Ideas thrive better under professional protection.

Dr. Andreas Oser

Dr. rer. nat., Dipl.-Chem., Master of Laws
German Patent Attorney, European Patent Attorney,
European Trademark and Design Attorney
Registered Representative before the Unified Patent Court

+49 89 69 39 21-0oser@pruefer.eu

Professional career

Andreas Oser has been working in the IP field since 1991, became a German and European patent attorney in 1995 and has been managing partner at Prüfer & Partner since 2002.
In addition he holds an LL.M. degree in International Intellectual Property Laws (University of Hagen).
Prior to working in the IP field, he studied chemistry at the University of Freiburg i. Brsg., and then completed his Ph.D. and postdoctorate scientific work at the Max Planck Institute for Biochemistry in Munich.

German, English, French

Specialist areas of activity


  • Patent prosecution (drafting, examination)
  • High number of opposition and appeal proceedings at the European Patent Office
  • Patent litigation:
    • Patent infringement proceedings before German courts
    • nullity proceedings up to the highest instance, the Federal Supreme Court; also covering coordinated and complex EU-wide litigation activities
  • Infringement and validity opinions, freedom-to-operate (FTO) analyses, due diligence

Andreas Oser was and is currently involved in many litigation cases, among others related to medical devices and important drug products.


chemistry, pharmaceuticals, life science and biotechnology, in particular:

  • medicaments and drugs (active substances, formulations), biopharmaceuticals
  • biological materials, DNA-related inventions and vaccines
  • therapeutic and diagnostic methods
  • medical products and devices and targeted drug delivery
  • polymers, fibre materials, composites
  • semiconductors, LEDs, OLEDs and other optical materials and optoelectronic devices,
  • batteries and their components

Publications and memberships:


Oser A. and Sonnenhauser S., JUVE Handbuch Wirtschaftskanzleien 2022/2023, 773-774: “Plausibilität – ein ungelöstes Problem bei der Patenterteilung”

Schmidt T. and Oser A., GRUR Int 2019, 737: “New medical uses of known medical devices – A new perspective on purpose-limited product protection for medical devices in Europe”

Oser A. in GRUR Int 1998, 648 (=IIC 30, 1-18, 1999): “Patenting (Partial-)Gene Sequences”

Oser A., PATENTS & LICENSING 1998, 30: “EU Directive on Legal Protection of Biotech Inventions”

Oser A. and Bavec S., AIPPI Japan 2004 (Vol. 49 No. 7), 503: “Biotech Inventions in Europe”

Oser A. in GRUR Int 2006, 539 (=IIC 37, 520-550, 2006): “European Patent Litigation Agreement – Admissibility and Future of a Patent Dispute Regulation in Europe”

Thieme R„ Lay H., Oser A., Lehmann J., Wrissenberg S. and Boos W., Eur, J.Biochem. 160, 83-91 (1986)

Oser A., Roth W.K. and Valet G., Nucl. Acids Res. 16, 1181-1196 (1988)

Oser A. and Valet G., Nucl. Acids Res. 16, 8178 (1988)

Rothe G., Oser A. and Valet G., Naturwissenschaften 75, 354-355 (1988)

Oser A., Collasius M. and Valet G., Anal.Biochem. 191(2), 295-301 (1990)

Oser A. and Valet G., Angewandte Chemie International Edition 29(10), 1167-1169 (1990)

Rothe G., Banati R., Oser A., Assfalg-Machleidt I., Mangel W.F., Machleidt W., Kreutzberg G.W. and Valet G., Journal Immunol. Methods. 138(1), 133-135 (1991)

Oser A. and Valet G. (1988), Patent Applications WO8907606A, DE3804243A


Chamber of Patent Attorneys
epi – European Patent Institute
Member of the Biotech Committee of the epi
AIPPI – International Association for the Protection of Intellectual Property
FICPI – International Federation of Intellectual Property Attorneys
LES – Licensing Executives Society
GDCh – Gesellschaft Deutscher Chemiker