This study investigates whether combining the TLR7 agonist PRTX007 with pembrolizumab enhances immune-mediated tumor response in the neoadjuvant setting for Stage III melanoma, with the goal of improving pathologic response rates and clinical outcomes while maintaining an acceptable safety profile.
Design This is a Phase 2, multi-center, open-label, single-arm study conducted in Australia. The study will enroll approximately 48 participants with resectable Stage III melanoma.
The study consists of two parts:
* Part A: 24 participants will be enrolled, including an initial dose-escalation safety run-in using a 3+3 design to evaluate tolerability and dose-limiting toxicities.
* Part B: An additional 24 participants will be enrolled if sufficient activity is observed in Part A.
Treatment Plan
Participants will receive neoadjuvant therapy consisting of:
* PRTX007: Oral administration for 3 days on and 4 days off per week for 9 cycles (7-day cycles)
* Pembrolizumab: 200 mg intravenous infusion every 3 weeks for 3 cycles Following completion of neoadjuvant therapy, participants will undergo definitive surgical resection.
Post-surgical treatment will be response-adapted:
* Participants achieving MPR may receive observation or pembrolizumab alone
* Participants without MPR will receive adjuvant PRTX007 in combination with pembrolizumab
