Rigel and Proteros renew X-ray protein crystallography collaboration

Martinsried, Germany, July 12, 2011. Proteros Biostructures GmbH
("Proteros") announced today that it has renewed its agreement with
Rigel Pharmaceuticals, Inc. (Rigel) to provide structural biology
services for a Rigel drug discovery program.

Under this agreement, Proteros will provide X-ray structure analysis
of protein-compound complexes for specific targets to support Rigel's
discovery efforts. Proteros will deploy its high throughput
crystallography platform and proprietary technologies.

Proteros focuses on providing structure based drug discovery services
and continues to invest in developing its service platform which
consists of X-ray protein crystallography, kinetic and thermodynamic
compound profiling and integrated lead discovery based on a novel
compound and fragment library of over 30,000 novel target directed

Cony D'Cruz, CBO and President of Proteros (US) Inc. said: "This
agreement continues the long-standing structural biology collaboration
between the two companies. We are pleased to be supporting Rigel with
its pioneering research efforts."

About Rigel Pharmaceuticals, Inc.:
Rigel is a clinical-stage drug development company that discovers and
develops novel, small-molecule drugs for the treatment of inflammatory
and autoimmune diseases, as well as muscle disorders. Rigel's
pioneering research focuses on intracellular signaling pathways and
related targets
that are critical to disease mechanisms. Rigel's productivity has
resulted in strategic collaborations with large pharmaceutical
partners to develop and market its product candidates. Current product
development programs include fostamatinib (R788), an oral syk
inhibitor in phase 3 clinical trials for rheumatoid arthritis
(w/AstraZeneca), and R343, an inhaled syk inhibitor that is in
clinical trials for asthma.

About Proteros biostructures GmbH:
Proteros is a privately held company that provides services and
proprietary technologies to support integrated drug discovery.
Proteros uses its technical expertise, industrial processes and unique
technologies for crystallography, kinetic and thermodynamic profiling
and fragment-based lead generation incorporating protein structure
inspired compound and fragment libraries. The platform enables
‘knowledge driven lead engineering' to accelerate and improve protein
structure analysis and structure-based drug discovery. Proteros
complements its clients' internal capabilities with external expertise
and access to flexible resources. Proteros currently provides services
to more than 80 pharmaceutical and biotechnology clients in North
America, Europe and Asia. Proteros US, Inc. is a wholly owned
subsidiary of Proteros established to serve the growing customer base
in North America.