Alteon Inc.'s aminoguanidine compound has been shown toinhibit the development of diabetic retinopathy in rats.
Diabetes is the leading cause of adult blindness in the UnitedStates. Pathologic retinal changes are found in virtually 100percent of patients having type I (juvenile onset) diabetes for15 years or longer and 70 percent of patients having type II(adult onset) diabetes for 15 years or longer.
The Northvale, N.J., company (NASDAQ:ALTN) is conductingPhase I trials of the compound and hopes to enter Phase II/IIItrials in the spring of 1992.
In the animal studies reported in the current Proceedings ofthe National Academy of Sciences, rats treated withaminoguanidine had a 3.6-fold increase in acellular capillaries,which are associated with blockage of blood flow to the retina,and no capillary microaneurysms.
By contrast, over the 75-week period, untreated diabetic ratsformed microaneurysms and developed an 18.6-fold increasein acellular capillaries.
Aminoguanidine inhibits the formation of advancedglycosylation end products (AGEs) formed as a result of glucosein the body's circulatory system. AGEs damage proteins byforming permanent attachments, or cross-links, with otherproteins.
A 26-week study showed that aminoguanidine prevented a2.6-fold increase in AGEs that otherwise would have beenexpected in the test animals. Those data provide evidence thatdiabetic retinopathy is caused by AGEs.
Alteon stock climbed $3.75 to $27.75 on Monday.
Two other companies last week reported results in rat studiesof pancreatic implants used to supply diabetics with insulin.Both are using polymers to evade tissue rejection of theimplants.
Writing in Science, researchers at CytoTherapeutics Inc. ofProvidence, R.I., seeded rat islet cells into hollow tubes ofacrylic copolymer and planted them under the skin of diabeticrats. The protected tissue supplied enough insulin to keep therats' blood sugar at normal levels for at least 60 days.
In the current issue of PNAS, BioHybrid Technologies Inc.showed that cross-species implants can work without rejection,using a similar encapsulating strategy.
BioHybrid, a Shrewsbury, Mass., subsidiary of W.R. Grace & Co.,encapsulated same-species or even cross-species grafts intoGrace's XM-50 acrylic polymer, which allowed the tissue tosurvive in the peritoneal cavity and provide insulin to diabeticrats for at least a month.
At privately held CytoTherapeutics, which last week changedits name from Cellular Transplants Inc., the EndoCRIB system isslated to enter human studies in 1993.
William Chick, BioHybrid's president, did not venture anestimate of when the company would test its implantprocedure in humans.
-- Roberta Friedman, Ph.D. Special to BioWorld
(c) 1997 American Health Consultants. All rights reserved.