AstraZeneca’s newest addition to its respiratory pipeline is an inhalable medication that could rival a Merck drug approved for treating chronic obstructive pulmonary disease (COPD).
The drug, TQC721, comes from the labs of Sino Biopharmaceutical. The Hong Kong-based drug developer announced on July 8 that AstraZeneca had agreed to pay one of its subsidiaries $200 million up front for rights to the clinical-stage asset.
TQC721 is a small molecule that offers a dual mechanism: Blocking PDE3 widens the airway while blocking PDE4 stops inflammation. That’s the same approach as Merck’s Ohtuvayre, an inhalable medicine administered via a nebulizer. In 2024, this drug became the first FDA-approved PDE3/4 inhibitor for COPD. Last year, Merck added Ohtuvayre to its portfolio through the $10 billion acquisition of its developer, Verona Pharma. Merck reported $178 million in Ohtuvayre sales for 2025; for the first quarter of this year, the product generated $131 million in revenue.
Sino describes TQC721inhibitor as potentially best-in-class PDE3/4 blocker, offering balanced inhibition of both targets. In addition to a nebulized formulation, the company is developing a dry powder inhaler version. The company says the two formulations offer breadth to reach different patient segments, disease severities, and commercial settings. The nebulized formulation has reached Phase 3 testing in China while the dry powder inhaler formulation is in Phase 2 testing.
Respiratory and immunology is AstraZeneca’s third-largest therapeutic area measured by revenue. The company’s top respiratory product is Symbicort, an inhalable combination drug with approvals in asthma and COPD. Symbicort accounted for more than $2.8 billion in sales last year. Though its patents have expired, AstraZeneca still has patents on the inhaler for this drug. With patents for several other respiratory products already expired or set to expire in coming years, AstraZeneca has been investing in its respiratory drug pipeline.
Internally discovered tozorakimab, an IL-33-targeting antibody, posted preliminary results in April showing it met the main goal of its Phase 3 clinical trial in COPD. Tezspire, a TSLP-blocking antibody drug approved for asthma, is in late-stage clinical testing for COPD. But AstraZeneca has also had some stumbles in this disease. Fasenra, an antibody drug initially approved in asthma, posted disappointing Phase 3 results in COPD last September. While the data readout showed numerical improvement, the change was not enough to meet the main goal of reducing COPD exacerbations compared to a placebo. AstraZeneca’s COPD R&D also includes small molecules. AZD6793, an internally discovered inhibitor of IRAK4, is in mid-stage clinical testing.
AstraZeneca’s deal with Sino gives it global rights to TQC721, excluding China. The pharma company also has rights to certain future development programs that were not specified. Inhibiting PDE3 and PDE4 has potential applications in other respiratory disorders. For example, Merck is continuing Verona’s work evaluating Ohtuvayre in non-cystic fibrosis bronchiectasis. If AstraZeneca’s research with TQC721 achieves milestones, Sino could receive up to $1.9 billion in milestone payments, plus royalties from sales of approved medicines.
Illustration: CIPhotos, via Getty Images
