ANTWERP, Belgium — September 14, 2026
Agomab Therapeutics NV announced positive Phase 1 results for AGMB-447, an investigational inhaled, lung-restricted small-molecule inhibitor of ALK5 (TGFβR1) being developed for idiopathic pulmonary fibrosis (IPF). Data from 10 IPF patients in Part C of the Phase 1 study showed a generally favorable safety and tolerability profile at 4.5 mg twice daily, while higher adverse-event incidence was observed at 6 mg twice daily without new specific or systemic safety signals. The most frequently reported events were cough and bronchospasm, with cough episodes generally short and limited to the inhalation period. The findings build on earlier healthy-participant data and provide clinical evidence supporting Agomab’s lung-restricted development strategy. The company also announced the design of its Phase 2 INSPIRIA study and said the Clinical Trial Application (CTA) has been submitted, with study initiation planned before year-end 202
AGMB-447 Demonstrates Lung-Restricted Pharmacokinetics
Pharmacokinetic findings showed high pulmonary exposure with low systemic exposure, supporting the intended lung-restricted profile of AGMB-447. In IPF patients receiving 4.5 mg twice daily, average bronchoalveolar lavage fluid concentrations remained above the IC90 for at least six hours after inhalation and above the IC50 for 24 hours. These results were consistent with observations from healthy participants and support the rationale for delivering the compound directly to the lungs while limiting systemic exposure. Agomab also reported robust target engagement, with more than 50% reduction in pSMAD3 in bronchoalveolar lavage cells at the 4.5 mg twice-daily dose. Because TGFβ signaling is considered a central driver of fibrosis, the demonstrated pharmacodynamic activity provides proof-of-mechanism for local ALK5 inhibition in patients with IPF. The company plans to present detailed Phase 1 findings at a future scientific conference.
INSPIRIA Phase 2 Targets Lung Function in IPF
Agomab’s planned INSPIRIA Phase 2 study will evaluate AGMB-447 in approximately 120 patients with confirmed IPF over 24 weeks. The randomized, double-blind, placebo-controlled trial will assign patients 2:1 to receive AGMB-447 at 4 mg twice daily or placebo, administered by inhalation on top of standard of care. The study will assess safety, pharmacokinetics and efficacy, with the primary endpoint defined as the change from baseline in forced vital capacity (FVC) at Week 24. The CTA has been submitted, and Agomab expects the study to begin in the second half of 2026 across a broad European clinical-site network. The program is designed to determine whether the pharmacokinetic and pharmacodynamic characteristics observed in Phase 1 can translate into clinically meaningful effects on lung function. Twice-daily inhaled administration could also allow AGMB-447 to be evaluated as either a potential monotherapy or in combination with systemic standard-of-care therapies..
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Agomab Builds Organ-Restricted Fibrosis Pipeline
The advancement of AGMB-447 into Phase 2 strengthens Agomab’s broader strategy of developing organ-restricted therapies for fibro-inflammatory diseases. AGMB-447 is designed to inhibit ALK5 locally in the lung while avoiding clinically relevant systemic exposure through inhaled administration and rapid plasma hydrolysis to an inactive metabolite. The approach is intended to potentially improve the therapeutic window of TGFβ pathway inhibition, an area historically associated with systemic safety challenges. IPF affects approximately 255,000 patients across the U.S., Japan and major European markets, and existing therapies can slow disease progression but do not halt the underlying disease. Agomab is therefore positioning AGMB-447 as a potential differentiated anti-fibrotic therapy that combines targeted pathway inhibition with localized delivery. Positive Phase 1 patient data, demonstrated lung target engagement and the planned INSPIRIA Phase 2 study now provide the company with a clear clinical development pathway for AGMB-447 in IPF.
Source: Agomab Therapeutics press release
