23andMe doses first patient in Phase 2a of Phase 1/2a study of 23ME-00610

23andMe Holding dosed the first patient in the Phase 2a portion of its Phase 1/2a study evaluating 23ME-00610, an investigational antibody targeting CD200R1, in patients with advanced solid malignancies. The Phase 2a portion of the study will evaluate the anti-tumor activity of the 23ME-00610 monotherapy in a number of previously disclosed expansion cohorts and will further characterize the safety, tolerability, pharmacokinetic and pharmacodynamic profile of 23ME-00610. The expansion cohorts will enroll patients with clear cell renal cell carcinoma; epithelial ovarian, fallopian tube or primary peritoneal carcinoma; neuroendocrine cancers; small cell lung cancer; and microsatellite instability-high or tumor mutational burden-high cancers that have progressed on standard therapies. A cohort of adolescents with locally advanced unresectable, or metastatic solid malignancies will also be enrolled. The tumor indications for the expansion phase were selected based on pre-clinical and published data of the activity and expression of CD200R1 and its ligand, CD200, together with immune cell and tumor characteristics that have the potential to increase the likelihood of a response to CD200R1 inhibition. The 23ME-00610 first-in-human dose escalation phase successfully identified a dose level and schedule for the Phase 2a portion of this study. The Phase 2a component will include assessment of objective response rate, progression-free survival and overall survival in the expansion cohorts. 23andMe anticipates that it will present an update from the Phase 1 dose escalation portion of the study at a scientific conference this year.