---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-309621"
form_type: "8-K"
ticker: "LYEL"
cik: "0001806952"
company_name: "Lyell Immunopharma, Inc."
filed_at: "2025-12-05T23:59:59+00:00"
generated_at: "2026-05-16T14:18:15.849304+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.15
calibrated_materiality_score: 0.15
confidence: "medium"
source: SEC EDGAR
---

# Lyell Immunopharma amends bylaws to modernize shareholder proposals and align with DGCL

## Summary
- Removed requirement for nominated directors to provide support information except on independence.
- Limited disclosure of supporting stockholders to those financially backing the proposal.
- Added disclosure requirements for certain extrinsic arrangements in director nomination notices.
- Clarified that updates to proposals (e.g., new nominees) constitute new proposals subject to same procedures.
- Conformed notice provisions and stockholder list requirements to DGCL Sections 232 and 219.

## SEC filing metadata
- accession: 0001193125-25-309621
- form_type: 8-K
- ticker: LYEL
- cik: 0001806952
- company_name: Lyell Immunopharma, Inc.
- filed_at: 2025-12-05T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.15
- calibrated_materiality_score: 0.15
- confidence: medium
- sec_items: 5.03, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1806952/000119312525309621/0001193125-25-309621-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1806952/000119312525309621/d13123d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-309621
- JSON: https://secwatch.observer/filing/0001193125-25-309621.json
- Plain text: https://secwatch.observer/filing/0001193125-25-309621.txt

## Key facts
- Governance Changes
  Lyell Immunopharma, Inc.: Amended and restated bylaws to modernize stockholder proposal procedures, clarify update rules, conform notice provisions to DGCL Section 232, simplify voting standards, and conform stockholder list requirements to DGCL Section 219 (effective 2025-12-03).
  - Change: bylaw amendment
  - Effective: 2025-12-03
  source text: On December 3, 2025, the Board of Directors (the “Board”) of Lyell Immunopharma, Inc. (the “Company”) amended and restated the Company’s Amended and Restated Bylaws (the “Amended Bylaws”), effective immediately.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1806952/000119312525309621/0001193125-25-309621-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.