Sanofi US News

First Pilot Study to Show Benefit Using Hyalgan® (sodium hyaluronate) in the Treatment of Osteoarthritis of the Ankle
Washington, D.C.
February 24, 2005
Positive results of Northern California Foot and Ankle Center study presented at the American Academy of Orthopaedic Surgeons 2005 Annual Meeting in Washington DC.

Sanofi-Synthelabo Inc., a member of the sanofi-aventis Group (NYSE: SNY), announced today results of a randomized, double-blind, placebo controlled trial evaluating the safety and efficacy of Hyalgan® (sodium hyaluronate) versus saline, in the treatment of osteoarthritis (OA) of the ankle.  The data from this pilot study were presented at the American Academy of Orthopaedic Surgeons 2005 Annual Meeting and suggested that five weekly intraarticular (IA) injections of HYALGAN provide sustained relief of pain and improved ankle function in patients suffering from OA of the ankle(1).

The trial, Use of Sodium Hyaluronate in Treating Osteoarthritis of the Ankle, conducted as an investigator initiated study by researchers from the Northern California Foot and Ankle Center in San Francisco and Santa Rosa, CA, showed a statistically significant time effect in mean Ankle Osteoarthritis Scale (AOS) scores (p<0.001) in both the HYALGAN and saline group.  Researchers also reported that 55.6% of the patients treated with HYALGAN had a clinically significant (>30 mm) improvement in their visual analog scales (VAS) scores compared to a 12.5% improvement in the saline group(1).

The Northern California Foot and Ankle Center trial is the first controlled study to show a benefit with HYALGAN in treatment of OA of the ankle and is consistent with previously published studies using HYALGAN in the knee.

“This is important information for patients that suffer from OA of the ankle,” said Dr. Robert Salk, Northern California Foot and Ankle Center, San Francisco, CA, “As surgery to treat OA of the ankle is often quite painful, HYALGAN may offer patients, who may not have had success with traditional pain medications, another option to treat their OA.  This study is encouraging as it continues to build on the existing data suggesting benefits from the use of Hyalgan in other joints.”


About the study
The pilot study was designed to determine the effects of Hyalgan® (sodium hyaluronate) versus saline (phosphate buffered saline, PBS) for osteoarthritis of the ankle.  Twenty patients were randomized at two test sites using a double-blind, saline-controlled experimental design. Treatment was one weekly, intraarticular administration of either 1 ml of HYALGAN or 1 ml of PBS for five injections(1).

The patients were selected on the basis of two criteria.  The first, confirmed diagnosis of ankle degenerative joint disease (DJD), stage II-IV by Kellgren-Lawrence classification.  The second criteria,  significant pain and disability as described by visual analog scales (VAS), a common system used to measure a patient’s pain . The primary outcome measurement was the Ankle Osteoarthritis Scale (AOS), a self-assessment instrument that specifically measures patient symptoms and disabilities related to ankle arthritis.  The injections were well-tolerated by patients in both groups(1).


About Osteoarthritis
A reported 21 million Americans are affected by osteoarthritis(2), a degenerative disease that affects the joints.  Osteoarthritis of the ankle is one of the more common forms of OA affecting the joints of the foot.  Often it can affect both a person’s balance and walk(3).



HYALGAN is indicated for the treatment of pain in osteoarthritis (OA) of the knee in patients who have failed to respond adequately to conservative nonpharmacologic therapy, and to simple analgesics, eg, acetaminophen.  HYALGAN is contraindicated in patients with known hypersensitivity to hyaluronate preparations.  Intra-articular injections are contraindicated in cases of past and present infections or skin diseases in the area of the injection site.

A HYALGAN treatment cycle consists of 5 injections given at weekly intervals by a doctor.  Some patients may experience benefit with 3 injections given at weekly intervals; this benefit has been noted in studies reported in the literature in which patients treated with 3 injections were followed for 60 days.  The effectiveness of a single treatment cycle of less than 3 injections has not been established.

In the US clinical trial of 495 patients, the only adverse event showing statistical significance vs. placebo was injection-site pain.

Other adverse events included gastrointestinal complaints, headache, local ecchymosis and rash, local joint pain and swelling, and local pruritus.  However, the incidence of these events was similar in the HYALGAN and placebo groups.

In other clinical studies, the frequency and severity of adverse events occurring during repeat treatment cycles did not increase over that reported for a single treatment cycle. 


About sanofi-aventis

The sanofi-aventis Group is the world’s 3rd largest pharmaceutical company, ranking number 1 in Europe.   Backed by a world-class R&D organization, sanofi-aventis is developing leading positions in seven major therapeutic areas: cardiovascular disease, thrombosis, oncology, diabetes, central nervous system, internal medicine, and  vaccines. Sanofi-Aventis is listed in Paris (EURONEXT : SAN) and in New York (NYSE : SNY).

The sanofi-aventis Group conducts business in the U.S. through its affiliates Sanofi-Synthelabo Inc. and Aventis Pharmaceuticals Inc.

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