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Bacterial Lysates

Sanofi · FDA-approved active Small molecule

Bacterial lysates stimulate innate and adaptive immune responses by exposing the immune system to bacterial antigens, enhancing respiratory tract defenses and reducing infection susceptibility.

Bacterial lysates stimulate innate and adaptive immune responses by exposing the immune system to bacterial antigens, enhancing respiratory tract defenses and reducing infection susceptibility. Used for Prevention of recurrent respiratory tract infections, Recurrent sinusitis, Recurrent otitis media.

At a glance

Generic nameBacterial Lysates
Also known asFan fusu
SponsorSanofi
Drug classImmunostimulant; bacterial lysate
ModalitySmall molecule
Therapeutic areaImmunology; Infectious Disease
PhaseFDA-approved

Mechanism of action

Bacterial lysates are preparations containing inactivated or lysed bacteria that act as immunostimulants. They work by activating pattern recognition receptors on immune cells, promoting the production of antimicrobial peptides, immunoglobulins, and cytokines that strengthen mucosal immunity in the respiratory tract. This enhanced immune priming reduces the frequency and severity of recurrent respiratory tract infections.

Approved indications

Common side effects

Key clinical trials

Primary sources

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SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results