ISIS 14803 is an antisense inhibitor of HCV produced by HepaSense, Ltd., a partnership of Isis Pharmaceuticals and Elan Corporation.
HepaSense has announced the results of a small phase I/II clinical trial with 11 people infected with HCV, all non-responders
to previous IFN mono or combo therapy, except one, and all genotype 1. The patients were given increasing doses of up to 2 mg/kg
intravenously of ISIS 14803, three times a week, for one month.
Responses, probably dose-dependent, developed after several doses of ISIS 14803 and persisted for 20 to 50 days.
In most cases, the responses were associated with a transient ALT flare. ISIS 14803 was well tolerated.
Adverse events reported were minor and non-specific. Liver biopsies performed on 2 experiencing an ALT flare revealed no
evidence of drug induced liver damage. More studies are being done with subcutaneous injections (AASLD Conference:
New Therapeutic Strategies for Hepatitis C, Chicago, June 15-16, 2001, Reported by Jules Levin) (
www.isip.com).
A phase II trial at a dose of 6 mg/kg IBW is currently in progress (Nov. 2002). Patients are being treated at this dose level
and a total of 40 patients are being evaluated in the study. Based on the data so far, it seems to be well tolerated at lower doses.
Transient reductions in plasma HCV RNA levels, even in genotype 1 patients, seem to indicate the drug has an antiviral effect (
www.isispharm.com).
AVI BioPharma (www.antivirals.com) Human clinical trials in more than 200 patients indicate that NeuGene antisense agents have a promising safety profile, with no drug-related adverse events.
Stanford University Studies were done on mice using morpholino phosphoramidate antisense oligonucleotides (morpholinos) which showed great
potential in inhibiting HCV (Hepatology. 2003 Aug;38(2):503-8.).