South Korean pharmaceutical giant Celltrion is in the spotlight after investors reacted coolly to a positive report on Phase 2 clinical trial results for its Covid-19 treatment, partly because U.S. health authorities had already authorised a rival treatment.

The market capitalizations of Kosdaq-listed Celltrion Healthcare and Celltrion Pharm shrunk by a combined four trillion won ($3.6 billion) in just one week after the report on Covid-19 candidate CT-P59, which is also known as Regkirona or regdanvimab.

Celltrion said on January 13 that CT-P59 reduces the recovery time for infected patients and decreases the likelihood of Covid-19 patients developing a severe infection, which would require hospital care, by 54%.

But investors were not impressed. The market capitalization of Celltrion Healthcare and Celltrion Pharm, which are the largest and second largest biotech firms in the tech-heavy Kosdaq market, had fallen 12% and 15% to 21.77 trillion won and 6.7 trillion won respectively from a week earlier when trading ended on January 15.

On the main bourse of the South Korean stock market, the market capitalization of Celltrion decreased by 5 trillion won to 44.4 trillion won during the same period.

The share price movements were partly in response to the U.S. Food and Drug Administration’s decision to grant emergency authorization for a Covid-19 antibody treatment made by Eli Lily and Regeneron. Prospects for positive clinical trial results by Celltrion may have already been reflected in its share prices.

In contrast, the share prices of Hugel and Oscotec rose by 9.5% and 6.5% respectively, while Cellivery Therapeutics and Dong Kook Pharmaceutical were up 0.4% and 3.7%.

Hugel holds sixth position among the top 20 pharmaceutical, biotech and healthcare companies listed on the Kosdaq, with a market capitalization of 2.47 trillion won. It has been awarded a sales license by China’s National Medical Products Administration and aims to secure more than 50% of the South Korean botulinum toxin market and 10% of the Chinese market this year.

Oscotec was ranked 13th with a market capitalization of 1.5 trillion won. Its share price recovered after losing 500 billion won in the previous week, amid hopes that the Ministry of Food and Drug Safety would approve Yuhan’s lung cancer treatment, lazertinib. Oscotec would receive royalty fees under a 2015 licensing deal with Yuhan.

Helixmith’s market capitalization has grown to 1.026 trillion won since its new shares were listed on January 12, and it has joined the top 20 in the rankings for the first time in four months. (Reporting by Aran Sim)