DGPR1008, a novel PSMA-targeted fluorescent contrast agent, can “illuminate” invisible tumors during prostate cancer surgery, helping doctors see tumor boundaries and reduce positive surgical margins. This single-arm, open-label Phase I/IIa trial aimed to assess its safety and efficacy for intraoperative imaging in radical prostatectomy.

The trial was conducted in China from June-December 2024 and is still ongoing. In Phase I, we evaluated the safety, tolerability and pharmacokinetics of DGPR1008 in 32 healthy volunteers with 24 received DGPR1008, 8 received placebo and divided into four dose groups: 0.01 mg/kg (n = 6 + 2), 0.02 mg/kg (n = 6 + 2), 0.04 mg/kg (n = 6 + 2), 0.08 mg/kg (n = 6 + 2). In Phase IIa, we evaluated the safety, tolerability and efficacy in 24 prostate cancer patients. Patients were administrated DGPR1008 at 0.02 mg/kg (n = 12) and 0.04 mg/kg (n = 12) 24 hours before surgery.

In Phase I, DGPR1008 was well-tolerated. 12 TEAE events (elevated triglycerides, diarrhea, sinus bradycardia, infusion - site reactions) were in 10 cases, all TEAEs were Grade 1-2. In 19 prostate cancer patients in Phase IIa, the negative predictive value (NPV) and positive predictive value (PPV) were 57.14% and 92.31% in the 0.02 mg/kg group, 74.51% and 97.44% in the 0.04 mg/kg group. In 15 patients, the positive coincidence rate of 27 additional resected sites (margins) illuminated by fluorescence was 83.33%. Ten lymph nodes which were pathologically confirmed as positive from 10 patients were all illuminated by fluorescence during the operation, and the sensitivity was 100%.

This study showed that using DGPR1008 for prostate cancer intraoperative visualization at the current optimal dose (0.04 mg/kg, 24 h pre-op) was safe and feasible. DGPR1008 guided fluorescence imaging can identify positive margins, lymph node metastases in the prostatectomy bed. We'll explore different drug-administration time windows further.