This is a randomized, double-blind, placebo-controlled phase 1/2 clinical study to evaluate the safety, tolerability, pharmacokinetics and preliminary efficacy of HS-10561 capsule in healthy Chinese adults and patients with chronic spontaneous urticaria.

Inclusion Criteria:

• Written informed consent must be obtained before any assessment is performed.(SD)
• Healthy adults aged 18-45 years (inclusive) at the time of signing the informed consent form;(SD)
• Male participants weighing ≥ 50 kg and female participants weighing ≥ 40 kg; body mass index (weight/square of height (kg/m2)) within the range of 18-30 kg/m2 (inclusive);(SD)
• Female participants and male participants (including their female partners) agree to use highly effective methods of contraception from the date of signing the informed consent form until 30 days after the last dose;(SD)
• Without history of severe respiratory, gastrointestinal (such as inflammatory bowel disease, Crohn's disease, chronic diarrhea, etc.), neurological, circulatory, urinary, endocrine, musculoskeletal, immune system disorders, or a history of tumors prior to screening.(SD)
• Written informed consent must be obtained before any assessment is performed.(MD and Phase 2)
• Healthy adults aged 18-65 years (inclusive) at the time of signing the informed consent form;(MD and Phase 2)
• Have been diagnosed with chronic spontaneous urticaria for ≥6 months at the time of screening;(MD and Phase 2)
• Female participants and male participants (including their female partners) agree to use highly effective methods of contraception from the date of signing the informed consent form until 30 days after the last dose.(MD and Phase 2)

Exclusion Criteria:

• Have clinically significant abnormalities in vital signs, physical examination, laboratory tests, chest X-ray/CT, or abdominal ultrasound during the screening period, which, as assessed by the investigator, may increase the participants' risk or affect the scientific validity of the study;(SD)
• Females with a positive blood pregnancy test, breastfeeding females, or participants planning to become pregnant during the study period;(SD)
• Any physiological or psychological condition or disease, as determined by the investigator, that could increase the risk, affect the participants' compliance, or impact the participants' ability to complete the study.(SD)
• Chronic urticaria with a clear primary or sole trigger (chronic inducible urticaria);(MD and Phase 2)
• Clearly defined predominant or sole trigger of their chronic urticaria (chronic inducible urticaria);(MD and Phase 2)
• Other diseases with symptoms of urticaria or angioedema;(MD and Phase 2)
• Other skin disease associated with chronic itching that might influence in the investigators opinion the study evaluations and results;(MD and Phase 2)
• Pregnant or nursing (lactating) women.(MD and Phase 2)