Celltrion Inc., a South Korean biopharmaceutical company, said Wednesday its second-quarter net profit plunged 48 percent from a year earlier due to costs following a merger with its sales and marketing affiliate last year.

Its net profit came to 78.5 billion won ($57.1 million), compared with 150.9 billion won a year ago, the company said in a regulatory filing.

Its operating profit also decreased 60.4 percent on-year to 72.5 billion won, but sales jumped 66.9 percent to 874.7 billion won.

Despite strong sales, the company said its net profit decreased due to cost-related effects from its merger with Celltrion Healthcare in December, including bigger inventory and amortization of intangible assets.

But Celltrion's quarterly sales surpassed 800 billion won for the first time in the April-June period, driven by the robust performance of its biosimilar products in global markets.

The combined market share of Remsima and Remsima SC, the subcutaneous version of the autoimmune disease treatment, hit 75 percent in Britain, Germany, France, Spain and Italy as of the first quarter.

Celltrion's other blockbuster biosimilars, Truxima and Herzuma, also had market shares of 25 percent and 21 percent in Europe, respectively.

The company said it listed Zymfentra, its new autoimmune disease treatment, on the formularies of three major pharmacy benefit managers in the United States and raised 220 million won of initial sales in the country.

Celltrion's third production facility also plans to start operations later this year to expand the company's manufacturing capacity to 250,000 liters. (Yonhap)