Data Confirms the Systemic Effects of DNA IL-12 Administered Locally with Electroporation
SAN DIEGO – July 22, 2012 — OncoSec Medical Inc. (OTCQB: ONCS), a company developing its advanced-stage ImmunoPulse DNA-based immunotherapy and NeoPulse therapy to treat solid tumors, announced interim immune response data from the company’s Phase II study of ImmunoPulse in patients with metastatic melanoma. Findings showed that OncoSec’s ImmunoPulse demonstrated a significant change in tumor immunity following treatment with DNA IL-12 and electroporation. Dr. Adil Daud, principal investigator at the University of California San Francisco, presented the data at the 8th World Congress of Melanoma in Hamburg, Germany.
Blood samples taken at baseline (Day 1) and Day 90 from subjects treated with ImmunoPulse were analyzed. Changes in activated T-cells and regulatory T-cells were quantified. At Day 90 following treatment, it was demonstrated that there was a significant decrease in circulating “exhausted” CD8/PD-1+ (p=0.0017) and CD8/CD69+ (p=0.008) T-cells. PD-1 is expressed in activated exhausted T cells, and blocking PD-1 is an emerging treatment modality for multiple cancers including melanoma. These results demonstrate that plasmid delivery of interleukin-12 (IL-12) can also result in a decrease in exhausted T-cells, which may lead to improvement in clinical outcomes for patients treated with ImmunoPulse.
In addition to changes in circulating T-cells, an increase in NK cell frequency and activation was also observed from baseline. It was also demonstrated that antigen-specific T-cell responses to melanoma were increased with DNA IL-12 while other antibody responses were modulated and appeared to narrow over time. These data confirm the systemic effects of DNA IL-12 administered locally with electroporation.
Punit Dhillon, President and CEO of OncoSec, said: “We are encouraged by these immune data, since they highlight a potential mechanism of action for ImmunoPulse, and demonstrate the biologic activity of this therapy after only a single cycle of treatment.”
Dr. Daud commented: “The statistical significance of these data is impressive and confirms our understanding of the mechanism of action of IL-12. We look forward to understanding further if these changes in immune responses also correlate with positive clinical outcomes. These data will be shared later on this year.”
OncoSec recently announced completion of enrollment for its Phase II melanoma trial. Previously, the company announced that ImmunoPulse demonstrated clinical benefit in both locally treated and untreated distant melanoma lesions, and that the therapy appeared to be safe and well-tolerated, after an interim analysis of safety and efficacy of the first 13 patients.
About the Phase II ImmunoPulse Study
A total of 25 patients with stage III or IV cutaneous and in-transit metastatic melanoma have been enrolled in this Phase II, single-arm, open-label and multi-center study. The trial is designed to assess local and distant objective response following treatment of cutaneous melanoma lesions with DNA IL-12 and electroporation with a primary endpoint of 24 weeks. One treatment cycle consists of three treatments applied to up to four lesions on days 1, 5 and 8 with a maximum dose of 1.5 mg DNA IL-12 per treatment cycle. At 12 months, patients are moved to the follow-up phase of the study and will be followed for up to five years for safety.