Horvath, Laura E.

11007 Background: Patients (pts) with metastatic sarcoma (SAR) have limited options. Nivolumab(N), a fully human anti-PD-1 mAb and ipilimumab (I), a humanized anti-CTLA-4 mAb, have favorable safety & efficacy in other tumors. Pembrolizumab demonstrated a response rate (RR) of 12% in SAR pts. We evaluated N, independently from N+I, in SAR pts. Methods: This open-label multi-center phase II study enrolled pts failing prior regimens. Randomized (non-comparative) pts received either N3 [N (3 mg/kg q2W)] or N3+I1 [N(3 mg/kg Q3W x4, then Q2W) & [I(1 mg/kg q3W x4)]. Treatment continued beyond progressive disease (PD) in 1st12 weeks. 5 confirmed responses in 38 evaluable pts yielded 90% power (0.05 1-sided alpha) to detect a 20% (vs 5%) confirmed RR. Other endpoints: adverse events (AEs), progression-free, overall survival (PFS, OS), and correlative studies including PD-L1 expression by IHC, mutational burden/neoantigen analysis, TCR clonality and TIL characterization. Results: 85 pts (43 - N3; 42 - N3+I1) were enrolled [mean age 54 yrs (21–81), 52% female). No significant differences in histological subtypes across cohorts: 36% LMS, 4% LPS, 10% UPS/MFH, 6% synovial, 5% bone, 5% Ewing’s, and 34% other. Pts were refractory to 1(20%), 2(22%), and ≥3 (58%) regimens. Grade 3-4 treatment related adverse events (TRAE) occurred in 7% (N3) and 14% (N3+I1) and 0 Gr 5 TRAEs. 8% of pts stopped due to AEs (2% N3, 14% N3+I1). 2/3 confirmed responses on N3, with 2 ongoing (range 1.1-3.2 months). 6/7 confirmed responses (2 complete) on N3+N1, with 5 ongoing (range 6-13 months). Responses occurred in 7 histologies. See Table for pt outcomes. Conclusions: N + I showed acceptable safety and encouraging antitumor activity with most responses ongoing across multiple SAR histologies, passing efficacy criteria. There was minimal activity observed with N alone. Increased TRAEs were observed in N3+I1. Correlative analyses ongoing. NCT02500797. Support: U10CA180821, U10CA180882, Conquer Cancer Foundation, BMS. Clinical trial information: NCT02500797. [Table: see text]

BACKGROUNDOxaliplatin in combination with either 5‐fluorouracil or capecitabine is commonly used as first‐line therapy for patients with small bowel adenocarcinoma. The addition of irinotecan improves survival in other gastrointestinal tumors but at the cost of hematologic toxicity. The authors performed a phase 2 cooperative group study (North Central Cancer Treatment Group N0543, Alliance) using genotype‐dosed capecitabine, irinotecan, and oxaliplatin (gCAPIRINOX), with dosing assigned based on UDP glucuronosyltransferase family 1 member A1 (UGT1A1) genotype to test: 1) whether the addition of irinotecan would improve outcomes; and 2) whether UGT1A1 genotype‐based dosing could optimize tolerability.METHODSPreviously untreated patients with advanced small bowel adenocarcinoma received irinotecan (day 1), oxaliplatin (day 1), and capecitabine (days 2‐15) in a 21‐day cycle and were dosed with gCAPIRINOX according to UGT1A1*28 genotypes (6/6, 6/7, and 7/7).RESULTSA total of 33 patients (17 with the 6/6 genotype, 10 with the 6/7 genotype, and 6 with the 7/7 genotype) were enrolled from October 2007 to November 2013; 73% were male, with a mean age of 64 years (range, 41‐77 years). Location of the primary tumor included the duodenum (58%), jejunum (30%), and ileum (9%). The regimen yielded a confirmed response rate of 37.5% (95% confidence interval, 21%‐56%), with a median progression‐free survival of 8.9 months and a median overall survival of 13.4 months. Neither hematologic toxicity (grade ≥3 in 52.9%, 30.0%, and 33.3%, respectively, of the 6/6, 6/7, and 7/7 genotype groups) nor tumor response rate (41.2%, 33%, and 33%, respectively) were found to differ significantly by UGT1A1 genotype.CONCLUSIONSUGT1A1 genotype‐directed dosing (gCAPIRINOX) appears to be feasible with favorable rates of hematologic toxicity compared with prior 3‐drug studies in unselected patients. Larger studies would be needed to determine the regimen's comparability to oxaliplatin and capecitabine (CapeOx) alone or if response/toxicity differs among patients with different UGT1A1 genotypes. Cancer 2017;123:3494‐501. © 2017 American Cancer Society.