Our Lead Program
HEX17 is NorthLinks Bio’s lead intranasal antiviral program designed to prevent respiratory viral infections by blocking viral attachment at the nasal mucosa.
The program is being developed as a broad-spectrum, host-directed approach to protect against multiple respiratory viruses.
Program Overview
HEX17 is a self-administered nasal spray being developed for the prevention of respiratory viral infections. Designed to act locally within the nasal airway, HEX17 is based on an engineered multivalent carbohydrate-binding module (mCBM) derived from carbohydrate-binding domains of Streptococcus pneumoniae sialidases.
The molecule was engineered as tandem-linked CBMs fused to a self-assembling trimerization domain, generating an oligomeric protein with substantially enhanced glycan-binding affinity and prolonged nasal residency. The program is being developed as a broad-spectrum antiviral approach for respiratory pathogens including influenza viruses, RSV, rhinoviruses, coronaviruses, and other respiratory viruses.
HEX17 Engineering Design
A multivalent sialic acid-binding protein engineered from carbohydrate-binding modules derived from bacterial glycosidases.
1 Single sialic acid-binding module (CBM)
Steptococcus pneumoniae neuraminidase (NanA)
2 Tandem-linked CBMs
Two CBMs linked by a short peptide
3 Fusion to trimerization domain
CBM-CBM tandem fused to the C-terminus of the trimerization domain from Psuedomonas aeruginosa sialidase
4 Self-assembly into trimer (HEX17)
Trimerization domains self-assemble into stable trimer
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Sialic acid-binding CBM (NanA)
Streptococcus pneumoniae neuraminidase
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Tandem CBMs
Two sialic acid-binding modules linked by a short peptide
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Short Connecting Peptide Linker
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Trimerization Domain
Psuedomonas aeruginosa sialidase
Self-assembles into a stable trimer
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HEX17 Key Features
6 sialic acid-binding domains per trimer
Multivalent binding for high avidity
Engineered from bacterial glycosidase CBMs for broad and potent antiviral activity
Broad protection. Healthy respiration.
By blocking the first step of infection, HEX 17 helps precent illness caused by major respiratory viruses.
HEX17 Nasal Spray:
Broad protection against respiratory viruses
Mechanism of Action
HEX17 is a multivalent sialic acid-binding protein engineered to achieve substantially enhanced glycan-binding affinity and prolonged residency on the surface of mucosal epithelium when delivered by nasal spray. By binding to sialic acids – ubiquitous cell-surface glycans present throughout the human respiratory tract and on certain viral glycoproteins – HEX17 masks host receptors utilized by many respiratory viruses for cell attachment and entry. For some enveloped viruses, including coronaviruses,
HEX17 may also directly bind viral surface glycans, providing an additional mechanism to inhibit infection. This dual host- and virus-targeted approach has demonstrated broad antiviral activity against multiple respiratory viruses from diverse viral families and may eliminate susceptibility to viral escape and the need for frequent strain-specific updates associated with conventional virus-targeted approaches.
Target Indications:
Influenza A and B
Respiratory Syncytial Virus (RSV)
Coronaviruses, including SARS-CoV-2
Human rhinoviruses
Parainfluenza viruses
Key Advantages/ Differentiators
HEX17:
Broad-spectrum, host-directed antiviral approach targeting multiple respiratory viruses
Non-invasive intranasal delivery designed for convenient self-administered prophylactic use
Mechanism designed to maintain activity despite viral evolution and emerging variants
Intended to support repeat use during periods of elevated respiratory virus circulation
Potential to provide rapid-response protection against seasonal and pandemic respiratory viruses
HEX17 has completed Phase 1 and Phase 2 clinical studies, including a successful influenza challenge study demonstrating reductions in symptomatic influenza infection and influenza viral load. NorthLinks Bio is advancing HEX17 toward further clinical development as a broad-spectrum intranasal antiviral prophylactic.
Phase 1 and Phase 2 clinical studies, including an influenza Controlled Human Infection Model (CHIM) study, demonstrate that HEX17 was well tolerated with no serious adverse events or safety signals observed.
Prophylactic administration of HEX17 prior to influenza virus challenge reduced the incidence of symptomatic influenza infection compared with placebo. Both single-dose and repeated-dose regimens demonstrated protective activity, supporting the continued clinical development of HEX17 as a broad-spectrum intranasal antiviral prophylactic for respiratory viral infections and the potential for flexible, prophylactic dosing strategies.
Clinical Evidence/Key results:
HEX17 demonstrated favorable safety and tolerability in Phase 1 and Phase 2 studies evaluating single and repeated intranasal dosing in healthy volunteers
No detectable systemic exposure was observed following intranasal administration
Phase 2 CHIM study demonstrated approximately 50% reduction in symptomatic influenza infection
HEX17 administration was associated with directional reductions in influenza viral load and reduced symptom severity following viral challenge
Clinical Summary/Development Status
The incidence of symptomatic influenza infection detected by viral culture in nasal samples in Phase 2 CHIM. In this randomized, double-blind, placebo-controlled Phase 2 CHIM study, 104 healthy adults received either placebo, a single 2.8 mg intranasal dose of HEX17, or daily 2.8 mg intranasal HEX17 for three days prior to influenza challenge. Participants were subsequently challenged with influenza A/H3N2 virus, and infection was monitored through serial nasopharyngeal swabs collected over eight days to assess symptomatic influenza infection and viral shedding.
The numbers in the bars are the number of participants (% of participants in dose arm).
Chi-square p values are presented, *p < 0.05, D-3 day − 3.
Preclinical Evidence/Key Results
High-affinity multivalent binding to host sialic acids and viral glycans
Broad in vitro antiviral activity against influenza, RSV, HRV, PIV, and SARS-CoV-2
Significant protection in influenza, RSV, and SARS-CoV-2 animal infection models
Favorable safety profile demonstrated across preclinical studies
Get in Touch
Connect with the NorthLinks Bio team.
