AstraZeneca has developed an inhalable medication that may compete with a recently approved Merck treatment for chronic obstructive pulmonary disease (COPD). The drug, TQC721, originates from the laboratories of Sino Biopharmaceutical. On July 8, the Hong Kong-based developer announced that AstraZeneca agreed to pay $200 million upfront for rights to the clinical-stage asset.
TQC721 is a small molecule with a dual mechanism of action: it blocks PDE3 to widen airways and PDE4 to suppress inflammation. This approach mirrors Merck’s Ohtuvayre, an inhaled medicine approved via nebulizer in 2024 as the first PDE3/4 inhibitor for COPD. Ohtuvayre generated $178 million in sales in 2025, with Q1 2025 revenues reaching $131 million following Merck’s $10 billion acquisition of its developer, Verona Pharma.
Sino Biopharmaceutical describes TQC721 as a potentially best-in-class PDE3/4 inhibitor, offering balanced inhibition of both targets. The company is advancing both nebulized and dry powder inhaler formulations, with the former now in Phase 3 trials in China and the latter in Phase 2 studies. The dual formulations aim to address diverse patient needs across disease severities and healthcare settings.
Respiratory and immunology represents AstraZeneca’s third-largest therapeutic area by revenue. Its flagship product, Symbicort, an inhalable asthma/COPD combination therapy, earned over $2.8 billion in sales last year. Though its patents have expired, AstraZeneca retains intellectual property for the inhaler device. To sustain its pipeline amid expiring patents on other respiratory drugs, the company has prioritized investments in novel therapies.
Internally discovered tozorakimab, an IL-33-targeting antibody, showed in April that it met its primary Phase 3 goal for COPD. Additionally, Tezspire—a TSLP-blocking antibody approved for asthma—is in late-stage testing for COPD. However, AstraZeneca faced setbacks, including Fasenra, an asthma antibody that failed to meet COPD Phase 3 endpoints in September, despite statistically significant improvements in exacerbation reduction.
AstraZeneca’s COPD pipeline also includes AZD6793, an IRAK4 inhibitor in mid-stage trials. The deal with Sino grants AstraZeneca global rights to TQC721 (excluding China), plus access to undisclosed future development programs. Sino may receive up to $1.9 billion in milestones and royalties if TQC721 achieves commercial approval. PDE3/4 inhibition also holds broader respiratory applications, such as Merck’s ongoing evaluation of Ohtuvayre in non-cystic fibrosis bronchiectasis.
Illustration: CIPhotos, via Getty Images
