Phase 1b Trial Completed for Potential HS Therapy NAV-240

Late last month, Navigator Medicines Inc announced the successful completion of participant visits in the phase 1b multiple-ascending dose study (MAD) of NAV-240, a bispecific antibody (bsAb) that targets both OX40L and TNFa. The trial studied the drug’s safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity after repeat dosing in 24 healthy volunteers.¹

“Achieving LPLV in the phase 1b MAD study of NAV-240 is an exciting step forward in our mission to unlock the potential of OX40L and TNFα dual inhibition.” said Dana McClintock, MD, chief medical officer of Navigator Medicines.

Hoping to build on a positive safety and tolerability profile established in the phase 1a single ascending dose (SAD) study presented earlier this year, findings from the MAD study are planned for release in Q1 2026.² Targeting 2 clinically validated pathways of complex and difficult to treat disorders, Navigator hopes NAV-240 will, “raise the efficacy bar for hidradenitis suppurativa (HS) treatment.”

The previous phase 1a SAD study reported “a good safety and tolerability profile across dose cohorts.” Researchers saw no serious adverse events or treatment-emergent adverse events leading to discontinuation. The company stated that the concentration of NAV-240 in the bloodstream increased in proportion to the dose ranging from 0.1 to 10 mg/kg, a key finding to support further development in predictable dosing. Full results from the phase 1a study are also expected in 2026.

“By targeting both OX40L and TNFα we aim to deliver a synergistic and more durable response to unlock potential benefits for patients well beyond TNFα therapy alone, which remains the most widely used treatment for inflammatory conditions,” said Tosh Butt, chief executive officer of Navigator Medicines, in a previous release. “These data provide a strong foundation for the continued clinical development of NAV-240, as an important part of our OX-40L/TNFα bispecific program of potentially best-in-class therapies for complex inflammatory disorders like hidradenitis suppurativa (HS), a debilitating inflammatory skin disease with a significant need for new treatment options.”

In addition to NAV-240, Navigator’s next-generation candidate is NAV-242, an OX40L and anti-TNFabaAb engineered for extended half-life. If approved, Navigator hopes NAV-242 could offer convenient, differentiated treatment for conditions like HS, Crohn’s disease, and ulcerative colitis.

References

1. Navigator Medicines completes last participant last visit (LPLV) in phase 1b trial of NAV-240, an OX40L and Anti-TNFα bispecific antibody for autoimmune diseases. News release. Navigator Medicines. Published November 20, 2025. Accessed December 2, 2025. https://www.navigatormedicines.com/press-release/navigator-medicines-completes-last-participant-last-visit-lplv-in-phase-1b-trial-of-nav-240-an-ox40l-and-anti-tnf%CE%B1-bispecific-antibody-for-autoimmune-diseases/
2. Navigator Medicines announces positive phase 1a data from its program of potential best-in-class bispecific antibodies; NAV-240 poised for further development in inflammatory disorders and autoimmune diseases. News release. Navigator Medicines. Published September 17, 2025. Accessed December 2, 2025. https://www.navigatormedicines.com/press-release/navigator-medicines-announces-positive-phase-1a-data-from-its-program-of-potential-best-in-class-bispecific-antibodies-nav-240-poised-for-further-development-in-inflammatory-disorders-and-autoimmune/