Wolfgang Wienand, Ph.D., Chief Executive Officer
Wolfgang Wienand (1972) was appointed CEO of Siegfried in January 2019. Before, from December 1, 2011, he led the departments Strategy, Mergers & Acquisitions, Legal and Intellectual Property Management and Regulatory Affairs. Since May 1, 2017, he was also responsible for Siegfried’s global Research and Development activities. He held this position previously from August 2010 to August 2012. Before joining Siegfried, he held senior management positions at Evonik Industries AG, formerly Degussa AG, with a focus on fine chemistry and custom manufacturing for the pharmaceutical industry. 

Wolfgang Wienand studied chemistry at the University of Bonn and subsequently obtained a Ph.D. in organic and bioorganic chemistry from the University of Cologne. In addition, he holds an Executive Master’s Degree in International Finance of HEC in Paris. 

Wolfgang Wienand is a German citizen.

Reto Suter, Ph.D., Chief Financial Officer
Reto Suter (1971) joined Siegfried on May 1, 2017, as Chief Financial Officer. Over the last 16 years, he has held a range of responsible positions in industry as well as in finance and private equity. In his last post as COO, CIO and Board Member, Reto Suter was responsible for overseeing the public takeover and subsequent delisting and restructuring of Lonrho, a long-established company headquartered in London (UK) and Johannesburg (SA).

Reto Suter studied economics at the University of Zurich and the University of Washington in Seattle and took his doctorate in banking and finance at the University of Zurich.

Reto Suter is a Swiss Citizen.

Arnoud Middel, Global Head Human Resources Global
Arnoud Middel (1971) joined the Siegfried Group in September 2011 as Head of Human Resources. Previously, he worked for various companies in the field of human resources. From 2003 to 2006, he held a leading position in the Human Resources department of the Baloise insurance Switzerland. From 2006 to 2008, he was Head HR for the region Continental Europe and Asia of the American industry- and reinsurance group XL-Insurance (today XL-Catlin). From 2008 to 2011, he worked as Head of HR Switzerland and Global Headquarters for Syngenta in Basel.

He completed his studies in biology and biochemistry at the University of Basel.

Arnoud Middel is a Dutch citizen.

Jürgen Roos, Ph.D., Chief Scientific Officer
Jürgen Roos (1968) joined Siegfried Group on 1 April 2019 as Chief Scientific Officer. Before that he had been working for Evonik Industries AG (formerly Degussa-Hüls and Degussa AG) since 1999, starting off as laboratory team leader in chemical research in the field of fine chemicals. In his last position, he was responsible as Vice President for Innovation Management of the Animal Nutrition business unit. In 2008, he had been appointed head of process development in exclusive synthesis following other professional posts within the R&D organization of Evonik, including several years in Canada and the United Kingdom. Subsequently, he took on global responsibility for research and development of the Health Care division. In this function he gathered broad experience in the field of chemical substances and finished dosage forms.

Jürgen Roos studied chemistry at the University of Stuttgart and subsequently obtained a Ph.D. in organic chemistry.

Jürgen Roos is a German citizen.

Marianne Späne, Global Head Business Development, Marketing & Sales
Marianne Späne (1962) joined the Siegfried Group in 2004 and was appointed Head of Business Development & Sales in March 2010. She headed the Siegfried Generics Division from 2008 to 2010 and was previously responsible for the Classical Generics Business Unit. From 2004 to 2008, Marianne Späne managed the Business Development Department and the Supply Chain for Generics. Prior to joining Siegfried, she worked in logistics, business development and as site manager for Boucheron, a cosmetics company. Later, Marianne Späne moved to the pharmaceutical industry and joined the pharma division of Schweizerhalle as Head of the Sales and Marketing department. Subsequently, she joined Aceto, a US-based company, where she developed European expansion strategies.

Marianne Späne holds degrees in finance, business administration and marketing from the Business Management School (KFS) in Basel and the Marketing & Business School in Zurich (MBSZ).

Marianne Späne is a German citizen.

Irene Wosgien, Global Head Technical Operations Drug Substances
Irene Wosgien (1973) has been heading Technical Operations Drug Substances since January 2021. In 2019, she joined the Siegfried Group as Multi-Site Head for several Drug Substance sites. She has many years of experience in custom manufacturing in the pharmaceutical and food industry. 

Before joining Siegfried, Irene Wosgien held various senior management positions at DSM Group, most recently as Vice President Operations Human Nutrition & Health. She holds a Master's degree in chemical engineering from Eindhoven University.

Irene Wosgien is a Dutch citizen.