ZURICH, June 26 (Reuters) - Roche's investigational haemophilia drug emicizumab cut the bleed rate by 87 percent in patients who had developed resistance to standard treatment, compared with those who instead got bypassing agents, the Swiss company said on Monday.
Roche is counting on emicizumab to wrest a share of the $11 billion-a-year haemophilia drug market now dominated by traditional treatments from Novo Nordisk and Shire .
The drugmaker released the data ahead of the International Society on Thrombosis and Haemostasis (ISTH) industry meeting in Berlin next month.
In the late-stage study, 62.9 percent of patients receiving emicizumab experienced zero treated bleeds compared to 5.6 percent of those receiving so-called bypassing agents, Roche said.
Haemophilia patients' blood does not clot properly, requiring life-saving infusions of clotting factors.
Development of resistance, or inhibitors, in many of those being treated can interfere with efforts to control their bleeding, so Roche is hoping its drug, also known as ACE910, will offer a new avenue of treatment.
Analysts called Monday's data release convincing, with Jefferies saying it underpins its $5 billion peak sales estimate for the medicine.
"If full presentation of the data at the ISTH reassure on safety, our mid-term EPS estimates and valuation could increase by 2 percent to 4 percent," Jefferies' Jeffrey Holford wrote in a note to investors.
Still, analysts continue to cite several adverse events in Roche's studies including thrombotic microangiopathy - damage to blood vessels in vital organs -- that accompanied repeated high doses of bypassing agents to treat breakthrough bleeds.
Though Roche has said one death came after a patient refused a blood transfusion for religious reasons, analysts' concern remains.
"From a safety perspective, treatment with this drug will require physicians to carefully manage the use of bypassing agents," wrote Vontobel's Stefan Schneider. That "could limit uptake", he said.
Roche plans to file the drug with the U.S. Food and Drug Administration for approval for patients with inhibitors later this year, with follow-on submissions in 2018. (Reporting by John Miller, editing by Louise Heavens)