The Phase 1 trial (NCT05351502) was a clinical proof-of-concept trial that assessed the intratumoral administration of UNO in patients with unresectable cutaneous or subcutaneous histologically confirmed primary or metastatic lesions. The trial enrolled ten heavily pretreated patients, including breast cancer (n=6), squamous cell carcinoma (n=2), and melanoma (n=2). Patients received a median of 4 prior systemic therapies and 11 total cancer-directed treatments. Six patients received 25,000 ppm UNO and four patients received 50,000 ppm UNO.

While the study was not designed to assess efficacy and lacks a control arm, these observations may suggest prolonged survival in this heavily pretreated population. Interpretation of these results is limited by the small sample size and early-stage design. Two patients with triple negative breast cancer continue to demonstrate no evidence of disease, based on available imaging, testing, and clinical examinations. Treatment demonstrated a generally favorable safety and tolerability profile, with most treatment‑related adverse events predominantly Grade 1 or Grade 2. One treatment-related serious adverse event (hypoxia) occurred during administration at 25,000 ppm; the event was not considered dose-limiting and resolved fully. Median overall survival had not yet been reached at last follow-up because more than 50% of patients remain alive at last follow‑up.