By Randall Osborne

West Coast Editor

Planning to use fetal stem cells for growing ¿mini-brains¿ in which to screen compounds that target neurological disorders, Psychiatric Genomics Inc. has entered a deal with UK-based ReNeuron Holdings plc.

¿They¿re providing the cells for us, and that¿s all,¿ said Richard Chipkin, CEO of PGI, founded in January 2000 in Gaithersburg, Md., to target psychiatric disorders.

Under the terms, PGI gets a worldwide exclusive license to use specific cell lines within the field of the agreement in exchange for an initial cash payment and warrants, which become exercisable upon the achievement of milestones. Further details were not disclosed by the two privately held companies.

¿What we¿re doing is using the stem cells in culture, to grow little mini-brains, with the characteristics of various areas of the brain,¿ Chipkin told BioWorld Today. ¿Without much provocation, the cells will grow up into the area they¿re taken out of, and you can use them to mimic the environment of the central nervous system.¿

He emphasized that ¿nobody is saying this is the brain. We¿re using the cells to screen for compounds.¿ Once PGI gets closer to determining drug candidates that seem promising, it will be better positioned to seek a pharmaceutical partner, he added. ¿Probably in the early part of next year, we¿ll be more aggressive about going out,¿ Chipkin said.

PGI, with 35 employees, is studying such conditions as bipolar disorder and schizophrenia, Chipkin said ¿ conditions believed to be related to specific brain areas.

¿Particularly in schizophrenia, the prefrontal cortex has been implicated in a variety of studies, and our sense is that this is an area that¿s involved,¿ he said.

PGI approaches the study of gene expression patterns from two directions, Chipkin said.

¿One is taking post-mortem disease tissue and looking at different areas of those brains ¿ in schizophrenia, the prefrontal [area] and maybe the cerebellum,¿ he said. Diseased brain can be compared with healthy brains, and ¿we can do a within-brain control as well,¿ Chipkin said. ¿We look for differences not only between the controls, but different brain areas. Then, we look for compounds that will revert the change in gene expression back to normal.¿

Also, he noted, drugs cause changes in gene expression patterns.

¿We look at the gene expression patterns of compounds, and by looking at a variety of them, we try to separate out the genes associated with a therapeutic benefit from those associated with side effects,¿ Chipkin said. ¿But to look for gene expression patterns, you have to use cells.¿

That¿s why PGI made the deal with stem cell company ReNeuron, which in June entered what it called a ¿broad strategic alliance¿ deal with VistaGen Inc., of Burlingame, Calif., to exploit stem cells and screening technology.

On its own, ReNeuron, in London, is developing a class of compounds called Neurins, including the lead compound ReN 1869, with which Phase II trials in neuropathic pain and inflammatory arthritis began this year in the UK and Ireland. (See BioWorld Today, Nov. 29, 2001.)

Chipkin said he isn¿t certain how long it will take to begin the first experiments with ReNeuron cells.

¿We¿re investigating that right now,¿ he said. ¿We don¿t know what the doubling time is. But we anticipate receiving the cells mid-January, and incorporating them into screening systems in the first quarter of 2002.¿

The recent uproar over stem cell research ¿certainly made us nervous, but I would stress these are fetal cells, not embryonic, and the fuss is about embryonic,¿ Chipkin said ¿ acknowledging that deriving cells from aborted fetuses is ¿a really touchy issue¿ as well.