Osteoporosis prevention and treatment has been rather overlooked in Korea, despite increasing medical burden and number of afflicted patients, according to Park Ye-soo, president of the Korean Society of Osteoporosis, Thursday.

Osteoporosis is a disease that weakens bones over time to make them thinner, more brittle, and more likely to break. The condition afflicts primarily the elderly and, in most cases, occurs without any warning symptoms.

“When patients come to get treatment for a bone fracture due to osteoporosis, it is often too late,” said Park who spoke at Amgen’s news conference in downtown Seoul. “Once a bone breaks, the possibility of a second fracture increases 3.2 times, the third by 9.8 times, and the fourth by 23.3 times. The number of deaths due to osteoporosis is rising as the elderly population grows in Korea – the country with the longest life expectancy in the world.”

The number of Korean osteoporosis patients has, in fact, steadily increased since 2012 to reach 854,215 in 2016, racking up a medical bill totaling 1.16 trillion won ($1.01 billion) over the past five years, according to Park.

The problem gets exacerbated mostly because 80 percent of women with the condition are left undiagnosed, and 90 percent of both males and females are not treating the disease, according to data from the Korean Endocrine Society.

“We need to be preventing osteoporosis before it occurs, but right now we are barely at the treatment stage. This is a crisis,” Park said. “Around 30 percent of people over 50 have the disease, but only one out of 10 patients gets treated while around 80 percent aren’t even aware they have the illness.”

Currently, bisphosphonate drugs are the most popular drugs prescribed to treat the condition. They dominate the Korean osteoporosis market with an 80 percent share, followed by selective estrogen receptor modulators (11 percent), hormone replacement therapy (8 percent), and injections (2 percent).

Bisphosphonate drugs, sold under the brand names of Fosamax and Actonel, slow bone loss by stopping cells that breaks bones down and allowing osteoblasts to continue making new bones.

Most bisphosphonate drugs are priced at around 5,000 won ($4.3) per pill in Korea, which is notably cheaper than newer drugs such as Amgen’s Prolia (215,678 won per injection) and Eli Lilly’s Forsteo (326,500 won per 2.4 mL).

Despite their affordability, experts have called for new types of treatment due to the rising number of reported side effects associated with these drugs.

“Bisphosphonate drugs are most frequently used, but they have been known to cause severe side effects such as kidney failure, gastrointestinal problems, and even fracturing of thigh bones. Many patients have stopped treatment as a result,” said Professor Yang Kyu-hyun of Yonsei University, department of orthopedic surgery.

Statistics showed around 70 percent of patients stopped treatment within a year.

“At this point we can only rely on new drugs [to treat the disease] and then hopefully, the drugs will become cheaper so that everyone can use it,” Park added.

Prolia (ingredient: denosumab) is one such new biologic drug that gained insurance coverage Thursday. The drug has been reportedly priced at 215,678 won ($188) per shot, roughly translating to around 20,000 won per month for patients, according to Amgen.

■ Related : Amgen Korea’s osteoporosis treatment gets insurance coverage

Although Prolia is not without side effects, such as allergic reactions, low blood calcium, and increased risk of broken bones after stopping treatment, the drug is now being eyed as a different type of therapy in the market with promising clinical data.

Lilly Korea, on the other hand, has launched Forsteo, which gained reimbursement in Korea before Amgen’s osteoporosis drug. It is a human-made daily injectable hormone and the only osteoporosis treatment that targets the cells that increase bone density. Although more efficient than bisphosphonates, clinical trials have shown that the drug could raise the risk of a type of bone cancer. The drug, therefore, can only be taken for up to two years.

Although a total of four types of treatments exist, none have proved to be without side effects, leaving domestic clinicians to wonder when, and how, Korea will be able to stop playing catch-up in treating the bone-breaking condition.