On March 6, 2015, FDA approved the first biosimilar under the Biologics Price Competition and Innovation Act (BPCIA), Sandoz's Zarxio®. Sandoz submitted Zarxio® as a highly similar, not interchangeable biosimilar, for the same indications as the referenced product. The BPCIA was signed into law in March 2010.

FDA designated "filigrastim-sndz" as the placeholder nonproprietary name rather than the innovator's name, filigrastim. FDA said that this nonproprietary name "should not be viewed as reflective of the agency's decision on a comprehensive naming policy for biosimilar and other biological products. While the FDA has not yet issued draft guidance on how current and future biological [biosimilar?] products marketed in the United States should be named, the agency intends to do so in the near future."

Accompanying the news release was a document "Biosimilars: More Treatment Options Are on the Way". The document includes various quotes and paraphrased statements by Leah Christl, Ph.D., Associate Director for Therapeutic Biologics, to help describe to consumers what biosimilar medications are. Below are some quotes and information from that document:

Biologics are medicines that generally come from living organisms, which can include humans, animals and microorganisms such as yeast and bacteria.

. . .

"Biologics are different from conventional medications. Conventional medications—drugs—are generally made from chemicals, or chemically synthesized, and therefore their structure can be relatively easily defined," explains Christl.

Unlike conventional medications, biologics can't be made by following a chemical "recipe." "Biologics come from living organisms which are variable in nature. In addition, they are generally more complex and not as easy to define and characterize," Christl explains. For that reason, manufacturing biologics is a far more complex process than manufacturing drugs.

Just as it does for drugs, FDA rigorously and thoroughly evaluates a biologic's safety and effectiveness before granting it licensure (approval). Currently, biologics are among the fastest growing segments of the prescription product market.

. . .

Christl explains that a biosimilar is a type of biologic that is highly similar to another, already FDA-approved biologic (known as the reference product).

"It is important to note that a biosimilar is not just like a generic drug," she adds. "Because of the differences in complexity of the structure of the biologic and the process used to make a biologic, biosimilars are not as easy to produce as generics, which are copies of brand name drugs." A biosimilar is not an exact duplicate of another biologic; rather, a biosimilar is highly similar to the reference product.

Before approving a biosimilar, FDA experts must also first verify that there are no clinically meaningful differences between the biosimilar and its reference product. In other words, it will work the same way as the reference product for its approved indications.

Also, the biosimilar must have the same strength and dosage form (injectable, for example) and route of administration as the reference product. The biosimilar must be manufactured following Current Good Manufacturing Practices.

"Patients can rest assured that they'll be able to rely upon the safety and effectiveness of an FDA-approved biosimilar, just as they can rely on the reference product that the biosimilar was compared to," Christl says. Like other biologics, biosimilars generally must be prescribed by a physician.

. . .

"Biosimilars are likely to create greater competition in the medical marketplace," says Christl. This could not only increase treatment options for patients, but also lead to less expensive alternatives to comparable products. With an increasing number of biosimilars on the market, consumers may expect to get equally safe and effective treatment, but at lower costs, she says.

Despite the significant achievement for FDA to approve the first biosimilar under the BPCIA, significant questions other than nonproprietary naming remain. First, Sandoz chose not to take advantage of the pre-approval patent exchange mechanism of the BPCIA, which could have addressed possible patent challenges that may prevent Sandoz from marketing Zarxio® until certain patents are invalidated, are found unenforceable, or have expired. Second, because this and other non-interchangeable versions of biosimilars are not expected to have automatic substitution based on the BPCIA, it remains unclear how ready physicians or patients will be to try a biosimilar version over its referenced product. Third, company representatives from Sandoz and other biosimilar manufacturers have not indicated at what price their biosimilar products will be sold, at times suggesting "at parity," which may cause reimbursement issues. Fourth, many states have enacted rules that include special physician notification provisions, even when interchangeable biosimilars are dispensed to patients. And there are still issues surrounding pharmacovigilance and risk management when there are innovator and corresponding biosimilar versions marketed. Nevertheless, FDA proclaims that more biosimilars are on the way, as additional companies have indicated that they have submitted or FDA has filed their biosimilar applications. Sandoz's Zarxio® then is just the tip of the iceberg of what is coming with more issues to be resolved along the way.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.