GSK plc has received FDA approval for a 200 mg/mL autoinjector formulation of Benlysta (belimumab) for subcutaneous injection in patients five years of age and older with active lupus nephritis who are receiving standard therapy. This approval marks a significant milestone as Benlysta becomes the first and only FDA-approved treatment specifically for lupus nephritis, a severe kidney complication of systemic lupus erythematosus.
Expanding Treatment Options for Pediatric Patients
The new autoinjector approval provides pediatric lupus nephritis patients and their caregivers with a first-of-its-kind subcutaneous option that can be administered at home. This represents a significant advancement from the traditional intravenous infusion approach, offering greater convenience and flexibility for families managing this challenging condition.
"Providing this at-home treatment option with the efficacy and safety of Benlysta is a testament to our ongoing commitment to the lupus community," said Court Horncastle, Senior Vice President and Head of US Specialty at GSK. "GSK is driven by the belief that our therapeutic solutions should always prioritize improving patients' well-being and easing their treatment journey, including for younger patients."
Clinical Evidence and Market Impact
The FDA approval is supported by results from the BLISS-LN trial, which demonstrated that 43% of patients treated with Benlysta achieved significant improvement in kidney function, compared with 32% of those in the control arm. The drug also showed improvements in secondary outcome measures, including time to death or kidney-related complications.
Lupus nephritis affects approximately 60% of the 300,000-plus severe SLE patients in the United States each year, with a quarter of those patients developing end-stage renal disease. This severe form of SLE can lead to late-stage renal failure and require dialysis or kidney replacement in the most severe cases.
Mechanism of Action and Treatment Evolution
Benlysta is a B-lymphocyte stimulator (BLyS) specific inhibitor that binds to soluble BLyS. By binding BLyS, the drug inhibits the survival of B cells, including autoreactive B cells, and reduces the differentiation of B cells into immunoglobulin-producing plasma cells. Notably, Benlysta does not bind B cells directly.
The drug's journey began with its original FDA approval in 2011 as an intravenous therapy for adults with SLE. GSK subsequently received approval for the subcutaneous formulation in 2017 and extended the label to include pediatric patients aged five and older in 2024. The 200 mg/mL autoinjector was previously approved for pediatric patients with active systemic lupus erythematosus in 2024.
Commercial Prospects and Manufacturing Expansion
Benlysta sales have grown steadily to reach £514 million (almost $700 million) in the first nine months of 2020, benefiting from its position as the only biologic approved to treat SLE. The lupus nephritis indication is expected to push the product above the $1 billion threshold into blockbuster sales territory.
"More than 80% of eligible patients remain untreated with Benlysta in the US and of course even more around the world," noted Luke Miels, GSK's head of global pharma. "The number treated will increase further with the lupus nephritis indication and so there's plenty of opportunity for growth."
GSK has been expanding its manufacturing capacity for Benlysta in anticipation of the new approval, including in-house capacity at its Rockville plant in Maryland and through a contract manufacturing agreement with Samsung Biologics.
Future Development Pipeline
GSK is currently conducting a phase 3 combination study of Benlysta with rituximab, called BLISS-BELIEVE, with the goal of driving the disease into clinical remission. Both drugs target B cells, which are thought to be central to the disease process in SLE. While Benlysta binds and neutralizes the B cell survival factor BAFF, rituximab targets CD20, a protein found on the surface of B cells.
Caregivers of children currently using intravenous infusions of belimumab to manage their lupus nephritis can work with their child's healthcare provider to determine if at-home administration via autoinjector is appropriate for their specific situation.
