(Bloomberg) -- The European Commission approved BeiGene Ltd.’s cancer drug Tevimbra, making it the first medicine of its kind developed in China to become available in the profitable, increasingly crowded western market. 

Despite the approval, BeiGene and Novartis AG jointly ended the partnership they entered into in 2021 to develop the drug, the second such termination between the companies in a little more than two months. 

BeiGene’s shares fell as much as 4.5% in Hong Kong on Wednesday, while shares traded in Shanghai dropped as much as 4.4%, the most in six weeks.

Tevimbra was approved for adults with a type of esophageal cancer that worsened after an initial treatment, the Beijing-based drug maker said in a filing Tuesday. Tevimbra is a so-called PD-1 inhibitor, similar to Merck & Co.’s blockbuster Keytruda, which harness a patient’s immune system to fight tumors. It’s also under review by the US Food and Drug Administration. 

While Tevimbra is widely used in China, the European approval marks this kind of therapy’s first successful foray into the western countries that account for the majority of PD-1 sales. Analysts expect the market, dominated by Merck and Bristol-Myers Squibb Co., to peak at $56.3 billion globally in 2026. 

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BeiGene is among a flurry of Chinese biotech firms that emerged during the past decade as Beijing embarked on a health care overhaul designed to encourage homegrown pharmaceutical innovation. The company made history in 2019 when its blood cancer therapy Brukinsa become the first Chinese cancer drug to be approved in the US.

Success in getting innovative therapies that were developed in China approved in the US and Europe has remained elusive for many companies. Chinese drugmakers have faced questions ranging from the patient composition in their clinical trials to their ability to prove the medicines work better than the current standard of care. 

Last year the FDA turned down Innovent Biologics Inc.’s application for approval of its PD-1 therapy, while another cancer medicine from HutchMed China Ltd. was also rebuffed. 

Read more: China’s $220 Billion Biotech Ambition Struggles to Take Off

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