Just a short while ago Amgen was rumoured to be planning a bid for Alexion. Now, it’s filed a patent infringement action against Alexion’s top-selling drug Soliris.
The US Patent and Trademark Office (USPTO) has been asked to review patents on Soliris (eculizumab), Alexion’s blockbuster treatment for a clutch of rare diseases including paroxysmal nocturnal haemoglobinuria (PNH) and atypical haemolytic uremic syndrome (aHUS).
Amgen’s challenge comes shortly after Alexion secured an extension to its patent protection for Soliris until 2027, and sparked a decline in the latter’s share price as investors reacted to the news of a fresh challenge to the company’s intellectual property. Its main patent on the drug expires in the US in 2021.
Amgen’s interest lies in a biosimilar version of the complement C5 inhibitor – called ABP 959 – that it has advanced into clinical testing.
The USPTO’s Patent Trial and Appeal Board, (PTAB) said on Friday it was launching a so-called inter partes review (IPR) of Soliris’ patents. That will force Alexion to defend its IP – specifically covering the drug’s main ingredient, formulation and use to treat PNH – and give Amgen an opportunity to invalidate those claims. The review is expected to take around a year to complete.
Alexion is expecting Soliris to make around $4.1bn in sales this year, up from $3.56bn in 2018, thanks in part to new indications such as generalised myasthenia gravis (gMG) and neuromyelitis optica spectrum disorder (NMOSD).
The drug currently accounts for more than 80% of Alexion’s sales, and the company needs the additional market exclusivity to give it time to switch patients to its follow-up PNH therapy Ultomiris (ravulizumab), which was granted an earlier than expected FDA approval last December.
In trials, Ultomiris matched Soliris for efficacy – with a trend towards superiority – and offers improved dosing. It is administered intravenously every eight weeks rather than every two weeks with Soliris, cutting the number of doses needed from 26 to six per year.
Alexion’s other products such as lysosomal acid lipase deficiency treatment Kanuma (sebelipase alfa) and Strensiq (asfotase alfa) for hypophosphatasia have a long way to go before they bring in enough revenue to reduce Alexion’s reliance on Soliris, so a lot is riding on its defence against Amgen.