ADH-503 (GB1275) is a potent agonist of the integrin CD11b to mitigate myeloid cell immunosuppression.

The partial activation of CD11b by a small-molecule agonist (ADH-503) leads to the repolarization of tumor-associated macrophages, reduction in the number of tumor-infiltrating immunosuppressive myeloid cells, and enhanced dendritic cell responses.?These actions, in turn, improve antitumor T cell immunity and render checkpoint inhibitors effective in previously unresponsive PDAC models.?These data demonstrate that molecular agonism of CD11b reprograms immunosuppressive myeloid cell responses and potentially bypasses the limitations of current clinical strategies to overcome resistance to immunotherapy.

ADH-503 had the mean half-life of 4.68 and 3.95 hours, a maximum concentration of 1716 and 2594 ng/mL and AUC0-t in the plasma of 6950 and 13962 ng.h/mL at 30 and 100 mg/kg dosing, respectively.

Animal Model:Male rats.Dosage:30,100 mg/kg (Pharmacokinetic Analysis). Administration:Oral gavage twice a day; on days 1 and 5