OPKO Surpasses 50% Enrollment in Second Phase 3 Trial of Rayaldy™

  OPKO Surpasses 50% Enrollment in Second Phase 3 Trial of Rayaldy™

Business Wire

MIAMI -- August 15, 2013

OPKO Health, Inc.(NYSE: OPK), has surpassed 50% enrollment in the second
phase 3 trial ofRayaldy™ to treat patients with secondary hyperparathyroidism
(SHPT), stage 3 or 4 chronic kidney disease (CKD) and vitamin D insufficiency.
This trial is the second of two identical randomized, double-blind, placebo
controlled, multi-site studies intended to establish the safety and efficacy
ofRayaldy™as a new treatment for SHPT in the targeted population. The
endpoints of both studies, which are being conducted in parallel, include
vitamin D status and changes in serum calcium, serum phosphorus and plasma
intact parathyroid hormone (PTH).

Each of the two phase 3 trials will involve 210 patients recruited at
approximately 40 sites in the U.S. These patients are being stratified by CKD
stage and randomized in a 2:1 fashion to receive six months of treatment with
eitherRayaldy™or placebo. Dosing withRayaldy™is titrated, as necessary, to
achieve the desired blood concentration and the targeted reduction in PTH.

“I am pleased to report that these pivotal trials with Rayaldy Capsules are
progressing as planned toward completion in the first half of 2014,” stated
Phillip Frost, M.D., OPKO’s Chairman and Chief Executive Officer. “Top-line
data are expected in mid-2014. We believe Rayaldy™ will prove to be superior
to high monthly doses of prescription vitamin D[2], a common therapeutic
approach which has been shown unreliable in correcting vitamin D insufficiency
in patients with chronic kidney disease and generally ineffective in
controlling elevated levels of parathyroid hormone. We look forward to
advancing the standard of care for this patient population when Rayaldy™ is
ultimately approved for marketing.”

AboutRayaldy™

Rayaldy™is a first-in-class oral vitamin D prohormone treatment being
developed for SHPT in stage 3 and 4 CKD patients with vitamin D insufficiency.
It has a proprietary modified-release formulation designed to gradually and
reliably raise serum total 25-hydroxyvitamin D (prohormone) concentrations to
targeted levels (at least 30 ng/mL) while avoiding upregulation ofCYP24, a
cytochrome P-450 enzyme that reduces the PTH lowering potency of current
vitamin D supplements. Activation of the product by the kidney is tightly
regulated, preventing excessive elevation of serum calcium and related side
effects which encumber current vitamin D hormone therapies and promote
vascular and renal calcification. Once approved,Rayaldy™will address the
approximately 4 million CKD stage 3 and 4 patients in the U.S. and many more,
elsewhere, with SHPT and vitamin D insufficiency.

About Chronic Kidney Disease

CKD is a condition characterized by a progressive decline in kidney function.
The kidney is normally responsible for excreting waste and excess water from
the body, and for regulating various hormones. CKD is classified in five
different stages — mild (stage 1) to severe (stage 5) disease — as measured by
the kidney's glomerular filtration rate. According to theNational Kidney
Foundation, CKD afflicts over 26 million people in the U.S., including more
than eight million patients with moderate (stages 3 and 4) and severe (stage
5) forms of CKD. In stage 5 CKD, kidney function is minimal to absent and
patients require regular dialysis or a kidney transplant for survival.

About Vitamin D Insufficiency

Vitamin D insufficiency is a condition in which the body has low vitamin D
stores, characterized by inadequate blood levels of vitamin D prohormones,
collectively known as 25-hydroxyvitamin D. An estimated 70-90% of CKD patients
have vitamin D insufficiency, which can lead to SHPT and resultant
debilitating bone diseases.

About Secondary Hyperparathyroidism (SHPT)

SHPT is a condition commonly associated with CKD in which the parathyroid
glands secrete excessive amounts of PTH. SHPT arises as a result of vitamin D
insufficiency or impaired kidney function that prevents sufficient production
of vitamin D hormones to properly regulate calcium and phosphorus metabolism,
and PTH secretion. Prolonged elevation of blood PTH causes excessive calcium
and phosphorus to be released from bone, leading to elevated serum calcium and
phosphorus, softening of the bones (osteomalacia) and calcification of
vascular and renal tissues. SHPT affects about 40-60% of patients with
moderate CKD and approximately 90% of patients with severe CKD.

AboutOPKO Health, Inc.

OPKO is a multi-national biopharmaceutical and diagnostics company that seeks
to establish industry-leading positions in large and rapidly growing medical
markets by leveraging our discovery, development and commercialization
expertise and our novel and proprietary technologies.

This press release contains "forward-looking statements," as that term is
defined under the Private Securities Litigation Reform Act of 1995 (PSLRA),
regarding product development efforts and other non-historical facts about our
expectations, beliefs or intentions regarding our business, technologies and
products, financial condition, strategies or prospects. Many factors could
cause our actual activities or results to differ materially from the
activities and results anticipated in forward-looking statements. These
factors include those described in our filings with theSecurities and
Exchange Commission, as well as risks inherent in funding, developing and
obtaining regulatory approvals of new, commercially-viable and competitive
products and treatments, including the risks that enrollment of patients for
the Phase 3 clinical trials for Rayaldy™may not be completed by the second
half of 2013 or at all, that top-line data may not be available by mid-2014,
that the Phase 3 clinical trials for Rayaldy™ may not be successful or achieve
the expected results or effectiveness, and may not generate data that would
support the approval or marketing of this product for the indications being
studied, that others may develop products which are superior to Rayaldy™, and
that Rayaldy™may not have advantages or prove to be superior over presently
marketed products, including the currently used high monthly doses of
prescription vitamin D[2, ]activated vitamin D hormone and over-the-counter
vitamin D supplements . In addition, forward-looking statements may also be
adversely affected by general market factors, competitive product development,
product availability, federal and state regulations and legislation, the
regulatory process for new products and indications, manufacturing issues that
may arise, patent positions and litigation, among other factors. The
forward-looking statements contained in this press release speak only as of
the date the statements were made and we do not undertake any obligation to
update forward-looking statements. We intend that all forward-looking
statements be subject to the safe-harbor provisions of the PSLRA.

Contact:

OPKO Health, Inc.
Steven D. RubinorJuan F. Rodriguez, 305-575-4100