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Biotech / Medical : Ligand (LGND) Breakout! -- Ignore unavailable to you. Want to Upgrade?

To: jayhawk969 who wrote (23004)	7/9/1998 9:28:00 PM
From: Henry Niman	Read Replies (1) \| Respond to of 32384

JD, I haven't read the patent yet, but LGND was way out in front on small molecules that control gene expression. In 1985 Ron Evans published the first sequence on non-polypeptide hormone receptors. It had homolgy to Erb A (chicken version of a truncated thyroid hormone receptor) and soon there were several sequences which readily define the DNA and hormone binding domain (I made monoclonals to these sequences in 1984). Vitamin A derivatives like tretinoin and isotretinoin had been studied for years and in 1988 Progenx (which later became Ligand) exclusively licensed the Evan's technology which included a co-transfection assay which was designed to identify small molecules that reacted with hormone receptors (transcription factors) that controlled gene expression. The OSIP press release refers to advances in the late 80's which followed the discoveries made by the Evan's technology.

To: jayhawk969 who wrote (23004)	7/9/1998 9:28:00 PM
From: jayhawk969	Respond to of 32384

"OSI Pharmaceuticals, Inc. (Nasdaq: OSIP - news) today announced it has been issued a fundamental patent (U.S. Patent No. 5,776,502) covering the use of small molecule drugs for the regulation of gene transcription." Relevent press releases regarding OSIP and their patent: biz.yahoo.com biz.yahoo.com biz.yahoo.com

To: jayhawk969 who wrote (23004)	7/9/1998 10:07:00 PM
From: Henry Niman	Read Replies (1) \| Respond to of 32384

OSI tries to get around prior art with the following claim: " bind to a protein through a domain of such protein which is not a ligand binding domain of a receptor which naturally occurs in the cell, the binding of a ligand to which ligand binding domain is normally associated with the defined physiological or pathological effect". Most of the earlier studies did target the hormone binding domain. The OSI patent was filed in 1995 so they appear to be focusing on "phantom effects" or allosteric changes which Ligand scientists have also described several years ago. Even this restricted claim may have some prior art problems.