Preliminary immunologic and clinical Phase 1b study outcomes from patients with ROSAH syndrome treated with the first-in-class ALPK1 inhibitor DF-003 2307448

J John Grigg (The University of Sydney) K Kathleen Digre (Moran Eye Center, University of Utah School of Medicine) P Paul Bernstein (Moran Eye Center, University of Utah School of Medicine) R Robyn Jamieson (Save Sight Institute, Faculty of Medicine and Health, The University of Sydney) E Elisa Cornish (Save Sight Institute, Faculty of Medicine and Health, The University of Sydney) V Vinit Mahajan S Sicong Geng (Shanghai Yao Yuan Biotechnology Ltd (Drug Farm)) C Carolyn Yanavich (Drug Farm USA LLC) J Jieqing Fan D Danyang Liu Z Zhengle Zhao S Shuai Zhang C Cong Xu (Department of Statistics and Data Science, College of Science) T Tian Xu (Department of Chemical and Biomolecular Engineering and Institute for NanoBioTechnology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States) H Henri Lichenstein N Neil Solomons (Drug Farm USA LLC)

Abstract

Abstract Introduction ALPK1 (alpha-protein kinase 1) is a key gene and protein involved in innate immunity and inflammation. ROSAH syndrome is an autosomal dominant disorder caused by pathogenic variants in ALPK1 (e.g., T237M) and characterized by ocular inflammation, headache, anhidrosis, splenomegaly, and systemic manifestations. Elevated levels of hsCRP and inflammatory cytokines, including CCL2, CXCL10, TNFα, IL-6, IL-1β, and IL-8, have been observed in affected patients. DF-003 is a first-in-class oral ALPK1 inhibitor under development for treating the genetic root cause of ROSAH syndrome. Methods This Phase 1b trial (NCT06395285) is a multicenter, single-arm, open-label study evaluating the safety and tolerability of DF-003. Six patients with ROSAH syndrome (T237M ALPK1) aged 18—65 received daily oral DF-003 for 4 weeks. Serum inflammatory biomarkers and clinical outcomes including quality of life (QoL), assessment of anhidrosis and arthralgia were evaluated. Spleen changes were evaluated by CT/MRI with the Mint Lesion™ system. Results Four out of 6 subjects reported the reversal of anhidrosis, improvements in QoL (reduced EQ-5D scores), and improvement in arthralgia. These benefits diminished following discontinuation of therapy. Of the 2 subjects with available immunological marker data, 1 whose markers were elevated at baseline showed pharmacodynamic improvement, with reductions in IL-6, IL-8, CXCL-10, and hsCRP to within normal ranges after 28 days. In the 1 subject that did not have splenectomy, there was a ∼20% reduction in spleen volume that reversed upon cessation of drug. All laboratory values remained within normal limits, with stable renal and hepatic function, and no serious or treatment-emergent adverse events were reported. Pharmacokinetic data available from 6 subjects support once-daily dosing. Conclusion Inhibition of ALPK1 with DF-003 demonstrated early evidence of clinical and pharmacodynamic improvements without safety concerns. These results warrant evaluation of DF-003 in a Phase 2 trial. Funding Source All funding was provided by Drug Farm Topic Categories Translational and Interventional Immunology (TI)

Article Details

Volume / Issue Vol. 215, Issue Supplement_1
Published August 01, 2026
ISSN 0022-1767
Publisher American Association of Immunologists

Authors (16)

J

John Grigg

The University of Sydney

K

Kathleen Digre

Moran Eye Center, University of Utah School of Medicine

P

Paul Bernstein

Moran Eye Center, University of Utah School of Medicine

R

Robyn Jamieson

Save Sight Institute, Faculty of Medicine and Health, The University of Sydney

E

Elisa Cornish

Save Sight Institute, Faculty of Medicine and Health, The University of Sydney

V

Vinit Mahajan

S

Sicong Geng

Shanghai Yao Yuan Biotechnology Ltd (Drug Farm)

C

Carolyn Yanavich

Drug Farm USA LLC

J

Jieqing Fan

D

Danyang Liu

Z

Zhengle Zhao

S

Shuai Zhang

C

Cong Xu

Department of Statistics and Data Science, College of Science

T

Tian Xu

Department of Chemical and Biomolecular Engineering and Institute for NanoBioTechnology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States

H

Henri Lichenstein

N

Neil Solomons

Drug Farm USA LLC