Amgen's 'Dmab' in need of differentiation: analyst
Trial results for an Amgen pipeline drug showed the biologic is comparable to existing therapies in its ability to boost bone density in women with cancer.
Denosumab (Dmab) is being studied for use as a twice-yearly injection in women taking hormone blockers to fight breast cancer. It's not the biggest market for Dmab. That would be postmenopausal osteoporosis, for which Wall Street is predicting $2 billion in sales. But the oncology data gave investors a peek at Dmab's efficacy ahead of other results, which Amgen is expected to use to file for the osteoporosis indication, arriving in 2008.
The biotech could use a commercial hit from its pipeline, especially after the pasting its anemia drugs Epogen and Aranesp took this year. That added to interest in the latest results. At 24 months, bone mineral density in the denosumab arm of the trial increased to 4.2% compared to placebo. This is in line with available therapies, a clinician from the trial noted in a conference call with analysts.
Despite the promising Phase III trial data and denosumab's ability to meet the trial endpoint, it may not be enough to distinguish the product, especially with Merck's Fosamax (alendronate) about to go generic in 2008.
“If Dmab is perceived—as it seems—to not have an obvious advantage over the currently available therapies (the soon-to-be-generic Fosamax and the every-six-month Zometa), then it will probably be relegated to second- or third-line in this setting,” wrote Friedman, Billings, Ramsey analyst Jim Reddoch, PhD, in a research note.
In light of this, Reddoch said an upcoming head-to-head trial vs. Fosamax becomes more important to differentiate Dmab. The head-to-head study, slated to be reported early next year, “could help Amgen make a stronger case for first-line use,” he noted. So could a three-year bone fracture study slated to arrive in the second half of 2008.
IMS Health estimates the US osteoporosis market at $4.3 billion, half of which is comprised of oral bisphosphonates including Fosamax, Procter & Gamble's Didronel (etidronate) and Actonel (risedronate), Roche/GlaxoSmithKline's Boniva (ibandronate) and Novartis' Aredia (pamidronate). Zometa/Reclast (zoledronic acid), sold by Novartis, is administered as an infusion.