Seo Jung-jin, the founding chairman of South Korean biopharmaceutical company Celltrion, has officially taken the 10th spot in the country’s list of stock rich billionaires, following Celltrion Healthcare’s initial public offering last Friday.

Celltrion Healthcare, the sales and marketing subsidiary of Celltrion, went public on the Kosdaq on Friday. Its shares soared 15.23 percent from its initial offering price to close at 53,000 won ($47.30), with its market capitalization at 6.88 trillion won, the second-largest on the bourse.

The firm’s Kosdaq debut raised the value of Seo’s stocks in ownership to 2.49 trillion won, making him Korea’s 10th stock rich billionaire, according to market research firm Chaebul.com on Sunday.

Seo owns a 36.2 percent stake in Celltrion Healthcare. Though Seo does not directly own any shares of Celltrion, he owns a 93.9 percent stake in Celltrion Holdings, an unlisted holdings company that controls the Celltrion Group.

The combined market cap of Celltrion, the top valued-company on the Kosdaq, and its now-public subsidiary Celltrion Healthcare currently reaches more than 20 trillion won.

Seo, 60, is the second non-chaebol, self-made businessman to be joining Korea’s top 10 richest stockholder list after Netmarble Games founder and Chairman Bang Jun-hyuk, who is currently in sixth place with shares worth 3.2 trillion won.

Both established by Seo, Celltrion develops biosimilars -- cheaper, near-replicas of live cell biologic drugs whose patents have expired -- while Celltrion Healthcare sells and distributes Celltrion’s drugs overseas.

Seo, a former salaryman at the now-defunct Daewoo Motors, founded Celltrion in 2002 to specialize in developing biosimilars, which he foresaw would form a huge industry after the patent expiry of some of the world’s most profitable drugs.

Celltrion was the first company to launch a biosimilar referencing Johnson & Johnson’s Remicade in Europe and the US, and has benefited from its exclusive market status.

It is also the only company currently selling a biosimilar referencing Roche’s Rituxan in Europe under the name Truxima. Celltrion has filed Truxima for approval by the US Food and Drug Administration. Its Herceptin-referencing biosimilar is also awaiting approval by the European Medicines Agency.

Meanwhile, members of the owner families of Korea’s top conglomerates were included in the country’s top 10 stock rich billionaires list.

Lee Kun-hee, the chief of Samsung Electronics ranked No. 1 with shares worth 17.96 trillion won, followed by his only son Lee Jae-yong with 7.85 trillion won.

Suh Kyung-bae, the chairman of Korea’s biggest cosmetics maker Amorepacific, came in third with 7.47 trillion won. Hyundai Motor Chairman Chung Mong-koo ranked fourth with 4.85 trillion won, while SK Group Chairman Chey Tae-won ranked fifth with 4.39 trillion won.

By Sohn Ji-young (jys@heraldcorp.com)