FREMONT, Calif., Jan. 4, 2012 /PRNewswire/ -- Quark Pharmaceuticals, Inc., a world leader in the discovery and development of RNAi-based therapeutics, today announced interim results from the first two cohorts of its Open Label, first-in-human Phase I clinical study of QPI-1007, the Company's proprietary synthetic siRNA drug candidate for ocular neuroprotection, in patients with recent onset of non-arteritic anterior ischemic optic neuropathy (NAION). QPI-1007 exhibited no dose limiting toxicities up to and including the highest dose of 6 milligrams enabled in this study, which is the highest dose of synthetic siRNA tested in the clinic following intravitreal administration. After 3 months of follow up, patients treated in the study by a single dose of QPI-1007 exhibited no further loss of visual acuity, whereas vision loss was observed in previous studies(1) in non-treated NAION patients with similar initial disease severity. With the exception of one patient whose vision remained stable, all patients exhibited letter gains compared to baseline at screening, with some patients gaining 3-lines or more by 3 months after treatment.
The ongoing Phase 1 open-label, dose-escalation study, which is being conducted in 22 sites in the USA and 6 sites in Israel, has enrolled a total of 38 patients in two strata: Stratum I was a dose-escalation safety study in patients who are legally blind secondary to chronic optic nerve atrophy or retinal degeneration and is fully enrolled; Stratum II was designed to further evaluate safety and to assess for potential biological activity of QPI-1007 in recent-onset NAION patients by monitoring changes in visual function following drug administration.
In Stratum II, two cohorts of ten patients each were given a single intravitreal injection of one of two doses of QPI-1007. After one month of follow-up, 40% of patients in Cohort 1 and 60% of patients in Cohort 2 gained 3 or more lines of visual acuity. At three months of follow up, for which historical data are available, the percentage of patients gaining three or more lines was 50-55% in both dosing cohorts. These values are higher than historical data reported in two different published clinical studies exploring the natural course of the disease where only 39 or 20% of patients, respectively, gained 3 or more lines at 3 months after disease onset(1). In the latter case, the advantages of treatment with QPI-1007 were strongly significant. Furthermore, at 1 month after the administration of QPI-1007, patients gained on average 13 and 16 letters in the two dose groups. At 3 months, average letter gain was 14 in both groups and none of the patients lost vision compared to screening data. A change of 15 letters is considered to be a substantial improvement in visual acuity. Evaluation of these patients is ongoing, with additional assessments planned at six- and 12-months post-injection.
"We are very encouraged by these interim clinical data. The data suggest that QPI-1007 may improve visual acuity in NAION patients. Based on the interim data from this clinical study, and from our positive results from preclinical studies in three different models of optic neuropathy, including a model of glaucoma, we believe QPI-1007 may protect neurons in the retina and optic nerve in NAION and in other types of optic neuropathy, the most common of which is glaucoma," said Dr. Daniel Zurr, Quark's Chief Executive Officer. "QPI-1007 represents Quark's first drug with proprietary RNAi structure, and we believe these interim results support our position as a world leader in the discovery and development of RNAi-based therapeutics."
Non-arteritic ischemic optic neuropathy (NAION) is the most common cause of sudden optic nerve-related vision loss. NAION is an acute ischemic disorder believed to be caused by insufficient arterial blood flow to the optic nerve via the posterior ciliary artery. Vision loss resulting from NAION is typically sudden and painless, and in most cases patients have permanent visual deficits. There are no approved therapies available for these patients.
About Quark Pharmaceuticals, Inc.
Quark Pharmaceuticals, Inc., is a clinical-stage pharmaceutical company engaged in discovering and developing novel RNAi-based therapeutics. The Company has a fully integrated drug development platform that spans therapeutic target identification based on its proprietary gene discovery technology, to clinical drug development. Quark has three product candidates in clinical development in five different disease indications of which four are in Phase 2. QPI-1007, a chemically modified synthetic siRNA, is Quark's first drug candidate based on novel siRNA structures developed though an internal program conducted by Quark in collaboration with BioSpring AG.
Quark is committed to leveraging a broad research pipeline of siRNA drug candidates and novel siRNA structures to develop additional RNAi drug candidates.
Quark is headquartered in Fremont, California and operates research and development facilities in Boulder, Colorado and Ness-Ziona, Israel. Additional information is available at www.quarkpharma.com.
(1) The Ischemic Optic Neuropathy Decompression Trial Research Group (1995). Optic Nerve Decompression Surgery for Nonarteritic Anteriror Ischemic Optic Neuropathy (NAION) is Not Effective and May Be Harmful. JAMA, Vol.273, pp.625 632; and (2) Hayreh S.S. & Zimmerman M.B. (2008). Non-arteritic Anterior Ischemic Optic Neuropathy. Natural History of Visual Outcome. J. Ophthalmology, pp.298-305.
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