By Frances Bishopp
In an effort to understand the correlation between mutations in HIV and response to HIV antiviral drugs, Glaxo Wellcome plc and Affymetrix Inc. will combine Glaxo Wellcome's HIV antiviral research and Affymetrix's proprietary GeneChip technology to build a data base of genetic information from a selected sampling of patients with the virus.
Under the agreement, Affymetrix will sell its commercially available DNA probe arrays or "chips" to Glaxo. The two companies initially will build a data base on a set of approximately 1,600 HIV samples. If the data base proves useful in understanding drug resistance, the collaboration will be expanded to collect data from tens of thousands of HIV patients who are being treated with different antiviral drugs or combinations of drugs.
Also planned are multiple centers for analyzing patient samples from HIV-infected patients under various therapeutic regimens, the first of which will be established at Affymetrix, in Santa Clara, Calif., and Glaxo Wellcome's research facility in Stevenage, U.K.
Financial details of the collaboration were not disclosed.
Kenneth Nussbacher, vice president and chief financial officer of Affymetrix, told BioWorld Today the two companies will be looking at which strains of virus respond to which drugs before the drugs are administered to the patient. "At the end of that," Nussbacher said, "hopefully, you're going to know what strains of virus will respond to what drugs before you just give it to them. So, by looking at enough people, you'll be able to pick the right therapy based on the genotype of the virus."
Currently HIV-infected patients get the full blast of antiviral drugs, Nussbacher explained, and some might not work for various reasons such as the patient might already be resistant to one or may not need them. If the patient turns up resistant to the "cocktail" (antiviral drug combination), then there is really not much left to do.
The alternative, he explained, is to see what strain of virus you have and know ahead of time what particular drug would work for it. "You don't have to give people drugs that won't work for them or pay for them because they are very expensive," Nussbacher said.
Another advantage, he pointed out, was that by using the drugs selectively, some drugs would be left in the "toolbox" and could be brought out if the patient becomes resistant to the drugs he or she is taking.
Nussbacher said the first phase of the collaboration, (finding out whether it works), would take approximately one year and, if it works, a larger study will be done that will continue for at least two years or more.
Glaxo Wellcome, of London, developed Retrovir, (AZT, zidovudine), the first antiviral medicine for use in adults and children with HIV, and introduced it for use in 1987. Another antiviral, Epivir/3TC, which was discovered by BioChem Pharma Inc., of Laval, Canada, and licensed to Glaxo in 1990, was approved by the FDA in 1995. Glaxo has discovered, developed and now markets various products for the treatment of HIV-related opportunistic infections.
Affymetrix, of Santa Clara, Calif., developed its GeneChip system to acquire, analyze and manage complex genetic information to improve the diagnosis, monitoring and treatment of disease. This system can build large arrays of single-stranded DNA probes on chips. When a sample of DNA is applied to the chips, the sequence is determined through the binding pattern on the sample to the probes on the chip. Each chip is designed to analyze a specific gene or set of genes.
In June 1996, Affymetrix, which is 46-percent owned by Glaxo, completed its initial public offering, selling 6 million shares of stock at $15 a share to raise gross proceeds of $90 million.
Affymetrix has collaborations with Genetics Institute Inc. of Cambridge, Mass., in the area of GeneChip technology, Incyte Pharmaceuticals Inc., of Palo Alto, Calif., to develop data bases comparing gene expression patterns in healthy and diseased cells for use by pharmaceutical and biotech companies in drug discovery and Hewlett-Packard Co., of Palo Alto, Calif., for development of advanced instruments used in the GeneChip system. The Hewlett-Packard collaboration also includes development and marketing of GeneChips by the computer company.
Affymetrix, as of Dec. 31, 1996, had $109 million in cash and a net loss for the year of $12.2 million.
Affymetrix stock (NASDAQ:AFFX) gained $1 Monday to close at $30 per share. *