The goal of this clinical trial is to evaluate the safety and efficacy of timolol maleate (TM) gel in subjects with superficial infantile hemangioma (IH) in the proliferative phase. The main question it aims to answer is:

• The primary endpoint (success or failure) assessment was a centralized and independent qualitative assessment based on blinded comparison on B-ultrasonography results and photographs of IH at W24 from baseline.

Researchers will compare TM gel to a placebo (a look-alike substance that contains no drug) to see if TM gel works to treat IH.

Participants will:

• Take the study drug 3 times daily (once in the morning, noon, and evening, respectively) for 24 weeks.
• The family members of patients are instructed to bring the patients to the clinic for regular follow-up visits at Week 4 (W4), Week 12 (W12), and Week 24 (W24) of the treatment period.
• Keep a diary of concomitant medications and adverse events.

Inclusion Criteria:

1. Male or female infants at the age of 35 ~ 150 days;
2. Infant subjects with definitive diagnosis of superficial hemangioma requiring treatment based on medical history, clinical manifestations, and imaging examination (B-ultrasonography, CT or MRI) results;
3. Infant subjects with single hemangioma lesion;
4. Infant subjects with the maximum hemangioma diameter being ≥ 1 cm but ≤ 10 cm;
5. Infant subject with CEA ≥ Grade 2; The guardians of the infant subject understood the study contents and risks of study treatment, signed the informed consent form (ICF), and were willing to cooperate with the study conduct.

Exclusion Criteria:

1. Infant subjects who were known to be allergic to or had history of severe allergy to timolol maleate or other β-receptor blockers;
2. Infant subjects who had previously been treated with systemic, intralesional or topical corticosteroids, vincristine, α-interferon, imiquimod, propranolol, or other β-receptor blockers;
3. Infant subjects breastfed by mother who was treated with β-receptor blockers, systemic (oral, intravenous or intramuscular) corticosteroids, vincristine or α-interferon while breastfeeding;
4. Infant subjects who born more than 2 months premature and younger than 60 days old;
5. Infant subjects who had previously been treated for hemangioma (including surgery, hormonal drugs, laser therapy, etc.);
6. Infant subjects with more than one type of hemangioma requiring treatment;
7. Infant subjects with other skin diseases on the hemangioma surface and surrounding skin areas, such as eczema, infantile eczema, etc.
8. Infant subjects who had atrioventricular block ≥ second-degree, bradycardia (heart rate < 100 bpm), sinoatrial syndrome, cardiogenic shock, or other congenital cardiac disorders;
9. Infant subjects who were suffering from respiratory disorders such as bronchial asthma, bronchospasm and pneumonia;
10. Infant subjects who were suffering from central nervous system disorders, or had symptoms of increased intracranial pressure, or had other underlying diseases that might cause or aggravate infantile hemangioma;
11. Infant subjects who had systolic blood pressure < 50 mmHg or diastolic blood pressure < 30 mmHg;
12. Infant subjects who received any other investigational drug within 4 weeks prior to screening; Infant subjects with other conditions not suitable for enrollment at the discretion of the investigator.