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Biotech / Medical : ARIAD Pharmaceuticals -- Ignore unavailable to you. Want to Upgrade?

To: Richaaard who wrote (1024)	2/12/2000 4:38:00 PM
From: Pseudo Biologist	Read Replies (1) \| Respond to of 4474

Richaaard, I have no specific knowledge of Parkinson's but can try to address your question in general terms. Let's say genomic research identifies a particular protein deficiency, which turns out to be the main cause for a particular disease. Classic examples of this include the hemophilias caused by defective or missing enzymes in the coagulation cascade. Note that even before we get into sexy new situations discovered by genomics, one may have an already long list of known situations with still unmet medical needs. Once you know that lack of functional protein X causes, or contributes to, disease Y, you have a number of choices, of which I list two major classes here: (1) you give the patient the protein in injectable form, and this may be something that the patient has to take every day or week or hour for the rest of his or her life. In the old days, proteins like this came from natural sources, like pooled human serum or even animals. In the last 10-15 years it is often possible to produce such protein recombinantly. See Genentech's human growth hormone or Genzyme's protein products for examples. Disadvantages of this approach include inconvenience and cost, but see below. (2) gene therapy. You give the patient a gene, a piece of DNA, that codes for the desired protein and this effectively "reprograms" the patient's cells to manufacture a good working version of the missing protein. This step of "giving the patient the gene" may need to be done, ideally, only once and for all, but in practice, may have to be repeated once a year, or something in the range. How this works exactly (whole issue of "vectors"), and which cells to choose are among the issues facing gene therapy in general and its use in particular situations. A number of companies are "pure plays" in gene therapy, including CEGE, TGEN, VLTS, AVGN to name a few. The therapeutic applications of ARIA's technology may be seen, in this context, as refinements of point (2). When (2) works perfectly, you have now a constant production of protein. There are many cases where this may not be desirable and one may want to have the flexibility of turning protein production on and off (which is what ARGENT can do), or have an "emergency switch" to kill the engineered cells under some situations ("failsafe" version of ARGENT), or allow the possibility of producing "bursts" of protein (RAPID). In each case in which one considers approach (2) or the potential enhancements by ARIA, call it "2-plus," one has to evaluate the competition of approach (1) and enhancements thereof such as use of more convenient delivery like pulmonary, (INHL, ALKS, ARDM) or even oral, EMIS, as well as improvements in production by potentially drastic reduction of costs, such as protein "manufacturing" in transgenic animals, like GZTC and others do or try to do. Other approaches that have a similar flavor to (1) in the sense that they may require frequent dosing may involve the use of orally available small molecule "mimics" of protein drugs. For an early, but intriguing example of the latter see: ncbi.nlm.nih.gov The above is, or course, not all inclusive, not even as far as Ariad's gene therapy applications go, but I hope helps to address your question. PB