A randomized phase III multi-institutional study of TNFerade biologic with 5-FU and radiotherapy for locally advanced pancreatic cancer: Final results
4055 Background: TNFerade biologic (TNF) is a novel means of selective delivery of TNF-α to tumor cells by gene transfer through intratumoral (IT) injection. TNF is a replication deficient adenovirus vector containing TNF-α cDNA ligated downstream from a radiation-inducible Egr-1 promoter, allowing spatiotemporal constraint of TNF-α production to the radiation field. Herein we report the final results of a multi-center, randomized, open-label, controlled phase III trial of TNF with chemoradiotherapy for locally advanced pancreatic ductal adenocarcinoma (PDA). Methods: Pts with locally advanced PDA were randomized 1:2 to standard of care (SOC; 5-FU/RT followed by GEM) versus TNF + SOC. RT dose was 50.4 Gy in 28 fractions. Concurrent 5-FU (200 mg/m2/day IV) started on day 1 of RT each wk. TNF was injected IT ~4 hrs prior to RT weekly by percutaneous (PTA) or endoscopic (EUS) approach. 4 wks after RT, GEM (1000 mg/m2 IV) was given until progression or toxicity. Results: Of 277 pts, 187 were randomized to TNF and 90 to SOC. Demographic/baseline characteristics were similar between arms (all NS), as was GEM received (67 vs. 68%; 7.0 vs. 7.6 total wks). Median f/up was 9.1 mos (range, 0.1-50.5). Median OS for TNF by ITT analysis was 10.1 mos (95% CI, 9.1-11.7) vs. 10.0 mos (95% CI, 7.6-11.2) for SOC (p=0.6). TNF delivery method did not affect OS (9.4 mos for PTA vs. 11.5 for EUS; p=0.7). Baseline CA19-9 > 1000 was found to impart independent risk to TNF pts (HR=1.7; p=0.02). Subgroup analysis (SGA) of 86 pts with T1-T3 disease showed an OS benefit for TNF compared to SOC (10.9 vs. 9.0 mos, respectively; p=0.04). TNF resulted in more grade 1-2 fever/chills (p<0.001) as well as grade 3 (p<0.001) and 4 (p=0.05) toxicities (commonly lymphopenia, hypo/hyperkalemia, abd/chest pain) than SOC. Use of PTA vs. EUS did not affect grade 3/4 toxicity rates. Conclusions: TNF + SOC did not prolong OS for locally advanced PDA. SGA reveals a possible OS benefit for early stage (T1-T3) tumors and CA19-9 < 1000. PTA and EUS injection achieved similar rates of efficacy and toxicity. Grade 1-2 toxicity typical of systemic exposure to TNF-α (pyrexia/hypotension/chills) was common, but grade 3-4 was minimal.