Soligenix, Inc., a Princeton, New Jersey–based late-stage biopharmaceutical company, revealed that the European Medicines Agency’s Committee for Orphan Medicinal Products (COMP) has issued a positive opinion recommending orphan drug designation for SGX945 for the treatment of Behçet’s disease. The opinion now awaits ratification by the European Commission.
SGX945 contains dusquetide, a synthetic peptide classified as an innate defense regulator (IDR) that modulates innate immune signaling through the p62/SQSTM1 pathway. The EMA action follows the US FDA’s grant of orphan drug and Fast Track designations for SGX945 for oral lesions associated with Behçet’s disease.
Under EU rules, orphan drug designation applies to life-threatening or chronically debilitating conditions affecting no more than five in 10,000 people. Incentives include 10 years of post-approval market exclusivity, regulatory protocol assistance, and centralized marketing authorization.
Disease burden and treatment landscape
Behçet’s disease is a chronic, relapsing inflammatory vasculitis with higher prevalence along the historical Silk Road region. Soligenix estimates approximately 18,000 cases in the US, more than 50,000 in Europe, and up to 1 million globally.
Current management relies on corticosteroids and systemic immunosuppressants such as cyclosporine, cyclophosphamide, and anti-TNF biologics in refractory cases. The only therapy specifically approved for Behçet’s disease is apremilast (Otezla), a phosphodiesterase-4 (PDE4) inhibitor approved in 2019 for oral ulcers associated with the condition.
Clinical development
The EMA’s recommendation was supported by Phase IIa data from an open-label pilot study (NCT06386744) enrolling eight patients with Behçet’s disease. The trial used mean number of oral ulcers over time as its primary endpoint, mirroring the Phase III study design that supported apremilast’s approval.
After four weeks of treatment, SGX945 demonstrated a 40% improvement relative to the historical placebo arm from the apremilast Phase III trial, compared to apremilast’s 37% improvement versus placebo in its own study. Four weeks after treatment cessation, improvement with SGX945 persisted at 32%. No treatment-related adverse events were reported.
The Phase IIa findings were published in Rheumatology (Oxford).
Dusquetide differs mechanistically from existing therapies by acting upstream at the level of intracellular innate immune regulation rather than targeting individual cytokines or broadly suppressing inflammatory signaling. There are no direct clinical-stage competitors targeting the p62/SQSTM1 pathway in Behçet’s disease, though larger controlled trials will be required to confirm the preliminary signal observed in this small study.