GSK said Monday that its projected asthma blockbuster depemokimab reduced asthma attacks by 54% in two large Phase 3 trials, but missed some secondary endpoints.
The company teased the results in May, announcing that the experimental long-acting antibody met its primary endpoints in two key trials for adolescents and adults with a form of severe asthma. On Monday, GSK said depemokimab reduced the annualized rate of clinically significant asthma attacks by more than half compared to placebo, according to a pooled analysis over 52 weeks.
The long-acting drug also reduced asthma attacks requiring hospitalization or an ER visit by 72% compared to placebo across both trials. The drug targets interleukin-5 (IL-5), a regulator of the body’s immune response and the same target as GSK’s currently approved asthma blockbuster Nucala. Depemokimab would be dosed every six months, as opposed to Nucala’s monthly dosing regimen.
Executives said that if depemokimab is approved, they expect it to reach £3 billion in peak annual sales, or $3.9 billion.
Kaivan Khavandi“Adherence and durability is perhaps going to be the key challenge to real-world management” for the chronic treatment of asthma, GSK’s senior VP and global head of respiratory and immunology R&D Kaivan Khavandi said during a Friday media briefing, according to a transcript of the call.
However, the drug missed statistical significance on secondary endpoints assessing quality-of-life and symptom-based measures. Khavandi said on the call that researchers saw improvements in the depemokimab arm, but also recorded a “significant placebo response, which obviously is an intrinsic challenge with PROs [patient-reported outcomes].”
“As a result of that, demonstrating a treatment effect was challenging,” Khavandi said.
In May, GSK told Endpoints News that it planned to file for approval in the US in the second half of 2024, and in the EU, China and Japan in 2025. When asked about regulatory plans on Friday, Khavandi said GSK is “immediately advancing to provide the relevant correspondence to the health authorities globally.” Khavandi added that it’s awaiting pivotal results in chronic rhinosinusitis with nasal polyps, and plans on “coordinating our submission strategy as part of now what’s going to be two sets of pivotal data available through Q3 and Q4 this year.”
“We are liaising with regulatory authorities and any updates will be announced at the appropriate time,” a GSK spokesperson told Endpoints on Monday.