SGNTGT-001: A phase 1 study of SEA‑TGT, an effector-function enhanced monoclonal antibody (mAb), in advanced malignancies (trial in progress).
2021 ASCO Annual Meeting
oregon; portland; chiles
Research Funding:Seagen Inc
Background:T-cell immunoreceptor with Ig and ITIM domains (TIGIT) is an inhibitory immune checkpoint receptor expressed on subsets of T cells and NK cells. SEA-TGT is an effector-function enhanced human mAb that targets TIGIT with pico-molar affinity and blocks TIGIT’s interaction with CD155 and CD112. SEA-TGT was developed to have amplified binding to and engagement of Fcγ receptors. Enhanced effector function increases TIGIT+ T-regulatory cell depletion, enhances innate immune cell activation, and augments naïve and memory CD8+ T-cell responses. Preclinically, SEA-TGT elicits superior anti-tumor immune responses compared to other TIGIT mAbs without effector-enhanced backbones, with curative anti-tumor activity as monotherapy and in combination with other immune-modulators.Methods:This phase 1, open-label, multicenter, dose-escalation/expansion study (NCT04254107) is assessing the safety, tolerability and preliminary activity of SEA-TGT monotherapy in up to 205 adults (≥18 years) with histologically or cytologically confirmed relapsed, refractory, or progressive metastatic solid tumors (non-small cell lung, gastric/GE junction carcinomas, cutaneous melanoma, head and neck squamous cell carcinoma, bladder cancer, ovarian cancer or triple-negative breast cancer) or lymphomas (classical Hodgkin lymphoma, diffuse large B-cell lymphoma, or peripheral T-cell lymphoma, not otherwise specified). SEA-TGT will be infused on Day 1 of 21-day cycles. In Part A, the safety and tolerability of SEA-TGT will be assessed in ̃25 subjects to identify the maximum tolerated dose and recommended phase II dose (RP2D). In Part B, the safety and antitumor activity of the RP2D will be assessed in ̃180 subjects in disease-specific expansion cohorts. Primary endpoints are adverse events, laboratory abnormalities, dose-limiting toxicities, and dose-level safety and activity. Secondary endpoints are objective response (OR) rates, duration of OR, complete response, progression-free survival, overall survival, PK, and antidrug antibodies. Exploratory biomarkers of SEA-TGT-mediated pharmacodynamic (PD) effects, PK-PD correlations, and correlative analyses of predictive and PD measurements with response, toxicity, and resistance will be explored. The study was opened April 2020 and is enrolling across sites in North America and Europe. Clinical trial information: NCT04254107
Earle A. Chiles Research Institute
Garralda, Elenda; Sanborn, Rachel E; and See list of authors in comments, "SGNTGT-001: A phase 1 study of SEA‑TGT, an effector-function enhanced monoclonal antibody (mAb), in advanced malignancies (trial in progress)." (2021). Articles, Abstracts, and Reports. 5519.