Amgen's top-selling Enbrel in balance as key court ruling nears
- A federal judge is expected to rule soon in a case crucial to the longevity of Amgen's patent defenses for its top-selling biologic drug Enbrel, which the company has protected from biosimilar competition in the U.S.
- The district court case pits Amgen against Novartis' generic unit Sandoz, the maker of an Enbrel biosimilar approved in the U.S. in August 2016. Sandoz has yet to sell a single syringe of its copycat version, however, after Amgen won an injunction blocking the drug's production or sale.
- At issue are two patents Amgen licensed from Roche that could protect Enbrel from competition for another decade. Sandoz has admitted its biosimilar infringes on Amgen's intellectual property but argues both patents should be invalidated. Closing arguments in the case were held in November and U.S. District judge Claire Cecchi is expected to issue a verdict as soon as this month.
First approved in 1998, Enbrel (etanercept) remains a large part of Amgen's business. And, if the biotech has its way in court, the drug could benefit from market exclusivity through 2029.
While sales of Enbrel have recently declined, the anti-inflammatory disease drug still accounted for a fifth of the biotech's product revenues last year.
Maintaining those blockbuster sales is crucial for Amgen, particularly as revenues from its newer drugs like Repatha (evolocumab) and Aimovig (erenumab) remain modest.
A court victory for Sandoz, however, would complicate matters, and could pressure Amgen shares if it were to occur, according to Wall Street analysts.
For its part, Amgen has maintained its confidence in the validity of the two patents contested by Sandoz.
"We feel good about the intellectual property around Enbrel," said Amgen Chief Financial Officer David Meline on a recent earnings call. "The district court needs to render a judgment and we think that will happen at some point later this quarter," he added, while acknowledging that timeline could run longer, too.
Kennen MacKay, an analyst at RBC Capital Markets, puts Sandoz's chances of prevailing at 20%, noting the tendency for district courts to side with current administrative frameworks.
"At the district level, we think that it's much more likely to go in Amgen's favor," MacKay said in an interview with BioPharma Dive. "Either way, if it goes in Amgen's favor or in Sandoz's favor, this is likely to see an appeal."
But a Sandoz victory could open up the possibility for the generic maker to launch its Enbrel biosimilar at risk, MacKay said, while the appeals process carries on. A fresh injunction on sales is also possible, according to the analyst.
Leerink analyst Geoffrey Porges, however, sees a 2021 launch as more likely in the event of a Sandoz victory, based on his estimate of any appeal process lasting between 12 and 13 months.
Erelzi (etanercept-szzs), as Sandoz's biosimilar is called, was the third copycat biologic approved by the Food and Drug Administration. That it has yet to launch is an example of the legal hurdles that have limited the impact of biosimilars in the U.S.
In a recent note to clients, Porges wrote that Sandoz expected to launch the drug soon after the main composition-of-matter patents protecting Enbrel expired in 2016.
But Amgen blocked Sandoz's path to market by asserting infringement of two patents it exclusively licensed from the Swiss drugmaker Roche in 2004. Those patents cover a fusion protein of the receptor that Enbrel targets.
Sandoz isn't the only company taking aim at Enbrel's $4.5 billion in U.S. sales, but it's the most advanced. Coherus BioSciences unsuccessfully attempted to invalidate the two patents Amgen licensed from Roche, and has yet to win an FDA approval.
In Europe, where Pfizer sells Enbrel, two biosimilars are already on the market.
Even without biosimilars competition, Amgen is facing branded rivals to Enbrel that have weighed on the drug's sales last year. Newer therapies like Novartis' Cosentyx (secukinumab) and Pfizer's Xeljnaz (tofacitinib) have been particularly successful.
Still, Amgen has proved capable at defending its businesses in the past.
"Many of Amgen's franchises have faced not only generic or bisoimilar competition, but also evolving branded competition," MacKay said. "They're very good at contracting in competitive marketplaces."
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