Amgen/UCB Poised For Osteoporosis Drug Filing On Back Of Mixed PhIII
This article was originally published in Scrip
Amgen Inc. and partner UCB will file their osteoporosis drug romosozumab this year on the back of mostly positive Phase III data in postmenopausal women – but where will the drug be positioned against Amgen's own Prolia (denosumab) and other available treatments?
The Phase III FRAME study testing romosozumab, an investigational bone-forming monoclonal antibody, in postmenopausal women with osteoporosis met its co-primary endpoint of reducing the incidence of new vertebral fracture through months 12 and 24. The data showed that women receiving subcutaneous injection of romosozumab monthly experienced a significant 73% reduction in the relative risk of a spine fracture through 12 months compared to those receiving placebo. Furthermore, the effect size persisted after both groups were transitioned to being treated with Prolia through the second year of treatment.
Specifically, through month 24, romosozumab followed by Prolia reduced the relative risk of new vertebral fractures by a 75% compared to placebo followed by Prolia.
However, in the trial the secondary endpoint of reducing the incidence of non-vertebral fractures through months 12 and 24 was not met.
Amgen and UCB anticipate a filing for romosozumab later this year, and the companies are currently holding discussion with global regulators. Still, analysts at Sagient Research's BioMedTracker noted that while the data for vertebral fractures is impressive, there is a large medical need for reduction in non-vertebral fractures as well.
BioMedTracker analysts highlighted that Radius Health, a biopharma company focused on osteoporosis therapies, released Phase III data in late 2014 showing statistically significant reduction for both vertebral and non-vertebral example fractures in patients treated with its drug, abaloparatide. "While this comparison will not affect the likelihood of approval of romosozumab, it could have implications for romosozumab's clinical uptake," BioMedTracker said.
Analysts added that ARCH, a second Phase III pivotal trial for romosozumab, is expecting top-line data in 2017. "ARCH enrolled a less healthy cohort of patients (postmenopausal women with at least one vertebral fracture). It will be interesting to see if romosozumab will reduce non-vertebral fractures in this population," analysts at BioMedTracker said.
BioMedTracker has granted romosozumab a likelihood of approval rating of 65%, 5% above the average for a product at a similar stage of development.
Competition
Romosozumab, if successful in gaining regulatory approval, will become the second fully-human mAb for use in osteoporosis patients, following in Prolia's footsteps. However, Amgen's marketed product is usually reserved for more serious cases. It is indicated specifically for postmenopausal women with osteoporosis at high risk for fracture, defined as a history of osteoporotic fracture, or multiple risk factors for fracture; or patients who have failed or are intolerant to other available osteoporosis therapy.
As such Amgen will be aiming to align the two products on the market, with romosozumab taking up a primary use position before patients with more serious cases transition to Prolia use. This plan is reflected in the interesting trial design for the Phase III FRAME study. It will avoid Amgen cannibalizing its own product with a new launch in the same patient population. Amgen re-acquired all rights to Prolia (60mg denosumab) and Xgeva (120mg denosumab) in 48 countries from previous licensee GlaxoSmithKline plc, in December 2015.
Amgen and UCB's more serious opposition will come from already approved first-line therapies such as the aging bisphosphonate drug class, which includes Merck & Co.'s Fosamax (alendronate), Allergan plc's Actonel (risedronate), Roche's Boniva (ibandronate sodium) and Novartis AG's Aclasta (zoledronic acid). The pair will have to demonstrate romosozumab's benefit over these generically available treatments and other late-stage pipeline products, like Radius' offering.