Seagen to Highlight Two Novel Antibody-Drug Conjugates (ADCs) at the SITC 36th Annual Meeting

Seagen Inc. (Nasdaq:SGEN), today announced the presentation of two new vedotin-based antibody-drug conjugate (ADC) programs at the Society for Immunotherapy of Cancer (SITC) 36th Anniversary Annual Meeting, taking place in Washington, D.C. and virtually, November 10-14, 2021. Each program combines antibodies targeted to an immune checkpoint [PD-(L)1 or B7-H4] with the cytotoxic properties of the vedotin payload. Preclinical data demonstrate promising antitumor activity. Both ADCs are set to enter first-in-human phase 1 studies in 2022.

“We are excited to advance two novel immune checkpoint vedotin ADCs, SGN-PDL1V and SGN-B7H4V, into phase 1 studies. These programs utilize a clinically validated payload and have the potential to be first in class ADCs,” said Roger Dansey, M.D., Chief Medical Officer at Seagen.

SGN-PDL1V is a novel, investigational vedotin ADC directed to the T cell checkpoint ligand, PD-(L)1. PD-(L)1 is a target with limited normal tissue expression and clinically validated expression across a variety of malignancies, including non-small cell lung cancer (NSCLC) and head and neck squamous cell carcinomas (HNSCC). SGN-PDL1V is engineered for efficient delivery of the therapeutic payload, monomethyl auristatin E (MMAE), and is proposed to have distinct mechanisms of action from other PD-(L)1-directed therapeutics, including direct cytotoxicity against PD-(L)1-expressing cells, bystander killing, and immunogenic cell death. SGN-PDL1V demonstrates robust antitumor activity in xenograft models, including in tumors with low, heterogenous PD-(L)1 expression, supporting the potential to treat patients across a wide range of PD-(L)1 expression levels. (Abstract #783)

SGN-B7H4V is a novel, investigational vedotin ADC directed to the T cell checkpoint ligand, B7-H4. B7-H4 expression is limited on normal tissue and overexpressed on a variety of solid malignancies, including breast, ovarian, and endometrial tumors. SGN-B7H4V is designed to bind and internalize the B7-H4/ADC complex from the surface of the tumor cells and release the therapeutic payload MMAE, inducing MMAE-mediated direct cytotoxicity, bystander killing, and immunogenic cell death, as well as antibody-dependent cellular cytoxicity (ADCC) and phagocytosis (ADCP). SGN-B7H4V demonstrates strong activity in xenograft models, including models with heterogenous B7-H4 expression. (Abstract #854)