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Stephen Mayo

Director at Allogene Therapeutics
Board

About Stephen Mayo

Stephen Mayo, Ph.D., is an independent director of Allogene Therapeutics (ALLO) serving since July 2022; he is 63 years old and brings deep scientific and governance credentials from academia and public company boards . He is the Bren Professor of Biology and Chemistry and Merkin Institute Professor at Caltech, elected to the National Academy of Sciences in 2004 for pioneering protein design, with prior leadership roles including Caltech Vice Provost (2007–2010) and Chair of the Division of Biology and Biological Engineering (2010–2020) . His education includes a B.S. in Chemistry from Penn State and a Ph.D. in Chemistry from Caltech, with postdoctoral work at UC Berkeley and Stanford School of Medicine .

Past Roles

OrganizationRoleTenureCommittees/Impact
CaltechBren Professor of Biology & Chemistry; Merkin Institute Professor1992–present Vice Provost for Research (2007–2010) ; Chair, Division of Biology and Biological Engineering (2010–2020)
Howard Hughes Medical InstituteInvestigator1994–2007 Advanced protein design research
National Science Board (NSF)Presidential appointee2013–2018 Governance of national science policy
American Association for the Advancement of ScienceElected Board Member2010–2014 Scientific community oversight

External Roles

OrganizationRoleSinceCommittees/Focus
Sarepta Therapeutics, Inc.Director2021 Research & Development; Audit
Merck & Co., Inc.Director2021 Audit; Research
Vida VenturesScientific Advisory Board memberN/A Scientific/strategic advisory
Xencor, Inc.Co‑founderN/A Antibody engineering (public company)
Molecular Simulations (now Biovia)Co‑founderN/A Computational tools
Protabit LLCCo‑founderN/A Protein design

Board Governance

  • Independence: Mayo is an independent director; the Board affirms independence for all directors except the Executive Chair (Belldegrun), CEO (Chang), and Kazam. Audit and Compensation/Nominating committee members meet enhanced SEC/Nasdaq independence standards .
  • Committees: Audit (member; chair is Deborah Messemer) and Research & Development (member; chair is Owen Witte) .
  • Attendance: Board met 6 times in 2024; each current director attended at least 75% of Board and committee meetings for which they served .
  • Board leadership: Lead Independent Director (Franz Humer) presides over executive sessions; independent directors meet at least twice per year without management .
  • Classified board: Directors serve staggered three‑year terms; Mayo is a Class III director continuing through the 2027 Annual Meeting .
  • Governance enhancements: Corporate Governance Guidelines adopted in Sept. 2024; director resignation policy for plurality elections; expanded board evaluations; active shareholder engagement .

Fixed Compensation

ComponentPolicy (Non‑Employee Director)2024 Actual – Mayo
Annual cash retainer$40,000 $47,500 fees earned
Audit Committee member$12,500 Included in fees (member)
Research & Development Committee member$10,000 Included in fees (member)
Committee chair feesNot applicable (Messemer/Witte are chairs) $0
Meeting fees (select committees)R&D: $5,000 per annual SAB meeting; IBDOC: $3,500 per meeting Not separately disclosed

Notes: In March/April 2025, Board added a $30,000 cash retainer for the Lead Independent Director and reduced IBDOC chair retainer; not applicable to Mayo .

Performance Compensation

Equity Element2024 Grant/OutstandingVesting/Structure
Option awards (grant‑date fair value)$298,650 Annual director option grants vest in 12 equal monthly installments over one year
RSU awards (grant‑date fair value)$0 Annual director RSUs vest semi‑annually over one year (if elected)
Options outstanding (total shares)361,689 Per director equity outstanding disclosure
RSUs outstanding (total shares)11,776 Per director equity outstanding disclosure
  • Mix and policy: Directors may elect initial and annual grants in options and/or RSUs within policy share caps; share limits added in April 2025 (not retroactive to 2024) .
  • Cash/equity mix signal (2024, Mayo): ~$47.5k cash vs ~$298.7k equity indicates an equity‑heavy structure aligning directors with shareholders .

Other Directorships & Interlocks

EntityNature of RelationshipPotential Interlock/Note
Sarepta TherapeuticsPublic company director; R&D and Audit committees Governance and R&D oversight experience
Merck & Co.Public company director; Audit and Research committees Large‑cap pharma governance perspective
Vida VenturesScientific Advisory Board member Vida Ventures affiliates hold ALLO shares via entities linked to Executive Chair; Board affirms independence; related‑party transactions are reviewed by Audit Committee

No related‑person transactions involving Mayo were disclosed in the “Transactions with Related Persons” section .

Expertise & Qualifications

  • Pioneering protein design scientist; National Academy of Sciences (2004) .
  • Deep academic leadership and governance experience (Caltech Vice Provost and Division Chair) .
  • Board‑level audit and R&D oversight experience at Sarepta and Merck .
  • Entrepreneurial and computational biology expertise (co‑founder of Biovia, Xencor, Protabit) .

Equity Ownership

MetricValue
Total beneficial ownership (shares)359,320; less than 1%
Direct shares held13,552
Options exercisable within 60 days345,768 (includes 3,027 unvested but exercisable)
RSUs outstanding11,776
Hedging/pledging statusCompany policy prohibits hedging and pledging of ALLO stock
Ownership guidelineDirectors: 5x annual retainer; all directors currently in compliance

Insider reporting: The Delinquent Section 16(a) disclosure lists late filings for certain officers; Mayo was not listed .

Governance Assessment

  • Board effectiveness: Mayo’s independent status and dual committee service (Audit; R&D) support strong oversight across financial reporting and scientific strategy .
  • Attendance/engagement: Board met six times; all directors met at least 75% attendance; Audit met five times; R&D met once—indicating regular engagement in relevant committees .
  • Alignment: Mayo’s compensation is predominantly equity‑based (2024: ~$299k options vs ~$48k cash), consistent with shareholder alignment and policy guidelines; hedging/pledging prohibitions and ownership requirements reinforce alignment .
  • Independence and conflicts: Board determined Mayo meets SEC/Nasdaq independence standards; related‑party transactions are overseen by the Audit Committee; no transactions involving Mayo disclosed .
  • Shareholder signals: Company responsiveness on compensation/governance, with say‑on‑pay approval improving to ~87% in 2024, adoption of Corporate Governance Guidelines, and addition of performance‑based PSUs in 2025 executive equity mix—not director‑specific but supportive of investor confidence .

RED FLAGS: None disclosed for Mayo (no related‑party transactions, no delinquent Section 16 filings, hedging/pledging prohibited) . Potential network interlock via Vida Ventures (SAB) is mitigated by Board independence determinations and committee oversight of related‑party transactions .