Montana Experimental Treatment Review Board Announces Review Decision on WST-057 Under SB 535

MONTANA, November 4, 2026

The Montana Experimental Treatment Review Board (ETRB) announces the completion of its review and the issuance of Review Decision Letter RDL-2026-003 under Montana SB 535 (69th Legislature, Chapter 621) and ARM 37.106.3301 through 37.106.3325.

On October 26, 2026, the Board voted unanimously (5-0) to approve, with conditions, WST-057 (Topical Pirenzepine 4%), submitted by WinSanTor, Inc. of San Diego, California, for the treatment of peripheral neuropathy in adults.

The approval is subject to binding conditions concerning informed consent revisions, adverse-event classification, and consistent eligibility criteria.

The approval becomes effective upon written confirmation by the Chair that the conditions have been satisfied and, for use at a given experimental treatment center (ETC), upon that ETC's valid designation of the Board as its ETRB.

The full Review Decision Letter, RDL-2026-002, sets forth the Board's determinations, conditions of approval, and continuing obligations.

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This approval reflects the Board's professional judgment on the record submitted. It is not FDA approval or clearance, is not a determination of efficacy or therapeutic benefit, is not medical advice or a recommendation to any patient, and is not a warranty that the treatment is safe. Responsibility for development, manufacture, supply, and clinical delivery rests with the Applicant, the ETC, and treating providers.


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