The A-B-T of biosimilars- Explaining contemporary life science issues



Summary
Depending on the perspective, biosimilars pose either the greatest threat to innovator drug company profits or have the greatest potential to save on healthcare drug spend. We take a recent perspective through the accidents, the bioequivalence arguments and the tender processes (the A-B-T of biosimilars) that will govern the ultimate role of biosimilar drugs.What is a biosimilar drug?
Around 10 years ago, the term biogeneric was superseded by biosimilar as it was recognised that the complicated structure of these biologic drugs meant they could not be exactly copied. Regulators, payers and physicians are now realising the place of biosimilars as the patents on the innovator drugs expire. This switch to biosimilar use has not been an easy transition and continues to face hurdles in acceptance by physicians and patients some of which are structural, but some are of the innovator companies’ making. We expect biosimilars will eventually replicate their dominance in Europe more widely. One Canadian province expects to save c 5% of its drug budget over three years by switching to biosimilars.Tenders, switching and interchangeability
The early examples of biosimilar products were directed towards demonstrating that although they might be slightly different molecules, they were effectively bioequivalent (the B in our A-B-T title). In typically small studies, strict bioequivalence might be difficult to prove and the more recent focus has been to show that patients can be switched from the innovator to biosimilar molecule without any detrimental effects. In the US, the FDA has recently formalised this process with its new interchangeable designation. Also important is how biosimilars are reimbursed by payers and the European experience has given us the aggressive biosimilar tender (the T in our A-B-T). Likely winners- Single payer healthcare systems: Such as NHS England, where bulk purchasing power for the lowest price biosimilar can result in significant savings to a national healthcare budget.
- Some innovator pharma and biotech companies: Some already have biologic development experience (such as Amgen, Biogen, Eli Lilly and Novartis) and can exploit therapeutic niches or manufacturing challenges.
- Patients: Those who are more likely to receive more cost-effective biosimilar drugs that provide them the same benefit as the innovator or reference molecules.
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- Smaller generic and pure-play biosimilar companies: Some have had early missteps in their clinical or regulatory programmes, or face a ‘race to the bottom’ in tender pricing as innovator companies attempt to retain market share.
| Roche | ||
| Novartis | ||
| Abbvie | ||
| Eli Lilly | ||
| Sanofi | ||
| Amgen | ||
| Biogen | ||
| Fresenius Medical Care | ||
| Teva Pharmaceutical | ||
| Laboratorios Farmacéuticos Rovi | ||
| Coherus | ||
| Momenta Pharmaceuticals | ||
| Formycon |
What is a biosimilar drug?
To help define biosimilar drugs, we must first explore the differences between classical small molecule drugs (such as aspirin or penicillin) and biologic drugs (for example, monoclonal antibodies, enzyme replacement therapies and even insulin, which was the first protein approved as a drug). Biologic drugs are mostly proteins but there are complex carbohydrates, peptides and even DNA or siRNA that can be classified as large molecule biologic drugs. Between 2008 and 2017, 22% of drugs approved by the FDA were biologics and there will therefore be a significant market for biosimilar competition to those drugs once the patents expire. Despite over 90% of prescriptions by volume in the US being for (small molecule) generic drugs, 40% of US drug spend by value was on biologics. As shown in Exhibit 1, a typical small molecule drug has a simple molecular structure that contains c 100 atoms or fewer. It is usually made by a short series of chemical reactions (in a synthetic route) and the scale-up from laboratory flask to industrial reactor vessel presents few unmanageable problems. As an aside, small molecule drugs are frequently taken by patients orally as tablets and this solid dose format is usually associated with years of shelf life. Small molecule drugs are mostly prescribed by primary care physicians for either acute or chronic, usually non-life-threatening conditions (such as a throat infection or high blood pressure) and aim to effectively cure the patient (even if chronic administration is required). For a competent chemist, small molecule drugs are easy to copy and in the earlier days of drug development, pharmaceutical companies routinely synthesized competitor drugs (from the information provided in the patent) to test and make better versions. Once the patent protection expires for small molecule drugs, it is routine to make a generic version and indeed the regulatory pathways (in the US and EU) provide for much smaller, and therefore cheaper, studies that in many cases only require the demonstration of bioequivalent blood levels in healthy volunteers compared to the innovator or reference molecule for the generic small molecule drug to be approved.

Before biosimilars, there were similar biologics
Before the legal and regulatory frameworks that allowed biosimilar drugs to be approved and marketed, there were biologic drugs that were almost identical to each other. The classical case was that of erythropoietin (EPO) and its derivatives. Human EPO is a 165 amino-acid glycoprotein (with four added sugar molecules) hormone that increases red blood cell production and is used to treat the anaemia associated with chronic kidney disease (CKD), or as a result of cancer chemotherapy. The original recombinant human EPO was approved by the FDA (as a drug, not a biologic) in the late 1980s with all the attendant clinical trial requirements of a new molecular entity. Early and protracted patent litigation between innovator companies manufacturing first-generation EPO derivatives eventually proved academic and gave way to improved and longer-acting EPO-based products such as Amgen’s Aranesp in 2001. With a large potential global market for these erythropoiesis-stimulating agents (ESAs) but no mechanism for approving a biosimilar even after the patent had expired, other innovator companies developed competing long-acting ESAs through the usual (and by then available) biological licence application (BLA). These were new biological drug entities that required long and expensive clinical trials and regulatory submissions. Thus Roche’s competing ESA Mircera was approved by the FDA and EMA in 2007, although additional US patent litigation delayed US marketing until 2014. In Europe in 2007, while biosimilar was still a nascent term, Roche used Mircera’s EU approval to establish competitive (biosimilar) price points in what was until then a branded-only market. This was an inspired move because Europe is comprised largely of single-payer public healthcare systems that are used to purchasing generic drugs in bulk and on a tender basis. This has helped establish Europe as the world’s leading biosimilar market, which we explore further below. The non-biosimilar ESA approvals also established early on that the ability to develop biosimilar products was easier if done by a company that already had innovator biological drug development and regulatory experience, such as Roche.An accidental history
The history of the development of biosimilars has been augmented with a few accidents that initially helped the innovator companies and at least delayed biosimilar competition. In 2009, before any biosimilar product was approved, Genzyme (now a Sanofi company) was prevented by the FDA from supplying its product, an enzyme replacement therapy for Pompe disease, from its 2,000 litre Allston manufacturing facility because there were (glycosylation) differences between the Allston-produced drug and the supposedly same product produced at Genzyme’s 160 litre pilot plant facility. The product manufactured at a third 4,000 litre facility in Belgium was eventually approved as the global supply site. Such was the caution by the FDA on the slightly different products manufactured by the same company at different US sites that, while they co-existed, they had separate brand names – Myozyme and Lumizyme.Tides turn slowly towards biosimilars
Since the early 2000s, a number of biotech companies specialising in biosimilar products have come to the public market. Although these products have eventually gained FDA approval, the lack of monopoly positions seems to be the main reason why significant commercial success remains elusive. Momenta Pharmaceuticals was founded in 2001 and listed on Nasdaq in 2004 on a sophisticated analytical platform that could determine and replicate the precise mix of complex biological products (initially carbohydrates). Today, through the collaborations with partner Sandoz (the generics arm of Novartis), there are two Momenta-derived biosimilar products on the market (generic Lovenox and Copaxone). However, because there have been multiple market entrants for both products, which the FDA has determined are substitutable for the innovator or reference product, pricing has fallen. As a result, Momenta recently had to restructure and remains loss-making. Building on the rising investor interest in biosimilars, Coherus Biosciences was founded in 2010 and listed on Nasdaq as a pure-play biosimilar company in 2014. Like Momenta, Coherus now has a product on the market, Udenyca, a biosimilar of Amgen’s Neulasta, which boosts white blood cell counts in chemotherapy-treated patients. Like Momenta’s biosimilar products, Udenyca shares the US market with Amgen’s innovator product and Mylan’s generic version Fulphila. Also, like Momenta, Coherus remains loss-making although its quarterly losses have halved in the last year as (unlike Momenta) it has started marketing Udenyca alone. Coherus has compared the weighted average cost per syringe of its biosimilar product Udenyca to Amgen’s Neulasta noting a 33% discount to the innovator product. This is a typical of the discount to the innovator biologic with limited biosimilar competition in the first few years of launch and in the US there are now three substitutable pegfilgrastim products (including the reference product Neulasta). In biosimilar launches where there is limited competition, discounts to the innovator product of between 30% and 40% are typical. These are much lower than the discounts of c 90% that would be expected with small molecule generics manufactured by many competitors. The pathway to a pure-play biosimilar company has not been easy and Udenyca had a chequered early history. In 2015 Coherus reported the pharmacodynamic (PD) and pharmacokinetic (PK) profiles of Udenyca (then known as CHS-1701) and Neulasta showing that one of the two Udenyca PK profiles was different to the other and to those of Neulasta. After consultation with the FDA, additional patients were dosed and the data included in a BLA under the FDA’s new (at the time) 351(k) biosimilar pathway. After the FDA issued a complete response letter in June 2017 requesting a reanalysis of the immunogenicity data, Udenyca was finally approved in Europe in September 2018 and the US in November 2018.Take-home point: due to the recent legislation that allows the approval of biosimilar drugs, there has been a second-mover disadvantage while companies become familiar with biosimilar clinical and regulatory requirements. Even so, while the regulatory requirements may now be clearer, investors have had to lower their expectations on the commercial potential of a competitive biosimilar market, relative to the previous monopoly innovator market. This implies incremental profits, rather than those associated with a new biological drug launch. In addition, the requirements for a biosimilar approval fall between those of a small molecule generic drug, and a new biologic entity in terms of cost and time.
B for bioequivalent biosimilars started in Europe
European biosimilar legislation started to be developed in 1998 and came to fruition in 2006 with the first approval of somatotropin. Paradoxically, while biosimilars established themselves in Europe, for nine years there was no legal route to approval in the US without going through a new BLA submission until the FDA’s guidance of 2010 and its first approval of a biosimilar to Amgen’s Neupogen five years later. As part of the FDA’s 351(k) pathway biosimilar legislation, innovator companies were compensated with a 12-year exclusivity period from first approval. This is much longer than the five year market exclusivity granted to small molecules approved in the US and a minimum of eight years exclusivity for biologics approved in the EU. Japan established a registrational biosimilar pathway in 2009. The first European biosimilar approval was for somatropin (a growth hormone with a simple structure), followed by biosimilar EPO in 2007 and filgrastim (first-generation Neulasta) in 2008. However, European biosimilar adoption and the commercial battles with innovator companies did not really start until the approval of a Remicade (infliximab) biosimilar in 2013. In all (EU, Japan and US) cases, the regulations evolved to address the initially perceived issues surrounding biosimilar drugs and prominent among these were bioequivalence and immunogenicity. The demonstration that an injection of a biosimilar product is bioequivalent to the innovator product may not be as simple as with a small molecule generic drug as Coherus discovered in the example above (due to patient PK/PD variability and inter-patient response rates). Much of the impetus on the regulatory requirement for bioequivalence in biosimilars might have come from the innovator companies to raise the bar for the competition to their reference products. In one respect, once bioequivalence had been established it became a double-edged sword for the innovator companies. For biosimilars approved in the EU, EMA regulations stipulate that once biosimilarity has been demonstrated in one indication, it can be extrapolated to all the other indications for which the originator product has been approved. This extension across all indications only had to be justified by sufficient scientific arguments, rather than expensive clinical trials, making the clinical programme to achieve approval for all the indications for a biosimilar drug – in biosimilar EPO’s case, for all the cancer and non-cancer indications – much cheaper and easier than it was for the reference molecule. Thus from 2016 in the EU, biosimilars to the branded anti-inflammatory Remicade (infliximab) were able to be prescribed for patients suffering from Remicade’s eight approved indications in gastroenterology, rheumatology and dermatology. By 2017, biosimilars to Amgen’s anti-tumour necrosis factor anti-inflammatory drug Enbrel (etanercept) and Roche’s oncology drug Rituxan (rituximab) had been approved by the EMA in multiple indications and by a number of different companies. The attraction of cheaper biologics for single-payer healthcare systems became embedded in the commercial realities of biopharmaceuticals in Europe.Biosimilar frictions and tenders
The innovator companies’ message to prescribers remained that because biosimilar molecules were non-identical to the reference molecule, patients’ responses could be different to the reference product, or worse, patients’ immune systems could recognise the biosimilar as foreign and raise anti-idiotypic antibodies against it. This mistrust amongst physicians is one of the reasons why biosimilars remain at an earlier stage in the US than Europe, where nine years of experience has largely assuaged them. The FDA’s recently finalised interchangeability guidelines may perhaps address this concern in the US. The issue of interchangeability has largely been removed in Europe by a number of switching studies, where patients are switched back and forth between reference and biosimilar products. The largest of these studies was the NOR-SWITCH study funded by the Norwegian government where nearly 500 patients receiving Remicade either remained on the reference drug or were switched to an infliximab biosimilar for 52 weeks. Switched patients had non-inferior clinical outcomes to those on the reference product. The healthcare systems in most European countries have provided a largely single-payer-driven preference for promoting the use of biosimilar products. Regional purchasers in European countries now often purchase biosimilar drugs in bulk tenders in the same way as for baskets of generic small molecule drugs. Tenders can be open, closed or mixed depending on whether the innovator company is included or possibly excluded. In each case, tenders (which can have durations of years) resulted in average biosimilar discounts in 2016 of c 40% in open tenders, c 60% in closed tenders and c 30% in mixed tender markets. In addition, biosimilars have been favoured more in some markets than others, with Norway and Denmark having close to 100% biosimilar infliximab uptake for example, compared to just under 25% in France in 2016. This is because in Nordic Europe, biosimilar tendering tends to be exclusive (which can exclude the innovator), more aggressive and pragmatic. Exhibit 2 demonstrates the effect of biosimilar tenders for infliximab in Finland. In the US, the longer period of market exclusivity for innovator products and counter-detailing by innovator companies continues to limit the uptake of biosimilars where they have been approved, as does the extended periods of patent exclusivity. The European patent for the world’s best-selling drug Humira (adalimumab, with c $20bn in 2018 sales) from AbbVie expired in October 2018 and there are now five approved biosimilars in Europe. Humira remains patent protected in the US until 2023, despite being first approved there in 2002. Eight Humira biosimilars have been approved by the FDA and are waiting to launch. In Q119 AbbVie Humira sales ex-US fell by 23% quarter on quarter, five months after the first biosimilar launch largely due to the aggressive European tender processes. Exhibit 2: The share between biosimilar and reference product treatment days (%) of infliximab in Finland

Biosimilar investment perspectives
Biosimilar drugs represent significant savings to global healthcare systems and offer patients in lower- to middle-income economies access to innovative biologic drugs for the first time. From an investment perspective, things may not be as positive. Just as in small molecule drugs, multiple biosimilar companies competing in tenders can aggressively drive prices down and, while the attractiveness of the generic small molecule drug sector has declined significantly over recent years as a smaller number of consolidated competitors compete for tender contracts, the biosimilar market may have similar (if not as aggressive) dynamics. Exhibit 3 shows the change in price per treatment day since biosimilars have been introduced in Europe. It is important to note in the right-hand panel of Exhibit 3 that although the total market may have declined by up to 27%, this is caused by many factors and is the combination of exclusion of the innovator companies in some tenders, discounting by new entrants and higher volumes of prescriptions. So, although the price for each biosimilar product may be up to 39% lower than the previous monopoly price, much higher volumes and few selling or marketing costs result in biosimilar manufacture being profitable. Exhibit 3: The change in price per treatment day and the total market for each product since the introduction of biosimilars in Europe
