The approval of Tislelizumab by the European Commission for non-small cell lung cancer, including first- and second-line use, is a significant milestone for BeiGene. This regulatory approval is likely to enhance the company's market position in Europe, potentially leading to increased sales and revenue. The news directly impacts BeiGene's stock as it reflects the company's growth prospects and its ability to expand its product offerings in key markets. Investors typically view such regulatory approvals positively, as they can lead to higher product sales and market penetration.