Provectus Pharmaceuticals Inc. ha presentato al meeting annuale della Society of Surgical Oncology uno studio non clinico sull’efficacia del PV-10 intralesionale sul melanoma, tale farmaco indurrebbe una risposta immunitaria verso il melanoma specifica.
Intralesional rose bengal (PV‐10, 10% RB in saline) can elicit selective chemoablation of solid tumors and an apparent bystander response in untreated lesions. In phase I (20 subjects with AJCC stage III‐IV melanoma), a single injection into a total of 114 lesions was well tolerated, yielding durable objective response (OR) at 12‐24 weeks in 40% of subjects (20% CR + 20% PR by modified RECIST) and locoregional disease control (CR+PR+SD) in 75% of subjects; 15% of subjects achieved an OR in their bystander lesions (43 lesions).
Results: The first 40 subjects (median age 74.5, range 37‐92) completing the study received PV‐10 into 486 lesions (mean 1.9 treatment sessions per subject). Adverse events were predominantly mild to moderate, locoregional and transient, the most common being pain at the treatment site (82% of subjects), vesicles or edema (50% each) followed by swelling, pruritus, skin discoloration or headache (18% each), with no grade 4 or 5 AEs attributed to PV‐10. Among all 40 subjects, 33% achieved CR, 28% PR and 20% SD of their target lesions; 33% of 21 subjects with evaluable bystander lesions achieved CR in these lesions, along with 10% PR and 14% SD. Mean PFS was 8.5 months (all subjects), while the OR cohort had significantly longer PFS (11.1 months) than SD or PD subjects (2.8 and 2.7 months, respectively). Plasma clearance was bi‐exponential (t1/2 of 6.3 hrs and 4.3 days) consistent with rapid uptake of extravasate and prolonged intralesional retention.