Durvalumab (D) and PET-directed chemoradiation (CRT) after induction FOLFOX for esophageal adenocarcinoma.

Abstract

226 Background: Based on the positive results of the CALGB 80803 study (J Clin Oncol 2017;35:1 [abstr]), we have added D to induction FOLFOX and pre-op CRT. Methods: Patients (Pts) had TanyN+ or T3-4NanyM0 esophageal and Siewert Type I-III GEJ adenocarcinoma staged by EUS, PET/CT and CT. Pts received mFOLFOX6 ×2 prior to repeat PET/CT. PET responders (PETr) received 5-FU or capecitabine and oxaliplatin with RT to 50.4Gy, while induction PET non-responders (PETnr) received carboplatin/paclitaxel with RT. All Pts received D 1,500 mg q4W ×2 starting 2 wks prior to and during CRT. Esophagectomy was planned 6-8 weeks after CRT. Pts who had R0 resections received adjuvant D 1,500mg q4W ×6. Results: 36 Pts have been enrolled: 25 GEJ, 11 esophageal; 23 N+ and 32 T3/4. 26 of 36 Pts (72%) are PETr. 2 Pts developed metastatic disease after CRT and 9 Pts remain on preop treatment. 25 Pts have had surgery (Table). Pathologic complete response (pCR) was seen in 6 (24%); 5 Pts (20%) had ypT1N0 tumors with 99% response and 2 Pts (8%) had ypT0N1 with 99% response. 20 Pts (80%) had >90% response. 3 Pts had MSI tumors (2 PETr; 1 pCR, 1 T1aN0 99% response, 1 ypT2N0 90% response). Notable grade (gd) 3/4 adverse events (AEs) observed were neutropenia in 8 Pts (22%), diarrhea and vomiting in 2 Pts each (6%). Notable gd 1/2 AEs in ≥20%: anemia (31 Pts), thrombocytopenia (29 Pts), nausea (21 Pts), fatigue (25 Pts), increased AST (20 Pts), constipation and diarrhea (9 Pts), diarrhea (8 Pts). Immune-related AEs noted were gd 2 dermatitis (2 Pts), gd 3 hepatitis and gd 1 hypothyroidism in 1 Pt each. Median length of post-op stay was 8 days, with 12% anastomotic complication rate, including 1 Pt who died of hematemesis 16 days after discharge from 55-day hospitalization. Conclusions: The addition of D to induction FOLFOX and PET-directed CRT is safe and feasible. pCR and near-pCR in ½ of operated Pts is encouraging and compares favorably to the pCR rate of 31% in CALGB 80803 Pts who received induction FOLFOX. The final pCR rate and correlatives for the fully accrued study will be presented. Clinical trial information: NCT02962063. [Table: see text]