23ME-00610

This engineering approach does not require a priori knowledge of structural and functional mapping of antibody-antigen interaction and thus is generally applicable for therapeutic antibody development when desired ortholog binding is lacking. These findings provide foundational insights as 23ME-00610 advances in clinical studies to gain understanding of the hCD200R1 immune checkpoint as a target in immuno-oncology.

P1/2, N=141, Active, not recruiting, 23andMe, Inc. | Trial completion date: Jun 2024 --> Mar 2025 | Trial primary completion date: Jun 2024 --> Mar 2025

23ME-00610 continues to show encouraging PKPD, safety, and disease control in a subset of unselected patients with advanced neuroendocrine cancers. Exploratory biomarker data warrant additional analyses to examine the potential for biomarker stratification on disease outcomes. Phase 2a expansion trials of 23ME-00610 utilizing retrospective biomarker analysis are ongoing in multiple indications.

P1/2, N=141, Active, not recruiting, 23andMe, Inc. | Recruiting --> Active, not recruiting

The irAEs are consistent with 23ME-00610-mediated immune modulation. The data continue to support evaluation of 1400 mg 23ME-00610 Q3W (RP2D) in the ongoing Phase 2a.

Doses in the linear PK range demonstrated sustained peripheral target engagement and 23ME-00610 had a manageable safety profile. The clinical PK, PD, safety, and translational data support evaluation of 23ME-00610 1400 mg Q3W in the ongoing Phase 2a.

23ME-00610 induced T-cell cytokine production and enhanced T cell-mediated tumor cell killing in vitro. Blockade of the CD200:CD200R1 immune checkpoint inhibited tumor growth and engaged immune activation pathways in an S91 tumor cell model of melanoma in mice.

23ME-00610 demonstrated an acceptable safety and tolerability profile, with favorable PK and peripheral CD200R1 saturation. Increased immune-related AEs were observed at higher, pharmacologically relevant dose levels. Based on Phase 1 data, 1400 mg 23ME-00610 Q3W will be evaluated in Phase 2a.

The statistical analyses will primarily be descriptive. Participants reflecting the characteristics for the indication-specific cohorts with regards to age, sex, race, and ethnicity, including those from the Black, Latinx/Hispanic and Indigenous communities, will be prioritized for enrollment.