![Spencer Berthelsen](data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" fill="%231b1b1b" class="bi bi-person-fill" viewBox="0 0 16 16"><path d="M3 14s-1 0-1-1 1-4 6-4 6 3 6 4-1 1-1 1zm5-6a3 3 0 1 0 0-6 3 3 0 0 0 0 6"/></svg>)
Spencer Berthelsen
Director/Board Member at
IONIS PHARMACEUTICALS, INC.
Net worth: 12 M $ as of 2026-05-30
Profile
Dr. Spencer R.
Berthelsen, MD, is an Independent Director at Ionis Pharmaceuticals, Inc. and a Chairman at KS Plan Administrators LLC.
He is on the Board of Directors at Ionis Pharmaceuticals, Inc. and St. Luke's Episcopal Hospital.
Dr. Berthelsen was previously employed as a Chairman by Kelsey-Seybold Medical Group PLLC, a Clinical Professor by Baylor College of Medicine, and a Professor by The University of Texas Health Science Center at Houston.
He also served on the board at Caremark National Pharmacy and Texas Academy of Internal Medicine.
Known holdings in public companies
| Company | Date | Number of shares | Valuation | Valuation date |
|---|---|---|---|---|
| 2026-05-31 | 156,083 ( 0.09% ) | 12 M $ | 2026-05-30 |
Spencer Berthelsen active positions
| Companies | Position | Start |
|---|---|---|
| IONIS PHARMACEUTICALS, INC. | Director/Board Member | 2002-04-30 |
St. Luke's Episcopal Hospital
 St. Luke's Episcopal Hospital Hospital/Nursing ManagementHealth Services Provides medical and health care services | Director/Board Member | - |
KS Plan Administrators LLC
 KS Plan Administrators LLC Life/Health InsuranceFinance Provides health insurance services | Chairman | - |
Former positions of Spencer Berthelsen
| Companies | Position | End |
|---|---|---|
Kelsey-Seybold Medical Group PLLC
 Kelsey-Seybold Medical Group PLLC Medical/Nursing ServicesHealth Services Operates cancer, women's health, ambulatory surgery and sleep centers | Chairman | 2016-03-31 |
Texas Academy of Internal Medicine | Director/Board Member | 2004-12-31 |
Caremark National Pharmacy | Director/Board Member | 2004-12-31 |
The University of Texas Health Science Center at Houston
 The University of Texas Health Science Center at Houston Other Consumer ServicesConsumer Services Functions as a College/University | Corporate Officer/Principal | - |
Baylor College of Medicine
 Baylor College of Medicine Other Consumer ServicesConsumer Services Functions as a College/University | Corporate Officer/Principal | 2004-12-31 |
Experiences
Positions held
Active
Inactive
Listed companies
Private companies
Connections
61
1st degree connections
8
1st degree companies
Male
Female
Members of the board
Executives
Linked companies
| Private companies | 8 |
|---|---|
Ionis Pharmaceuticals, Inc.
 Ionis Pharmaceuticals, Inc. Pharmaceuticals: MajorHealth Technology Discovers and develops antisense drugs | Health Technology |
St. Luke's Episcopal Hospital
St. Luke's Episcopal Hospital Hospital/Nursing ManagementHealth Services Provides medical and health care services | Health Services |
Baylor College of Medicine
Baylor College of Medicine Other Consumer ServicesConsumer Services Functions as a College/University | Consumer Services |
Kelsey-Seybold Medical Group PLLC
Kelsey-Seybold Medical Group PLLC Medical/Nursing ServicesHealth Services Operates cancer, women's health, ambulatory surgery and sleep centers | Health Services |
Texas Academy of Internal Medicine | |
Caremark National Pharmacy | |
KS Plan Administrators LLC
KS Plan Administrators LLC Life/Health InsuranceFinance Provides health insurance services | Finance |
The University of Texas Health Science Center at Houston
The University of Texas Health Science Center at Houston Other Consumer ServicesConsumer Services Functions as a College/University | Consumer Services |
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