GlaxoSmithKline’s Nucala needs a win in its fight against AstraZeneca’s Fasenra. Now, it can at least tout a first-data advantage in a rare inflammatory disease.
In a phase 3 study, the rate of hypereosinophilic syndrome (HES) patients on Nucala who experienced a disease flare-up was only half that of placebo, or 28% versus 56%, over the 32-week study period, GSK revealed Wednesday.
The British drugmaker was quick to point out that Nucala is the first treatment to demonstrate a reduction in HES flares, which are marked by worsening symptoms or increasing numbers of the white blood cell eosinophil that requires stronger therapy. Data in hand, GSK is now planning to file for regulatory approvals in 2020.
HES is a rare inflammatory disorder that affects about 20,000 people globally, according to GSK. The disease's hallmark is an overproduction of eosinophils, a type of cell that normally helps the body fight certain parasites and infections. When elevated, eosinophils can cause inflammation and organ damage that can be life-threatening.
“[Nucala] is thought to work by reducing blood eosinophil levels and evidence suggests it has potential as a targeted treatment option for a range of inflammatory diseases driven by raised eosinophils,” Gerald Gleich of the University of Utah said in a statement.
The IL-5 antibody, as an add-on to standard-of-care treatment, also showed significant improvements in several secondary endpoints of the study, which comprised 108 patients with severe HES. The risk of a first HES flare was 66% lower for patients treated with Nucala compared with placebo, and fatigue scores were also better in patients taking the GSK drug.
Nucala’s archrival, AstraZeneca’s Fasenra, also works by inhibiting IL-5 to reduce eosinophil levels. In a 20-patient trial unveiled in April, the AZ drug showed it could cut HES patients’ blood eosinophil counts by at least half in 90% of patients after 12 weeks of treatment. In comparison, only 30% of placebo patients saw the same result.
Should both drugs win approval in HES, they'd be fighting over a small number of patients—smaller than the severe asthma variety Nucala and Fasenra are currently approved to treat. And in the eosinophilic asthma arena, later-to-market Fasenra is gaining ground.
In the third quarter, Nucala posted £203 million ($261 million) in sales, growing slightly from the £195 million in the previous quarter and 3% ahead of the Street’s consensus. Fasenra jumped to $202 million during the same period, right before it matched up to Nucala with its own at-home auto-injector nod.
For now, Nucala holds the crown as the leading asthma biologic in total sales, GSK pharma chief Luke Miels—who was previously with AstraZeneca—said on a company conference call in October.
“The launch of the at-home administration combined with improved execution has increased our performance in the U.S. retail segment and assisted in our ability to remain the market leader despite competition,” he said.
The “competition” could refer to Sanofi and Regeneron’s Dupixent as well. Its 2018 FDA nod in eosinophilic asthma puts pressure on both Nucala and Fasenra.