Roche’s bid to enter the multibillion-dollar market for haemophilia drugs has moved closer, after its lead candidate for haemophilia A cleared a phase III trial.
Emicizumab (ACE910) – discovered by Roche’s Japanese affiliate Chugai – is a double-headed (bispecific) antibody targeting clotting factors IXa and X and mimics the function of factor VIII, the usual treatment for haemophilia A.
Emicizumab is being positioned initially as another treatment option for haemophilia A patients who develop a type of antibody (inhibitor) that attacks their factor VII drug, reducing its ability to stop blood clots. Inhibitor development is currently the most significant treatment complication seen in patients with haemophilia, estimated to occur in 5% to 13% of patients, depending on the severity of their disease.
The HAVEN 1 showed prophylactic dosing of emicizumab achieved a statistically significant reduction in the number of bleeds over time compared to no prophylaxis in haemophilia A patients aged over 12 with inhibitors. Roche says it intends to discuss the data with regulatory authorities in 2017 with a view to filing for marketing approval.
“Since the mid-1990s, there have been incremental improvements in the treatment of haemophilia A with inhibitors,” said Alain Baumann, chief executive of the World Federation of Haemophilia (WFH).
“The current burden of treatment is significant [and] filling this need would be a significant advance in our quest to achieve ‘Treatment for All’, including those living with inhibitors.”
Analysts at Credit Suisse have suggested that sales of emicizumab could be $600m in 2020 for haemophilia A patients with inhibitors, rising to $1bn if Roche and Chugai can also gain approval for non-inhibitor patients.
If approved, emicizumab will break into a market split between Shire (Baxalta), Bayer, Novo Nordisk, Pfizer and CSL Behring for many years.
Biogen joined the pack in 2014 with the launch of longer-acting therapies for haemophilia A and B – also tipped as potential blockbusters – and the established players are also rolling out improved and longer acting products.