Plexxikon bolsters R&D

BERKELEY, Calif.—Four-year-old drug discovery company Plexxikon, Inc. in December strengthened its R&D team as it prepares to move multiple drug candidates into pre-clinical and clinical testing.

Joining the company, based here, as senior vice president and chief science officer is Keith B. Nolop, M.D., a former CoTherix and Schering-Plough executive. Dr. Nolop will be responsible for shepherding promising compounds created by Plexxikon and its partners through IND and NDA applications.

"In the past we have used outside consultants for this kind of work and will continue to do that," says K. Peter Hirth, Ph.D., Plexxikon chief executive officer. "But from a business standpoint we are now clearly positioned to take compounds that we have been developing into late stage. That is important from a business perspective in how the company is perceived, not as a boutique that plays around with a few compounds, but as a serious enterprise that is capable and has the structure to take lead compounds into the clinic and up the value chain."

Also promoted were Dean R. (Rick) Artis, Ph.D., to vice president for lead generation and Gideon E. Bollag, Ph.D., to vice president of discovery biology. Artis has been with Plexxikon for nearly three years as the company's senior director of informatics and will now also be responsible for the entire chemistry and structural biology functions. Bollag's work will focus on the biology side of the equation including molecular biology, protein chemistry and screening.

The move to further strengthen the R&D function at Plexxikon comes on the heels of a multi-product collaboration with Wyeth Pharmaceuticals announced in late October which focuses on the development of PPAR compounds and the December announcement that its dual c-Kit and FMS kinase inhibitor, developed in collaboration with Phenomix Corp., has been selected as a development candidate for the treatment of inflammation.

Kathy Glaub, president and chief financial officer, says that the development of PLX204 — the PPAR compound — was taken from target concept to human trials in only two years and PLX647, which is targeted for the treatment of rheumatoid arthritis, was developed in 12 months as part of its collaboration with Phenomix. It is expected to enter human trials by late 2005.

"To bring compounds along this quickly, in less than two years, and have them in human trials is really quite remarkable," says Glaub. "With PLX647, which we anticipate will be in trials by late this year, human trials would come less than two years since we announced our collaboration with Phenomix."

Plexxikon credits the short development times to the proprietary platform it calls Scaffold-Based Drug Discovery. A key component of this method, according to the company, is the reliance on structural screening of compounds against particular criteria prior to initiating chemistry. Using this structure-based approach, Plexxikon develops "scaffolds" which have binding affinity for multiple members of a protein family. This leverages inherent structural similarities of targets in a protein family and allows the company to apply a systems approach to drug development that it says can produce leads for pre-clinical testing in as little as six months. To date, Plexxikon has discovered multiple scaffolds in each of three protein families: kinases, nuclear receptors and phosphodiesterases.