Actigen正在开发的GNR-055是一种用于治疗粘多糖累积症II型（MPS II）的新型脑穿透性依杜醛酸-2-硫酸酯酶替代疗法。由于MPS II的病程是可变的，并且随着儿童的逐渐发育而变得复杂，出生时看起来正常的儿童通常在2-4岁时开始表现出身体症状，包括呼吸和心脏功能障碍、认知缺陷、行为缺陷、神经系统受累和各种其他症状。GNR-055是专门设计的，通过抗体片段中的重组融合蛋白来解决体细胞和中枢神经系统缺陷，抗体片段可用于治疗MPS II。该抗体片段识别人胰岛素受体α-亚基的细胞外表位，并可通过血脑屏障运输。

Actigen, a privately funded UK company, is currently developing GNR-055, A novel brain-penetrating iduronate-2-sulfatase enzyme replacement therapy for treatment of MPS II. Because the course of MPS II is variable and complicated by the gradual development of the child, children who appear normal at birth typically begin to exhibit physical symptoms, including respiratory and cardiac dysfunction, cognitive deficits, behavioral deficits, neurological involvement, and a variety of other symptoms by the age of 2-4 years.GNR-055 is specifically designed to address both the somatic and CNS deficits through a recombinant fusion protein in the antibody fragment, an antibody fragment that can be used to treat MPS II. recombinant fusion protein, the antibody fragment recognizes the extracellular epitope of the α-subunit of the human insulin receptor and can be transported across the blood-brain barrier.