Amgen keeps dominating Korea’s osteoporosis treatment market

Amgen Korea, which had conquered Korea's osteoporosis treatment market with Prolia and Evenity, set a new milestone last year by becoming the first company to surpass 100 billion won ($81.3 million) in annual sales.

According to IQVIA, a drug market research company, sales of Prolia's (ingredient: denosumab) and Evenity (Ingredient: romosozumab-aqqg) reached 92.1 billion and 12.3 billion won in 2021, up 22.7 and 220.3 percent from the previous year. As a result, the combined sales of the two products amounted to 104.4 billion won.

Evenity reduces the bone formation of osteoblasts, promotes bone resorption of osteoclasts, targets sclerostin, a protein that inhibits bone formation, and has a dual effect of inhibiting bone resorption and increasing bone density. In addition, Prolia is the first biologic drug in osteoporosis treatment that targets RANKL (Receptor Activator of Nuclear Factor Kappa-B Ligand), a protein essential for the formation, activation, and 솓 the survival of osteoclasts that destroy bones.

In patients with high-risk osteoporosis who have a fracture or a high risk of fracture, the current treatment strategy is to continue treatment with Prolia after receiving Evenity. Thanks to such an atmosphere, Amgen is dominating the osteoporosis treatment market.

Also, the company may further increase its reach in the market if it could expand reimbursement scope for the two drugs.

The treatment period for osteoporosis drugs is based on the T-Score, a value of bone density. Only patients with a T-Score of -2.5 or less are eligible for reimbursement. If the number is higher than -2.5 during a follow-up of one year after the treatment’s administration, the health authorities do not provide further reimbursement.

However, Korean physicians have long urged the government to change the reimbursement criteria, arguing that the baseline of -2.5 is an obstacle that makes continuous treatment difficult.

These doctors have claimed that those exposed to the risk of osteoporosis are not receiving treatment continuously due to overly strict standards.

The Korean Society for Bone and Mineral Research called for improving the osteoporosis treatment environment by, for instance, increasing pay for the early treatment to prevent re-fractures in high-risk groups and ensuring continuous administration of advanced new drugs for osteoporosis.

"Korea is the only country in the world where it is difficult to continue treatment because of the reimbursement standards that limit treatment period for osteoporosis drugs based on the bone density T value," Professor Lee Yu-mi of the Department of endocrinology at Severance Hospital said at an online policy debate on Monday.

For bone resorption inhibitors that have confirmed their safety and efficacy for increasing bone density for a long time according to the latest international guidelines, the government should improve reimbursement standards so that hospitals can continuously treat osteoporosis without limiting the administration period according to bone density, Lee added.

In contrast to the success of Prolia and Evenity by becoming a standard treatment, the sales of bisphosphonate-based drugs have continued to decline in 2021.

Lily's Forsteo, preciously touted as the strongest player in the market, saw a 24.8 percent decline in sales, from 17.1 billion won in 2020 to 12.9 billion won last year.

During the same period, Daewoong Pharmaceutical's Daewoong Zoledronic Acid Inj. also fell 12.9 percent from 11.2 billion won to 9.8 billion won.

Only MSD's Fosamax lineup maintained its sales by recording 12.1 billion won in 2021, down 100 million won from the previous year.