Provectus provided updated data from an ongoing Phase 1 clinical trial of investigational cancer immunotherapy PV-10 (rose bengal sodium) for the treatment of uveal melanoma (UM) metastatic to the liver (mUM) (NCT00986661). mUM patients enrolled in this study received 1 or more cycles of PV-10 injection into 1 or more hepatic metastases. Where indicated, standard of care immune checkpoint blockade (CB), as either monotherapy pembrolizumab or the combination of ipilimumab and nivolumab (IN), was also administered.

To date, 25 mUM patients have received monotherapy PV-10 or PV-10 in combination with CB: Median age 64.3 years, range 32-80, 14 male (56%), 11 female (44%), 17 Stage M1a (68%), 7 M1b (28%), 1 M1c (4%), Median of 1 line of prior therapy for metastatic disease, 12 patients were CB-refractory (48%), 16 patients received =2 treatment cycles of PV-10 (64%), Median of 2 hepatic lesions were injected per patient (range 1-10), and 11 patients received CB of IN concurrent with or after PV-10 (44%). Acceptable safety was observed, with no mortality or permanent Grade 3 or higher morbidity attributed to study treatment. Objective response of PV-10-injected hepatic lesions was assessed using 2D-EASL imaging measurement, which accounts for changes in viable and necrotic tumor: 1 patient achieved complete response (4%), 7 patients achieved partial response (28%); 32% objective response rate, and 8 patients achieved stable disease (32%); 64% disease control rate.

Median overall survival (mOS) of all patients was 11.0 months via Kaplan-Meier: mOS of all M1a patients was 30.6 months (2.6 years), and mOS of M1a patients receiving PV-10 + IN was 50.0 months (4.2 years). An exploratory assessment of 9 patients by PET-CT revealed durable complete metabolic responses (CMRs) in 4 M1a pts: 1 patient received monotherapy PV-10; 3 patients received PV-10 + IN, All CMR patients are alive after a median follow-up of 39 months (3.3 years), range 24.6-61.6 months (2.1-5.1 years); mOS has not been reached yet, and CMR patients represent 24% of M1a patients and 16% of all patients.