Demand for Greater Transparency, More Data in Demonstrating Biosimilars' Interchangeability

The Biologics Prescribers Collaborative (BPC), an organization comprising 6 member groups whose memberships prescribe biologic agents, has released its comment letter to the FDA on the agency’s Considerations in Demonstrating Interchangeability With a Reference Product draft guidance.

In its letter, BPC commended the FDA for its care in developing the draft guidance, yet called upon the agency to “promote transparency and patient safety by paying particular attention to the data, including robust clinical switching studies, required to demonstrate interchangeability” as a means by which to build prescribers’ confidence in treating patients with interchangeable biosimilars.

BPC’s comment letter included 5 key requests:

• The FDA should expand its recommendation of a general standard for data to support interchangeability by considering what baseline percentage of an identical response level should constitute a minimum for each condition treated, and biochemical measures be identical.
• Clinical switching studies should include a minimum of 3 switches between the reference product and the proposed interchangeable biosimilar product, and the FDA should both consider standardizing testing procedures and require the use of US-licensed reference products in switching studies.
• Caution should be exercised in granting indication exploration, because when interchangeability is only demonstrated for a single indication, prescribers and pharmacists may find it challenging to protect patient safety and prevent inadvertent substitution.
• Labels should include statements concerning interchangeability of biosimilars with reference products (or with other biosimilars), along with a statement on the indications for which a product has been demonstrated interchangeable.
• Sponsors who seek to develop new presentations for proposed interchangeable products should provide data demonstrating interchangeability for all presentations that they seek to license. Differences in product presentation could impact the ability of clinicians, patients, or caregivers to properly administer products.

Such calls for further studies and a greater burden of evidence are consistent with research showing that US clinicians lack familiarity with and confidence in prescribing biosimilar products, and that they require further data before they will be receptive to the idea of switching to biosimilars from reference products.

While it is unsurprising that provider groups such as BPC would call for greater evidence of the safety and efficacy of biosimilar products, some industry voices point out that more robust studies may cause patients to shoulder an extra burden. Anna Rose Welch of Biosimilar Development noted the increased workload that the BPC’s recommendations would require of patients. “This work won’t just be on companies’ shoulders,” Welch writes. “A lot of this pressure will also be placed on the patient…studies involve lots of blood samplings and can boast higher dropout rates, which suggest this high burden on patients.”