Roche has revealed final analysis from a Phase IIIb study confirming the ‘favourable’ safety profile of its haemophilia A treatment Hemlibra.

The final analysis of the STASEY study included data from 193 participants with haemophilia A with factor VIII inhibitors who received Hemlibra (emicizumab) prophylaxis once-weekly for up to two years.

According to this analysis, no new cases of thrombotic microangiopathy or serious thrombotic events related to Hemlibra were identified.

In this study, the most common adverse events occurring in 10% or more of participants were joint pain (17.1%), common cold symptoms (15.5%), headache (15%), injection site reaction (11.4%) and fever (10.9%).

In addition, 18.1% of participants in the STASEY study reported a Hemlibra-related adverse event, with injection site reactions being the most common.

The study also reinforced findings that Hemlibra is associated with a low incidence of anti-drug antibody (ADA) development, Roche added in a statement.

In the Phase IIIb study, only 5.2% of participants tested positive for ADAs – 2.6% of whom were classified as having ADAs that were neutralising in vitro.

Among all participants who tested positive, ADA development did not affect the efficacy and safety of Hemlibra, Roche added.

“As the treatment landscape evolves, determining the long-term benefit/risk profile of medicines for people living with haemophilia A remains a top priority for the community,” said Levi Garraway, chief medical officer and head of global product development, Roche.

“These results provide further confidence in Hemlibra’s favourable safety profile in people with haemophilia A with factor VIII inhibitors, who have historically faced significant treatment challenges,” he added.

Haemophilia A – a serious inherited condition in which a person’s blood does not clot properly – is believed to affect around 900,000 people globally.

People with haemophilia A either lack or do not have enough of the clotting protein factor VIII, with a serious complication of treatment being the development of inhibitors to factor VIII replacement therapies.