Phase 2a Evaluation of Dual OX40L/TNFα Antibody Begins in HS

Navigator Medicines Inc. recently announced that the US FDA has cleared a phase 2a clinical trial of NAV-240, an experimental antibody therapy for people living with hidradenitis suppurativa (HS). At the same time, Navigator is continuing early clinical testing of a next-generation version of the therapy, signaling a broader move toward patient-focused clinical development.¹

HS is a long-lasting and often painful skin condition that causes inflamed lumps, abscesses, and scarring, most commonly in areas such as the underarms and groin. The disease can significantly affect quality of life, and treatment options remain limited. While some patients benefit from currently available biologic medicines, including those that block the inflammatory protein TNF, many do not achieve adequate or lasting symptom relief.²

NAV-240 is designed to block 2 separate drivers of inflammation at the same time. In addition to TNF, it targets OX40 ligand (OX40L), a molecule involved in activating immune cells that contribute to ongoing inflammation. By addressing both pathways together, the therapy is intended to reduce inflammation more effectively than treatments that focus on a single target. Whether this approach leads to better outcomes will be evaluated in clinical trials.

The newly cleared phase 2a study will test NAV-240 in people with moderate to severe HS. The trial will build on earlier research that examined the safety of the drug in healthy volunteers. In a phase 1 study involving 40 participants, NAV-240 was generally well tolerated across a range of doses. No serious adverse effects were reported, and no participants stopped treatment due to adverse reactions. The study also showed predictable levels of the drug in the bloodstream, which helps support consistent dosing in later trials.³

Researchers also observed reductions in a blood marker linked to inflammatory skin diseases, suggesting that the drug was having the intended biological effect. These early findings do not demonstrate clinical benefit but provided enough reassurance for regulators to allow further testing in patients with HS.

Navigator has also completed enrollment in an additional early study that tested repeated doses of NAV-240. Results from that study are expected in early 2026 and may help guide how the drug is used in the phase 2 program.

In parallel, the company is developing NAV-242, a newer version of the same dual-target approach that is designed to stay in the body longer. This could allow for less frequent dosing, which may be more convenient for patients. Australian regulators have approved the first human study of NAV-242, which will assess safety and how the drug behaves in the body. Initial results from this trial are expected in late 2026.

Navigator has also expanded its global rights to both NAV-240 and NAV-242 outside of Korea, including China. This move gives the company greater flexibility to develop and potentially commercialize these treatments internationally, pending successful clinical results.

While these developments represent meaningful progress, both NAV-240 and NAV-242 remain investigational therapies. Larger and longer studies will be needed to determine whether targeting 2 inflammatory pathways can offer clear benefits over existing treatments for HS and other inflammatory diseases.

References

1. Navigator Medicines accelerates anti OX-40L and TNFα bispecific antibody clinical development pipeline into phase 2a and first-in-human trials. News release. Navigator Medicines. Published January 8, 2026. Accessed January 9, 2026. https://www.globenewswire.com//news-release/2026/01/08/3215323/0/en/navigator-medicines-accelerates-anti-ox-40l-and-tnf%CE%B1-bispecific-antibody-clinical-development-pipeline-into-phase-2a-and-first-in-human-trials.html
2. Virone M, Zappia E, Di Caro A, et al. Hidradenitis suppurativa: state-of-the-art review and update. Dermatol Reports. Published online August 27, 2025. doi:10.4081/dr.2025.10328
3. 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 January 9, 2026. 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/