Inclusion Criteria:
1. Male or female subjects aged 18-75 years (inclusive) \[as of the date of signing the informed consent form (ICF)\];
2. Body weight≥ 40 KG and body mass index is between 18-40 kg/m2;
3. Diagnosis of asthma with a medical history of at least 1 year;
4. Those who have received a moderate-to-high dose of ICS (≥ 250 μg fluticasone propionate dry powder formulation equivalent total daily dose) for ≥ 3 consecutive months prior to screening, combined with at least one asthma control drug that has been maintained a stable treatment regimen and dose for ≥ 1 month prior to screening;
5. At least 1 asthma exacerbation within 12 months prior to screening;
6. 40% ≤ FEV1 \< 80% of predicted normal value pre-bronchodilator at screening;
7. There is a record of reversibility test result of FEV1 ≥ 12% and ≥ 200 mL within 12 months prior to randomization, or the reversibility test result meets FEV1 ≥ 12% and ≥ 200 mL at screening;
8. ACQ-6 score ≥1.5 prior to randomization;
9. No birth planning and voluntarily use effective contraception throughout the study until 6 months after the last dose;
Exclusion Criteria:
1. Clinically significant lung diseases other than asthma (e.g., active lung infection, chronic obstructive pulmonary disease (COPD), bronchiectasis, pulmonary fibrosis, cystic fibrosis, obesity hypoventilation syndrome, lung cancer, α1-antitrypsin deficiency, and primary ciliary dyskinesia) or pulmonary or systemic diseases other than asthma that results in peripheral blood eosinophil count increased (e.g., allergic bronchopulmonary aspergillosis/mycosis, Churg-Strauss syndrome, hypereosinophilic syndrome).
2. Any disease judged as unstable by the investigator, including but not limited to unstable cardiovascular, gastrointestinal, hepatic, renal, nervous system, musculoskeletal, infectious, endocrine, metabolic, hematological, and psychiatric diseases or major physical injury.
3. Subjects with current or a history of cancer (except skin squamous cell carcinoma in situ, basal cell carcinoma or cervical carcinoma in situ without any signs of recurrence for more than 5 years after complete response following radical treatment);
4. History of clinically significant infection within 14 days prior to screening, which includes upper respiratory tract infection (URTI) and lower respiratory tract infection (LRTI), requiring antibiotic or antiviral treatment;
5. Major surgery within 8 weeks prior to screening or planned surgery requiring general anaesthesia or hospitalization for \> 1 day during the study period;
6. Helminth parasite infection diagnosed within 6 months prior to screening, not receiving or responding to standard of care;
7. Current smoker or quit smoking less than 6 months ago at screening, or with a history of smoking ≥ 10 pack-years (Note: 1 pack = 20 cigarettes, 10 pack-years = 1 pack/day \* 10 years, or 1/2 pack/day \* 20 years);
8. Subjects with a history of alcoholism or drug abuse or dependence.
9. Those with active tuberculosis infection or latent tuberculosis requiring treatment at screening;
10. Those who are allergic or intolerant to components of HB0056 injection or placebo or have a history of severe drug allergy or anaphylactic shock;
11. Subjects who are considered inappropriate to participate in this clinical trial by the investigator.
