Ten years have passed since Amgen’s “Prolia,” the so-called first biological drug to treat osteoporosis, hit the foreign market. Ahead of its launch in the Korean market, industry watchers wonder whether it can create a sensation here, too.

Bisphosphonate drugs have dominated the domestic osteoporosis therapy market of about 200 billion won ($177 million). Despite concerns about side effects, such as jawbone necrosis, people have used these drugs for a long time because they were cheap and there had not been proper alternatives.

As Lily’s “Forsteo” (Teriparatide), a bone formation accelerator PTH parathyroid hormone), began to receive insurance benefits recently, and Prolia is expected to do so shortly, changes are likely in store in the market structure, however.

Prolia in particular, which has secured the ease of taking medicine, long-term safety and cost effectiveness, is likely to be the eye of a typhoon in the osteoporosis therapy market.

Prolia has won the approval as the therapy to treat women with osteoporosis patients after menopause, and to increase bone density in men with osteoporosis in Korea, and had been used as the primary treatment in the United States.

Given the situation, it is appropriate for Prolia to compete directly with bisphosphonate drugs as the first therapy. As seen from the case of Forsteo, however, the situation can turn out to be different

Forsteo has also won the approval as the drug to treat osteoporosis in women after menopause and of men with high risks of fracture as well as to treat osteoporosis of women and men with high risks of fracture about continuous glucocorticoid therapy, but the standard for insurance coverage was different.

The regulatory authorities have limited the beneficiaries of insurance benefits to only patients who fail to see effects from or cannot use one or more of the bisphosphonate drugs. Even among them, the would-be recipients should be 65 or older, have T-Score of –2.5 SD or lower as a result of bone density test measured at the bone center by dual energy radiation absorbers, and had more than two osteoporosis-related fractures.

Its drug price is unlike to show much difference from bisphosphonate drugs.

Patients have only to pay 20,000-30,000 won ($17.7-$26.6) a month for the best-selling drug among bisphosphonate drugs, Fosamax (compound: alendronate, one time a day), and vitamin-D complex Fosamax Plus Dtm (one time a week). Forsteo’s drug price is 320,000 won a month.

The price of Prolia is also in the 300,000-won range like Forsteo’s, but given it is a subcutaneous injection administered once every six months, the drug price patients pay is in the 50,000-won range. The price will go down further if it gets medical coverage.

‘Prolia is more economical than bisphosphonate drugs’

According to Amgen, as a result of the cost effectiveness study of denosumab vs. oral bisphosphonates for postmenopausal osteoporosis, released in the U.S. in 2013, the incremental cost-effectiveness ratio (ICER) of Prolia was $7,900 per quality-adjusted life year (QALY), showing the highest price effectiveness of all competing drugs. They conducted the study on women 70 or older with osteoporosis after menopause and who had T score -3.0 or lower with experiences of a spine fracture.

In the study of cost-utility of denosumab for the treatment of postmenopausal osteoporosis in Spain in 2015, too, Prolia reduced the fracture risk most compared with other therapies while drastically increasing QALY figures.

According to the study of 10 years of denosumab treatment in postmenopausal women with osteoporosis published in Lancet, osteoporosis, when used as primary therapy, osteoporosis patients showed a significant increase in bone density in the third year of use.

Also, when they went ahead with treatment with Peoria, the bone density increased continuously for 10 years especially in the hip joint that has lots of cortical bone (hard part that constitutes outer sides of bones) without the interruption of treatment.

The study evaluated the safety and drug tolerance of Prolia for 10 years on 4,550 women aged 60-90 with osteoporosis after menopause who had T score of -2.5- -4.0 of bone density in the lumbar or whole hip joints.