Pilot study of gemcitabine, nab-paclitaxel, PEGPH20, and rivaroxaban for advanced pancreatic adenocarcinoma: An interim analysis.

Abstract

405 Background: PEGPH20 (P) degrades hyaluronan (HA), a key component of pancreatic adenocarcinoma (PDAC) tumor microenvironment, leading to reduction of tumor interstitial pressure, decompression of tumor blood vessels and improvement in delivery of chemotherapeutics. A prior study of P with chemotherapy in PDAC (HALO-202) found an increased risk of thromboembolic (TE) events, 43%, effectively reduced with subcutaneous enoxaparin treatment. Rivaroxaban (R) is a safe and effective oral anticoagulant for treating cancer-related TE. Methods: 28 patients with advanced PDAC, KPS ≥ 70 and without prior TE were enrolled from January to June 2017. Patients received treatment with PAG (P; 3 µg/kg IV 2x/wk x 3 wks in C1, then 1x/wk x 3 wks in C2+, plus AG) every 28 days, with R (15 mg twice daily for 21 days, followed by 20 mg once daily). Primary endpoint is symptomatic TE event rate; secondary endpoints include PFS, OS, major bleeding rate and RR. Results: All 28 patients are evaluable for efficacy and safety. Key patient characteristics: age = 62 (range 45-76), M/F = 15/13, stage III/IV = 4/24, KPS 70/80/90 = 1/13/14. Median follow-up is 5.4 mo. No symptomatic and one grade 2, asymptomatic TE event (DVT) occurred (1/28 = 3.6%). Two grade 3 GI hemorrhages occurred. Best responses: partial response 11 (39%), stable disease 13 (46%), progressive disease 4 (14%), and overall disease control rate of 86%. Median PFS and OS have not been reached. Conclusions: Interim analysis shows R is safe and effectively prevents TE events in patients receiving PAG. Responses and disease control rate are encouraging in this tumor HA-level unselected patient population. Updated safety and efficacy data will be reported. Clinical trial information: NCT02921022.