Andrew Hack

About Andrew A. F. Hack

Andrew A. F. Hack, M.D., Ph.D., age 51, has served on Mersana’s board since January 2017 and is currently an independent director. He is a Partner at Bain Capital Life Sciences (since March 2019) and previously served as Chief Financial Officer of Editas Medicine (2015–2019). Dr. Hack holds an A.B. in Biology, an M.D., and a Ph.D. in Molecular Genetics and Cell Biology from the University of Chicago. He also serves on the board of Nuvalent, Inc. (since April 2021) .

Past Roles

External Roles

Board Governance

• Independence: The board determined six of eight directors are independent, including Dr. Hack; only the CEO (Huber) and former CEO (Protopapas) are non-independent .
• Committee assignments and expertise:
  • Audit Committee member from Jan 1, 2024 through Mar 31, 2025; designated an “audit committee financial expert” during his term .
  • As of Apr 29, 2025, he is not shown as a member of the standing committees (Audit, Compensation, Nominating & Corporate Governance) .
• Attendance and engagement: The board met 10 times in 2024; each director attended at least 75% of the board and applicable committee meetings. Non‑employee directors (and committees) regularly met in executive session; all directors attended the 2024 annual meeting .
• Leadership structure: Independent Chair (David Mott) separate from CEO; committees are fully independent and operate under written charters .

Fixed Compensation (Non‑Employee Director)

• Structure (annual cash retainers):
  • Board retainer: $40,000; Board Chair: $70,000
  • Committee retainers: Audit $7,500 (Chair $15,000); Compensation $5,000 (Chair $10,000); Nominating & Governance $4,000 (Chair $8,000) .
• Equity:
  • 2024 policy: Initial option grant 110,000 shares for new directors; annual option grant 55,000 shares at the 2024 annual meeting (Jun 11, 2024) .
  • Accelerated vesting: Outstanding director initial and annual equity awards fully vest upon death, disability, or change in control .
  • Amended Dec 4, 2024 (effective 2025): Initial option 123,000 shares; annual option 61,500 shares; 10-year term, exercise price at grant-day close, time‑based vesting .
• 2024 compensation for Dr. Hack:

  Component	Amount (USD)
  Fees Earned or Paid in Cash	$47,500
  Option Awards (grant-date fair value)	$105,996
  Total	$153,496

• Director election to receive equity in lieu of cash retainers (retainer grant election) is permitted; Hack received standard cash for 2024 (only Mr. Alleva elected options in lieu of cash) .

Performance Compensation

• Mersana does not use performance-based cash or PSU metrics for non‑employee director pay; director compensation is a mix of fixed cash retainers and time‑based stock options per the Non‑Employee Director Compensation Policy .

Other Directorships & Interlocks

• Significant interlock: Dr. Hack serves on Nuvalent’s board while Mersana director Anna Protopapas is Chair of Nuvalent’s board, indicating an external board network tie .
• Bain Capital Life Sciences tie-in: Hack is a Partner; another Mersana director, Allene Diaz, is a senior advisor to Bain Capital Life Sciences (context for potential information channels) .

Expertise & Qualifications

• Financial expertise: Former public-company CFO (Editas) and designated “audit committee financial expert” while on Mersana’s Audit Committee .
• Scientific/medical credentials: M.D., Ph.D. in Molecular Genetics & Cell Biology; industry experience across biotech investing and operations .

Equity Ownership

• Beneficial ownership (as of Apr 15, 2025):

  Holder	Shares/Derivatives	Amount	Notes
  Andrew A. F. Hack (direct)	Common shares	14,467	Directly held
  	Stock options (exercisable within 60 days)	253,793	Vested/exercisable window
  Andrew A. F. Hack (aggregate line item)	Total beneficial ownership	8,931,993	7.2% of outstanding; includes shares held by Bain Capital Life Sciences entities by virtue of relationships; Hack disclaims beneficial ownership except to extent of pecuniary interest .
  Bain Capital Life Sciences entities	Common shares	8,663,673	Disclosed 5%+ holder group; shared voting/dispositive power; address and control relationships detailed in footnote .

• Stock ownership guidelines: Non‑employee directors required to hold equity ≥3x cash base annual retainer; compliance measured each June 30, with five years to comply (existing directors expected to comply by June 30, 2028). Unexercised options do not count; RSUs (vested/unvested) do count .
• Hedging/pledging: Company policy prohibits hedging and pledging; directors require pre‑clearance for trades and are subject to window periods .

Governance Assessment

• Strengths and alignment
  • Independent director with dual finance and scientific credentials; demonstrated financial oversight as an audit committee financial expert .
  • Active engagement: at least 75% attendance; board and committee executive sessions; independent committee structure and charters in place .
  • Director compensation balanced toward equity (approximately 69% equity in 2024 for Hack), promoting alignment with shareholders; no perquisites or tax gross‑ups for executives; clawback and stock ownership guidelines enhance governance discipline .
• Potential conflicts and watch items
  • RED FLAG: Significant shareholder affiliation. Bain Capital Life Sciences entities own ~7.0% of shares; Hack is a Partner and may be deemed to share voting/dispositive power (disclaims beneficial ownership except pecuniary interest). This creates a potential perception of influence by a large holder and should be monitored for related‑party sensitivities; the company has a related‑party transaction policy overseen by the Audit Committee .
  • RED FLAG: External board interlock with a fellow Mersana director at Nuvalent (Hack is director; Protopapas is Nuvalent board chair). While common in biotech, interlocks can concentrate information flows and should be evaluated for conflicts if counterparties overlap with Mersana’s partners or competitors .
  • Mitigants: Board affirmatively determined independence of committee members; Hack rotated off the Audit Committee as of Mar 31, 2025; company maintains robust related‑party review and prohibits hedging/pledging .
• Shareholder signals
  • Say‑on‑pay support was ~99% at the 2024 annual meeting, indicating strong investor confidence in compensation governance (for executives) .

Appendix — Key Reference Tables

Director committee service snapshot

Non‑employee director cash retainer schedule (policy)

Director equity awards (policy)