Hybridon Inc. has received notice of allowance on a patentcovering a new type of antisense compound designed for longerlife and enhanced uptake into cells.

Antisense molecules stop protein production by binding tomessenger RNA, thereby halting the readout of geneticinstructions. Diseases such as cystic fibrosis or familialhypertension are subjects of antisense research, but Hybridon'sfirst target is AIDS, company President Edward Neiss toldBioWorld.

Hybridon's antisense molecules will make use of an alteredbackbone, which can resist digestion. The patented backboneingredients will permit modulation of uptake into cells as well,said Sudhir Agrawal, vice president of discovery, by enablingthe antisense molecules to enter cells more easily.

When antisense molecules bind to targeted RNA, the targetsegment is digested by an enzyme called RNase H. Thesynthetic backbone covered by the patent prevents the enzymefrom working. Other covered backbone building blocks doactivate the enzyme.

By crafting backbones with particular placement of elements,the company hopes to gain precision in antisense targeting.

The privately held company has filed for or already hasexclusive rights from the Worcester Foundation to 10 antisensepatent applications. Hybridon also has exclusive rights from thefoundation to a basic patent that the company said covers theuse of antisense in treating AIDS, AIDS-related complex andother viral disorders.

The lead AIDS compound, which blocks readout of the HIVgene called TAT, is in preclinical toxicology testing. Hybridonplans to compile this summer an investigational new drugapplication to test the drug in HIV-positive patients, said Neiss.

Hybridon, based in Worcester, Mass., has just completed aprivate placement that will finance Phase I testing of the AIDStherapeutic, although the company has also been talking topotential corporate partners.

Seed capital for the company, which was founded in 1989, wasobtained from Medical Science Partners in Brookline, Mass.

-- Roberta Friedman, Ph.D. Special to BioWorld

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