• Signed informed consent form and assent form, as appropriate

• Male or female ≥12 years of age at Screening Visit 1

• Asthma-related criteria

• Documented physician diagnosis of asthma for ≥12 months prior to Screening Visit 1.

• Treatment of asthma, participants must satisfy all the below (items a to c):

∙ Participants who have received asthma controller medication with medium or high dose inhaled corticosteroids (ICS; ≥500 μg/day fluticasone propionate dry powder formulation daily or clinically comparable, per Global Initiative for Asthma (GINA) 2021) on a regular basis for at least 12 months prior to Screening Visit 1.

‣ Documented treatment with a stable dose of either medium or high dose ICS for at least 3 months prior to Screening Visit 1. The ICS may be contained within an ICS/LABA (long-acting β2 agonist) combination product. Daily oral corticosteroids are an allowed concomitant medication; participants on daily oral corticosteroids must be on a stable dose for 3 months before Screening Visit 1.

‣ Use of one of more additional daily maintenance asthma controller medications according to standard practice of care is required. Use of a stable dose of any additional asthma controller medications must be documented for at least 3 months prior to Screening Visit 1.

• Pre-bronchodilator forced expiratory volume (Pre-BD FEV₁) ≥40% and \<80% (\<90% for participants 12 to 17 years of age) of predicted at Screening Visit 2.

• Variable airflow obstruction documented with at least one of the following criteria:

∙ Bronchodilator reversibility at Screening Visit 2, as evidenced by ≥12% and ≥200 mL improvement in FEV₁, 15 to 30 minutes following inhalation of 400 μg (four puffs) of albuterol/salbutamol (≥12% and ≥160 mL for ages 12 to17). Participants who do not meet the bronchodilator reversibility inclusion criterion but have ≥10% and ≥160 mL reversibility, may repeat the reversibility spirometry assessment once during the Screening period, at an unscheduled visit at least 7 days prior to baseline.

‣ Bronchodilator reversibility, using the criteria above, documented in the past 24 months prior to Screening Visit 1.

‣ Peak flow variation of ≥20% over a 2-week period, documented in the past 24 months prior to Screening Visit 1.

‣ Airflow variability in clinic FEV₁ ≥20% between two consecutive clinic visits, documented in the past 24 months prior to Screening Visit 1.

‣ Airway hyperresponsiveness (provocative concentration causing a 20% fall in FEV₁ of methacholine \<8 mg/mL) documented in the past past 24 months prior to Screening Visit 1.

• ACQ-6 ≥1.5 at Screening Visit 2.

• Documented history of at least two asthma exacerbations requiring treatment with systemic corticosteroids (intramuscular, intravenous, or oral) within the past 12-month period prior to Screening Visit 1.

• General medical history

• Negative urine pregnancy test for women of childbearing potential (WOCBP; after menarche) at the Screening Visit 2 and Baseline Visit.

⁃ WOCBP must use either of the following methods of birth control, from Screening Visit 1 through the End of Study Visit:

• A highly effective form of birth control (confirmed by the investigator). Highly effective forms of birth control include: true sexual abstinence, a vasectomized sexual partner, Implanon, female sterilization by tubal occlusion, any effective Intrauterine device (IUD), IUD/intrauterine system (IUS), Levonorgestrel Intrauterine system, or oral contraceptive.

• Or

∙ Two protocol acceptable methods of contraception in tandem.

• Women not of childbearing potential are defined as women who are either permanently sterilized (hysterectomy, bilateral oophorectomy, or bilateral salpingectomy), or who are postmenopausal. Women will be considered postmenopausal if they have been amenorrheic for ≥12 months prior to the planned date of the Baseline Visit without an alternative medical cause. The following age specific requirements apply:

∙ Women \<50 years old would be considered postmenopausal if they have been amenorrheic for 12 months or more following cessation of exogenous hormonal treatment and follicle stimulating hormone levels in the postmenopausal range.

∙ Women ≥50 years old would be considered postmenopausal if they have been amenorrheic for 12 months or more following cessation of all exogenous hormonal treatment.