Leadership Team

Tim Walbert joined Horizon in June 2008 as president and chief executive officer and has served as chairman of the company’s board of directors since 2010. Before joining Horizon, he served as president, chief executive officer and director of IDM Pharma Inc., a public biopharmaceutical company which was acquired by Takeda America Holdings Inc., or Takeda, in June 2009. Before IDM, Walbert served as executive vice president, commercial operations at NeoPharm Inc., a public biopharmaceutical company. From 2001 to 2005, he served as divisional vice president and general manager, immunology, at Abbott, now AbbVie, leading the global development and launch of the multi-indication biologic HUMIRA, and served as divisional vice president, global cardiovascular strategy. From 1998 to 2001, Walbert served as director, CELEBREX North America, and arthritis team leader, Asia Pacific, Latin America and Canada, at G.D. Searle & Company. From 1991 to 1998, he also held sales and marketing roles with increasing responsibility at G.D. Searle, Merck & Co. Inc. and Wyeth.

Walbert received his Bachelor of Arts in business from Muhlenberg College in Allentown, Pa. He serves on the boards of Aurinia Pharmaceuticals Inc. and the Executive’s Club of Chicago. Walbert is also a member of the National Organization for Rare Disorders (NORD) Advisory Board, the Wall Street Journal CEO Council and serves on the Board of Trustees of Muhlenberg College. He previously served on the board of directors for Raptor Pharmaceutical Corp., a public biopharmaceutical company, from 2010 to 2014; XOMA Corporation, a public biotechnology company, from 2011 to 2017; and Sucampo Pharmaceuticals Inc., a public biopharmaceutical company, from 2016 to 2018.

Sean Clayton joined Horizon in February 2022 and has nearly 20 years of experience representing public and private biotechnology companies in general corporate matters and securities laws, as well as a wide range of transactions, including public and private financings. Before joining Horizon, Sean served as a partner at Cooley LLP where he led the firm’s San Diego corporate practice. He led the Cooley team that represented Horizon in its initial public offering in 2011 and subsequently advised Horizon’s management team and board of directors on corporate and transactional matters.

Sean received his doctorate in jurisprudence from Stanford Law School and his Bachelor of Arts in political science and economics from the University of California, San Diego.

Aaron Cox joined Horizon in 2016 and has served in various roles across finance, business development and corporate development, including as executive vice president, finance; chief of staff for the chairman, president and chief executive officer; and senior vice president, corporate development, where he had responsibilities spanning financial planning, corporate strategy, mergers and acquisitions (M&A), acquisition integration, capital markets planning, real estate, security and investor relations. Cox also previously spent time on Horizon’s business development team, where he supported multiple acquisitions, financings and licensing transactions.

Before joining Horizon, Cox was vice president, capital markets at BMO Capital Markets, where he advised clients on debt financing transactions across various levels of the capital structure. Before BMO, he held investment banking roles at JMP Securities and Stout, where he provided advisory services, including for capital raising and M&A activities, to companies across a wide range of sectors.

Cox earned a Master of Business Administration from the University of Chicago and a Bachelor of Business Administration in finance from the University of Notre Dame.

Geoffrey M. Curtis joined Horizon in 2015 and has more than two decades of global health care communications experience.

Before joining Horizon, Curtis served as senior vice president at Edelman Public Relations and as part of its National Health Media Team he led media strategy and execution for a large portfolio of pharmaceutical, biotech and medical device clients. He was responsible for developing and maintaining media relationships, as well as implementing media strategies to support regulatory and product milestones, data publication and global medical meetings.

Previously, Curtis was group director of the media practice at WCG, a W20 Group company, where he provided product and corporate communications counsel and handled ongoing media relations for a broad range of health care clients. Before WCG, he held a similar role at GCI Group.

Before joining GCI, Curtis served as a public affairs manager in the Pharmaceutical Products Division at Abbott (now AbbVie), where he led internal and external communications programs for the immunology, neuroscience and oncology franchises.

Curtis received a Bachelor of Arts in English from Lake Forest College in Lake Forest, Ill., and a Master of Arts from DePaul University in public relations and advertising. He serves on the boards of directors of the Illinois Science and Technology Coalition and Institute (ISTC/I) and the Child Restoration Outreach and Support Organization (CROSO) and is a member of the Lake Forest College board of trustees, as well as a trustee for the Institute for Public Relations.

Michael DesJardin joined Horizon in October 2016 as part of the Raptor Pharmaceutical Corp. acquisition. He brings more than 39 years of experience in pharmaceutical development and before joining Horizon, he served as senior vice president of technical operations at Raptor, where he was responsible for quality, manufacturing, supply chain and pharmaceutical development. From July 2004 to March 2015, DesJardin served in various positions including senior vice president of product development at Jazz Pharmaceuticals plc. In addition, he was responsible for manufacturing, supply chain, program management and technical development in addition to leading the chemistry manufacturing and controls (CMC) diligence for Jazz's acquisitions of Orphan Medical Inc., Azur Pharma Ltd, EUSA Pharma and Gentium SpA.

Before Jazz, DesJardin served in positions of increasing responsibility at ALZA Corporation for nine years and spent 15 years at the Dow Chemical Company/Marion Merrill Dow working in both pharmaceutical and agricultural chemical development. DesJardin has led technical development and commercial manufacturing for chemical and pharmaceutical products, which incorporated several drug delivery technologies, including oral, implantable and injection systems. He is an inventor on 36 U.S. patents.

DesJardin received a Bachelor of Science in chemical engineering from the University of California, Berkeley, and is a registered professional engineer in the state of California.

Jane Gonnerman joined Horizon in October 2021. Before Horizon, Gonnerman spent 15 years at Bain & Company, a leading global consulting firm, where she most recently served as a partner and led work with global pharmaceutical and biotechnology companies in addition to advisory work with private equity clients focused on pharmaceutical services. Her areas of focus were across organizational and strategic issues, specifically organizational effectiveness, business unit and launch strategy, operating model, portfolio strategy, clinical trial strategy governance and post-merger integration.

Gonnerman earned a Master of Business Administration from the University of Chicago as well as a Bachelor of Science in mathematics and a Bachelor of Science in statistics from the University of Florida. She serves on boards focused on women’s health. 

Vikram Karnani joined Horizon in July 2014 and has held a number of leadership positions with increasing responsibilities during his time at the company. Currently, Karnani leads the U.S. and international commercial organizations, as well as global medical affairs. 

Before joining Horizon, Karnani was with Fresenius Kabi, a global health care company that specializes in lifesaving medicines and technologies for infusion, transfusion and clinical nutrition, where he served as vice president of the therapeutics and cell therapy business, with a focus on sales, marketing and clinical implementation. He also held various positions in business development, corporate strategy and strategic marketing within Fenwal Inc., a private equity owned global medical device company, that was acquired by Fresenius Kabi.

Karnani brings more than 20 years of cross functional expertise across a multitude of industries, including medical devices, management consulting, semiconductors and cellular telecommunications.

Karnani has a Master of Business Administration from the Kellogg School of Management at Northwestern University, a master's degree in electrical engineering from Case Western Reserve University and a bachelor's degree in electrical engineering from University of Bombay, India.

Irina Konstantinovsky joined Horizon in 2017. Before joining Horizon, she was vice president of global talent at Baxter International Inc. where she led a team of talent professionals worldwide and oversaw organizational effectiveness, leadership development, inclusion and diversity and talent acquisition. She and her team were responsible for talent management strategies, programs and systems for more than 50,000 employees worldwide.

Before Baxter, Konstantinovsky spent 15 years in senior partner and director roles at Towers Watson (currently Willis Towers Watson), a global human resources consulting firm serving Fortune 1000 companies. While in these roles, she served as the interim chief human resource officer at Capital BlueCross for two years.

Konstantinovsky has a Bachelor of Arts in education from the University of Buenos Aires and master's degrees in higher education and industrial and labor relations from Cornell University. In addition, she currently serves as the Chair of the Board of Directors for the Human Resource Management Association of Chicago and is also on the YWCA of Metropolitan Chicago board.

Andy Pasternak joined Horizon in November 2019. Before joining Horizon, Pasternak led the health care practice in the Americas at Bain & Company Inc., a global management consulting firm. At Bain, he advised boards of directors, CEOs and leadership teams at biopharmaceutical and medical technology companies, as well as private investment funds. His experience spans growth strategy, M&A strategy and execution, organizational design, executive and board governance and performance improvement. Pasternak was also a member of Bain’s Mergers and Acquisition practice, where he served as a leading expert on biopharmaceutical transactions, including acquisitions, business development, licensing deals and divestitures.

Before joining Bain, Pasternak was a founding partner in the Health & Life Sciences practice at Oliver Wyman, a global management consultancy. He also worked in the corporate finance group of J.P. Morgan Securities.

Throughout his career, Pasternak has worked across a wide range of specialty therapeutic areas (including rare diseases) and functions, including commercial, operations and R&D.

Pasternak earned a Master of Business Administration from the University of Chicago and a Bachelor of Arts in economics from Northwestern University.

Dr. Jeffrey W. Sherman joined Horizon in June 2009 as executive vice president, development and regulatory affairs and chief medical officer and throughout his time at Horizon has assumed various responsibilities in addition to chief medical officer.

Before joining Horizon, Dr. Sherman served as senior vice president of research and development and chief medical officer at IDM Pharma, which was acquired by Takeda in 2009. Before IDM Pharma, he served as vice president of clinical science at Takeda Global Research and Development and from September 2000 to June 2007, Dr. Sherman served as chief medical officer and executive vice president at NeoPharm Inc. From October 1992 to August 2000, Dr. Sherman served as director, senior director and executive director of clinical research, and was head of oncology global medical operations at Searle/Pharmacia, or Searle. Dr. Sherman started in industry at Squibb/Bristol-Myers Squibb from April 1988 to September 1992 in clinical pharmacology and clinical research.

Dr. Sherman currently serves as a Drug Information Association (DIA) liaison to the Clinical Trial Transformation Initiative (CTTI), a public-private partnership founded by the U.S. Food and Drug Administration and Duke University to improve the quality and efficiency of clinical trials. From June 2009 to June 2010 he served as president and board member of the DIA. He also serves on the board of advisors of the Center for Information and Study on Clinical Research Participation (CISCRP) a nonprofit organization dedicated to educating and informing the public, patients, medical/research communities, the media and policy makers about clinical research and the role each party plays in the process.

Dr. Sherman is a member of the Global Genes Medical and Scientific Advisory Board and involved with the National Organization for Rare Disorders (NORD) and the European Organisation for Rare Diseases (EURORDIS). He is also an adjunct assistant professor of medicine at the Northwestern University Feinberg School of Medicine and is a member of a number of professional societies, as well as a diplomat of the National Board of Medical Examiners and the American Board of Internal Medicine. Dr. Sherman also serves on the boards of directors of Strongbridge Biopharma and Xeris Pharmaceuticals.

Dr. Sherman received his medical degree from the Rosalind Franklin University/Chicago Medical School. He completed an internal medicine internship, residency and chief medical residency at Northwestern University, as well as fellowship training at the University of California, San Francisco (UCSF). Dr. Sherman was also a research associate at the Howard Hughes Medical Institute at UCSF.

Dr. Elizabeth H.Z. Thompson joined Horizon in June 2018 as an accomplished drug development professional with two decades of experience and roles in the development of multiple marketed medications. In her time at Horizon, she has been responsible for the guidance of clinical development activities across the portfolio, including the expedited filing and approval of TEPEZZA and its successful FDA Advisory Committee meeting.

Before joining Horizon, Dr. Thompson was a group scientific director in pharmaceutical development at AbbVie, where she was the clinical lead for risankizumab (SKYRIZI), supporting global submissions and approvals. Before AbbVie, Dr. Thompson has had a career spanning clinical development, business development and medical communications, and has also worked at Raptor, InterMune and Amgen.

Dr. Thompson holds a bachelor’s degree in chemistry from Harvey Mudd College and a doctorate in macromolecular and cellular structure and chemistry from the Scripps Research Institute. She is a member of the Americares Bay Area Committee Leadership Council.

Tina Ventura joined Horizon in 2015 and has more than two decades of experience in global health care investor relations and communications.

Before joining Horizon, Ventura was divisional vice president, investor relations at Abbott, a diversified health care company with product offerings in diagnostics, medical devices, nutritionals and pharmaceuticals, where she served in positions of increasing responsibility in communications and investor relations.

Ventura earned a Bachelor of Science in communications with a concentration in economics at Northwestern University in Evanston, Ill., and earned her Master of Business Administration with a concentration in finance and accounting at Loyola University in Chicago. She serves on the board of directors of the Lake Forest Open Lands Association and is a member of the Lake Forest Country Day School board of trustees.

Keli Walbert joined Horizon in 2018 and has more than 25 years of pharmaceutical and health care industry experience primarily focused on building integrated marketing teams and leading medicine launches. She previously led the U.S. commercial organization, overseeing the infused medicines portfolio, including the Horizon launches of TEPEZZA and UPLIZNA, life-cycle management and consumer and digital marketing. She currently leads Horizon’s strategic and corporate marketing.

Before joining Horizon, Walbert was with AbbVie where she led the consumer, advocacy and patient services functions as well as the overall launch of a drug-device combination product, DUOPA. Before AbbVie, she built and led the consumer organization at Abbott (now AbbVie) for the launch of HUMIRA. Walbert also held senior marketing and advertising leadership roles at the American Medical Association (AMA) and Draft Worldwide (now FCB), a global advertising agency.

Walbert has a bachelor’s degree in communication from the University of Louisville and a master’s degree in marketing communications from Northwestern University.

Tim Walbert joined Horizon in June 2008 as president and chief executive officer and has served as chairman of the company’s board of directors since 2010. Before joining Horizon, he served as president, chief executive officer and director of IDM Pharma Inc., a public biopharmaceutical company which was acquired by Takeda America Holdings Inc., or Takeda, in June 2009. Before IDM, Walbert served as executive vice president, commercial operations at NeoPharm Inc., a public biopharmaceutical company. From 2001 to 2005, he served as divisional vice president and general manager, immunology, at Abbott, now AbbVie, leading the global development and launch of the multi-indication biologic HUMIRA, and served as divisional vice president, global cardiovascular strategy. From 1998 to 2001, Walbert served as director, CELEBREX North America, and arthritis team leader, Asia Pacific, Latin America and Canada, at G.D. Searle & Company. From 1991 to 1998, he also held sales and marketing roles with increasing responsibility at G.D. Searle, Merck & Co. Inc. and Wyeth.

Walbert received his Bachelor of Arts in business from Muhlenberg College in Allentown, Pa. He serves on the boards of Aurinia Pharmaceuticals Inc. and the Executive’s Club of Chicago. Walbert is also a member of the National Organization for Rare Disorders (NORD) Advisory Board, the Wall Street Journal CEO Council and serves on the Board of Trustees of Muhlenberg College. He previously served on the board of directors for Raptor Pharmaceutical Corp., a public biopharmaceutical company, from 2010 to 2014; XOMA Corporation, a public biotechnology company, from 2011 to 2017; and Sucampo Pharmaceuticals Inc., a public biopharmaceutical company, from 2016 to 2018.

Michael Grey has served on the board of directors since September 2011 and as lead independent director of the company since August 2012. Grey has served as chairman of the board of directors of Mirum Pharmaceuticals Inc., a public biotechnology company, since January 2020, and as executive chairman from March 2019 to December 2019. Before that he served as chief executive officer of Mirum from the company’s inception in March 2018. He has served as executive chairman of Spruce Biosciences Inc., a public biotechnology company, since April 2017; Amplyx Pharmaceuticals Inc., a private pharmaceutical company, since January 2017; Reneo Pharmaceuticals Inc., a private pharmaceutical company, since December 2017; and as chairman of Plexium Inc., a private biotechnology company, since August 2020. He has also served as a venture partner at Pappas Ventures since January 2010. Grey served from October 2015 to January 2017 as the president and chief executive officer of Amplyx, from September 2014 to December 2017 as chairman and chief executive officer of Reneo and from May 2019 until April 2020 as executive chairman of Curzion Pharmaceuticals Inc., a private pharmaceutical company. From February 2011 to June 2014, Grey served as president and chief executive officer of Lumena Pharmaceuticals Inc., a biotechnology company, which was acquired by Shire plc in June 2014. He has 45 years of experience in the pharmaceutical and biotechnology industries and has held senior positions at a number of companies, including president and chief executive officer of SGX Pharmaceuticals Inc. (sold to Eli Lilly and Company in 2008), president and chief executive officer of Trega Biosciences Inc. (sold to LION Bioscience Inc. in 2001) and president of BioChem Therapeutic Inc. Before these, Grey served in various roles with Glaxo Inc. and Glaxo Holdings plc, culminating in his position as vice president, corporate development and director of international licensing. Grey also serves on the boards of directors of BioMarin Pharmaceutical Inc. and Mirati Therapeutics Inc., both public biotechnology companies.

Grey received a Bachelor of Science in chemistry from the University of Nottingham in the United Kingdom.

William F. Daniel joined the board of directors in September 2014. Daniel, a chartered director and chartered accountant, is currently chairman of the board of directors of Malin Corporation plc, an Ireland-based public global life sciences company. Daniel was president of the Institute of Directors of Ireland from May 2013 to May 2015, and he was originally elected to the board of the Institute of Directors in Ireland in June 2010. Before that, Daniel was executive vice president and company secretary of Elan Corporation plc, a public biotechnology company, and served in that role from December 2001 to December 2013, until the merger of Elan with Perrigo Company plc. He was previously an executive director of Elan between 2003 and 2007, having joined the organization as financial controller in 1994.

Daniel graduated with a degree in commerce from University College Dublin.

Dr. Jeff Himawan has served on the board of directors since July 2007. Dr. Himawan has been a managing director of Essex Woodlands Health Ventures, a venture capital firm, since 2004. Before that, he was an adjunct partner at Essex Woodlands from 1999 to 2001, and he was a venture partner from 2001 to 2004. Dr. Himawan co-founded Seed-One Ventures, an early-stage venture capital firm, where he served as a managing director from 1996 to 2001. Dr. Himawan also currently serves on the boards of directors of MediciNova Inc., a public biopharma company, and NexEos Bio Inc., a private biotechnology company. Previously, Dr. Himawan served on the board of directors of Catalyst Biosciences Inc., a public biopharma company, from 2010 to 2020.

Dr. Himawan received a Bachelor of Science in biology from the Massachusetts Institute of Technology and a doctorate in biological chemistry and molecular pharmacology from Harvard University.

Dr. Susan Mahony joined the board in August 2019. Dr. Mahony serves on the boards of directors of Zymeworks Inc., a public biopharma company; Vifor Pharma AG, a public pharmaceutical company; Assembly Biosciences Inc., a public biotechnology company; Cereius Inc., a private biotechnology company and Altis Biosystems, a private biotechnology company. Previously, Dr. Mahony served as senior vice president and president of Lilly Oncology and was a member of the executive committee at Eli Lilly and Company from 2009 until her retirement in August 2018. Before that, Dr. Mahony served in a variety of leadership roles at Eli Lilly and Company, including senior vice president, human resources and diversity; president and general manager, Lilly Canada; and executive director, global brand development. Dr. Mahony worked in sales and marketing at Bristol-Myers Squibb Company from 1995 to 2000, at Amgen Limited from 1991 to 1995 and at Schering Plough from 1989 to 1991. Dr. Mahony also serves on the board of Chordoma Foundation, a nonprofit organization dedicated to improving the lives of those affected by chordoma.

Dr. Mahony earned a Bachelor of Science and Doctorate of Philosophy (Ph.D.) in pharmacy, as well as a Master of Business Administration from London Business School. She was awarded an honorary doctorate from Aston University.

Gino Santini has served on the board of directors since March 2012. Santini currently serves on the boards of directors of Intercept Pharmaceuticals Inc., Collegium Pharmaceutical Inc. and Allena Pharmaceuticals Inc., all of which are public biopharma companies. Santini also serves on the boards of directors of Artax Biopharma Inc. and Enalare Therapeutics Inc., each a private biopharma company, and is retired from a distinguished career with Eli Lilly and Company. He served as chairman of the board of directors of AMAG Pharmaceuticals Inc., previously a public biopharma company, from February 2012 until November 2020, when AMAG was acquired by Covis Group S. à r.l. Santini also previously served on the board of directors of Sorin SpA, a public medical products group, from 2012 to 2015, when it was acquired by LivaNova plc, and also on the board of directors of Vitae Pharmaceuticals Inc., a public biotechnology company, from 2014 to 2016, when it was acquired by Allergan plc. During his tenure at Eli Lilly and Company from June 1983 to December 2010, Santini held various leadership positions.

Santini, fluent in four languages, holds an undergraduate degree in mechanical engineering from the University of Bologna and a Master of Business Administration from the University of Rochester.

Dr. James Shannon joined the board in August 2017. Dr. Shannon currently serves as chairman of the board of directors of MannKind Corporation, a public biopharma company focused on treatments for diabetes, and on the board of directors of ProQR Therapeutics NV, a public biotechnology company. From May 2012 to March 2015, Dr. Shannon served as the chief medical officer of GlaxoSmithKline (GSK), a public biopharma company, where he was responsible for matters of patient safety, general medical governance, medical ethics and integrity, medical information as well as investigations involving human subjects relating to any GSK medicine in development or on the market.

Before that, Dr. Shannon spent more than a decade with Novartis, a public pharmaceutical company. In his last role with the company, as global head of pharma development, he was responsible for all of Novartis’s development activities, from pre-clinical through Phase 4 and oversaw an annual development budget of approximately $4 billion.

Dr. Shannon received his science and medical degrees from Queen’s University in Belfast, Northern Ireland. He also serves as chairman of the board of directors of Kyowa Kirin (NA), a private biopharma company and subsidiary of Kyowa Kirin, and on the boards of directors of Immodulon Therapeutics Limited, a private biopharma company, Leyden Labs, a private biopharma company, and MyTomorrows, a private health-based platform that collaborates with drug developers to provide early access to treatments for patients who have exhausted all other options.

H. Thomas Watkins has served on the board of directors since April 2014. Watkins currently serves as a member of the board of directors of HemoShear Therapeutics LLC, a private biotechnology company. Before that, he was director, president and chief executive officer of Human Genome Sciences Inc. (HGS), a public biopharma company, from 2004 until HGS was acquired by GlaxoSmithKline in 2012. Before leading HGS, Watkins spent more than 20 years in senior roles at Abbott Laboratories and its affiliates in the United States and Asia, most recently serving as the president of TAP Pharmaceutical Products Inc. (TAP), which was jointly owned by Abbott and Takeda Pharmaceutical Company Inc. During his tenure, he led the growth of TAP from approximately $2 billion to over $4 billion in annual revenue. Watkins began his career in 1974 with Arthur Andersen & Co. From 1979 to 1985, he was a management consultant with McKinsey and Company Inc., working with multinational companies in the United States, Europe and Japan.

Watkins holds a bachelor’s degree from the College of William and Mary and a Master of Business Administration from the University of Chicago Graduate School of Business. Mr. Watkins previously served on the board of directors of Vanda Pharmaceuticals Inc., a public biopharma company, from September 2006 until June 2022.

Pascale Witz joined the board of directors in August of 2017. Witz founded PWH Advisors, a strategic consultancy firm advising health care and investment companies, in November 2016 and has served as its president since that time. From September 2015 to May 2016, Witz served as executive vice president, global diabetes and cardiovascular at Sanofi, a pharmaceutical company, which she joined in July 2013 as executive vice president, pharma and CHC divisions. During her tenure at Sanofi, she launched multiple medicines across three continents and strengthened the pipeline through licensing and partnerships.

Before Sanofi, Witz served more than 17 years at GE Healthcare where, in her final role as president and chief executive officer of its pharmaceutical diagnostics business, she ran a $2 billion integrated pharmaceutical organization that encompassed research and development through commercialization. Witz also serves on the boards of directors of Fresenius Medical Care AG & Co. KGaA, a public medical supply company; Regulus Therapeutics Inc., a public biotechnology company; PerkinElmer Inc., a public company focused on human and environmental health, PWH Advisors, Arkuda Therapeutics Inc., a private biopharma company; CellCarta Biosciences, a private biopharma services company, and Value Demonstration Group Holdings, a private equity fund. Witz previously served on the boards of directors of Savencia SA, a public food and dairy company, from 2016 to 2018, and Tesaro Inc., then a public biopharma company, from 2018 to January 2019.

Witz received her Master of Business Administration in economics and marketing from INSEAD and her Master of Science in biochemistry from INSA Lyon.