Swedish Orphan Biovitrum (Sobi) has the US approval it sought for Gamifant, an ultra-rare disease therapy it licensed from Novimmune for $452m a few months ago.
Gamifant (emapalumab) – an antibody which neutralises interferon gamma – has been cleared by the FDA for primary haemophagocytic lymphohistiocytosis (HLH), an orphan disease characterised by widespread destruction of blood cells, extremely high iron levels in the blood, coagulation problems and excessive growth of organs.
There is currently no approved treatment for HLH, a genetic disorder which can be passed on by carrier parents or occur as a spontaneous mutation and results in overexpression of IFN gamma that in turn causes an autoimmune-like syndrome. Symptoms develop shortly after birth and it can be fatal if left untreated.
Gamifant was tested in a phase 2/3 clinical trial involving 27 paediatric patients with HLH who were not responding to the first-line therapy with corticosteroids, immune-suppressing drug methotrexate, and chemotherapy drug etoposide, which is used to prepare patients for a haematopoietic stem cell transplant (HSCT), which has improved survival rates in HLH in recent years but still carries a high risk of mortality.
In non-responders, Gamifant achieved a 63% response, and in 70% of cases patients were well enough to proceed to a stem cell transplant, according to an FDA statement.
Sobi says it plans to launch Gamifant early next year, but hasn’t yet revealed what it intends to charge for the drug, which is delivered as an intravenous infusion twice a week until the transplant procedure.
The Swedish company took a global license to the drug from Switzerland-based Novimmune in July, saying at the time that Gamifant could eventually develop into a $330m product, assuming it can also get approval in follow-up indications such as secondary HLH and acute graft failure in HSCT. It’s the first IFN gamma inhibitor to be approved for marketing.
In Europe, emapalumab has been granted orphan designation and PRIME (PRIority MEdicine) status by the EMA, and has been filed for approval with a verdict due in 2019.
Earlier this month, Sobi agreed to acquire the US rights to AstraZeneca’s respiratory syncytial virus (RSV) prevention drug Synagis (palivizumab) in a deal worth $1.5bn.
Sobi’s Guido Oelkers
“Gamifant will add significant strength to Sobi’s Immunology franchise, along with Kineret and the recent acquisition of the US rights to Synagis,” said Sobi President and CEO Guido Oelkers.
We would like to acknowledge the excellent work done by Novimmune to develop and bring this important treatment to approval and Sobi will now focus on ensuring a successful commercialisation of Gamifant for the benefit of HLH patients in the US.”