LONDON (Reuters) - AstraZeneca's experimental injection for severe asthma cut substantially the need for patients to take problematic oral steroid drugs in a late-stage study, boosting hopes for a medicine that is expected to reach the market later this year.
But the British drugmaker's established Bydureon medicine for diabetes failed to show a hoped-for benefit in reducing heart risks, putting it at a disadvantage to Novo Nordisk's rival Victoza in the so-called GLP-1 drug class.
Novo's next-generation GLP-1 drug semaglutide, currently awaiting approval, has also shown such a heart benefit.
The mixed news left AstraZeneca's shares little changed in early dealings on Tuesday.
While most investor focus is on AstraZeneca's cancer research, particularly the immunotherapy drug durvalumab, the company also has a long history in respiratory therapy and a significant presence in diabetes.
It plans to build on the lung expertise with new asthma drug benralizumab, which will compete with GlaxoSmithKline's Nucala and Teva's Cinqair - two other recently approved antibody drugs for severe asthma.
AstraZeneca hopes its product's potency and convenient dosing will give it an edge, despite being third to market.
Data from the 28-week Phase III clinical trial presented at the American Thoracic Society and published in the New England Journal of Medicine on Monday showed the median reduction in oral steroid dose was 75 percent for patients on benralizumab.
Overall, patients treated with benralizumab were more than four times as likely to cut steroid use than those on placebo and there was also a 70 percent reduction in the rate of serious asthma attacks, known as exacerbations.
Tom Keith-Roach, head of AstraZeneca's respiratory, inflammation and autoimmune business, said the results were good news for the sickest patients, who currently rely on oral steroids that can cause weight gain, mood changes and other side effects.
Data from the latest trial, along with results from two earlier studies, were included in regulatory submissions for benralizumab in various countries, including the United States, where an approval decision is due in the fourth quarter.
The picture was less favorable for Bydureon, where a separate clinical trial showed that while the injectable drug did not raise heart dangers, it failed to demonstrate a statistically significant reduction in cardiovascular risks.
Consensus industry analyst forecasts point to annual benralizumab sales of $915 million in 2023, while Bydureon is expected to sell $854 million, according to data compiled by Thomson Reuters.
In addition to competition from GSK and Teva, benralizumab also faces a potentially serious challenge from Sanofi and Regeneron, whose drug dupilumab is being tested for severe asthma after winning a green light in eczema.
Benralizumab works by directly killing off inflammatory cells found in the lungs called eosinophils and, unlike the two existing drugs, it is given only every eight weeks rather than monthly.
"There are around 2 million severe uncontrolled asthmatics worldwide in our top 12 markets and I certainly think based on this profile we would expect to have a really competitive share of that market," Keith-Roach said.
Editing by Susan Thomas