How much power does the Centers for Medicare & Medicaid Services (CMS; Baltimore) have? Exactly how much influence does it have in determining the success or failure of a medical product?

Those looking for answers to these questions might consider the sales and general uptake of the Charité lumbar artificial disc over the next year or so.

CMS has just issued a decision memo stating a proposed national non-coverage determination for the Charité , produced by the DePuy Spine (Raynham, Massachusetts) unit of Johnson & Johnson (J&J; New Brunswick, New Jersey), and the first and only such artificial disc approved thus far by the FDA for commercialization in the U.S.

That approval came in 2004, with generally optimistic predictions that its entrance to this orthopedic space would provide a broad new benefit to those suffering back pain, as well as new opportunities for the other companies positioning to receive similar approvals.

What then will be the result of a final non-coverage decision?

As basis for its proposed ruling, CMS said it has determined that “the evidence is not adequate to conclude that lumbar artificial disc replacement with the Charité lumbar artificial disc is reasonable and necessary.“ And it supports this statement with 20 pages of accompanying documentation raising a variety of issues concerning the Charité , specifically for its Medicare population of older patients but also perhaps for use in general.

In developing its decision, CMS said it received 138 public comments from a wide range of sources – “the vast majority“ from orthopedic surgeons and neurosurgeons – and it said that “the majority“ of these comments said the coverage request should be denied. Comments from five professional societies emphasized the lack of scientific support for Medicare coverage, but some expressed concerns that non-coverage could retard advancement of the technology.

Using its standard protocol before issuing a final determination, CMS is inviting public comments on its decision over a 30-day period, saying it is “particularly interested in comments that include evidence we did not review or that assess how we evaluated the evidence included.“ A final determination is to be issued 60 days further out.

In its “Conclusions“ section of the memo, the agency says: “Important questions about the Charité lumbar artificial disc remain, [primarily] issues of patient selection, adverse events, and long-term outcomes.“

And in reference to the Medicare population, it states: “Very few patients over the age of 65 have been treated with the Charité disc technology. Therefore, there is insufficient evidence for those over age 65 to determine net health benefit, with the suggestion that the Charité disc is not indicated in this population for a variety of reasons.“

And the conclusions point specifically to the “premarket approval noninferiority trial“ for the Charité, saying that its results “are unconvincing as a demonstration of net health benefit.“

Commenting on the CMS statement, market analyst Lawrence Biegelsen of Prudential Financial (New York) issued a report saying that it makes “the reimbursement environment even more difficult“ for the Charité , given the tendency of private payers to follow the agency's lead.

“We estimate U.S. sales of Charité were about $35 [million] in '05 and we forecast $66 [million] in '06 which may be difficult for J&J to achieve as a result of the CMS statement.“ He did not, however, see this as impacting per-share earnings for J&J.

While the memo purportedly is deciding about the uses of the Charité for the Medicare population, often disabled as well as older, it does lay out a broad variety of issues concerning this device that some – payers especially – are likely to generalize to all of those targeted for implants of the disc.

Focusing on the dearth of information concerning the Charité , the memo frequently notes limitations to the various studies of the product.

It cites a review of cases in 2003 that notes “good“ or “excellent“ results from the implant ranging from 50% to 81%, but that the numbers “were difficult to interpret as there was no comparison group and no standardized method of reporting to compare study outcomes.“ And it says that “various complications were observed in 3[%]-50% of patients.“

It adds: “The disc has been promoted as an alternative to fusion; yet, even in these short-term studies, spontaneous and surgical fusion occurred. As the disc will be required to function for many years, important information about longer term benefits and risks, such as satisfaction, adjacent segment problems, and rate of re-operations, could not be answered by these earlier studies.“

The memo also refers to the randomized controlled trial supporting the company's premarket application for FDA approval, noting once again that data from that study offers only 24 months of experience, which it categories as “short term“ and thus not providing evaluation for the many years of use that the disc must withstand.

It also questions the validity of the control group, a comparison group using Bagby and Kuslich (BAK) cages.

These, it says, “may not be the current favored surgical fusion method, as other cages and techniques have shown a higher success rate and better ODI and VAS scores than either group in the Charité clinical study.

“What implications this has for health benefits in the context of a noninferiority trial is not clear, where the Charité disc has been shown to be noninferior to a device that has fallen out of favor in the clinical community due to unsatisfactory outcomes.“

Further, the memo says, “The short-term adverse event data from the Charité randomized controlled trial are not easy to interpret.“

Some adverse events reported, it says, may need additional treatment “and may not easily resolve“; some patients may have “more than one adverse event, a circumstance which is not differentiated in the reporting“; and “there is a distinction between device-related complications and approach-related complications, which may not reflect the overall risk for the procedure.“

And it says that “the adverse effects noted in the analysis by the FDA are of potential concern.“

The memo pays considerable attention to a study by van Ooij, which points to a series of issues making assessment of the product and procedure difficult: weakness of analogies made to hip and knee prostheses because of the “multidimensional motion of the spine“; questions concerning the shock-absorbing function of an artificial disc; lack of long-term understanding of the biomaterials used in the region of the spine; the effect of “spinal implant debris on local and systemic tissues“; and the risks of the anterior approach used in disc placement and revision replacement.

The memo concludes, however, with a large ray of hope for both the Charité and the other discs likely to be coming on board in the near term.

It acknowledges the presence of these other products and the many clinical trials being carried out to support them, and it promises that CMS “by external request or internal direction,“ will reconsider its decision “with a thorough review of the evidence for each new disc implant.“