A phase Ib/IIa study of combination therapy with gemcitabine and Atu027 in patients with locally advanced or metastatic pancreatic adenocarcinoma.

385 Background: Atu027 is a liposomally formulated short interfering RNA with anti-metastatic activity, which silences expression of protein kinase N3 (PKN3) in the vascular endothelium. PKN3 acts as a Rho effector downstream of PI3K. This trial was designed to assess safety, pharmacokinetics and efficacy of Atu027 in combination with gemcitabine in advanced pancreatic carcinoma (APC). Methods: 23 patients (pts) with APC stage 3 or 4 were enrolled and randomly assigned to different Atu027 dosing schedules (arm 1: 0.253mg/kg once weekly, n = 11; arm 2: 0.253mg/kg twice-weekly, n = 12) but identical gemcitabine regimen. Response was evaluated according to RECIST 1.1. Quality of life was assessed with EORTC questionnaire QLQ-C30. Results: Combination therapy with Atu027 and gemcitabine was given up to 7.8 months until progression. Grade 3 adverse events (AEs) were reported by 9/11 pts (82%) in arm 1 and 11/12 pts (92%) in arm 2. Grade 4 AEs were reported by two pts in each arm. Interestingly, there was a difference in median progression free survival (mPFS) between the two treatment arms. Arm 1 showed an mPFS of 1.8 [95%CI: 0.4-5.5] months vs. 5.3 [95%CI: 1.5-6.0] months in arm 2, p= 0.399. In a post-hoc analysis of metastatic disease only, the difference in mPFS between the two arms reached statistical significance (1.6 [95%CI:0.4-2.1] vs 2.9 [95%CI:1.0-7.3] months, n = 9 vs 10, p= 0.025). Disease control during treatment was achieved in 4/11 (36%) pts in arm 1 and in 7/12 (58%) pts in arm 2. New lesions occurred in all (6/6) pts in arm 1 who had at least one RECIST re-evaluation but only 5/10 pts (50%) in arm 2. In quality of life analysis, pts in the once-weekly arm showed a stable global health status while pts in the twice-weekly arm reported an improvement (0-100 score change from baseline: -2.3 vs +21.6 after one cycle, N = 7 vs 7). Conclusions: Combination of Atu027 with gemcitabine for the treatment of APC is safe and was well tolerated. Despite the small patient number, there is a clear signal that twice-weekly Atu027 dosing might be superior to the once-weekly regimen. These results suggest efficacy of Atu027 and warrant further investigation with Atu027 added to standard of care in APC. Clinical trial information: NCT01808638.