News & Events

selectION Announces Initiation of Phase 1b Clinical Trial Evaluating si-544 in Patients with Psoriasis Vulgaris or Psoriatic Arthritis

  • New study follows completion of first-in-human Phase 1b trial in atopic dermatitis patients, in which selectION observed safety and tolerability of si-544 in the treatment of T cell autoimmunity
  • Recruitment is underway, with topline results expected in 4Q24

– San Diego, CA, USA, and Munich, Germany – May 28, 2024 – selectION, Inc. (“selectION” or the “Company”), a clinical-stage biopharmaceutical company developing novel treatments for T cell-mediated autoimmune diseases, today announced the initiation of a Phase 1b trial with its lead compound si-544 in adult patients with psoriasis vulgaris (Ps) or psoriatic arthritis (PsA). si-544 is a selectivity-optimized peptide blocking the Kv1.3 ion channel. Kv1.3 is a key target in autoimmunity, which the Company believes has the potential to set a new standard for safety and tolerability in the treatment of T cell autoimmunity. Enrollment is ongoing and topline data are expected in the fourth quarter of 2024.

This new clinical study is designed as a multicenter, Phase 1b, double-blind, placebo-controlled trial in adults with mild to severe Ps or PsA. The Company anticipates enrolling up to 40 patients with Ps, of which up to 16 patients may also have PsA.

This psoriasis study follows the recent completion of the Company’s first-in-human Phase 1b trial in atopic dermatitis patients, in which the Company observed safety and tolerability of si-544 in adult patients with mild to severe atopic dermatitis. The current Phase 1b trial design in patients with Ps or PsA should also allow for the evaluation of efficacy signals. Patients will undergo a 4-week treatment period and a subsequent 12-week follow-up period.

While the primary endpoints of the trial are safety and tolerability, secondary endpoints include the assessment of PD markers such as inflammatory cytokine levels.

Andreas Klostermann, PhD, Chief Scientific Officer and co-founder of the Company said, “We are focused on expanding clinical development of si-544 in autoimmune indications, and we are looking forward to the results of this second, larger trial in a T cell-driven disorder.

Antonius Schuh, PhD, Chairman and CEO of selectION, Inc. added, “The promising data from our successful clinical study in atopic dermatitis patients provide further evidence that direct targeting of disease-associated, chronically activated T cells via Kv1.3 inhibition may provide effective and safe treatments for patients living with a broad variety of autoimmune diseases.


About selectION, Inc.

selectION, Inc., is a clinical-stage biopharmaceutical company developing novel peptide therapies for autoimmune diseases and select cancer indications by targeting autoreactive, chronically activated T cells.

The Company has established an efficient, unique technology platform to develop potent and highly selective peptide blockers for ion channels involved in various diseases. The platform enables systematically optimized target selectivity, providing the opportunity to develop drugs with significantly improved efficacy and safety profiles.

selectION, Inc. is supported by SDL Ventures and Global Source Ventures. The Company is headquartered in San Diego, CA, USA, with a clinical R&D subsidiary in Munich/Martinsried, Germany.

For further information, please visit

About si-544

si-544, the Company´s lead drug candidate, is blocking Kv1.3, a specific ion channel involved in the activation and proliferation of TEM cells, with what the Company believes to be class leading selectivity. TEM cells lie at the root of many autoimmune indications such as atopic dermatitis, psoriasis, rheumatoid arthritis, or multiple sclerosis, but also of certain rare cancers like lymphomas.

si-544 has demonstrated what the Company believes is an excellent safety and tolerability profile in a recently completed Phase 1b clinical trial in atopic dermatitis patients, with study results also indicating an initial efficacy signal. Previously, si-544 has demonstrated what the Company believes is excellent efficacy in animal and human T cell models.

The compound is a potent immuno-selective agent addressing a significant unmet medical need by functionally inhibiting and eliminating disease-specific, chronically activated TEM cells while maintaining full immunocompetence.

Forward Looking Statements

This press release includes forward-looking statements related to selectION, Inc. (the “Company”), including statements regarding the prospects of si-544 and the value of the phase 1b trial evaluating si-544 in patients with atopic dermatitis (the “Trial”). These forward-looking statements are based upon information that is currently available to the Company and its current expectations, speak only as of the date hereof, and are subject to risks and uncertainties that could cause actual results to differ materially from those projected, including risks that the Company does not realize the expected benefits of si-544 or the Trial; risks that the results of the Trial may not be accurate; risks that prior clinical trial results may not be repeated; and general economic and market factors. Any of these may cause the Company’s actual results, performance, or achievements to differ materially and adversely from those anticipated or implied by the Company’s forward-looking statements. The Company expressly disclaims any obligation, except as required by law, or undertaking to update or revise any such forward-looking statements.


Media Contact:
Dr. Ludger Wess / Ines-Regina Buth
Managing Partners
[email protected]
T: +49 40 88 16 59 64 /
T: +49 30 23 63 27 68

Investor Contact:
selectION, Inc.
Steve Zaniboni
Chief Financial Officer
[email protected]
T: +1 858 967 8014