Kymab Presents Update on Lead Immunocytokine Program KY1043 at Society of Immunotherapy for Cancer 34th Annual Meeting

Cambridge, UK; November 8, 2019: Kymab, a clinical-stage biopharmaceutical company developing antibody-based therapeutics, will today present a poster detailing an expanding body of evidence for the activity of the company’s novel immunocytokine, KY1043. The poster will be presented at the Society of Immunotherapy for Cancer (SITC) 34^th Annual Meeting being held today at the Gaylord National Hotel and Convention Center, National Harbor, Fort Washington, Maryland, United States.

KY1043 is a novel, fully-human, PD-L1-based, IL-2Ra (CD25)-directed immunocytokine that is designed to both inhibit the interaction between PD-L1 and the T cell checkpoint receptor PD-1 and stimulate T cells via interaction of a mutated form of IL-2 that preferentially activates antigen experienced T cells to promote the immune response against tumors.

Data presented in the SITC poster demonstrate that KY1043 retains the ability to effectively inhibit PD-1/PD-L1 interaction and binds preferentially to the IL-2Ra (CD25)-containing high-affinity trimeric IL-2Rabg receptor present on antigen-experienced and activated T cells as well as on regu­latory T cells (Treg). In vitro, KY1043 increases antigen-specific T cell-mediated killing of tumor cells. In vivo, KY1043 administration produces profound tumor growth suppression in an established MC38 tumor model, leading to the regression of tumors in a dose-dependent manner. Mice treated with KY1043 are resistant to subsequent tumor challenge, indicating the potential for long-term anti-tumor memory responses. Mechanism-of-action studies indicate that while Treg cells are increased in the periphery as expected, in the tumor CD8 effector cells are increased without a concomitant increase in intratumoral Treg.

"Our preclinical studies show that targeting PD-L1 and IL-2Ra with KY1043 is a valid approach for inducing a strong anti-tumor immune response," said Sonia Quaratino, M.D., Ph.D., Chief Medical Officer of Kymab. "Our team is now working on bringing this novel therapy to the clinic."

The poster can be viewed during SITC in the following session:

Title:  KY1043, a novel PD-L1 IL-2 immunocytokine directed towards CD25, delivers potent anti-tumour activity in vitro and in vivo

Presenter:  Cassie Van Krinks

Location:  Poster Hall (Prince George AB)

Poster board #:  P625  

Date and Time:  Friday 8^th November, 12.30-2:00 p.m. and 6.30 and 8:00 p.m. EDT