Q&A: Dr Kimberly Maxfield Explains How BsUFA III Will Advance the US Biosimilar Industry

Kimberly Maxfield, PhD

Image credit: Whitehurst Lab at UT Southwestern

At the Academy of Managed Care Pharmacy (AMCP)’s annual Nexus meeting, The Center for Biosimilars^® (CFB) spoke with Kimberly Maxfield, PhD, pharmacologist at the FDA, who clarified some of the major policy changes expected to impact the US biosimilar industry over the next few years and commented on how international policies could influence FDA policy decisions moving forward.

Within the FDA, Maxfield serves as the scientific lead on the Biosimilar User Fee Act (BsUFA) III in the FDA's Office of Therapeutic Biologics and Biosimilars.

CFB: What do you wish more people understood about what the FDA is doing to uplift the US biosimilar industry?

Maxfield: The biosimilar lifecycle includes many pieces of the health care market and industry. We have the development, we have the marketing, we have the formulary access, we have the clinician comfort. The FDA has purview in sort of that lifecycle, at the development phase, and in that education phase.

The regulatory science program is very focused on the time and cost of licensure, so it's very focused on the actual development program, the data package that's submitted as part of a 351(k) application.

However, the FDA is also doing a lot of educational efforts that are targeting patients, that are targeting providers, that are targeting pharmacists to inform them about what a biosimilar is and how it is different from a generic; that's just to increase comfort.

There's a lot of confusion between biosimilarity and interchangeability, and even in the FDA's efforts to streamline the development process, we're never compromising on the statutory requirements or the safety and efficacy. Everything we're doing is trying to build on our experience, to build on others' experience. In the product quality information for biosimilars, every biosimilar and every interchangeable is exactly the same.

CFB: Around this time last year, President Biden reauthorized the Biosimilar User Fee Act through 2027, which enables the FDA to assess and collect fees for biosimilars. Since the reauthorization, what actions has the FDA taken with this funding and what does it plan to achieve over the next 4 years?

Maxfield: BsUFA III included a lot of different enhancement areas, and that's all outlined in the commitment letter, which is public online. Some of the things that we've done thus far is there's been additional meeting types that biosimilar developers can request that are related to how much data you have when you submit the request. Additionally, for BIA [Biosimilar Initial Advisory] meetings, those previously had requirements for analytical data and now no longer have those requirements.

Additionally, we have met some of the requirements involving the reg sci program [the regulatory science pilot program], which I know we'll talk about a little bit later. The other commitment that we've achieved so far is the labeling guidance, so a new labeling guide for biosimilar products came out at the end of August, and that was a commitment; the major highlight there would be the interchangeability statement is now no longer a part of the labeling.

CFB: A big part of BsUFA III is the creation of demonstration projects. What do these projects entail and what impact will they have on the biosimilar industry in the long run?

Maxfield: The demonstration projects are part of the regulatory science pilot program commitment. So, the commitment was for the FDA to explore areas and fund support areas that will enhance the regulatory decision-making and scientific recommendations in regard to biosimilar development and interchangeable development.

As part of that letter, as part of that commitment, there are 2 aims, or demonstration projects. The first is advancing the development of interchangeable products, and the second is increasing the efficiency of biosimilar development. Those were our starting point for the reg sci program, where we have now since defined regulatory impacts and research priorities to inform our efforts to move that forward.

CFB: In the FDA's recent webinar on biosimilar development, there was a lot of discussion on the role of clinical efficacy testing in biosimilar development and whether it should be used in the future. How has the FDA's outlook on these tests evolved and where does the agency currently stand on them?

Maxfield: That's a really big area for biosimilar development right now. Before I jump into that, I just I did want to highlight that the FDA has licensed several biosimilars, but did not necessarily have certain clinical data associated with them. So, there's a couple examples: There are the pegfilgrastim products that used a pharmacodynamic biomarker instead of a comparative efficacy study, and then there's the insulin products where it was determined that clinical safety studies weren't necessary—again, they used another pharmacodynamic biomarker. And so that made those programs much smaller and more efficient.

Most recently, the natalizumab biosimilar [that was approved] at the end of August, again, instead of a clinical efficacy study uses a set of pharmacodynamic biomarkers. So, this is something the FDA has been working on or thinking about for a long time. And then moving forward, there's a lot of global discussion and harmonization about how to move this forward now that we have over a decade of experience and we now can see that the analytical data are much more sensitive at detecting differences than a clinical efficacy end point. There's just a lot of discussion about how to move that paradigm forward.