This is a Phase 2b, global, multicenter, randomized, double-blind, placebo-controlled, parallel group, dose ranging study to assess the efficacy, safety, and tolerability of add-on therapy with SC lunsekimig in adult participants aged 18 to 80 years, (inclusive) with moderate-to-severe asthma.

Inclusion Criteria:

• A physician-diagnosed moderate-to-severe asthma for ≥12 months based on GINA guidelines Steps 4 and 5
• Participants with existing treatment with moderate-to-high doses of ICS therapy for in combination with at least 1 but no more than 2 additional controller medications at least 3 months with a stable dose ≥1 month prior to Visit 1
• At least 1 asthma exacerbation in the past year, with at least one exacerbation occurring while on treatment with moderate to high doses of ICS therapy
• ACQ-5 score more than 1.5 at Screening (Visit 1)

Exclusion Criteria:

• Chronic obstructive or other lung diseases (eg, COPD, idiopathic pulmonary fibrosis, etc) which may impair lung function, or another diagnosed pulmonary or systemic disease.
• Current smoker or former smoker with cessation within 6 months of Screening or history of >10 pack-years. Active vaping of any products and/or marijuana smoking within 6 months of Screening.
• Participants who experience a deterioration of asthma that results in emergency treatment or hospitalization, or treatment with systemic steroids within 1 month prior to the Screening
• Participants who have experienced an upper or lower respiratory tract infection within the 4 weeks prior to Screening
• For participants on chronic OCS use for the maintenance treatment of asthma: history of a serious infection requiring hospitalization within the past 12 months prior to Randomization (Visit 2).
• Participants with active tuberculosis (TB), latent TB, a history of incompletely treated TB, suspected extrapulmonary TB infection, or who are at high risk of contracting TB (such as close contact with individuals with active or latent TB) or received Bacillus Calmette-Guérin (BCG)-vaccination within 12 weeks prior to Screening
• Severe concomitant illness that would in the Investigator's opinion inhibit the participant's participation in the study, including for example, but not limited to, hypertension, renal disease, neurological conditions, heart failure and pulmonary disease
• The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial

Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org