6012 Background: EAGLE is a phase 3 study evaluating efficacy of D (anti-PD-L1 mAb) monotherapy and D+T (anti-CTLA-4 mAb) vs standard of care (SOC) in pts with R/M HNSCC who progressed following platinum-based therapy (NCT02369874). Methods: Pts were randomized 1:1:1 to D 10 mg/kg IV every 2 weeks (Q2W), D+T (D 20 mg/kg IV Q4W + T 1 mg/kg IV Q4W for 4 doses, then D 10 mg/kg IV Q2W), or SOC (investigator’s choice: cetuximab, taxane, methotrexate, or fluoropyrimidine-based regimen). The primary endpoint was overall survival (OS) with dual primary objectives of D+T vs SOC and D vs SOC. Additional endpoints included objective response rate (ORR), duration of response (DoR), and adverse events (AEs). Results: 240 pts were randomized to D, 247 to D+T and 249 to SOC. An imbalance for Eastern Cooperative Oncology Group performance status (ECOG PS) was seen in favor of the SOC arm (D, PS 0 = 26%, PS 1 = 74%; D+T, PS 0 = 26%, PS 1 = 74%; SOC, PS 0 = 32%, PS 1 = 68%). The risk of death was not statistically significantly different for D compared with SOC (HR: 0.88; 95% CI: 0.72–1.08; P = 0.20) or D+T vs SOC (HR: 1.04; 95% CI: 0.85–1.26; P = 0.76). Efficacy data are provided in the table. Treatment-related AEs Grade ≥3 were reported in 10.1% of pts (regardless of causality Grade ≥3 AEs were 41.4%) in the D arm, 16.3% (51.2%) for D+T, and 24.2% (44.2%) for SOC. Following treatment, 2% of pts in D, 5% in D+T and 15% in SOC received immunotherapy. Conclusions: D and D+T did not demonstrate a statistically significant improvement in OS compared to standard chemotherapy in pts with R/M HNSCC. Median OS and ORR of D arm were similar to other studies with checkpoint inhibitors. The SOC arm outperformed what has been seen for SOC arms in previous studies; subsequent immunotherapy may have confounded the OS analyses. The safety profile for D and D + T in R/M HNSCC is consistent with previous trials. Clinical trial information: NCT02369874. [Table: see text]
509 Background: SB3, a proposed biosimilar to the originator trastuzumab (TRZ), demonstrated similarity to its originator in terms of biological activities and pharmacokinetic (PK) equivalence. This study compared SB3 to TRZ in terms of efficacy, safety, PK, and immunogenicity in patients treated by neoadjuvant therapy for HER2 positive early breast cancer (NCT02149524). Methods: Phase III, randomized, double blind, multicenter study compared neoadjuvant SB3 or TRZ for 8 cycles concurrently given with chemotherapy (docetaxel followed by 5-fluorouracil/epirubicin/cyclophosphamide). Then patients underwent surgery followed by 10 cycles of SB3 or TRZ. The primary endpoint was breast pathologic complete response (bpCR) rate. Equivalence was declared if the 90% confidence interval (CI) of the ratio or the 95% CI of the difference of the bpCR rates in the per-protocol set (PPS) were contained within the pre-defined equivalence margins (0.785, 1.546) and (-13%, 13%), respectively. Secondary endpoints were total pathologic complete response (tpCR), overall response rate (ORR), event-free survival, PK, immunogenicity, and safety. Results: 800 patients were included in PPS. The bpCR rates were 51.7% for SB3 and 42.0% for TRZ. The ratio of bpCR rate was 1.259 and its 90% CI was 1.112-1.426, within the pre-defined equivalence margin. The difference of bpCR rate was 10.70% and its 95% CI was 4.13-17.26; the lower margin was contained within, the upper margin was outside the pre-defined equivalence margin. Secondary endpoints were comparable between SB3 vs TRZ: tpCR rate (45.8% vs 35.8%); ORR (96.3% vs 91.2%). Safety was comparable between SB3 vs TRZ during neoadjuvant period: incidence of treatment-emergent adverse events (96.6% vs 95.2%), most commonly neutropenia, alopecia, and nausea; incidence of serious adverse events (10.5% vs 10.7%). PK equivalence was demonstrated and immunogenicity between SB3 vs TRZ was comparable (0.7% vs 0.0%). Conclusions: Equivalence was demonstrated between SB3 and TRZ based on the ratio of bpCR rates. Safety, PK, and immunogenicity were similar. Complete safety and survival data will follow. Clinical trial information: NCT02149524.
Avelumab is a human anti-PD-L1 IgG1 monoclonal antibody that has shown antitumor activity in early phase studies in advanced/metastatic gastric/gastroesophageal junction cancer, including as first-line maintenance therapy. Here, we describe the design of JAVELIN Gastric 100 (NCT02625610), an open-label, Phase III trial. A total of 499 patients with locally advanced/metastatic HER2- gastric/gastroesophageal junction cancer adenocarcinoma, who had achieved at least stable disease following 12 weeks of first-line oxaliplatin/fluoropyrimidine chemotherapy, have been randomized 1:1 to receive avelumab maintenance therapy or continue chemotherapy. The primary objective is to demonstrate superior overall survival in all randomized patients or in the PD-L1+ population. Secondary objectives are to demonstrate superiority for progression-free survival and objective response rate, compare quality of life measures, and determine safety.