Amgen-UCB bone drug cuts fractures in osteoporosis for older women

New data for Amgen and UCB’s bone drug romosozumab (aka romo) showed it could help lower certain fractures in older women as it awaits an FDA approval decision next year.

In new figures posted in The New England Journal of Medicine, the two companies said their co-developed experimental med romo “significantly reduced the incidence of vertebral fractures in postmenopausal women with osteoporosis” through one and two years, hitting its co-primary endpoints.

The Phase III Frame study of more than 7,000 women saw romo--an antibody designed to block the protein sclerostin--injected once a month created a statistically significant 73% reduction in the relative risk of a new vertebral (spine) fractures over a year, the first primary endpoint, when compared to a dummy treatment (fracture incidence 0.5% versus 1.8%).

It also hit the second primary endpoint in those who were given romo in the first 12 months and had their fracture risk reduction continued after two years, and after both groups moved on to Amgen’s marketed bone drug Prolia (denosumab) in the second year of the study. In this part of the study, there was a statistically significant 75% reduction in the risk of vertebral fracture at month 24, according to the companies’ statement.

It missed one of its secondary endpoints, however, with romo seeing a 25% reduction compared to placebo in the relative risk of nonvertebral fractures through month 12--but this was not statistically significant.

The biopharma was, however, still positive on the data, with Sean Harper, EVP of R&D at Amgen, saying: “These positive Frame study results are the basis of our Biologics Licensing Application that we submitted to the FDA in July, and we look forward to working with regulatory authorities to help make this potential treatment option available to patients.”

This also builds on positive data posted just over a year ago when romo met its main goal in a late-stage trial, clearing what was then its first Phase III hurdle by besting Eli Lilly’s ($LLY) blockbuster osteoporosis drug Forteo (teriparatide), which is approved for men and women. The drug is however set to succumb to biosimilars by 2018. 

Amgen ($AMGN) and UCB first planned to develop romosozumab as a bone-healing agent but ditched that indication in 2013 in light of the antibody's Phase II performance, pivoting to the more lucrative osteoporosis market.

Back in March, romo also hit its Phase III Bridge study primary endpoint of increasing bone mineral density of lumbar spine at 12 months, when compared with placebo, in men with the bone-wasting disease.

The drug is in a race with rival biotech Radius Health ($RDUS) and its treatment abaloparatide. Radius is set for an EU approval by the end of the year, and is also filing for an FDA endorsement in 2017. But where Radius’ drug is injected daily, Amgen's treatment is only once a month--giving it a big advantage when it comes to administration, although some analysts believe Radius' med may be more effective. 

The consensus forecast for romo is for a 2017 launch with 2020 revenue of $650 million--although analysts at Leerink have previously posted a much more pessimistic sales figure of $390 million, to as low as $230 million--by the end of the decade. Meanwhile, abaloparatide could bring in $467 million by 2022, according to EvaluatePharma sell-side consensus. 

A month ago, Cambridge, MA-based Radius posted new results from its late-stage trial in women with osteoporosis as it looks to shore up its data ahead of an expected U.S. approval next spring.

The data, published in JAMA, showed that nearly 2,500 female osteoporosis patients in the Active Phase III trial, when treated with a daily injection of abaloparatide for 18 months, had a significantly greater reduction in the incidence of new vertebral fractures when compared to placebo.

Abaloparatide works as a synthetic peptide that engages the parathyroid hormone receptor and is designed to help with bone-building activity.