The China National Medical Products Administration (NMPA) has recently approved Swedish Orphan Biovitrum’s (Sobi) Gamifant (emapalumab) for the treatment of primary haemophagocytic lymphohistiocytosis (pHLH) in adult and pediatric (newborn and older) patients. Its approval in China will pave the way for targeted treatment of the debilitating disease, says GlobalData, a leading data and analytics company.

According to GlobalData’s Pharma Intelligence Center, there are currently eight drugs across all stages of clinical development for the treatment of HLH globally, with three drugs in Phase II and above. Gamifant is also undergoing a Phase III study, titled EMERALD, for macrophage activation syndrome (MAS) in rheumatic disease, with the rationale for pursuing this indication likely due to MAS being a secondary form of HLH.

Gamifant is the first and only approved therapy for primary HLH globally. The US FDA first approved the biologic in 2018 as a second-line treatment for primary HLH patients, who have refractory, recurrent or progressive disease or intolerance to conventional HLH therapy. The UAE was the second country to approve Gamifant, with approval gained in 2019.

HLH primarily affects infants from birth to 18 months but can affect individuals of any age. There are five subdivisions of HLH, including familial HLH (FHL), familial erythrophagocytic lymphohistiocytosis, primary HLH, secondary hemophagocytic lymphohistiocytosis, and MAS.

Primary HLH is highly underdiagnosed with very high morbidity and mortality. Moreover, its diagnosis is difficult owing to the different signs and symptoms disease sufferers present with. As a result, primary HLH has a dismal prognosis and can rapidly become fatal if left untreated; with a median survival of less than two months after diagnosis. Treatment regimens include immunosuppression, immune modulation, chemotherapy, and biological response modification, followed by hematopoietic stem-cell transplant (HSCT).

Anupama Mishra, Pharma Analyst at GlobalData, comments: “Primary HLH (pHLH) diagnosis is challenging and is a rare hyperinflammatory disorder. The immediate goal of treatment includes controlling inflammation and preparing patients for HSCT. Despite HSCT, many patients experience unfavorable outcomes and severe toxicities. Notably, prior to Gamifant’s approval in 2018, there were no targeted therapies for pHLH, with conventional chemotherapy and steroids forming the mainstay of treatment before HSCT therapies.

“Gamifant has a unique targeted mechanism of action. If approved for secondary HLH, Gamifant could prove to be an effective and holistic treatment for HLH patients.”