Biogen's blockbuster Tysabri loses a key patent in Europe, adding to company's worries: analyst

As if Biogen didn’t have enough on its plate these days, now comes concern for its multiple sclerosis blockbuster Tysabri in Europe.

With Europe revoking a patent for the drug earlier this month, Biogen could face biosimilar competition earlier than expected, Bernstein analyst Ronny Gal wrote in his weekly note to investors. In some markets, a copycat could arrive as soon as next year.

Tysabri generated European sales of $849 million last year, so the development is "somewhat material," the analyst added.

Sandoz and Polpharma brought the Tysabri patent challenge in Europe and recently scored a win at the European Patent Office's Opposition Division, according to Juve Patent. The duo have a commercial agreement for the distribution of their Tysabri biosimilar and are already in phase 3 testing.

In Biogen's 2020 annual SEC filing, the company said the EU patent was set to expire in 2027. In some European countries, Biogen has another patent on the drug in effect until 2023, Gal wrote.

But Biogen has a ready biosim defense: In April, the company scored European approval for a subcutaneous version of the drug with a lower dosing frequency. With that, the patent setback is "not clearly a full franchise loss," Gal wrote.

Biogen confirmed the patent decision but declined to comment on an "ongoing legal matter," according to a spokesperson.

After working through safety concerns following its launch in 2006, Tysabri has been a force in the MS market in recent years. In 2020, the drug posted worldwide sales of $1.95 billion, a 5% increase from 2019.

RELATED: Biogen gets EU approval for subcutaneous Tysabri

In the U.S., Biogen still has work to do to get the subcutaneous version of Tysabri approved. The FDA rejected it in May with a complete response letter.

Biogen’s attention clearly is divided these days as it tries to fend off attacks and launch controversial Alzheimer’s disease drug Aduhelm. Late last week, FDA acting chief Janet Woodcock called on the Office of Inspector General to probe the approval. The company also faces scrutiny from lawmakers and pushback from payers on its new medicine.

RELATED: FDA rejects Biogen’s subcutaneous Tysabri in multiple sclerosis

Meanwhile, Biogen's important drugs Spinraza and Tecfidera have been weathering competitive pressures in recent months. Spinraza sales fell 2% last year as a new gene therapy from Novartis, an oral option from Roche and the coronavirus pandemic took a toll. 

At the same time, Biogen's big-selling oral multiple sclerosis drug Tecfidera is facing new U.S. copycats, denting sales. Follow-on treatment Vumerity has yet to make up the difference.