The Food and Drug Administration expects to issue its guidance on biosimilars by the end of 2011, more than a year after legislation designed to make cheaper generic versions of therapeutic biologics available was incorporated into the Patient Protection and Affordable Care Act of 2010.
A year earlier, the Biologics Price Competition and Innovation Act of 2009 (BPCI) established an abbreviated approval pathway for biological products that are shown to be "highly similar" or "biosimilar" to, or "interchangeable" with, an FDA-approved biological product, according to the FDA’s summary of the legislation.
The complex issues related to its implementation are still being worked out by a special committee at the agency, which met in November 2010 to discuss the issues and challenges of implementing the BPCI Act. Manufacturers of biologic therapeutics, generic pharmaceutical companies, patient groups, and other interested parties provided their input at that meeting.
An FDA spokesperson noted that the agency "continues to carefully review and consider all comments from the November 2010 hearing and from the docket as we move forward in our implementation" of the statute. Biosimilars are also referred to as "follow-on biologics."
Of the major biologics, etanercept (Enbrel) will be the first to lose its patent, in 2012.
Dr. Steven Kozlowski, director of the FDA’s Office of Biotechnology Products, and other FDA officials noted that access to expensive biologic therapies "may be limited, not infrequently because of their cost" and emphasized the challenges the agency faced in implementing the act in a "Perspective" article published online on Aug. 4 in the New England Journal of Medicine (2011;365:385-8.)
The coauthors of the article, titled "Developing the Nation's Biosimilar Program," were Dr. Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research; Dr. Karen Midthun, director of the Center for Biologics Evaluation and Research; and Dr. Rachel Behrman Sherman, director of the Office of Medical Policy.
"Reconciling the science of biosimilar development with the new regulatory framework required by the BPCI Act presents the FDA with numerous challenges," primarily, establishing scientific criteria "that address the key question: how similar is similar enough when it comes to the substitution of complex biologic drug products in clinical practice?" They cited immunogenicity as "a critical factor" when evaluating biosimilars, and noted that product-specific safety monitoring should be included in the process.
For now, it remains difficult to predict when these more affordable generic formulations of the expensive biologic treatments for rheumatoid arthritis and other inflammatory diseases will become available.
A spokesperson for the Generic Pharmaceutical Association (GPhA) said that the legislation left a lot to the FDA’s discretion. FDA’s regulations must not be burdensome and should not create barriers to making these products available, he said. "Ultimately, we want patients to have access to these drugs at affordable prices." A representative of the GPhA made a presentation at the November 2010 meeting and submitted formal comments to the docket in December.
The Importance of Cheaper, Reliable Biologics
In an interview, Dr. Karen S. Kolba, chair of the American College of Rheumatology’s committee on rheumatologic care, said that the issue of more affordable generic biologics is as critical as ever for rheumatologists. It is important that cheaper versions of these products, with reliable clinical effects and acceptable safety profiles, become available for patients with rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis, she said. Many patients who could benefit from these products do not receive them because of their cost, a problem in the United States and worldwide, noted Dr. Kolba, a rheumatologist in private practice in Santa Maria, Calif.
While these products are not without risks, she said, with such huge profit margins at stake, "there’s no reason it can’t be done in a safe responsible way."
Currently, Medicare covers the costs of infliximab (Remicade), rituximab (Rituxan), and tocilizumab (Actemra) under Part B, because they are administered as infusions in the office. But just because they are covered does not make the high cost of these drugs acceptable, she said. Her patients who self-administered adalimumab (Humira) or etanercept (Enbrel) must still pay copayments that are high even when the patients qualify for company assistance programs. These patients also would benefit from cheaper versions.
An example of the perspective of the biologic manufacturers is provided in a statement on biosimilars on the Genentech website, which states that Genentech, a member of the Roche group, which manufactures rituximab and other biologics, believes that indication-specific clinical trials should be used to establish every indication for a biosimilar to ensure the product’s safety and efficacy. In addition, "biosimilars should only be substituted for an innovator biologic if comparative clinical trials demonstrate that substitution is appropriate," and that they should be "uniquely identified and should be traceable to ensure patient safety."