Key Humira patent gets struck down for the second time in as many months

A win by Boehringer Ingelheim in a case challenging the patents on AbbVie's Humira marks the latest threat to the top-selling drug.

A little less than two months after Coherus BioSciences succeeded in upturning a key IP shield on AbbVie’s Humira, yet another company seeking to launch a biosimilar rival to the blockbuster rheumatoid arthritis drug has scored the same victory. 

On Thursday, after an inter partes review (IPR), the U.S. Patent and Trademark Office’s Patent Trial and Appeal Board (PTAB) ruled in favor of Boehringer Ingelheim in a case that challenged five claims for the ‘135 methods patent on Humira. The ‘135 patent is considered important because it covers the dosing and treatment frequency of the drug—which any biosimilar developer will need in order to win FDA approval of a biosimilar drug. 

RELATED: Key Humira patent goes down via IPR—but biosims makers shouldn't celebrate yet, analysts warn

The ruling follows a May IPR win for Coherus that struck down the same patent. But BI's success could make it more difficult for AbbVie to overturn the PTAB's rulings; now, AbbVie will have to appeal both decisions, which it said in an emailed statement that it plans to do. 

More rulings affecting AbbVie’s Humira patents are expected later this summer. The ‘619 patent, which covers the formulation of Humira, is also under challenge through IPR. 

Patent challenges are par for the course in pharma, but this isn’t just any patent challenge. Humira is not only the world’s top-selling drug, it accounts for more than 60% of AbbVie’s revenues. So when sales of the drug kept missing analysts’ estimates last year, the company’s shares took a dive.

AbbVie staged a comeback in the first quarter of this year, recording a 15% increase in Humira sales. That helped drive total revenues up 10% to $6.5 billion and net earnings up 11% to $1.7 billion—results that beat the company’s own forecasts.

AbbVie continues its efforts to diversify beyond Humira, but with decidedly mixed results. One of its biggest successes is its blood cancer drug Imbruvica, which is now prescribed as a first-line treatment to 21% of patients with chronic lymphocytic leukemia (CLL), CEO Richard Gonzalez reported during the first-quarter earnings call. The drug chalked up its fifth FDA approval earlier this year, and sales in the first quarter jumped 45% to $551 million.

But AbbVie’s hepatitis C combo, Viekira Pak, has struggled to compete against Gilead’s Harvoni. What’s more, the hep C market is rapidly shrinking, since the drugs in the newest generation are essentially cures. Sales of Viekira Pak dropped 36% in the first quarter to $263 million.

RELATED: Resurgent Humira sales make up for hep C decline, powering AbbVie to Q1 beat

The biosimilar threat to Humira, however, is real—and already an issue overseas. Just last month, the European Medicines Agency recommended that the Humira biosimilar Imraldi be approved. That drug, made by Samsung Bioepis and Biogen, would be the second Humira biosimilar to market in Europe after Amgen’s Amjevita.

The EMA’s recommendation came just months after a U.K. court ruled it would not enforce AbbVie’s European patents on Humira for treating rheumatoid arthritis, psoriasis and psoriatic arthritis.

RELATED: Humira facing building pressure in EU as Samsung, Biogen get nod for biosimilar

Meanwhile, the Illinois company is already bracing for Humira’s decline. In May, UBS Analyst Marc Goodman reported in a note to investors that AbbVie executives are predicting Humira will peak overseas next year before biosimilars take a significant bite out of sales. Then it expects to see international sales decline 15% a year through 2020.