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Biotech / Medical : VD's Model Portfolio & Discussion Thread -- Ignore unavailable to you. Want to Upgrade?

To: Biomaven who wrote (6224)	1/5/1999 11:11:00 AM
From: Vector1	Read Replies (1) \| Respond to of 9719

<< I don't think 5-FU is even approved for pancreatic cancer, so it's hard for the FDA to require a comparison. >> From the SUPG Web site. <<SuperGen is conducting randomized clinical trials for patients with advanced pancreatic cancer. Patients that have had no previous chemotherapy will be randomized (have a 50:50 chance) to receive either gemcitabine (GemzarÒ) or RFS 2000. Patients who have received gemcitabine as their only prior chemotherapy, and have progressive disease will be randomized to either 5-fluorouracil (5-FU) or RFS 2000.>> 5 FU in combination with other chemo agents is the preferred protocol. Gemzar is a joke. Any reliance soley on a Gemzar comparison is risky. Yes the bar should be low but we are talking about the FDA. The bar on ALS should be low as well. The Stehlin Clinic in Houston is quite controversial. I will leave it at that. Not sure on the Extra stuff. V1

To: Biomaven who wrote (6224)	1/5/1999 11:16:00 AM
From: Russian Bear	Read Replies (1) \| Respond to of 9719

Peter, There are, apparently, analogues of Camptothecin which offer a closer murine-human match, with regard to the time interval that the lactone ring remains closed. The following abstract is interesting (other relevant abstracts can be found through a CANCERLIT search for "camptothecin lactone.") ************************** Title Alkyl esters of camptothecin and 9-nitrocamptothecin: synthesis, in vitro pharmacokinetics, toxicity, and antitumor activity. Author Cao Z; Harris N; Kozielski A; Vardeman D; Stehlin JS; Giovanella B Address Stehlin Foundation for Cancer Research, Houston, Texas 77003, USA. Source J Med Chem, 1998 Jan, 41:1, 31-7 Abstract Eleven camptothecin esters, 6a-e and 7a-f, were prepared by straightforward acylation of camptothecins with the corresponding acylating reagents such as organic anhydrides and carboxylic acid chlorides. The in vitro pharmacokinetic determination of lactone levels of esters 6a and 7b showed that the biological life span of their lactone forms in human and mouse plasma significantly increased when compared with their mother compounds, camptothecin (3) and nitrocamptothecin (4). The differences of lactone levels between human plasma and mouse plasma for 6a and 7b were much smaller than what was observed for their mother compounds. The in vivo antitumor activity and toxicity studies demonstrated that some of these esters were very active against human tumor xenografts in nude mice and had an exceptional lack of toxicity in nude mice, even at enormous doses. Language of Publication English Unique Identifier 98100831 ************************** My question is, How to untangle the web of patents and licenses that surround these compounds? RFS 2000 certainly looks interesting (barring a total collapse in PIII, I have to believe that it should sail right through the FDA.) The next generation of Camptothecin analogues, however, appears to be even more promising, potentially. Only, who has the rights to these compounds? RTI? BMY? Stehlin? IDEC? SUPG? Thanks, RB