Genzyme Corp. has announced that it has filed with the U.S. Food and Drug Administration (FDA) for approval of Synvisc-One, the single treatment of Synvisc (hylan G-F 20) that provides up to six months of pain relief from osteoarthritis (OA) of the knee.
If approved, Synvisc-One would be the only viscosupplementation product available worldwide proven to provide this duration of pain relief from a single injection. Genzyme believes this product line extension of Synvisc can simplify OA knee pain management and reduce the overall cost of therapy. The company expects the FDA to take action on this submission by the end of the year.
"The submission for approval of Synvisc-One is based on positive data which demonstrated that combining three doses of Synvisc in a single treatment is safe and effective in providing pain relief for up to six months in patients with knee osteoarthritis," stated Ann Merrifield, president of Genzyme Biosurgery, the business unit of Genzyme Corp. that manufactures and markets Synvisc. "We strongly believe that delivering the benefits of Synvisc through one treatment rather than three will provide additional options for physicians and their patients to reduce the cost and burden of multiple injections."
Synvisc is currently delivered through three intra-articular administrations of two milliliters each given at one-week intervals. Synvisc- One is delivered as three combined doses in one single six milliliter administration.
Genzyme's product marketing authorization (PMA) for Synvisc-One is based on final data from a prospective, randomized, double-blind, placebo-controlled study that involved 253 patients at 21 sites across Europe. Data from the study were presented last week at the European League Against Rheumatism annual meeting in Barcelona, Spain. Submission of these data to obtain a CE mark for Synvisc-One in Europe is expected to occur next month.
"Synvisc-One has been shown to be effective in providing long-term pain relief with the convenience of a single treatment without the systemic safety risks associated with traditional OA therapies such as NSAIDs and COX2 inhibitors." stated Xavier Chevalier, M.D., professor of rheumatology, Hopital Henri Mondor, Creteil, France. "The data show that Synvisc-One demonstrated a sustained response rate up to six months and an excellent safety profile in first and repeat courses. This is a unique opportunity for physicians to treat patients with a single injection viscosupplement which offers a very good risk-benefit profile."
The only other single treatment viscosupplement available in Europe offers only six weeks of pain relief.
Synvisc-One Study Findings
Patients in the study were randomized to receive one six-milliliter treatment of Synvisc or one six-milliliter injection of placebo (saline). In the primary endpoint, patients were evaluated over six months according to the WOMAC A scale, a validated and commonly used measurement of osteoarthritis pain. These data resulted in statistically significant improvement in pain from osteoarthritis of the knee over 26 weeks when compared to pain relief for patients receiving placebo treatment. Data from the study also show that Synvisc-One demonstrated a 36 percent reduction in pain over 26 weeks as compared to baseline.
The statistically significant findings of the primary endpoint were supported by a number of secondary outcomes, most notably a statistically significant treatment effect in favor of Synvisc-One in assessments completed by patients and their physicians of the severity of knee osteoarthritis symptoms. Both patients and physicians completing these assessments were blinded, meaning that they were unaware of whether the patient had received Synvisc-One or placebo.
In addition to the treatment advantage seen in the Synvisc-One group, data showed comparable safety information between the treatment and placebo arms. Eight patients (6.5%) in the Synvisc-One group and six patients (4.6%) in the placebo group experienced procedure or study treatment related AEs following initial treatment. Four patients (3.3%) in the Synvisc-One group and two patients (1.5%) in the placebo group experienced mild to moderate adverse events determined to be related to the study treatment in the first course, and one patient (1.3%) experienced target knee adverse events determined to be related to the study treatment in the repeat course.
Synvisc continues to be the market-leading viscosupplementation product in the U.S. It is marketed in more than 60 countries and has been used to treat more than 3 million people worldwide.
These new Synvisc-One data add to the growing clinical evidence that further supports the use of Synvisc in treating OA knee pain. Results announced last year from an independent investigator's clinical study found Synvisc to be superior in magnitude and duration of pain relief, functional improvement and patient satisfaction to another viscosupplementation product in treating patients with OA of the knee. These independent data were presented at several meetings throughout Europe and the U.S., and are expected to be submitted for publication.
In addition to its efficacy in relieving osteoarthritis knee pain, Synvisc, as a non-systemic treatment, has the advantage of avoiding some of the side effects associated with some non-steroidal anti-inflammatory drugs including the COX-2 inhibitors, and may be beneficial in wider patient care.
Synvisc is indicated for the treatment of pain due to osteoarthritis (OA) of the knee in patients who have failed to respond adequately to conservative nonpharmacologic therapy and simple analgesics, for example, acetaminophen. Synvisc is currently approved in Europe and Canada to treat pain due to osteoarthritis in the knee and hip, and also approved in Europe for the ankle and shoulder indications.
In clinical trials, the most commonly reported adverse events were transient local pain, swelling, and/or effusion in the injected knee. In some cases, these symptoms have been extensive. Other side effects such as rash have been reported rarely. Synvisc is contraindicated in patients with known hypersensitivity to hyaluronan products or patients with infections in or around the knee. Healthcare practitioners should exercise caution when using Synvisc in patients allergic to avian proteins, feathers, or egg products; who have evidence of venous or lymphatic stasis in the leg to be treated; or who have severe inflammation in the knee joint to be treated. Patients should be advised to avoid strenuous or prolonged weight-bearing activities after treatment. Strict adherence to aseptic technique must be followed to avoid joint infection. The safety and effectiveness of Synvisc in children and in pregnant or lactating women have not been established. It is unknown whether Synvisc is excreted in human milk.