SK Chemicals said on the 11th it has launched Joinst-Filmtab 300 mg (Joinst F), a version of its osteoarthritis drug "Joinst" with a higher amount of the active ingredient.
Joinst F is a high-dose product that increases the active ingredient 1.5 times compared with the existing "Joinst 200 mg." The recommended daily dose is 600 mg, allowing twice-daily dosing instead of three times a day for the existing product. Joinst recorded cumulative sales of 700 billion won on Feb.
Osteoarthritis is a representative chronic disease that occurs with aging, and many patients take medications for a long period to manage symptoms. The company expects the high-dose formulation, which reduces the number of doses, to improve dosing convenience.
Drug costs are also expected to decrease in part. The maximum reimbursed price of Joinst F, which was listed for coverage on the 1st of this month, is 488 won. Based on dosing directions, the daily drug cost is 976 won, about 16% lower than the 1,170 won per day for the existing Joinst 200 mg.
Although Joinst F increased the amount, the tablet size grew only about 5–10% compared with the existing product, and the thickness was actually reduced to lessen the burden when taking it.
The original Joinst, launched in 2002, was Korea's first natural-origin drug with three herbal extracts—Clematis mandshurica, Trichosanthes kirilowii radix, and Prunella vulgaris—as active ingredients. Long-term prescribing has since confirmed pain improvement and safety.
A phase 3 study of Joinst F released by SK Chemicals showed similar results. The study enrolled 278 patients aged 20–75 with primary knee osteoarthritis and was conducted over 12 weeks by administering Joinst F and nonsteroidal anti-inflammatory drugs (NSAIDs) separately.
The results showed effects equivalent to existing anti-inflammatory analgesics in assessments of joint pain and function improvement, with no significant difference in the incidence of adverse events. No serious adverse events were reported.
SK Chemicals plans to strengthen its push into the symptomatic slow-acting drugs for osteoarthritis (SYSADOA) market based on data obtained from additional clinical trials. SYSADOA refers to a class of treatments taken long term to relieve pain and improve joint function in patients with osteoarthritis.
According to the pharmaceutical market research firm IQVIA, the domestic SYSADOA market size in 2025 was tallied at about 196 billion won. It has posted an average annual growth rate of about 5% over the past five years. Among these, Joinst recorded sales of about 59.5 billion won last year, taking around a 30% market share.
Park Hyun-seon, head of business at SK Chemicals, said, "Osteoarthritis is common among older adults, and when symptoms worsen, it can lead to reduced activity and a decline in quality of life," adding, "We will continue to improve dosing convenience by reflecting the opinions of patients and the medical field."