Radius Health Inc. won FDA approval, albeit mildly delayed, of injected Tymlos (abaloparatide) for postmenopausal women with osteoporosis at high risk for fracture defined as history of osteoporotic fracture, multiple risk factors for fracture, or patients who have failed or are intolerant to other available osteoporosis therapy.

"We are impressed with the rapid approval just one month into what was expected to be three-month PDUFA extension," J.P. Morgan analyst Jessica Fye wrote in a research report, adding that she "see[s] today's news as a clear positive that should drive the stock higher as this approval transforms Radius into a commercial-stage company. Importantly, the label is in line with our expectations."

Shares (NASDAQ:RDUS) closed Friday at $39.07, up 35 cents.

In mid-March, U.S. regulators offered few details when they pushed the PDUFA date from March 30 to June 30, saying they needed more time. The company said the holdup was not related to manufacturing of Tymlos, a synthetic peptide analogue of human parathyroid hormone-related protein. (See BioWorld Today, March 13, 2017.)

Behind subcutaneously (SC) delivered Tymlos in Radius' pipeline is a transdermal (TD) patch version for which investors hold high hopes. Canaccord analysts have predicted that the TD formulation could overtake the SC version by the end of 2022, though it's yet to be seen whether the FDA will accept a bioequivalence study of the TD formulation now that the SC version is approved, or if Radius will be required to perform a separate bone mineral density study. Officials at Waltham, Mass.-based Radius scheduled a conference call for Monday with investors to discuss the approval.

In preparation for the launch of Tymlos, Radius has been beefing up its sales force, recruiting personnel from the likes of osteoporosis player Amgen Inc., of Thousand Oaks, Calif., and Indianapolis-based Eli Lilly and Co., and the firm is expected to target high-volume prescribers of Lilly's Forteo (teriparatide) at first.

Radius' marketing authorization application for SC abaloparatide for postmenopausal osteoporosis was validated and is undergoing regulatory review by the EMA.

Jefferies analyst Eun Yang said the Tymlos approval "has been largely expected." In a report, she compared the label with that of Forteo, approved in 2002. The Lilly drug bears a black-box warning for "potential risk of osteosarcoma" vs. Tymlos' black-box warning for "risk of osteosarcoma," she noted, with both labels recommending against use in patients at increased risk of osteosarcoma.

Other warnings in the Tymlos label include a recommendation to monitor orthostatic hypotension and hypercalciuria/ urolithiasis, and to avoid use in hypercalcemia patients. Forteo's label recommends monitoring serum/urinary calcium, serum uric acid, and orthostatic hypotension, warning against use in patients with Paget's disease of bone, open epiphyses, prior external beam/ implant radiation, bone metastases, history of skeletal malignancies, and metabolic bone disease or hypercalcemic disorders.

"While FDA approval is positive, we continue to see significant commercial hurdles as likely given the competition," Yang wrote, referring to Forteo.

Also, Amgen's romosozumab is nearing its PDUFA date of July 19, and a generic Forteo entry could come as early as 2019. What's more, the wide use of Amgen's Prolia (denosumab) has been delaying use of anabolic agents such as Forteo and Tymlos.

Last February, Amgen and partner UCB SA, of Brussels, Belgium, unveiled their long-awaited phase III data for romosozumab on reducing the risk of fracture in osteoporosis. Although romosozumab hit the primary endpoint of reducing the risk of new vertebral fracture over 12 and 24 months, the effect size was deemed inferior to that attained by Radius' abaloparatide. (See BioWorld Today, Feb.23, 2016.)