Abstract 128P
Background
Tislelizumab, an investigational monoclonal antibody with high affinity and specificity for PD-1, was engineered to minimize binding to FcγR on macrophages in order to abrogate antibody-dependent phagocytosis, a mechanism of T-cell clearance and potential resistance to anti-PD-1 therapy. In prior reports, tislelizumab, as a single agent and in combination with various chemotherapies, was generally well tolerated and had antitumor activity in pts with advanced solid tumors. This phase 2 study (NCT03469557) assessed tislelizumab plus chemotherapy as first-line therapy in pts with inoperable, locally advanced, or metastatic GC/GEJC or ESCC.
Methods
Patients with GC/GEJC received tislelizumab (200 mg IV Q3W) + oxaliplatin (130 mg/m2 IV Q3W for ≤6 cycles) and capecitabine (1000 mg/m2, Days 1-15 orally BID Q3W); pts with ESCC received tislelizumab + cisplatin (80 mg/m2 IV Q3W for ≤6 cycles) and 5FU (800 mg/m2/d, Days 1-5 IV Q3W for ≤6 cycles). Response was assessed using RECIST v1.1, Kaplan-Meier analysis estimated survival, and adverse event (AE) monitoring examined safety/tolerability.
Results
As of 31 Mar 2019, 30 pts with GC/GEJC and ESCC (n = 15 each) were enrolled. Median age was 61 yr; most pts were male (n = 25). Clinical responses were observed during treatment (Table). In pts with ESCC, treatment-emergent AEs (TEAEs) of grade ≥3 occurring in ≥ 2 pts were vomiting and dysphagia (n = 4 each), hyponatremia (n = 3), and anemia, leukopenia, fatigue, lung infection, and decreased weight (n = 2 each). No grade ≥3 TEAEs occurred in ≥ 2 pts with GC/GEJC. One pt with ESCC had a fatal AE (hepatic dysfunction) attributed to treatment by the investigator, but which may have been confounded by progressive disease and underlying hepatitis.Table:
128P
GC/GEJC (n = 15) | ESCC (n = 15) | |
---|---|---|
PR, n (%) | 7 (46.7) | 7 (46.7) |
SD, n (%) | 3 (20.0) | 5 (33.3) |
PD, n (%) | 1 (6.7) | 0 (0.0) |
Non-CR/non-PD, n (%)* | 2 (13.3) | 0 (0.0) |
NE, n (%) | 2 (13.3) | 3 (20.0) |
ORR, % (95% CI) | 46.7 (21.3, 73.4) | 46.7 (21.3, 73.4) |
Median DoR, (95% CI) | NR (3.0, NR) | 12.8 (3.5, 12.8) |
Median PFS, mo (95% CI) | 6.1 (3.8, NR) | 10.4 (5.6, 15.1) |
Median OS, mo (95% CI) | NR (7.0, NR) | NR (5.6, NR) |
Median follow-up, mo (95% CI) | 15.4 (14.7, 17.2) | 13.0 (12.3, 14.0) |
Patients who have non-target lesions at baseline.
Abbreviations: CI, confidence interval; CR, complete response; DoR, duration of response; ESCC, esophageal squamous cell carcinoma; GC/GEJC, gastric/gastroesophageal junction cancer; mo, month; NE, not evaluable; NR, not reached; ORR, objective response rate; OS, overall survival; PD, progressive disease; PFS, progression-free survival; PR, partial response; SD, stable disease.
Conclusions
Tislelizumab plus chemotherapy was generally well tolerated and antitumor activity was observed in pts with advanced GC/GEJC or ESCC.
Clinical trial identification
NCT03469557.
Editorial acknowledgement
Writing and editorial support for this abstract was provided by Agnieszka Laskowski, PhD, and Elizabeth Hermans, PhD, of OPEN Health Medical Communications (Chicago, IL).
Legal entity responsible for the study
BeiGene Co., Ltd., Beijing, China.
Funding
BeiGene (Beijing) Co., Ltd., Beijing, China.
Disclosure
X. Li: Full / Part-time employment: BeiGene (Beijing) Co., Ltd. Y. Li: Full / Part-time employment: BeiGene (Beijing) Co., Ltd. X. Wang: Full / Part-time employment: BeiGene (Beijing) Co., Ltd. S. Yang: Full / Part-time employment: BeiGene (Beijing) Co., Ltd. All other authors have declared no conflicts of interest.
Resources from the same session
490P - Outcomes of sequential epidermal growth factor receptor tyrosine (EGFR) tyrosine kinase inhibitor (TKI) therapy in patients with advanced non-small cell lung carcinoma (NSCLC)- a real-world institutional experience
Presenter: Yvonne Ang
Session: Poster display session
Resources:
Abstract
498P - An observational retrospective study to evaluate the incidence of acquired EGFR T790M resistance in NSCLC patients with EGFR mutation following progression after at least one prior EGFR TKI treatment in Taiwan: ARISE study
Presenter: Shang-gin Wu
Session: Poster display session
Resources:
Abstract
501P - Clinical characteristics and efficacy in non-small cell lung cancer patients with EGFR exon 20 insertion and EGFR amplification
Presenter: Xin Gao
Session: Poster display session
Resources:
Abstract
502P - Epidermal growth factor receptor tyrosine kinase inhibitor treatment response in advanced non-small cell lung cancer with uncommon mutations: A multicenter observational study
Presenter: Masaki Kanazu
Session: Poster display session
Resources:
Abstract
482P - Interim analysis from a phase IIIb, open-label study of afatinib in EGFR TKI-naïve patients (pts) with EGFR mutation-positive (EGFRm+) NSCLC
Presenter: Filippo De Marinis
Session: Poster display session
Resources:
Abstract
483P - A phase IIIb, open-label study of afatinib in EGFR TKI-naïve patients with EGFR mutation-positive NSCLC: A biomarker analysis
Presenter: Rafael Rosell
Session: Poster display session
Resources:
Abstract
484P - Activity of afatinib in patients (pts) with EGFR mutation-positive (EGFRm+) NSCLC and baseline brain metastases: Pooled analysis of three large phase IIIb trials
Presenter: Maya Gottfried
Session: Poster display session
Resources:
Abstract
491P - Clinical outcomes of leptomeningeal metastases in EGFR-mutant lung adenocarcinoma
Presenter: Chia-I Shen
Session: Poster display session
Resources:
Abstract
510P - Paclitaxel as continuation maintenance therapy in patients with advanced non-small cell lung cancer
Presenter: Suzy Gohar
Session: Poster display session
Resources:
Abstract
496P - Higher osimertinib introduction rate achieved by multiple repeated re-biopsy after acquired resistance to first/second generation EGFR-TKIs
Presenter: Taira Ninomaru
Session: Poster display session
Resources:
Abstract