With a fresh endorsement from the FDA, the last of five major drug approvals has fallen into place for GSK in 2025.
Tuesday, the U.S. regulator greenlit GSK’s depemokimab, an ultra-long-acting biologic, as a new add-on maintenance therapy for severe asthma with an eosinophilic phenotype in patients ages 12 and older. The drug will hit the market under the Exdensur brand name, GSK said in a Dec. 16 press release.
GSK has drafted lofty sales ambitions for Exdensur, an IL-5 antagonist that is injected just twice a year. The British pharma has previously estimated the inflammatory disease med could reel in sales of 3 billion pounds sterling ($4 billion) at peak.
The are some 2 million Americans living with severe asthma by GSK’s reckoning, and more than half of those patients experience frequent exacerbations that can lead to hospitalizations or emergency room visits. Despite an influx of biologics for the inflammatory condition, just 20% of eligible severe asthma patients in the U.S. are receiving one, GSK added.
Exdensur’s asthma nod hinged on results from GSK’s replicate phase 3 studies Swift-1 and Swift-2, in which GSK’s monoclonal antibody helped patients reduce asthma exacerbations by 54% over a year when compared to placebo, according to a pooled analysis. Exdensur was also linked to a 72% reduction in clinically significant exacerbations requiring hospitalization or a visit to an emergency department.
Exdensur performed less impressively on several secondary Swift endpoints around quality of life, asthma control and the amount of air patients could exhale. In a call with Fierce Biotech earlier this year, GSK’s global head of respiratory and immunology R&D, Kaivan Khavandi, M.D., Ph.D., attributed those secondary misses to “significant placebo response, which is obviously an intrinsic challenge with patient-reported outcomes.”
He singled out exacerbation prevention as the prime clinical outcome in asthma and stressed that the less-than-stellar secondary endpoint results didn’t alter GSK’s strategy for Exdensur “at all.”
GSK plans to launch Exdensur in the U.S. in January, a company spokesperson told Fierce Pharma. The British drugmaker plans to unveil the med’s price closer to its market debut, the spokesperson added.
“Physicians in the US now have the option to provide sustained protection from exacerbations for patients living with severe asthma with an eosinophilic phenotype in just two doses a year," Khavandi said in GSK's release Tuesday. "Exdensur could redefine patient care and further establish the use of biologics for those who continue to experience exacerbations despite treatment.”
With the approval, Exdensur is now destined to lock horns in the market with rival asthma biologics like Amgen and AstraZeneca’s Tezspire, AZ's Fasenra, Sanofi and Regeneron’s Dupixent and others.
Prior to GSK’s FDA nod, Tezspire was newest on the scene, having scored its first U.S. approval as an add-on maintenance therapy for severe asthma in December 2021. In October, the FDA also cleared Tezspire to treat chronic rhinosinusitis with nasal polyps (CRSwNP), where GSK's Exdensur has picked up nods in Europe and the U.K.
Tezspire has already left a major mark on the asthma market, reeling in sales of $1.2 billion in 2024 and delivering $826 million in the first half of 2025. Still, Exdensur’s infrequent dosing could give it a convenience edge over Tezspire, which is administered as an injection every month.
Meanwhile, in a departure from Exdensur's recent overseas approvals, the FDA has declined to approve GSK's treatment for CRSwNP, an inflammatory condition of the sinuses.
"I can confirm we received a [complete response letter] for the CRSwNP indication and remain in active dialogue in with FDA on the indication," a GSK spokesperson told Fierce over email.
Exdensur comprises one of 15 hoped-for approvals GSK is jockeying for in a bid to reach sales of more than 40 billion pounds sterling (about $54 billion) in 2031. The company picked up four key approvals already in 2025 ahead of Exdensur, consisting of the 5-in-1 meningococcal vaccine Penmenvy; Blujepa, a new first-in-class antibiotic for uncomplicated urinary tract infections; Nucala in chronic obstructive pulmonary disease; and Blenrep in multiple myeloma.