Sylentis Completes Phase I Trial with SYL040012 to Treat Elevated Intraocular Pressure and Glaucoma

MADRID, July 7, 2010 - Sylentis, a biopharmaceutical subsidiary of Grupo Zeltia (MC: ZEL) and a
pioneer in the research and development of new drugs based on gene silencing
(interference RNA, RNAi), has completed Phase Ia of its first clinical trial
with SYL040012 in the form of ophthalmic drops to treat elevated intraocular
pressure and glaucoma.

This is the first product based on RNAi technology to be
developed clinically in Spain.

The trial received approval from the Spanish Medicines and
Health Products Agency in June 2009, and was conducted by specialists in
pharmacology and ophthalmology at Navarra University Clinic.

The trial's endpoint was to determine the tolerance and safety
of SYL040012 ophthalmic drops; it was administered to 30 healthy volunteers
aged 18 to 33. Patients showed excellent local and systemic tolerance to
SYL040012, leading to very positive trial results. Sylentis plans to commence
a Phase I/II clinical trial in patients with elevated intraocular pressure as
soon as possible.

About SYL040012

In preclinical trials with SYL040012, the siRNAs administered
topically to treat ocular hypertension associated with open angle glaucoma
have proven effective both in vitro and in vivo. In those trials, SYL040012
effectively prevented the increase in intraocular pressure induced in the
ocular hypertension model that was used. Ocular tolerance studies have shown
excellent local and systemic tolerance to the administration of SYL040012 in
much larger doses than required for therapeutic effectiveness.

About Sylentis

Founded in 2006 as a spin-off from Grupo Zeltia subsidiary
Genómica, S.A.U., Sylentis is a subsidiary of Grupo Zeltia and a key player
in the search for new therapies based on interference RNA (RNAi). Its
strategy focuses on the efficient design of siRNAs using proprietary
technology: SIRFINDER(R), which finds small fragments of RNAi (short
interfering RNAs, siRNAs) with pharmaceutical potential by searching the
appropriate sequences using bioinformatics; once the disease's target gene
has been identified, SYLENTIS develops a quick and economical solution for
siRNAs to silence that gene.

About interference RNA (RNAi)

Interference RNA (RNAi) has arisen in recent years as a
promising technology with therapeutic applications. Discovered in plants in
the 1990s, RNAi consists of highly efficient selective and specific
inhibition of gene expression (Fire et al., 1998). Interference RNA is
mediated by small fragments of double-stranded RNA, consisting of 19-23
nucleotides, which promote degradation of mRNA, thus inhibiting synthesis of
the proteins for which they code. As this mechanism is used naturally by
cells to regulate gene expression in a way that is both non-toxic and highly
effective, RNAi has great therapeutic potential.

About open angle glaucoma

Primary open-angle glaucoma (POAG) is the most prevalent form
of glaucoma, accounting for approximately two-thirds of all diagnosed cases
of glaucoma. It is defined as a multifactorial optic neuropathy consisting of
a loss of retinal ganglion cells and characteristic atrophy of the optical
nerve leading to progressive, irreversible blindness. The risk factors of
POAG include high intraocular pressure (IOP), a family history of the
disease, and old age (Marquis and Wilson, 2005). Although the
physiopathological mechanisms by which high pressure leads to neuron damage
are not known, most current therapies seek to reduce IOP to a level that
prevents progressive loss of vision.

For more information, contact Zeltia at +34-91-444-4500.

This note is also available in the "News" section of the
Zeltia (www.zeltia.com) and Sylentis (www.sylentis.com)
websites.

Zeltia, +34-91-444-4500