FDA Prioritizes Sobi's sBLA for Gamifant Approval

STOCKHOLM, Feb. 27, 2025 /PRNewswire/ -- Sobi® has announced a significant development in the treatment of hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) associated with Still's disease. The U.S. Food and Drug Administration (FDA) has accepted the supplemental Biologics License Application (sBLA) for Gamifant® (emapalumab-Izsg), a treatment aimed at both adult and pediatric patients who exhibit inadequate responses or intolerance to glucocorticoids, or experience recurrent MAS. This application has been classified under Priority Review with a targeted decision date of June 27, 2025.

HLH/MAS is recognized as a severe and potentially life-threatening complication of rheumatic diseases, typically occurring in individuals with Still's disease. This encompasses systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still's disease (AOSD). The condition is characterized by hyperinflammation, with symptoms including persistent high fever, elevated ferritin levels, cytopenias, coagulopathies, and hepatosplenomegaly.

Dr. Lydia Abad-Franch, who leads research and development at Sobi, remarked on the seriousness of HLH/MAS in Still's disease, underlining the urgent need for effective therapies. At present, there are no approved treatments specifically for HLH/MAS. Gamifant® (emapalumab-Izsg) functions by selectively neutralizing interferon gamma (IFN-γ), which is a critical contributor to hyperinflammation. The drug's approval could potentially lessen the dependency on high-dose glucocorticoids for these patients.

The application for Gamifant® is supported by pooled data from two pivotal studies, EMERALD (NCT05001737) and NI-0501-06 (NCT03311854), involving 39 patients. Results showed that after eight weeks, 53% of patients achieved a complete response, and 85% had achieved a complete response at some point during the studies. Additionally, there was a notable reduction in weekly glucocorticoid doses by 70.1% after just two weeks of treatment.

Already approved by the FDA in 2018, Gamifant® (emapalumab-Izsg) is utilized to address primary HLH in both adults and children, including newborns, particularly when the disease is refractory, recurrent, or progressive, or when there is intolerance to conventional HLH therapies. The drug is a monoclonal antibody designed to bind and neutralize IFN-γ, and was originally approved based on data from phase 2/3 studies (NCT01818492 and NCT02069899).

Macrophage activation syndrome (MAS), a serious complication associated with rheumatic diseases like sJIA and AOSD, often leads to severe outcomes such as fever, liver dysfunction, and multi-organ failure if not properly addressed. It shares a classification with HLH as a syndrome marked by excessive inflammation.

Sobi® is a biopharmaceutical company that focuses on transforming the lives of individuals with rare diseases. With a strong presence across Europe, North America, the Middle East, Asia, and Australia, the company employs around 1,800 professionals. In 2024, Sobi's revenue was reported at SEK 26 billion. The company’s stock is publicly traded on Nasdaq Stockholm under the symbol STO:SOBI. Through initiatives like these, Sobi continues to advance its mission of providing innovative treatments for people facing rare and debilitating conditions.