Disease Analysis: Type 1 Diabetes

Disease definition

Diabetes mellitus is a group of chronic endocrine disorders characterized by hyperglycemia due to insufficient levels of insulin, a hormone responsible for regulating blood sugar. Symptoms include excessive excretion of urine (polyuria), thirst (polydipsia),
constant hunger, weight loss, vision changes, and fatigue. According to the World Health Organization (WHO), approximately 8.5% of adults had diabetes in 2014. Type 1 diabetes accounts for around 5–10% of the total diabetic population. The majority of cases of type 1 diabetes may be classified as type 1a, an autoimmune disease characterized by the destruction of pancreatic beta cells, with a minority of cases making up type 1b, which is described as idiopathic diabetes mellitus.

Latest key takeaways

• Despite the presence of multiple well-established products, the type 1 diabetes market is expected to see limited growth over the next decade. Future growth opportunities are expected to be limited by the market’s saturation with multiple maturing insulins, pricing pressures following the launches of biosimilars, and the expected failure of sodium-glucose cotransporter-2 (SGLT-2) inhibitors to gain approval in the lucrative US market.
• In the basal insulin segment, with the advent of biosimilars/follow-on copies to segment leader Sanofi’s Lantus, Sanofi and Novo Nordisk have introduced next-generation, longer-acting products; however, due to continued price pressures, especially in the US, these have not prevented overall sales declines. Sanofi’s longer-acting Toujeo does have some signals for a hypoglycemia benefit over Lantus, but not as much in type 1 diabetes as in type 2, and does allow some patients who require twice-daily Lantus to inject once-daily. However, KOLs interviewed by Datamonitor Healthcare suggest that the advantages are somewhat limited, and with modest sales in the US due to competition with Basaglar, a follow-on copy of Lantus, Toujeo has not prevented a 40% drop in combined worldwide sales with Lantus over the past five years, despite slight combined growth ex-US. Prescriptions of Lantus and Toujeo have stabilized somewhat over the past few years in the US, but the introduction of another follow-on copy, Semglee, in 2020 could introduce further pricing pressures.
• For Novo Nordisk’s basal analog Levemir, which requires twice-daily dosing in many type 1 patients, Datamonitor Healthcare expects patients will continue to switch to its successor product Tresiba due to the company’s promotion of Tresiba’s longer-acting duration of 42+ hours and its flexible dosing window (it can be administered at different times each day), which offer improved convenience for patients. Tresiba also has hypoglycemia benefits over Lantus, with a reduction in severe hypoglycemia in a large outcomes study, albeit in type 2 diabetes, with data appearing on its US label. Nevertheless, while Tresiba appears more differentiated than Toujeo, it has been difficult to discern whether there are substantial differences in other clinical benefits between the two, because each sponsor has conducted head-to-head PK/PD and longer-term hypoglycemia studies, but those studies have either shown equivalence or an advantage for the sponsor’s drug (the larger studies have been in type 2). While Tresiba has helped increase combined usage of the Novo Nordisk franchises, it has come at the expense of increasing rebates in the US, so in recent years, despite combined sales growth ex-US, worldwide sales have declined somewhat.
• Payers are severely restricting the use of specific insulin brands in the US. While list prices are increasing, rebates are also rising, particularly in the past few years. Interviewed endocrinologists emphasized the impact of pricing on prescribing trends, as formulary changes in the US lead to regular switching among patients.
• Dynamics are somewhat different in the fast-acting/bolus segment of the market, due to more exclusive contracting in the US which has made it more difficult for biosimilar/follow-on copies to gain a foothold, though they still contribute to pricing pressure. It has also been more difficult to differentiate next-generation, faster-acting products.
• The segment leaders have been Eli Lilly’s Humalog and Novo Nordisk’s NovoLog. Interviewed KOLs believe there are no definitive clinical differentiators between the two in a real-world setting, and worldwide sales have not differed by more than around 10% over the past five years, though there are differences within particular geographic regions (and there can be some impact from exchange rates). While the introduction of Sanofi’s biosimilar/follow-on copy to Humalog, Admelog, has only led to modest sales, primarily in the Medicaid market in the US, it did prompt the other manufacturers to launch “authorized follow-ons/generics” with 50% lower list prices in 2019–20, in order to increase competitiveness in plans such as US Medicare Part D, where patients can end up having to pay a portion of a drug’s gross cost. It appears, though, that Sanofi is pursuing US approval as an interchangeable insulin for its biosimilar of NovoLog, SAR341402, so it will be interesting to see whether that makes a difference. Largely due to price pressures, Humalog and NovoLog sales have declined in the US over the past five years, and sales gains for both outside the US have not been enough to prevent modest declines overall.
• Novo Nordisk’s faster-acting Fiasp can be injected at the start of a meal or within 20 minutes after, rather than immediately before or soon after for NovoLog. Nevertheless, clinicians have been underwhelmed as its faster onset of action has not provided a substantial therapeutic benefit, so uptake has been limited so far. Eli Lilly’s faster-acting Lyumjev launched in mid-2020 in major markets, and while it can also be injected within 20 minutes after a meal, its data are somewhat weaker than Fiasp’s, and expectations are limited.
• Pipeline product teplizumab has shown promising potential to prevent or delay the onset of type 1 diabetes, as Phase II data have demonstrated that a single course of the drug significantly delayed disease onset in at-risk patients by a median of two years. Provention Bio expects to complete a rolling BLA by the end of 2020, with possible US approval in mid-2021 if granted a priority review. However, repeat dosing has not been tested, and patients are still being followed. Hence, it will face the challenge of appropriate pricing to reflect the market value of delaying or preventing diabetes while ensuring that a high upfront cost does not prevent reimbursement or lead to overbearing prior authorization. Another challenge is the lack of existing screening programs to detect patients who are at risk for type 1 diabetes, which could limit the drug’s target population (at least initially). Teplizumab’s commercial success will therefore require healthcare services, physicians, and industry to collaborate on creating and integrating accessible screening programs into different health services globally.
• SGLT-2 inhibitors may offer benefits to type 1 diabetes patients beyond improved glycemic control (such as blood pressure reduction, weight loss, and cardiorenal benefits), but the FDA has now rejected all three members of the class that have been filed for regulatory approval (Farxiga, Jardiance, and Zynquista). Datamonitor Healthcare’s base case is that the class will not gain FDA approval for type 1 diabetes without additional studies to further investigate the risk of diabetic ketoacidosis (DKA), the durability of glycemic benefits, and the effectiveness of proposed risk-management strategies. Thus far, none of the companies have publicly announced any intention to conduct such studies. In fact, Eli Lilly decided to discontinue further development of Jardiance for type 1 diabetes in April 2020, and AstraZeneca has not provided any further updates on Farxiga’s supplemental New Drug Application (sNDA) since its initial rejection by the FDA in July 2019, thus we expect that the company will also abandon US development. Lexicon has expressed its reluctance to conduct additional trials for Zynquista, and has instead unsuccessfully appealed twice to the FDA to overturn its initial rejection. While Lexicon claimed it still has options available for Zynquista’s US approval in its Q1 2020 earnings call, we believe that the FDA is highly unlikely to approve the drug in the absence of new trial data.
• Datamonitor Healthcare estimates that in 2018, there were approximately 46.6 million prevalent cases of type 1 diabetes in adults aged 20 years and over worldwide, and forecasts that number to increase to 51.8 million prevalent cases by 2027.
• Datamonitor Healthcare estimates that in children and adolescents aged below 20 years, there were approximately 1.08 million prevalent cases of type 1 diabetes worldwide in 2018, which are expected to increase to 1.12 million prevalent cases by 2027.
• The overall likelihood of approval of a Phase I type 1 diabetes asset is 14.6%, and the average probability a drug advances from Phase III is 75%. Type 1 diabetes drugs, on average, take 9.1 years from Phase I to approval, compared to 9.4 years in the overall endocrine space.