Results of the randomized phase II portion of NRG Oncology/RTOG 0848 evaluating the addition of erlotinib to adjuvant gemcitabine for patients with resected pancreatic head adenocarcinoma.

Abstract

4007 Background: NRG/RTOG 0848 is a 2-step study designed to determine whether erlotinib (E) added to gemcitabine (G) (randomized Ph II) &/or adjuvant radiation with concurrent 5-FU or capecitabine following 6 months of systemic chemotherapy (Ph III), improve survival in patients (pts) with resected pancreatic head adenocarcinoma. The erlotinib results are reported here. Methods: Eligible pts include those with resected pancreatic head adenocarcinoma, pathologic stage T1-T3, N0-1, M0; PS 0-1, & CA19-9 ≤ 180 IU/L. Pts in Arms 1 & 2 received G 1 gm/m2 weekly for 3 weeks in a 28-day cycle for 6 cycles. Pts in Arm 2 also received E 100 mg/day. The primary hypothesis for the E portion was that G+E would increase overall survival (OS) compared to G alone. With a 1-sided alpha of 0.15, 200 OS events provide 80%/90% power to detect a signal for an increase in median OS from 22 to 28.8/30.6 months (mos). OS was estimated by the Kaplan-Meier method & arms compared using the log rank test. The Cox proportional hazards model was used to analyze treatment effect. Results: 336 pts were randomized from 11/17/2009 to 2/28/2014, with 163 pts evaluable for G and 159 for G+E. Median age was 63 years (39-86). Most pts had pathologic T3 disease (78%) & CA19-9 ≤ 90 (93%). There are 32 pts (20%) with grade 4 adverse events (AEs) & 2 pts (1%) with grade 5 AEs on G and 27 (17%) & 3 (2%) on G+E arm, respectively. There are fewer grade ≥ 3 GI AEs on the G arm (22%) as compared to the G+E arm (28%), and 110 (69.2%) & 93 (59.6%) pts received at least 85% of planned G dose for the G & G+E arms, respectively. 58% of E pts received at least 85% of planned E dose. The median follow-up for alive pts is 42.5 mos (min-max: < 1-75). With 203 deaths, median & 3-yr OS (95% CI) are 29.9 mos (21.7-33.4) & 39% (30, 45) for G and 28.1 mos (20.7-30.9) & 39% (31, 47) for G+E; log-rank p = 0.62. The hazard ratio (95% CI) comparing OS of G+E to G is 1.04 (0.79- 1.38). Conclusions: The addition of adjuvant E to G did not provide a signal for increased OS in pts with resected pancreatic head cancer compared to G alone. Accrual to the trial is continuing to answer the Ph III radiation question. Clinical trial information: NCT01013649.