FDA gives AstraZeneca-Amgen drug broad approval

Asthma Antibody

With good Phase III results in 2020, it seemed likely that the FDA was going to approve Amgen and AstraZeneca’s long-incubating antibody for asthma, unless there were any manufacturing delays or major statistical problems. The big concern was the number of asthma patients that would be approved by regulators, and the number was big. In spite of mixed data in some places, the FDA approved tezepelumab for just about any patient 12 years or older with severe asthma.

According to the National Laboratory of Medicine, part of the National Institutes of Health, “One of the most promising biologic drugs for asthma treatment is tezepelumab, a fully human monoclonal antibody that specifically interacts with TSLP, thus preventing its binding to the TSLP receptor complex [28]. Given the relevant importance of TSLP as a master player of asthma pathobiology, this alarmin, acting as an upstream inducer of strategic proinflammatory and remodeling pathways, appears to be a potential suitable target for perspective biological therapies of severe asthma. Therefore, tezepelumab deserves close attention as a possible future anti-asthma biologic.”

Tezepelumab has the kind of broad label analysts expect could rocket the drug to blockbuster status, according to Jason Mast of BioPharma Dive. As he explained, “For many patients, particularly those with no or low levels of an immune cell called eosinophils, the Amgen-AstraZeneca drug will be the only biologic option. Regeneron-Sanofi blockbuster Dupixent, while approved for many people with asthma, failed in those patients. Amgen estimates that group accounts for approximately 30 percent of the 1 million US patients with uncontrolled severe asthma.”

According to AstraZeneca R&D chief Mene Pangalos, “The drug has the potential to transform care for a broad population of severe asthma patients.”

Tezepelumab will be marketed as Tezspire. Because the approval came early, a price has not yet been established. FDA approval had been anticipated in the first quarter of 2022, although the US approval came almost a full decade after Amgen and AstraZeneca first signed a broad deal on inflammation. At that time they agreed to jointly develop and commercialize five different candidates. One of those drugs, brodalumab, garnered FDA approval in 2017 as Siliq for plaque psoriasis.

Tezepelumab had greater challenges. The antibody, which blocks TSLP — a cytokine common in the epithelium — originally failed in atopic dermatitis, the autoimmune disease that made Dupixent into a major drug. The data “always looked more promising in asthma, where there was also a slightly less crowded market,” according to Mast. Significant results came a year ago, when the partners revealed that a Phase III trial demonstrated that the drug significantly reduced the number of asthma exacerbations — or asthma attacks — as compared to placebo. The companies showed in detailed follow-up data that winter, for both the broad population and for patients with low eosinophils counts, where other drugs failed.

While the drug failed in one trial on severe asthma patients in December 2020, the companies blamed the results on a design flaw. The FDA agreed that the data overall point to tezepelumab benefit. In spite of the broad label and a monopoly in a subgroup of patients, analysts predict a slow commercial rollout as Omicron begins to sweep across the world. Many new drugs have had trouble launching during the pandemic.

As Jefferies analyst Michael Yee said, “Overall this is a positive … in our view, appreciating that investors will be a bit cautious on the launch given the Omicron Covid environment. New drugs do not launch well these days in these areas, so investors will need patience on a launch.”