Microvascular Tissue, Inc – FDA Warning Letter, Apr 8, 2025

The FDA issued a Warning Letter to Microvascular Tissue, Inc. on December 3, 2025, following an inspection conducted from March 31 to April 8, 2025. The letter addresses significant violations concerning the company"s product, mVASC®, which is derived from hypodermis and intended for allogeneic use. The FDA determined that mVASC® is an unapproved new drug, violating section 505(a) of the Federal Food, Drug, and Cosmetic Act (FD&C Act), and an unlicensed biological product, violating section 351(a)(1) of the Public Health Service Act (PHS Act).

Furthermore, the company"s manufacturing processes were found to have significant current good manufacturing practice (CGMP) violations under section 501(a)(2)(B) of the FD&C Act and 21 CFR parts 210 and 211, rendering the product adulterated. The FDA concluded that mVASC® does not meet the criteria for minimal manipulation or homologous use as an HCT/P under 21 CFR part 1271, because its processing alters the original relevant characteristics of the tissue and it is not intended to perform the same basic function in the recipient as in the donor. Microvascular Tissue, Inc. must promptly address these violations, obtain necessary FDA approvals, and bring its operations into compliance with all applicable regulations.