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Biotech / Medical : CYPB - Cypress BioScience -- Ignore unavailable to you. Want to Upgrade?

To: Jay Lowe who wrote (165)	5/12/1998 7:04:00 PM
From: John S. Baker	Read Replies (1) \| Respond to of 586

Like you and the Gruss analyst, I consider the recently-established research effort to discover exactly why the Prosorba Column actually works to be very important. Without an understanding of the mechanisms involved, it remains just "something from the witch doctor's tool kit." And I suppose it is possible, as muddphudd is perhaps suggesting, that once we understand the mechanism, then we may be able to find other profitable applications as well. Disclosure: long in CYPB since January.

To: Jay Lowe who wrote (165)	5/12/1998 10:26:00 PM
From: muddphudd	Read Replies (2) \| Respond to of 586

Hi Jay, I got a call back from a 'scientific consultant' named Susan Anton (RN). She was very pleasant. Here is the scoop (so far): 1) Yes, the Prosorba column is a protein-A column. She wasn't sure if they ever tested protein-G columns. 2) She said that the original FDA application for the Prosorba Column was intended for a wider indication (other autoimmune diseases). However, since most of their data at the time (circa 1986) was on ITP patients the FDA gave approval to use the column in ITP patients only. She did acknowledge that some physicians have used the column in other auto-immune disorders (Lupus, Myasthenia, etc..). That is good news. She hedged a bit as to whether CYPB is currently pursuing approval, through other clinical trials, for these auto-immune disorders; but did say that it makes sense to do so. She emphasized Lupus more than Myasthenia. 3) I also asked how this technology differs from conventional plasmapheresis. Apparently, only a fraction of the patient's serum is passed over the column (slowly) at one time. Therefore, the therapy requires multiple sessions. Interestingly, since only a fraction of the serum is treated at a time, there is no risk of immunocompromising the patients (something I was concerned with since the column removes antibodies of all types). This differs from plasmapheresis in that plasmapheresis is a complete bulk exchange. That is, all the blood is treated at one time. This, however, does not obviate the need for multiple plasmaphereses, as in the case with myasthenia gravis. Moreover, patients treated with plasmapheresis are susceptible to rebound phenomenons (the condition may transiently get worse after treatment). 4) She did not know how Prosorba compares with Immunex's TNF-Receptor-Fc drug. She did say that they plan on conducting a phase IV clinical trial, after they submit their FDA NDA, to compare Prosorba to other treatments available. Didn't specify. She did say that Immunex's drug is considered a short-term treatment and the Prosorba column would aim for longer term results. 5) I asked whether any work has been done on the eluates of the Prosorba column after serum has been passed over it. Some background: Typically, in molecular biology when someone wants to purify antibodies from serum, they pass the serum over a protein-A column. They then wash the column to remove non-specifically bound serum proteins. Finally, the antibodies are eluted with an acid wash and neutralized. One can further purify antibodies by passing them over an affinity-column which contains the antigen 'your' antibodies recognize. This technique separates your antibody from the other serum IgG antibodies that you are not interested in. Anyway, since patients with Rheumatoid Arthritis respond well to treatment with the Prosorba Column, I was wondering whether they can detected any differences in the pattern of IgG isotypes eluted from the columns compared to the pattern of control subjects. If there is enrichment of a particular type of antibody in the serum of RA patients then it may help us further understand the etiology of the disease. One could, in theory, try and isolate the antigen itself! Well, I hope I didn't lose anyone. Her response was that they are looking precisely into that right now. They want to understand why the column works so well in RA patients. That is all for now. I still wish I could get someone on the phone that knows the science well. I'll try your suggestion. Thanks. I'll keep you posted. Let me know what you think of the above. Regards to all.