Marcella Kuhlmann Ruddy
About Marcella Kuhlmann Ruddy
Marcella Kuhlmann Ruddy, M.D., age 62, joined Sionna Therapeutics’ board on January 6, 2025 and serves as an independent Class II director with her term expiring at the 2026 annual meeting. She is a pulmonologist with over 20 years of drug development experience; currently Chief Medical Officer at Tectonic Therapeutic (NASDAQ: TECX), and previously Vice President of Clinical Development, Immunology at Regeneron, where she oversaw Dupixent’s clinical development; education includes a B.A. in history from Princeton and an M.D./M.S. from Washington University School of Medicine.
Past Roles
| Organization | Role | Tenure | Committees/Impact |
|---|---|---|---|
| Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) | Vice President, Clinical Development, Immunology; oversaw Dupixent | Jun 2016 – Jun 2021 | Led major immunology program clinical development (Dupixent) |
| Massachusetts General Hospital | Founder/Leader, Adult Cystic Fibrosis Center | 1999 – 2004 | Established and led CF clinical center; pulmonology practice |
| Merck & Co., Inc. (NYSE: MRK) | Drug development roles (start of industry career) | Post-2004 (not specified) | Transition from academic medicine to biopharma R&D |
External Roles
| Organization | Role | Tenure | Exchange/Notes |
|---|---|---|---|
| Tectonic Therapeutic, Inc. (NASDAQ: TECX) | Chief Medical Officer | Jul 2021 – Present | Public company CMO |
| Upstream Bio, Inc. (NASDAQ: UPB) | Director | Jan 2023 – Present | Public company directorship |
| Polarean, Inc. | Director | Aug 2022 – Jun 2024 | Prior board service |
Board Governance
- Independence: The board determined all directors except the CEO are independent under Nasdaq and SEC rules; this includes Dr. Ruddy.
- Committees: Member, Nominating and Corporate Governance Committee (Chair: Paul Clancy); not on Audit or Compensation committees.
- Attendance/Engagement: The full board met seven times in 2024; all then-serving members met at least 75% attendance. The nominating committee was established in December 2024 and did not meet in 2024; Dr. Ruddy joined the board in January 2025—her attendance will be reported in the next proxy cycle.
- Leadership: Independent chair structure (Paul Clancy) separate from the CEO; board charters posted publicly.
Fixed Compensation
| Component | Amount | Timing/Terms | Source |
|---|---|---|---|
| Annual cash retainer (Director) | $40,000 | Payable quarterly in arrears | |
| Committee fee (Nominating & Corporate Governance Member) | $4,500 | Payable quarterly in arrears | |
| Initial stock option grant | 39,919 shares | Granted Feb 6, 2025; 3-year annual vesting; 10-year term; exercise price = FMV at grant; full acceleration on sale event |
Director engagement letter (Dec 18, 2024) terminated Feb 6, 2025 in connection with IPO; compensation thereafter governed by non-employee director compensation policy.
Performance Compensation
| Award Type | Performance Metrics Tied | Vesting | Status |
|---|---|---|---|
| Annual stock option grant (if continuing post-AGM) | None disclosed (time-based only) | 19,959 options, vest in full by next AGM or first anniversary; 10-year term; sale event acceleration | Policy applies to continuing non-employee directors; grants made on each annual meeting date |
No director performance-conditioned awards (PSUs/TSR-linked) disclosed; compensation recovery policy (clawback) applies to incentive-based compensation for executive officers in the event of restatements.
Other Directorships & Interlocks
- Interlocks to monitor: Dr. Ruddy is CMO at Tectonic Therapeutic (TECX). Another Sionna director, Bruce Booth, previously served on the board of AVROBIO, Inc. (now Tectonic Therapeutic, Inc.), creating a potential network linkage, though no related-party transactions were disclosed.
- Large shareholders affiliated with other Sionna directors (RA Capital, TPG, OrbiMed, Atlas, Enavate) participated in Sionna’s Series C financing and IPO; board independence and related-party review processes are highlighted in the proxy.
Expertise & Qualifications
- Pulmonology/CF expertise; built CF center at MGH; clinical development leadership for Dupixent (immunology).
- Executive biopharma track record (CMO at TECX; prior VP at REGN); board experience at UPB and Polarean.
- Academic pedigree: Princeton (B.A.), Washington University School of Medicine (M.D., M.S.).
Equity Ownership
| Holder | Shares Beneficially Owned | % of Outstanding | Notes |
|---|---|---|---|
| Marcella Kuhlmann Ruddy, M.D. | — | <1% | As of April 15, 2025; beneficial ownership includes options exercisable within 60 days—none reported for Ruddy; anti-hedging/pledging policy in place for all insiders |
Company policy prohibits hedging and pledging of company stock by directors, officers and employees.
Governance Assessment
- Positive signals: Independent status; service on governance committee; strong clinical development and CF domain expertise aligned with Sionna’s therapeutic focus; independent consultant (Pearl Meyer) advising compensation committee with no conflicts.
- Alignment and incentives: Mix of modest cash retainer plus time-based stock options with 10-year term and sale-event acceleration; no performance-conditioned director equity disclosed.
- Attendance/engagement: Board met seven times in 2024 with strong attendance; Dr. Ruddy joined in 2025—her attendance will be evaluable next cycle.
- Conflicts/related parties: No related-party transactions involving Dr. Ruddy disclosed since Jan 1, 2023; monitor potential interlocks with TECX and broader investor-affiliate ecosystem (RA Capital, TPG, OrbiMed, Atlas, Enavate), though the proxy details robust related person transaction review.
- Risk indicators: Insider trading and clawback policies disclosed; no director-specific legal proceedings; EGC status means no say-on-pay history yet (vote not required).
RED FLAGS to monitor: Potential cross-company interlock via TECX; ensure no overlapping commercial relationships or shared consulting arrangements emerge; confirm director equity guideline adherence once disclosed; track Form 4 filings for any hedging/pledging anomalies (policy prohibits such transactions).
Insider Trades
| Date | Transaction | Shares | Price | Source |
|---|---|---|---|---|
| Not disclosed in proxy | — | — | — | Proxy does not include Form 4 data; monitor SEC Form 4 filings for SION insiders (Marcella K. Ruddy). |
Notes on Say-on-Pay and Peer Group
- As an emerging growth company, Sionna did not hold say-on-pay votes or provide pay-versus-performance disclosures; peer group specifics for director compensation are not disclosed (Pearl Meyer advises the committee).