Biosimilars: More Treatment Options Are on the Way

FDA scientist foresees less-expensive therapies as competition grows

The medical marketplace is about to get bigger. The FDA cleared a second biosimilar product—Inflectra (infliximab-dyyb, Janssen Biotech), a biosimilar to Remicade (infliximab, Janssen)—on April 5 and expects to approve other biosimilars in the future. The agency gave the nod to Zarxio (filgrastim-sndz, Sandoz), a biosimilar to Neupogen (filgrastim, Amgen), in March 2015.

Inflectra was approved for the treatment of several conditions, including Crohn’s disease, ulcerative colitis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and plaque psoriasis. The most common expected adverse effects of Inflectra are respiratory infections. These can include sinus infections, sore throat, headache, cough, and stomach pain.

Gene-based and cellular biologics, at the forefront of biomedical research today, may make it possible to treat a variety of medical conditions, including illnesses for which no other treatments are available, according to the FDA.

Biologic products replicate natural substances, such as enzymes, antibodies, or hormones, and can be composed of sugars, proteins, or nucleic acids, or a combination of these substances. They may also be living entities, such as cells and tissues.

“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,” explained Leah Christl, PhD, Associate Director for Therapeutic Biologics at the FDA.

“Biologics come from living organisms that are variable in nature. In addition, they are generally more complex and not as easy to define and characterize,” she said. Because of that, developing biologics is a far more complex process than manufacturing drugs.

Biologic products also differ from conventional drugs in that they tend to be heat-sensitive and susceptible to microbial contamination. This requires sterile processes to be applied from initial manufacturing steps.

“Biosimilars are likely to create greater competition in the medical marketplace,” Christl said. 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 said.

The Patient Protection and Affordable Care Act (PPACA), signed into law in March 2010, amended the Public Health Service Act to create an abbreviated licensure pathway for biologic products that are demonstrated to be “biosimilar to” or “interchangeable with” an FDA-licensed biologic product. This pathway is provided in the part of the PPACA known as the Biologics Price Competition and Innovation Act. Under this act, a biologic product may be demonstrated to be “biosimilar” if data show that, among other things, the product is “highly similar” to an already-approved biologic product.

A biosimilar product is a biologic product that has been approved based on a showing that it is highly similar to an FDA-approved biologic product, known as a reference product, and has no clinically meaningful differences in terms of safety and efficacy from the reference product. Only minor differences in clinically inactive components are allowable in biosimilar products.

An interchangeable biologic product is biosimilar to an FDA-approved reference product and meets additional standards for interchangeability. An interchangeable biologic product may be substituted for the reference product by a pharmacist without the intervention of the health care provider who prescribed the reference product.

The FDA requires licensed biosimilar and interchangeable biologic products to meet the agency’s standards of safety and efficacy.

Sources: FDA; April 7, 2016; and FDA; February 22, 2016.