When it comes to taking a shot in the knee joint to reduce the pain of osteoarthritis (OA), who wouldn't opt for one over three or more injections? Now that the FDA has granted marketing approval for Genzyme's (Cambridge, Massachusetts) Synvisc-One (hylan G-F 20), patients have that choice.

Synvisc-One, so far the only single-injection visco supplement approved for the treatment of OA knee pain in the U.S., will likely pump up Genzyme's market share, which stands at about 40%.

"I see our competitors circling the booth here and they are taking great interest," Dan Deardorf, vice president, orthopedic marketing for Genzyme Biosurgery, told Medical Device Daily from the American Academy of Orthopaedic Surgeons annual meeting in Las Vegas this week. "We think the bigger gain is growing the market to a broader set of patients, but we'll take some increased share of the market too."

Even if the healthcare practitioner who delivers the injections has a light touch and the injection is painless, the opportunity to avoid three or more consecutive weekly trips for the knee therapy is sure to gain broad appeal.

Synvisc-One is the same formulation as the original three-injection variety, but has been combined into a larger, 6mL dose. Viscosupplementation therapy is the injection of hyaluronic acid or a derivative such as Synvisc's hylan G-F 20 into the knee joint to replace synovial fluid that degrades in with osteoarthritis. The hyaluronic acid relieves pain and improves the knee joint's natural shock absorbing abilities for an estimated six months.

"It's the same indication, but we know that there are a lot of times when physicians choose not to offer this therapy because of the logistics of three sessions," Deardorf said. "They may choose steroids as a one-injection modality. So now we think we'll pick up those patients. We also know there are a lot of patients who are busier, younger and can't take three weeks in a row to visit their doctors. We think it will be used earlier in the treatment algorithm because it's much easier to get. For the first time, we can offer six months of pain relief with one simple intervention. We think this will revolutionize treatment of osteoarthritis knee pain."

Synvisc-One will be priced exactly as Synvisc, in the neighborhood of $700, but the company is being asked by the Centers for Medicare & Medicaid Services (CMS) to revisit the coding application process.

"We've been in communication with CMS and they informed us they want us to use a miscellaneous code and we have to go through the coding application process," Deardorf said. "So, for all of 2009, we may have to use the miscellaneous code J3490. We've built a lot of support systems, with a reimbursement hotline to support physicians."

Genzyme is planning, at least in the short term, to continue offering the original Synvisc.

"We'll keep it," Deardorf said. "We think physician-patient choice is important. It's conceivable that patients who previously got it may want to get the same thing. But from a patient's and physician's perspective, the market will likely move to Synvisc-One."

One shot vs. three may seem like a no-brainer, but there was a small hurdle last year when it was reviewed by the FDA. He said the FDA reviewer had a "sticking point" related to the study data, specifically the statistical significance of the endpoint and whether or not it was clinically meaningful (MDD, Dec. 11, 2008).

So the company took the unusual step of requesting that an advisory panel review the PMA supplement.

"We requested that, which is not normal," he said. "But it's an option that's available to industry manufacturers. We had that one particular sticking point and we went to a panel in order to try and get a set of outside experts to opine on what the data meant."

The outcome was a unanimous vote in favor of approval.

Deardorf said Genzyme will start delivering product by early in the second quarter.

Synvisc-One already is approved in the European Union with a CE mark and in several Asian and Latin American countries. Genzyme reports that 10,000 patients have been treated with Synvisc-One since it was first approved in Europe in 2007.

"You can look at this from a simplistic standpoint: We took three doses and stuffed them into one, but we've also done rigorous studies to prove it's just as effective," he said. "We believe it's truly innovative and will be a big win for patients."