of somatic alterations was ongoing. Conclusions: Combined JS001 and AG can be safely given to chemotherapy naïve PDAC patients. Efficacy appears to be promising over previously reported results for standard AG chemotherapy every 28 days gemcitabine and nab-paclitaxel dosing. Comprehensive data available was ongoing to analysis the potential effect to efficacy of the combination.