PV-10 Mechanism of Action

Overview

Provectus is collaborating with H. Lee Moffitt Cancer Center and Research Institute in an investigator initiated study (ClinicalTrials.gov ID: NCT01760499) to ascertain the feasibility of detecting immune cell infiltrates in injected melanoma tumors. This study is also measuring circulating immune cells in peripheral blood post PV-10 treatment.

Status

  • A Phase 1 trial is currently in progress and enrollment has been completed.
  • Over 270 cancer patients have been treated with PV-10, including 12 in a Phase 1 recurrent breast cancer study, 6 in a Phase 1 metastatic liver cancer study, 20 in a Phase 1 melanoma study, 80 in a Phase 2 melanoma study, 10 in an investigator-initiated study of PV-10 chemoablation followed by radiotherapy, and over 140 patients enrolled in the Compassionate Use Program for PV-10. Additionally, 11 of the 80 Phase 2 melanoma study subjects continued with the Compassionate Use Program.

Phase 1 Clinical Trial

  • In November 2015 study data were presented at the Society for Immunotherapy of Cancer 30th Annual Meeting by Moffitt Cancer Center researchers in a poster presentation entitled "Intralesional Rose Bengal in Melanoma Elicits Tumor Immunity via High Mobility Group Box 1". In the reported work, the authors showed that tumor-specific T cells were increased in the blood after tumor ablation with PV-10. This was initiated by tumor cell necrosis, leading to release of High Mobility Box Group 1 (HMBG1), one of a class Damage-Associated Molecular Pattern molecules (DAMPs) released by dying cancer cells that can lead to activation of dendritic cells. HMBG1 release was observed in vitro and after ablation of melanoma tumors. This was also correlated with dendritic cell activation and infiltration into lymph nodes draining ablated tumors.
  • In March 2015 enrollment was completed, meeting the target enrollment of 15 patients.
  • A Phase 1 study titled "Detection of Immune Cell Infiltration Into Melanomas Treated by PV-10, a Feasibility Study" was initiated in January 2013 by the H. Lee Moffitt Cancer Center and Research Institute. The main purpose of this study is to find out more about how PV-10 works in melanoma tumors. Researchers also want to find out if there are changes in the body's immune cells (cells that fight infection and illnesses) after PV-10 is given, both inside the melanoma tumors and circulating in the blood.

    Primary Outcome Measures:

    • Occurrence of Change in Infiltration of Immune Cells

      [ Time Frame: At baseline and 7-14 days after PV-10 treatment ]

      [ Designated as safety issue: No ]

      • The pre-treatment blood sample and tumor biopsies will be the control for the post-PV-10 blood samples and resected tumor samples. Tumor core needle biopsies will be collected from the designated injected and uninjected lesions one week prior to intralesional PV-10 therapy. Biopsy samples will be fixed in formalin and embedded in paraffin for immunohistochemical (IHC) staining. On day 0, the injected lesion will be treated with up to 5 mL of PV-10. Seven to 14 days after intralesional PV-10 treatment, the injected and uninjected lesions will be resected. A portion of each tumor equivalent to a core needle biopsy specimen will be fixed in formalin and embedded in paraffin for IHC staining. Immune cell infiltration will be compared between untreated baseline lesions and post-treatment lesions (injected or uninjected) by a blinded pathologist at Moffitt Cancer Center. Measurement is the ordinal level of the T-cell infiltration into tumors with three levels: 0, no brisk, and brisk.

    Secondary Outcome Measures

    • Frequency and Phenotype of Circulating Immune Cells in Peripheral Blood Mononuclear Cells (PBMC)

      [ Time Frame: At baseline, 7-14 days after treatment and 21-28 days after treatment ]

      [ Designated as safety issue: No ]

      • This secondary endpoint is to enumerate and phenotype patient immune cells in peripheral blood before and after intralesional (IL) PV-10 treatment. The pre-treatment blood sample and tumor biopsies will be the control for the post-PV-10 blood samples and resected tumor samples. T cells will be enumerated and phenotyped in patient blood one week prior to and 7-14 days after intralesional PV-10 therapy. An additional blood draw 14 days post surgery will take place at the end of the study at the time of the surgical follow-up/end of study visit. These samples will be used for in vitro experiments in order to determine the frequency and phenotype of T cells in the blood by flow cytometry.
    • Titer of Anti-tumor IgG in the Serum

      [ Time Frame: At baseline, 7-14 days after treatment and 21-28 days after treatment ]

      [ Designated as safety issue: No ]

      • This secondary endpoint is to enumerate anti-tumor immunoglobulin G (IgG) in peripheral blood before and after IL PV-10 treatment. Titer of anti-tumor IgG in the serum prior to, 7-14 days after, and 21-28 days after PV-10 treatment. The pre-treatment blood sample and tumor biopsies will be the control for the post-PV-10 blood samples and resected tumor samples. Serum will be phenotyped from patients one week prior to, 7-14 days after and 21-28 days after IL PV-10 therapy. Serum will be isolated from peripheral blood by centrifugation and will be used to stain patient tumor samples obtained from surgical resection. Bound serum antibodies will be detected by staining with antihuman IgG antibodies and detected by flow cytometry.
    • Occurrence of Adverse Events (AEs)

      [ Time Frame: During PV-10 administration visit, after 7-14 days, at study end (day 28 or early termination) ]

      [ Designated as safety issue: Yes ]

      • Local and systemic toxicity signs and symptoms per the Common Terminology Criteria for Adverse Events v4.0 (CTCAE). Any adverse experiences associated with participation on the trial will be recorded. Adverse events will be assessed within 30 minutes following PV-10 administration and 4 hours after PV-10 administration. Adverse events assessment: Questions about how participants have been feeling and any changes in the way participants feel immediately after the study drug was given and 4 hours later.

NEWSLETTER
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