(Reuters) – China’s Bio-Thera Solutions Ltd has won a regulatory approval for its version of AbbVie Inc’s blockbuster rheumatoid arthritis treatment Humira, paving the way for the first such biosimilar to enter the world’s second-largest drug market.

Humira is the world’s top-selling drug, with sales of $20 billion last year, but now faces competition from cheaper versions in Europe and a 2023 expiration of its patents in the United States, by far the most profitable market.

The National Medical Products Administration (NMPA), in a statement on its website on Thursday, said Bio-Thera’s Qletli “was highly similar to the approved reference drug in terms of quality, safety and effectiveness.”

The drug has been approved for the treatment of three autoimmune diseases, including rheumatoid arthritis, ankylosing spondylitis, and plaque psoriasis, Bio-Thera said in separate a statement https://www.bio-thera.com/EN/ShowNews.asp?id=60.

“The NMPA approval of Qletli is a very important milestone for our biosimilar portfolio, providing an new affordable treatment option for patients in China with several types of autoimmune diseases,” Bio-Thera CEO Shengfeng Li said.

(Reporting by Roxanne Liu in Beijing and Shubham Kalia in Bengaluru; editing by Uttaresh.V)