Sino Biopharmaceutical Limited (HKG: 1177) announced that its subsidiary Chia Tai Tianqing Pharmaceutical Group Co., Ltd. (CTTQ) has completed enrollment of all subjects in the Phase III pivotal registrational clinical trial (PACER‑III) of TQC3721 inhalation suspension, a national Category 1 innovative dual‑target PDE3/4 inhibitor, for the maintenance treatment of chronic obstructive pulmonary disease (COPD) – advancing the candidate toward a potential position as the first domestically developed inhaled PDE3/4 dual inhibitor approved in China.
Regulatory Milestone
| Item | Detail |
|---|---|
| Sponsor | Chia Tai Tianqing Pharmaceutical Group (CTTQ), subsidiary of Sino Biopharmaceutical Limited |
| Trial | PACER‑III – Phase III pivotal registrational clinical trial |
| Milestone | All subjects enrolled (enrollment complete) |
| Product | TQC3721 inhalation suspension (nebulised formulation) |
| Drug Class | National Category 1 innovative drug; dual‑target PDE3/4 inhibitor |
| Indication | Maintenance treatment of chronic obstructive pulmonary disease (COPD) |
| Formulation Pipeline | Nebulised inhalation suspension (Phase III enrolled); Dry powder inhalation (Phase II advancing) |
| Announcement Date | 9 Oct 2026 |
Drug Profile & Mechanism of Action
- Molecule: TQC3721 – a dual‑target phosphodiesterase 3 and 4 (PDE3/4) inhibitor, developed as a national Category 1 innovative drug with independent intellectual property
- Dual Mechanism:
- PDE3 Inhibition: PDE3 is highly expressed in airway smooth muscle; its inhibition promotes airway smooth muscle relaxation, improving ventilation and airflow obstruction
- PDE4 Inhibition: PDE4 is widely expressed in inflammatory cells; its inhibition suppresses chronic airway inflammation, addressing a core pathological driver of COPD that current bronchodilator therapies inadequately target
- Scientific Basis: Phosphodiesterases (PDEs) are an enzyme superfamily that regulates pathological and physiological processes by catalyzing the hydrolysis and inactivation of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) – key second messengers in smooth muscle tone and inflammatory signaling
- Formulation Strategy: Two complementary delivery formats developed to address different patient populations, disease severity levels, and clinical settings:
- Nebulised inhalation suspension – suited for moderate‑to‑severe patients and hospital/clinic settings (Phase III enrolled)
- Dry powder inhalation – designed for convenience in outpatient and maintenance settings (Phase II advancing)
- Differentiation: TQC3721 combines bronchodilation and anti‑inflammatory activity in a single inhaled molecule, addressing the two core pathological mechanisms of COPD simultaneously
Clinical Context – COPD Treatment Landscape
| Current Therapy | Mechanism | Strengths | Limitations |
|---|---|---|---|
| LAMAs (long‑acting muscarinic antagonists) | Bronchodilation | Improves lung function | Limited anti‑inflammatory efficacy |
| LABAs (long‑acting β2‑agonists) | Bronchodilation | Improves lung function | Limited anti‑inflammatory efficacy |
| ICS (inhaled corticosteroids) | Anti‑inflammatory | Reduces acute exacerbations in combination regimens | Limited benefit in low blood eosinophil patients; increased pneumonia risk |
| TQC3721 (PDE3/4 inhibitor) | Dual: bronchodilation + anti‑inflammatory | Addresses both airflow obstruction and inflammation in one molecule | Phase III data pending |
COPD is the third leading cause of death worldwide, affecting more than 391 million patients globally. The disease is characterized by chronic respiratory symptoms (dyspnea, cough, sputum production) driven by chronic airway inflammation and persistent airflow obstruction. Current standard‑of‑care combinations (LAMA/LABA ± ICS) improve symptoms but fail to adequately address the inflammatory component in many patients, creating an urgent need for novel drugs that combine anti‑inflammatory effects with airflow improvement.
Clinical Evidence – PACER‑III Phase III Trial
| Endpoint | Detail |
|---|---|
| Trial Name | PACER‑III |
| Phase | Phase III pivotal registrational |
| Status | Enrollment complete; data readout pending |
| Population | Patients with COPD requiring maintenance therapy |
| Formulation | TQC3721 nebulised inhalation suspension |
| Phase II Evidence | Demonstrated best‑in‑class potential in Phase II studies |
| Specific Phase III Endpoints & Data | Not disclosed (enrollment milestone only) |
| Dry Powder Formulation | Concurrently advancing in Phase II clinical trials |
The PACER‑III trial represents the pivotal registration‑enabling study for TQC3721 inhalation suspension in COPD. Completion of enrollment is a critical milestone that typically precedes top‑line data readout within 6–12 months, depending on the treatment duration and follow‑up period. The Phase II data, described as demonstrating best‑in‑class potential, provides a strong efficacy signal that the Phase III trial is designed to confirm at registrational scale.
Market Impact & Outlook
- Global COPD Market: With 391 million patients worldwide and COPD ranking as the third leading cause of death, the maintenance therapy market is substantial and growing, driven by aging populations and persistent smoking prevalence in key markets including China.
- China COPD Landscape: China bears one of the highest COPD burdens globally, with an estimated 100 million patients. The domestic COPD drug market is dominated by imported inhaled therapies from multinational companies (AstraZeneca, GSK, Boehringer Ingelheim). A domestically developed, first‑in‑class dual‑target therapy could capture significant market share through pricing advantages and domestic manufacturing scale.
- Therapeutic Differentiation: TQC3721’s dual PDE3/4 inhibition mechanism offers a fundamentally different approach from existing LAMA/LABA/ICS combinations. By delivering both bronchodilation and anti‑inflammatory effects through a single non‑steroidal molecule, TQC3721 could address the ICS‑related pneumonia risk and the low‑eosinophil patient population that derive limited benefit from current anti‑inflammatory options.
- First‑in‑China Potential: TQC3721 is expected to become the first domestically developed inhaled PDE3/4 dual inhibitor approved in China, establishing a first‑mover advantage in a novel therapeutic class for COPD maintenance treatment.
- Dual‑Formulation Commercial Strategy: The parallel development of nebulised suspension (for moderate‑to‑severe/hospital use) and dry powder inhalation (for outpatient convenience) creates a comprehensive commercial platform that can capture patients across the full disease severity spectrum and care settings.
- Sino Biopharmaceutical’s Respiratory Franchise: This Phase III milestone strengthens CTTQ’s growing presence in respiratory medicine, complementing its established franchises in oncology, hepatology, and cardiovascular therapeutics.
- Next Steps: Top‑line Phase III data readout timing, NDA filing plans, and commercialization strategy Not disclosed.
Forward‑Looking Statements
This brief contains forward‑looking statements regarding the clinical development, regulatory trajectory, and commercial potential of TQC3721 inhalation suspension in COPD. Completion of Phase III enrollment does not guarantee positive trial results or marketing approval. Actual outcomes may differ due to risks including clinical trial data readouts, regulatory decisions, competitive dynamics, reimbursement environments, and the inherent uncertainties of pharmaceutical development.-Fineline Info & Tech
