Precision oncology company, Parthenon Therapeutics, and ImaginAb Inc., a global biotech have entered into a multi-year, non-exclusive license and supply agreement.
Under the agreement terms, Parthenon will use ImaginAb’s CD8 ImmunoPET imaging technology in its phase 1 trial evaluating its lead compound, PRTH-101, which is expected to begin in 2023.
ImaginAb is developing 89Zr crefmirlimab berdoxam (CD8 ImmunoPETTM) imaging agent and next generation radiopharmaceutical therapies (RPT) products while Parthenon is inventing a class of anti-cancer therapies that reprogram the tumor microenvironment (TME).
“Parthenon is developing an entirely new class of anti-cancer therapies that can modulate the TME in immune-excluded tumors through our proprietary approach that utilizes biomarkers to match our therapeutic approaches to individual patients based on the specific characteristics of their cancer,” said Laurent Audoly, chief executive officer and co-founder of Parthenon Therapeutics.
Parthenon to use ImaginAb technology
“ImaginAb’s CD8 ImmunoPET technology will provide us with critical insight into the infiltration of CD8 T cells in the TME, not only for a small part of a single lesion but also for an entire tumor as well as all tumors throughout a patient’s body. This approach is less invasive compared to the current biopsy-based standard of care and is consistent with the objective of generating a rich dataset of biomarker endpoints leveraging orthogonal approaches in the earliest phases of our clinical trial.”
Audoly explained that PRTH-101 targets discoidin domain receptor 1 (DDR1) to punch holes in the mechanical barrier that characterizes immune-excluded tumors, thereby making them vulnerable to attack by the immune system.
She added: “The CD8 ImmunoPET data will be used in our Phase 1 trial to quantify the degree of immune infiltration into tumors before and after dosing and be used to identify tumors that are ‘hot’, ‘cold’ or ‘immune excluded’. This knowledge will help us design a clinical strategy to focus on those patients who will benefit the most from treatment with PRTH-101.”
Hot tumors are characterized by the presence of CD8+ T cells that are able to infiltrate the tumor parenchyma. These tumors often respond to immune checkpoint inhibitors, unlike cold tumors which have few to no CD8+ T cells. In contrast to both hot and cold tumors, immune excluded tumors have CD8+ T cells in the tumor bed, but these cells are relegated to the tumor stroma by collagen and/or other barriers, thereby preventing them from interacting with tumor cells to perpetuate an anti-tumor response.
PRTH-101 targets the collagen barrier of immune excluded tumors, thereby enabling CD8+ T cells to interact with and kill tumor cells. Immune-excluded tumors can represent up to 75 percent of a TME phenotype across different tumor types highlighting the potential for identifying therapeutics that can help many patients.
“We are excited to provide our cutting edge CD8 imaging technology to Parthenon which allows changes in CD8+ T-cell distribution to be visualised before and after therapy,” said Ian Wilson, chief executive officer at ImaginAb.
“Parthenon joins an increasing number of pharma and biotech companies incorporating our CD8 ImmunoPET agent into their clinical trials to precisely understand the therapeutic activity and treatment outcomes of investigational novel oncology assets in cancer patients at a very early stage.
“CD8+ T-cells play a pivotal role in immunotherapy and CD8 ImmunoPETTM has demonstrated the potential to track CD8+ T-cells using whole body PET scans in clinical trial subjects.”
ImaginAb – actively investing
Under the terms of the agreement, ImaginAb will supply clinical doses of its investigational CD8 ImmunoPET technology to Parthenon Therapeutics for use in the clinical development of PRTH-101 at clinical trial sites across the United States.
Initially, Parthenon Therapeutics will investigate CD8 status in a Phase I dose escalation clinical trial of PRTH-101, both in monotherapy and in combination with anti-PD(L)1 therapy. The trial is expected to initiate in 2023, with the ability to add dose expansion cohorts at a later date to explore additional rational combination opportunities and tumor types.
ImaginAb will receive payments for providing dose manufacturing and ongoing technical, clinical and regulatory support to enable the successful implementation of its CD8 ImmunoPET technology into Parthenon Therapeutics’ clinical trials.
ImaginAb is actively investing in the clinical and global supply chain development of CD8 ImmunoPET agent to provide simple turnkey access to its novel technology for use in clinical research and development. By collaborating with leading biotech companies, ImaginAb is making progress towards the company’s goal of being a key partner in the development of new immunotherapies across multiple cancer types and geographies.