The development of a biosimilar product normally carries substantial patent infringement risks. While the base patent protecting the lead product may have expired, a collection of patents dealing with dosage regimes and formulations is often built up. The biosimilar producer may be obliged to follow the features and dosing programme of the lead product in order to obtain regulatory approval. So, although the patent monopoly for the original product has run its course, an effective monopoly position may be maintained for a long time afterwards.
Sometimes tactical behaviour involving applications for patent of this kind can be used in a way that chills competition, while protecting the as yet ungranted patents from invalidity proceedings. The normal route for a competitor is to challenge any conflicting patent before launching their product, to test whether it is in fact valid, and includes claims that cover the competing product. But you cannot do this before the patent has been granted. So if the patentee maintains pending applications, it can create ongoing commercial uncertainty for potential competitors.
In the UK, judges have recently shown a willingness to stop tactical use of applications with “Arrow declarations” (discussed here). These involve granting the biosimilar developer a declaration that their product, and any relevant features of its dosing regime and formulation, would have been known or obvious by the time any threatening patent application was filed. So no patent resulting from the application would be able to prevent the marketing of the biosimilar product.
The courts have explained that Arrow declarations are only granted in exceptional circumstances. A recent ruling shows the limits of this approach.
Pfizer's Avastin biosimilar
Pfizer asked the court recently for an Arrow declaration in advance of the launch of its biosimilar product to Roche’s oncology drug, Avastin. That application failed. Why?
Roche’s basic patent, together with Supplementary Protection Certificate and paediatric extension, is due to expire in June 2020. Pfizer is aiming for biosimilar launch soon after that.
If the UK court did grant an Arrow declaration it would reduce the uncertainty for Pfizer in launching its product across Europe. European judges do pay attention to decisions in other countries.
No UK applications remain
Although UK applications had existed at the outset, during the litigation Roche removed the UK designation from all pending European applications. The judge inferred that this was to shield the European patents from the risk of an adverse ruling in the UK.
If any of the UK applications remained, the court would have been willing to look in detail at the validity and infringement questions with a view to granting the declaration, but there were none. That meant that a declaration would have no value in the UK, despite being helpful in other parts of Europe. The judge was not prepared to grant an Arrow declaration in order to influence patent litigation elsewhere.