Key Considerations For Biosimilar Clinical Pharmacology Studies

Biologics have become the fastest-growing class of therapeutic compounds, with the majority of the 10 top-selling drugs in 2017 being biologics, each exceeding sales of US$5 billion. They represent almost 40 percent of all prescription drugs spending and accounted for 70 percent of growth in drug spending from 2010 to 2015. The size of the market globally is expected to grow to US$287.14 billion by the end of 2020. Biologics have provided treatment options for people who suffer from some of the most serious medical conditions, such as cancer and genetic disorders. About 300 biologics are now available for human use, and the demand is growing exponentially due to the generally fewer side effects than the more broadly acting small molecule drugs. It is estimated that US$67 billion worth of biologic patents are set to expire before 2020. The expiration of patents and other intellectual property rights for originator biologics over the next decade opens up opportunities for biosimilars to enter the market and increase industry competition.

A biosimilar is a copy of a biologic medicine that is similar, but not identical, to the original medicine. It enters the market subsequent to the patent expiration of a previously authorized version of a biologic. A biosimilar is approved only after showing that it is “highly similar” to an approved biological product, known as the reference product, in terms of structure, purity, potency, safety, pharmacokinetics, and in many cases, efficacy, with allowable minor differences. To be called a biosimilar, these compounds need to demonstrate in vitro and in vivo functional similarities with comparable pharmacokinetic (PK) and pharmacodynamics (PD) properties to the reference product. Biosimilars are usually given the same indications as the originator drugs but with reduced development cost, which translates to a lower market price, making them more accessible and affordable to patients.