# Regeneron Pharmaceuticals chair entity: /record/regeneron-pharmaceuticals.md predicate: chair page: /record/regeneron-pharmaceuticals/chair as_of: 2026-11-12 cite: AsOf. "Regeneron Pharmaceuticals chair: Leonard S. Schleifer", as of 2023-06-09. Claim clm_E84D1B159AB1, https://asof.is/claim/clm_E84D1B159AB1, accessed 2026-11-12. Source: https://www.sec.gov/Archives/edgar/data/872589/000110465923045897/0001104659-23-045897-index.htm. As of November 12, 2026, Regeneron Pharmaceuticals's chair on the AsOf record is Leonard S. Schleifer, dated June 9, 2023, from a primary source (sec.gov). 1 claim on Regeneron Pharmaceuticals's chair, 1 open and 0 superseded, each dated and sourced; a replaced value is closed with an end date, never deleted. ## Current chair What the record asserts on 2026-11-12. - [Regeneron Pharmaceuticals](/record/regeneron-pharmaceuticals.md) | chair | Leonard S. Schleifer | valid 2023-06-09 to present | conf 0.95 | valid | [clm_E84D1B159AB1](/claim/clm_E84D1B159AB1.md) sources: https://www.sec.gov/Archives/edgar/data/872589/000110465923045897/0001104659-23-045897-index.htm ## Every dated value One claim per line, oldest first. Superseded claims stay visible. - [Regeneron Pharmaceuticals](/record/regeneron-pharmaceuticals.md) | chair | Leonard S. Schleifer | valid 2023-06-09 to present | conf 0.95 | valid | [clm_E84D1B159AB1](/claim/clm_E84D1B159AB1.md) sources: https://www.sec.gov/Archives/edgar/data/872589/000110465923045897/0001104659-23-045897-index.htm ## Questions this record answers ### What is Regeneron Pharmaceuticals's current chair? Leonard S. Schleifer, dated June 9, 2023, from a primary source (sec.gov). The record asserts this claim as of November 12, 2026 (status valid, confidence 0.95). ## Read on - This page: /record/regeneron-pharmaceuticals/chair (markdown: /record/regeneron-pharmaceuticals/chair.md) - Entity twin: /record/regeneron-pharmaceuticals.md ยท timeline: /timelines/regeneron-pharmaceuticals.md - Every company's chair: /facts/chair.md --- AsOf is a temporal fact ledger: a structured, dated, sourced record of what is true and what changed, built for AI retrieval.