ISOPP Releases Position on Biosimilars, Voices Opposition to Treating Biosimilars as Interchangeable

The International Society of Oncology Pharmacy Practitioners (ISOPP), which convened in London, United Kingdom, this week for its 18th international symposium on oncology pharmacy practice, has issued a new global position statement on biosimilars in therapeutic and supportive oncology.

The position indicates that switching from reference drugs to biosimilars—within institutions or for individual patients—is acceptable and even encouraged. However, it takes a clear stand against considering biosimilars as interchangeable with their references, and says that biosimilars should not be automatically substituted (pharmacy-level substitution is a practice that is currently permitted by law in the United States for eventual interchangeable biosimilars, in Australia for “a-flagged” biosimilars, and in France for products in the same therapeutic group).

The position comes at a time when stakeholders worldwide have been calling for regulators to recognize the interchangeability of biosimilars, arguing that interchangeability should be understood as a scientific concept, and attempting to disabuse stakeholders of the idea that an FDA designation of interchangeability denotes a higher standard of quality.

Notably, the position reflects the language of US law, stating that interchangeable products must demonstrate that the same clinical results can be expected in “any given patient,” and says that “Currently, the only regulatory agency with the facility to assign an ‘interchangeable’ designation to a biosimilar is the FDA.” It claims that, “Given the possible risks associated with transitioning between biotherapeutic products and the absence of an interchangeability designation, automatic substitution with biosimilars is discouraged.”

The position also makes a distinction between multiple biosimilars of the same reference, saying that biosimilars should not be considered equivalent to one another.

Among less controversial statements in the position are those that state that biosimilars licensed by internationally recognized regulators, like the European Medicines Agency, World Health Organization, or FDA, should be considered therapeutically equivalent to their reference products, but copy biologics that do not meet stringent approval criteria should not be used.

The position also states that the extrapolation of all indications is appropriate provided that the totality of the evidence supports extrapolation. Inactive components of biosimilars should be considered insofar as they can impact tolerability, sensitivity, or immunogenicity, and ongoing patient-outcome monitoring and pharmacovigilance will help with the collection of real-world evidence.

With respect to institutional considerations, where financial barriers or other issues—such as established subcutaneous administration of reference drugs like trastuzumab or rituximab—prevent full implementation of biosimilars, partial implementation may be desirable. Using best practice guidelines on labeling and storage will help to reduce selection error, and the statement recommends that, where no guidelines exist, pharmacists use the brand name or US 4-letter biosimilar suffix in patients’ medical records. Multidisciplinary teams should guide the institutional use of biosimilars, and both medical staff and patients should be educated with evidence-based resources. Finally, cost savings should be used to keep patients’ costs manageable and to stabilize institutional budgets.

The position was created by ISOPP task force members representing the United States, United Kingdom, Canada, Australia, Japan, Brazil, and other nations.