si-544

si-544 is a selectivity-optimized peptide drug that acts as a highly selective blocker of the Kv1.3 potassium ion channel, which is predominantly expressed on disease-associated effector memory T (TEM) cells. By inhibiting Kv1.3, si-544 disrupts the chronic activation and proliferation of these TEM cells, which are implicated in driving inflammation in autoimmune diseases such as atopic dermatitis, psoriasis (including plaque psoriasis and psoriatic arthritis), rheumatoid arthritis, and certain rare lymphomas like cutaneous T-cell lymphoma. The drug has demonstrated high selectivity for Kv1.3 with no significant binding to other related ion channels (Kv1.5, hERG, Kv1.1, or Kv1.2), resulting in an improved safety profile compared to less selective agents[2][5]. In preclinical models and early clinical trials (Phase 1b), si-544 has shown excellent safety and tolerability with promising efficacy signals—75% of treated patients experienced objective clinical improvement in atopic dermatitis studies[5][6][7]. Developed by selectION as their lead candidate therapy for T cell-mediated autoimmune diseases.

Other names

si 544si544si-544