TC-SP 14, also known as compound 14, is a highly active and potent S1P1 agonist with oral bioavailability. It exhibits an EC50 value of 0.042 μM, indicating its strong binding affinity to the S1P1 receptor. Notably, its interaction with the S1P3 receptor is minimal, as evidenced by an EC50 value of 3.47 μM. TC-SP 14 demonstrates significant pharmacological effects, including a marked reduction in blood lymphocyte counts and the attenuation of delayed type hypersensitivity response to antigen challenge [1].

S1P3 receptor:3.47 μM (EC50), S1P1 receptor:0.042 μM (EC50)

TC-SP 14 (compound 14) does not inhibit or induce human cytochrome P450 enzymes, is nonmutagenic, and does not significantly inhibit the hERG channel [1].

TC-SP 14, administered orally at doses ranging from 0-3 mg/kg, induces a dose-dependent reduction in circulating lymphocytes 24 hours after administration, with maximal lymphopenia observed at 3.0 mg/kg, showing a 74% reduction compared to the control [1]. Daily oral administration of TC-SP 14 for 10 days at similar doses significantly mitigates ovalbumin (OVA)-induced ear swelling in a dose-dependent manner, with effective reduction starting from 0.3 mg/kg [1]. When administered either intravenously (IV) or orally (PO) at doses between 2-15 mg/kg, TC-SP 14 displays favorable pharmacokinetic properties, including low clearance rates, moderate steady-state volume of distribution, and moderate to long mean residence times, with acceptable oral bioavailability observed in Pharmacokinetic analysis involving female Sprague-Dawley rats and male Cynomolgus nonhuman primates [1]. These findings demonstrate TC-SP 14's potential as an immunomodulatory agent, with both acute and chronic administration showing beneficial effects on reducing lymphocyte counts and inflammatory responses effectively.