Novo Nordisk has halted the development of its haemophilia drug vatreptacog alfa after patients developed antibodies to the medicine.
The company dropped vatreptacog alfa, which was intended to stop bleeding in patients with haemophilia and inhibitors, following phase III trial results showing the immune system of several patients had targeted the treatment, including one with a “potentially neutralising effect”.
This trial involved 72 haemophilia patients with an existing inhibitor – an antibody to the product used to treat or prevent bleeding episodes.
These patients were treated on demand with either vatreptacog alfa or Novo's NovoSeven. Both drugs demonstrated an ability to stop bleeding episodes, with 93 per cent of incidents halted with three doses or less of either medicine.
The vatreptacog alfa findings contrast with previous research into NovoSeven, during which no anti-drug antibodies have previously been reported when used for haemophilia patients with inhibitors.
NovoSeven will soon lose patent protection and vatreptacog alfa had been touted as a replacement product for the company. However, the risks associated with development of anti-drug antibodies in patients taking vatreptacog alfa, including antibodies that also targeted NovoSeven, look to have ended Novo's hopes that the investigational drug would help cover the $1.43bn black hole in sales it faces from generic competition to NovoSeven.
Novo's financial results have already taken a hit from declining sales of NovoSeven, which fell six per cent during the first quarter of 2012.
The Danish pharma firm attributed this to "a low level of surgeries involving NovoSeven treatment, stricter budgetary controls in hospitals, a low level of acquired haemophilia cases and also an increase in inhibitor patients participating in clinical trials".