One of the persistent themes at the Association for Accessible Medicines’ first GRx+Biosims meeting was an existential one. Authorities such as Gillian Woollett, PhD; Hillel Cohen, PhD; and several industry experts worried that without a change in mindset and intervention by government, payers, and the industry itself, the US biosimilar industry may not survive its infancy. And failure to attain US biosimilar market success would have grave consequences for the global biosimilars industry.

In her session, Avalere Health’s Senior Vice President Gillian Woollett, discussed the three mountains that biosimilar manufacturers had to climb in order to be successful. These were, in sequence, Mount FDA Approval, Mount Exclusivity and Intellectual Property, and Mount Commercialization. Indeed, it seems that FDA approval in many ways may be the easiest hill to summit.

Twelve biosimilars have been approved by FDA, but this is a far cry from attaining biosimilar market success. The eight drugs that are approved but have not yet reached the market are testament to this problem. Most have fallen victim to the lengthy delays associated with the exclusivity and intellectual property difficulties, none more so than the adalimumab biosimilars. For US biosimilar makers, each year that Humira® (and etanercept [Enbrel®] which will likely be introduced before 2020) face no market competition represents billions of dollars in unrecoverable revenue, as well as tens of billions of lost savings to the health system. Of course, it also means billions of additional revenues to the reference drug makers and their shareholders, which is substantially why these delays occur in the first place.

Don’t Look to the US, not Yet

Dr. Woollett asked, “Can there be a sustainable multisource specialty market in the US? I don’t think this is a foregone conclusion in the US.” She explained that the US is 50% of the market by dollar volume, yet it is home to only 5% of the world’s population. With aggressive tenders in many EU member countries, manufacturers are looking toward the US market to ensure long-term profitability. “Can the US carry the return on investment for biosimilars for the rest of world? I’m not convinced,” asserted Dr. Woollett.

Dr. Woollett pointed to another potential limiting factor in the commercialization of biosimilars. No interchangeable version of a biosimilar has yet been approved by FDA. However, switching matters greatly to the anti-inflammatory biosimilar drug maker, because it determines the size of the initial market opportunity. She explained, “If it applies to entire anti-TNF market, that’s $30.4 billion for infliximab. If you consider only treatment-naïve patients, that market is much, much smaller. If it is restricted to treatment-naïve patients, then no, these biosimilars will not be viable.” Switching is not a formidable issue for cancer biosimilars, as these are used as chronic treatments; nearly all patients are new to treatment.

She also noted a decline in the number of biosimilar development programs registered with FDA, which may be a signal of problems in the perception of manufacturers regarding their market opportunity.

Limited Reference Biologics Targeted
“Interest in biosimilar development only occurs for successful originator biologics,” Dr. Woollett pointed out. When filtering out biologics that are also not nearing patent expiration, it leaves a limited set of very expensive reference medications.

In making the business decision whether to develop a biosimilar, drug makers consider a number of questions, including the ease and cost of obtaining samples for evaluation, potential need for expensive clinical studies, and finally, what expense and time may be required for commercialization (including patent litigation). If a company plans on making the biosimilar available in a number of countries, it may be required to prove its molecule is adequately similar to samples obtained from each country or region. This could mean the need to purchase over 100 lots from the manufacturer, which is often not willing to sell to potential competitors. This is the reason for legislation like CREATES Act, which attempt to make this easier for potential biosimilar manufacturers.

Lowering Costs Through Harmonization of Comparators
However, Dr. Woollett and her colleagues in the biosimilars industry threw their support behind a different approach in 2017. Theirs is an initiative to establish “global reference comparators.” Under this approach, a manufacturer would only have to prove biosimilarity with a single licensed version of the reference product. “If the reference product is the same worldwide, then oughtn’t the biosimilar be able to be, too?” she asked. “Requirements for different datasets cannot be justified,” said Dr. Woollett. “Biologics been around for a very long time.

Once approved, complexity is no longer a relevant argument.” This would eliminate the need for biosimilar makers to confirm equivalence in bridging studies between their molecule and the licensed standard approved by each jurisdiction.

This approach reflects a growing understanding that the lot-to-lot variations seen in usual manufacturing of biologics (and over time) do not generally represent a risk to patients in terms of clinical effectiveness or safety. This, Hillel Cohen, PhD, Executive Director, Scientific Affairs, Sandoz, has just not shown to be an issue over 20-odd years of biologic production (outside of the Eprex® incident in 1998). In essence, today’s biologics are biosimilars to the original product approved by the FDA or EMA decades ago, without adverse effect on efficacy or safety. He pointed out that bridging studies that have been required add time and complexity to biosimilar development. Global comparators would help resolve this, and it can be applied to both biosimilarity and interchangeability comparisons as well. Dr. Cohen noted that “the FDA’s draft interchangeability guidelines still require comparison with US-licensed reference products only.”

Interchangeability not a Guarantee of Biosimilar Market Success 

Dr. Cohen said that when a biosimilar product is so extensively studied as to its comparability with the reference product, “I cannot imagine scientifically why we thought switching would be a problem. In the opinion of the EU, these agents are substitutable, under proper supervision, with clinical monitoring. Indeed, the concept of interchangeability is unique to US regulations. However, even this designation may not hold the key to biosimilar market success.

Leah Christl, PhD, FDA, agrees with EMA that biosimilars in theory are interchangeable with their reference for the purpose of MD prescribing (meaning they are substitutable). This helps address the question of whether a noninterchangeable biosimilar is somehow a lower quality or less equivalent to a reference product than an interchangeable biosimilar might be. In fact, Dr. Cohen pointed out, “There is no definition of a ‘noninterchangeable biosimilar’ in the BPCIA.”

The cost of development of biosimilars, which may be in the hundreds of millions of dollars, is very high, considering that only four have been launched in the US. Dr. Woollett thinks that something will have to change in order for biosimilar manufacturers to maintain their interest in this sector. Yet, in view of the limited options available in the US to remedy the situation, Dr. Woollett remains pessimistic. “These investments in biosimlars of up to $500 million will be reconsidered,” she concluded.

At the GRx+Biosims meeting, Secretary Azar’s assistant Daniel Best restated the administration’s desire to preserve the biosimilar industry for the benefit of lowering prices and greater competition. He said, “We absolutely have to find a market for biosimilars. We can’t allow it be be eradicated through the perverse incentives in the marketplace.”

In fact, the only biosimilar market success story to date, Zarxio®, may be as much the result of a certain set of preconditions as that of Sandoz’s marketing efforts. First, another branded product, tbo-filgrastim (Granix®), was already available and was eroding the share of Amgen’s reference product. Second, this agent, though not technically a biosimilar by the regulatory approval pathway, cleared away some of the patent issues for Sandoz in its development of Zarxio. Third, Amgen eventually yielded the top position to Sandoz (at around 40% of marketshare). This set of circumstances is a bit unlikely for the introduction of other biosimilar drugs. Many will be looking to Mylan and its commercialization of pegfilgrastim as the next test of biosimilar market success.