Circassia has agreed to pay AstraZeneca $50m worth of its ordinary shares under the deal, which is expected to complete in the second quarter of this year.
Circassia also agreed to pay AstraZeneca $100m upon either approval of Duaklir in the US or June 30, 2019, whichever comes first.
The company will also pay up to an additional $80m if it exercise its option to sublicense commercial rights to Tudorza in the US.
Duaklir’s submission for US regulatory review is likely to be done next year.
The two companies said they will equally share US profits from Tudorza, with AstraZeneca continuing to book US product sales of Tudorza until Circassia exercises its option.
If the option is exercised, Circassia will pay AstraZeneca tiered percentage royalties on potential future US sales of Duaklir.
In addition, Circassia will contribute up to $62.5m toward development of the medicines.
Circassia CEO Steve Harris said: “This proposed transaction is an ideal fit with Circassia’s strategy and respiratory focus. It represents a transformational opportunity for the company.
“As part of the long-term strategic collaboration with AstraZeneca, we will immediately double our US sales force to promote Tudorza as our priority, as well as our existing NIOX products, transforming Circassia into a world-class respiratory business.”
AstraZeneca global product & portfolio strategy executive vice president Mark Mallon said: “Tudorza and Duaklir are important components of AstraZeneca’s respiratory franchise globally and this collaboration will support their commercialisation in the US for the benefit of the millions of COPD patients.
“It also further sharpens our focus on Symbicort, Bevespi Aerosphere, benralizumab and other respiratory development programmes. Circassia will be an important strategic partner for AstraZeneca in the US and we look forward to working closely together.”