Idenix Reports Positive Proof-of-Concept Data for Lead Nucleotide Prodrug, IDX21437
Idenix on Track to Initiate All-Oral Pan-Genotypic Phase II Combination Clinical Study of IDX21437 and Samatasvir in mid-2014
Idenix Initiates Phase I Clinical Trial of Follow-on Nucleotide Prodrug, IDX21459
Idenix to Host Conference Call / Webcast at 8:00 a.m. ET today
CAMBRIDGE, Mass., April 7, 2014 (GLOBE NEWSWIRE) — Idenix Pharmaceuticals, Inc.
(Nasdaq:IDIX), a biopharmaceutical company engaged in the discovery and
development of drugs for the treatment of human viral diseases, today
announced continued progress of the Company’s program to develop
nucleotide prodrug inhibitors for the treatment of hepatitis C virus
(HCV) infection. Idenix is reporting potent antiviral activity of mean
maximum 4.2-4.3 log10 IU/mL reductions for patients infected
with HCV genotype 1, 2 or 3 receiving 300 mg once daily of IDX21437 in
the seven-day proof-of-concept portion of a phase I/II clinical trial.
Based on this progress, the Company’s goal is to initiate a combination
clinical trial of IDX21437 and samatasvir, a
pan-genotypic NS5A inhibitor, in mid-2014. In addition, Idenix has
selected a follow-on uridine-based nucleotide prodrug, IDX21459, from
its ongoing nucleotide discovery program and initiated enrollment for
the healthy volunteer portion of a phase I clinical trial.
“As more all-oral regimens become available to treat hepatitis C, an
increased number of patients will be diagnosed and treated. It will be
important to have simple, short duration options for our patients. These
early data for IDX21437 support its potential to be part of future
treatment combinations.” said Professor Edward Gane, MD, Deputy Director and Hepatologist, New Zealand Liver Transplant Unit, Auckland City Hospital in New Zealand,
and a clinical investigator in the IDX21437 proof-of-concept study.
“Nucleotide-based treatment combinations are favored because of safety,
efficacy, high barrier to resistance and low drug-drug interaction
potential and we look forward to seeing further results from studies
“We are very pleased with these positive data for IDX21437 and we are
excited to have two nucleotide prodrug candidates in the clinic,” said Ron Renaud,
Idenix’s President and Chief Executive Officer. “With the initiation
of the phase II study of IDX21437 and samatasvir later this year, we
will be one of a few companies with an all-oral, pan-genotypic,
nucleotide-based combination approach in the clinic. We believe this
regimen has the potential to play a significant role in advancing HCV
care for the benefit of patients, physicians and payers.”
IDX21437: Topline 7-Day Phase I/II Clinical Results
In January 2014, Idenix initiated the seven-day
proof-of-concept portion of a phase I/II clinical trial for IDX21437.
The trial completed enrollment of 44 treatment-naïve, genotype (GT) 1, 2
or 3 HCV-infected patients. Patients were randomized to receive
once-daily doses of placebo, 50 mg, 150 mg, or 300 mg of IDX21437 for
seven days. The topline clinical results include:
IDX21437 was well-tolerated with no observed pattern of adverse events or laboratory abnormalities.
Treatment with IDX21437 exhibited potent pan-genotypic activity in a dose-dependent manner:
In GT 1 HCV-infected patients (n=8), the mean maximal viral load reduction was 4.2 log10 IU/mL in the 300 mg arm.
The mean maximal viral load reduction of 4.3 log10 IU/mL was achieved in GT 2 and 3 HCV-infected patients in the 300 mg arm (n=10).
More detailed findings are expected to be presented at a future scientific meeting.
Based on these findings, the 300 mg dose of IDX21437 has been chosen
for the anticipated phase II combination study with samatasvir.
IDX21459: Phase I Clinical Program
In April 2014, Idenix initiated enrollment for the healthy volunteer portion of a phase I clinical trial of IDX21459 in Europe.
This portion of the study is expected to enroll approximately 50
healthy volunteers and will evaluate once-daily doses of IDX21459
ranging from 10 mg – 300 mg. The proof-of-concept portion of the study
is expected to enroll a total of 40 treatment-naïve, genotype 1
HCV-infected patients who will receive once-daily doses of placebo, 50 –
300 mg of IDX21459 for seven days. IDX21459 has shown a favorable
preclinical profile including potent, pan-genotypic activity and
favorable safety with respect to cardiac, mitochondrial and genotoxicity
Additional Nucleotide Candidates
Idenix’s primary efforts in nucleotide development will continue to
focus on its lead candidate, IDX21437, and follow-on prodrug candidate,
IDX21459, as well as earlier-stage nucleotide prodrugs. An important
objective for the discovery program is to identify nucleotides offering
distinct resistance profiles that can be combined with one of the
Company’s current nucleotide clinical candidates to treat HCV. Idenix
also announced today that the Company has elected not to continue its
clinical development program for HCV nucleotide prodrug, IDX20963,
previously placed on clinical hold by the U.S. Food and Drug Administration (FDA).
CONFERENCE CALL AND WEBCAST INFORMATION
Idenix management will host a conference call at 8:00 a.m. ET today. To access the call, please dial (877) 640-9809 (U.S./Canada)
or (914) 495-8528 (International) and enter passcode 26004979. A live
webcast will be available through the Investor section of the Idenix
website at www.idenix.com
under “Events & Presentations”. The archived webcast will be
available for two weeks following the call on the Idenix website.
IDX21437, Idenix’s lead uridine-based nucleotide prodrug inhibitor, has
completed the single-dose and seven-day proof-of-concept portions of a
phase I/II clinical trial. Extensive preclinical testing for IDX21437
has demonstrated favorable antiviral activity across genotypes 1-6 and a
safety profile which supported advancement into clinical trials. Based
on this progress, the Company’s goal is to initiate an Idenix-sponsored
combination clinical trial of IDX21437 and samatasvir in mid-2014.
Samatasvir is an NS5A inhibitor with low picomolar, pan-genotypic antiviral activity in vitro.
To date, samatasvir has been safe and well-tolerated after single and
multiple doses of up to 150 mg in healthy volunteers up to 14 days
duration, and in HCV-infected patients up to 12 weeks duration.
Samatasvir has demonstrated potent pan-genotypic antiviral activity in
HCV-infected patients with mean maximal viral load reductions up to
approximately 4.0 log10 IU/mL across HCV genotypes 1-4 in a proof-of-concept, three-day monotherapy study.
Under a non-exclusive collaboration with Janssen Pharmaceuticals, Inc.,
Idenix is evaluating all-oral, direct-acting antiviral HCV combination
regimens including samatasvir, simeprevir (TMC435), a once-daily
protease inhibitor jointly developed by Janssen R&D Ireland
and Medivir AB, and TMC647055/r, a once-daily non-nucleoside polymerase
inhibitor boosted with low-dose ritonavir being developed by Janssen.
In this program, Idenix is conducting two ongoing phase II 12-week
clinical trials, HELIX-1 and HELIX-2.