Sheffield Medical Technologies announced that it has acquiredexclusive rights to a technology involving the reconstitution ofmembrane CD4 in the lipid membrane of liposomes andencapsulation of a cytotoxic agent in the liposome-CD4.

The technology, acquired from an individual named Basil Hone,will complement its red blood cell-CD4 technology (RBC-CD4)and may ultimately provide a "tandem" treatment for AIDS, theHouston company said.

The liposome-CD4 technology was based on research by ClaudeNicolau, director of the Blood Research and DevelopmentLaboratory at CBR Laboratories Inc.

Sheffield also announced that it is negotiating a sponsoredresearch agreement with CBR Laboratories, a subsidiary of theCenter for Blood Research Inc. and an affiliate of HarvardMedical School. Under the proposed agreement, CBR wouldconduct preclinical testing of the liposome-CD4 complex underfunding from Sheffield. The first phase of research, for whichSheffield would provide $600,000, would cover the productionof purified, recombinant, full-length CD4; the preparation,standardization and optimization of the liposome-CD4 complex;and in vitro studies of the cytotoxin-bearing complex's activityagainst HIV from infected patients and SIV from M. rhesusmonkeys.

The company's red blood cell-CD4 technology can be used tocarry cytotoxins that destroy HIV, a Sheffield representativesaid. The cytotoxin, however, can only be targeted to virus inthe bloodstream. Liposomes, on the other hand, can be targetedto lymph nodes, which will be the target of the company's firstclinical studies. The combination of blood- and lymph node-related therapeutics may constitute a "complete package" forthe treatment of AIDS, according to Sheffield's president andchief executive officer, Douglas Eger.

Sheffield (ASE:SHM) met with FDA representatives earlier thismonth to discuss a protocol for a Phase II trial of its red bloodcell-CD4 therapy in AIDS patients. The company hopes to begina randomized, double-blind, placebo-controlled trial in 12patients, measuring the effects of its red blood cell-CD4complex on viral load as measured by p24 antigen level. Underan earlier agreement, CBR will produce and purify recombinant,full-length CD4 for the trial.

Sheffield also announced Thursday that it is calling in all833,334 of its outstanding redeemable stock purchase warrantsissued in connection with its public offering in February 1993.Each unit consisted of two common shares and one warrant.The company stipulated that it could call the warrants if itsstock traded at $5 per share or more over 20 consecutive-daytrading period during the life of the warrants. Investors mustredeem each warrant for a share of stock at $3.75 per share byMarch 25 or the company will be able to reacquire thewarrants for five cents apiece. Sheffield raised approximately$5 million in its February 1993 financing.

The company will bring in $3.1 million from the redemption ofits warrants, which it will apply toward its CD4 programs aswell as other projects. Sheffield currently has approximately5.2 million shares outstanding and cash on hand of about $1million. Operating with a burn rate of roughly $150,000 permonth, the company would have conducted a financing roundin June if it had not called the warrants, a companyrepresentative said. Money raised from the redemption ofwarrants should carry Sheffield through the year, she added.

Founded in 1991, Sheffield finances the development ofbiomedical research at universities and other researchinstitutions in exchange for licenses to commercialize thetechnology.

Sheffield's stock closed at $8.38 a share on Thursday, down 50cents.

-- Karl A. Thiel Business Editor

(c) 1997 American Health Consultants. All rights reserved.