Toxicologic Evaluation of RC-0315, a Mesenchymal Stem Cell-Derived Secretome, Following Repeated Intratracheal Administration in Mice

RC-0315 is a chemotherapy-exposed mesenchymal stem cell-derived secretome developed as a potential advanced therapy for idiopathic pulmonary fibrosis (IPF). A Good Laboratory Practice (GLP)-compliant repeated-dose toxicity study was conducted to evaluate the safety of RC-0315 following intratracheal (ITR) instillation in immunocompetent ICR and SCID mice. Animals received two cycles of three repeated ITR instillations of RC-0315 performed within a 7-day period and separated by a two-week interval. Mice were assigned to saline, vehicle, low-dose, or high-dose groups and were monitored for 3 days (main phase) or 13 weeks (recovery phase) post last administration. No test article-related mortality or toxic clinical signs were observed in either strain. Clinical pathology parameters, body weight, food consumption, and ophthalmologic findings remained within normal limits, with no dose-dependent alterations. Histopathological examination revealed no RC-0315-related adverse findings in the lungs or other organs, and no local toxicity was evident at the site of administration. These findings support the favorable safety profile of RC-0315 when administered via the clinically intended route.