Common Ground on Biosimilar Coding

Despite FDA approval of seven biosimilars through October 2017, only three have come to market due to heated patent disputes and continued debate over biosimilar naming and interchangeability. Innovators maintain the need for distinct names to facilitate postmarket identification and tracking of safety issues for brand vs. follow-on therapies and continue to question the adequacy of limited clinical testing to assess immunogenicity.

The result is lingering concerns in the medical community about the safety of switching patients to new therapies. Biosimilars in the U.S. have experienced limited uptake, prompting FDA to launch an educational and outreach campaign to encourage prescribing and health plan coverage of these therapies, as recently described by FDA commissioner Scott Gottlieb.

So it’s somewhat of a surprise that all sides recently applauded a new final rule from the Centers for Medicare and Medicaid Services (CMS) that assigns separate healthcare product codes for biosimilars covered under Medicare Part B. This reverses the current policy that put biosimilars to the same reference product under the same Healthcare Common Procedure Coding System (HCPCS) code, which places common biosimilars together for calculating reimbursement rates.

The Biosimilars Council, which represents biosimilar makers, praised the CMS decision, citing an analysis that separate codes would save the federal government $11.4 billion over the next ten years. And the Biosimilars Forum backed by innovator firms stated that  unique codes for biosimilars will support development of “a thriving biosimilars market in the U.S.” It may take years to see how the policy change actually affects prices and payments in the market, as analysts anticipate that a unique code for each approved biosimilar may initially limit competition among multiple therapies. But the experts predict that over time this approach will encourage more manufacturers to develop follow-on products, which will generate more market competition that lowers prices overall.

Statistical pitfall

Meanwhile, biosimilar sponsors have applauded FDA’s “step-wise” approach for developing these products and its emphasis on relying on the assessment of analytical similarity through biological and physiochemical product characterization, which reduces the need for extensive clinical trials. Yet there’s now some push-back from manufacturers to a much-anticipated new statistical analysis guidance that further describes a risk-based approach for evaluating that a biosimilar is “highly similar” and has no “clinically meaningful differences” to the reference product. The draft guidance outlines how to develop an analytical similarity assessment plan for determining the quality attributes most critical in characterizing the structural and functional properties of the reference product and for evaluating these attributes based on potential impact on clinical performance.

But Martin Schiestl, chief science officer at Novartis’ Sandoz, raised concerns at the Biosimilars Conference sponsored by the  Drug Information Association (DIA) in October that FDA’s approach creates “a substantial pitfall” for biosimilar developers that could lead regulators to reject true biosimilars at random. Schiestl specifically challenged FDA’s recommendation for  assessing key quality attributes through statistical comparison to a pre-set mean for the reference product. FDA staffers responded that failure to meet pre-defined acceptance criteria on a statistical test does not necessarily preclude a determination of “highly similar.” The agency will review comments on the guidance, which are due in November, and work with industry to reach consensus on a viable approach.